International Journal of Chemistry and Research

ISSN: 2642-1615

European Chemistry Conference 2018

July 4-6, 2018, Rome, Italy
Poster Session Abstracts
DOI: 10.18689/2642-1615.a1.003

Synthesis and Characterization of Polymeric Membrane for the Removal of Selected Heavy Metal Ions from Aqueous Media

M. A. Jafar Mazumder*, Amir Al-Ahmed and S. A. Ali

Chemistry Department, King Fahd University of Petroleum and Minerals, Saudi Arabia

A series of new specialty sulfonated diamine monomers containing oxygen, amine and sulfonate (having chelating properties) were synthesized from inexpensive and commercially available diamine. Sulfonated polyimides containing sulfonated diamine monomers 1,4,5,8-naphthalene tetra carboxylic dianhydride and readily available nonsulfonated diamines were synthesized and characterized with tremendous scientific and technological interest. Sulfonated polyimides were characterized by various spectroscopic techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance Spectroscopy (NMR) and Thermal Gravimetric Analysis (TGA). The physicochemical and mechanical properties of the sulfonated polyimides based composite membranes were studied in great details. Pore generating agent, poly vinyl pyrrolidone of different molecular weights were added during composite membrane preparation to control the pore size. The selected composite membrane was explored to study their efficiencies for the removal of metal ions from the aqueous solutions. Effect of commercially available complexing agent like, functionalized chitosan on the membrane performance will also be discussed.

Dr. M. A. Jafar Mazumder completed his PhD in Chemistry from McMaster University, Canada, currently working as an Associate Professor of Chemistry at King Fahd University of Petroleum & Minerals (KFUPM), Saudi Arabia. Dr. Mazumder secured 5 US patents, edited 2 books, published more than 35 journal articles and presented his research more than 20 international conferences. His main researches focused on synthesis and characterization of various organic and polymeric biomaterials for their potential use in the inhibition of mild steel corrosion in oil and gas industries and for the removal of heavy metals and organic contaminants from aqueous samples.

NMR and Electron Microscopy Structural Studies of the E. coli Class Ia Ribonucleotide Reductase

Alexander T. Taguchi1*, Gyunghoon Kang1, Qing Zhe Ni1, Thach V. Can1, Robert G. Griffin1, Catherine L. Drennan1, Jo Anne Stubbe1 and Qinghui Lin2

1Massachusetts Institute of Technology, USA
2Zhejiang University School of Medicine, China

Ribonucleotide reductase (RNR) catalyzes the conversion of ribonucleotides into deoxyribonucleotides. RNR is thus an essential component of life in all organisms and serves as a drug target for a wide range of diseases including cancer. Despite its medical relevance an atomic resolution structure of the active complex has yet to be achieved. Here a dual NMR (Nuclear Magnetic Resonance) and electron microscopy approach is undertaken to investigate the molecular structures of the active (α2β2) and inactive (α4β4) forms of the E. coli class Ia RNR. A special double mutant E52Q/F3Y122 is shown to stabilize α2β2 for at least 2 hours. The E52Q/F3Y122 construct allows for a negative stain electron microscopy map to be obtained at sub-20 Å resolution for the first time. The α2β2 active complex is found to have an asymmetric mode of binding, contrary to the previously proposed symmetric docking model. DNP (Dynamic Nuclear Polarization) enhanced solid-state NMR measurements on mixed labeled samples reveal atomic resolution distance constraints at the α/β interface. The assignment of these NMR resonances requires MD (Molecular Dynamics) simulations constrained to the electron microscopy map.

Alexander T. Taguchi career as a magnetic resonance spectroscopist began at the University of Illinois at Urbana-Champaign (USA) Biophysics graduate program. He studied photosynthetic reaction centers using pulsed Electron Paramagnetic Resonance to obtain high-resolution insight into the structurefunction relationships of the electron transport processes. He then transitioned into the field of iron-sulfur clusters as a postdoctoral fellow at the Nippon Medical School in Tokyo, Japan. Currently he has been working as an NIH postdoctoral fellow on solid-state Nuclear Magnetic Resonance fast magic angle spinning on protein complexes at the Massachusetts Institute of Technology.

Relationship between Sweetness and Structure of Sweet-Tasting Protein, Brazzein

Kwang-Hoon Kong*, Hyun-Joo Jo and Hyung-Min Lee

Department of Chemistry, Chung-Ang University, South Korea

To date, only eight sweet-tasting proteins have been known to elicit sweetness. Among them, brazzein (molecular mass of 6.4 kDa) is the smallest sweet-tasting protein isolated from the fruit of the West African plant Pentadiplandra brazzeana Baillon. Brazzein has attracted attention as a candidate for sweeteners for the control of obesity, oral health and diabetic management, because of its potential sweetness, sugar-like taste and good stability at high temperature and wide pH ranges. To elucidate the relationship between the structure and sweetness of highly sweet-tasting protein we have constructed several brazzein variants of residues in the flexible loops and the N- and C-termini of brazzein by site-directed mutagenesis. The brazzein variants were expressed in E. coli BL21 and purified the same method as pET26b(+)-brazzein. The variants of the residues that located in the loop between β-strand III and β-strand II showed similar sweetness to the wild-type brazzein. On the other hand, the variants of the residues that located in the β-strand III, in loop between α-helix, β-strand and the residues in N- &C- termini increased sweetness. Particularly, His31 and Glu41 residues in the flexible loops and Glu36 residue in the β-strand III of the brazzein were the critical residues of the molecule for eliciting sweetness. We have also made multiple mutations of three residues. All double mutations made the molecules sweeter than wild-type brazzein and three single mutants. The increasing order of their sweetness were triple variants> double variants > single variants. These results strongly support the hypotheses that brazzein binds to a non-continuous and multi-sites of the sweet taste receptor. We also found that mutations of Lys5 to Asp or Glu at position 5 of the N-terminal significantly decreased sweetness and mutation of the Glu53 to Arg at position 53 of the C-terminal made the molecules significantly sweeter than brazzein. From these results, we suggest that the positive charge at the Lys5 in the N-terminal was necessary for structural integrity, whereas the charge and length of side chain at position 53 in the C-terminal play an important role in the interaction between brazzein and the sweet taste receptor. Taken together, our findings also support the previous results that mutations increasing the positive charge favor sweet-tasting protein potency.

Kwang-Hoon Kong got his PhD from Tokyo University of Japan in 1993. He is the professor of the Department of Chemistry at Chung-Ang University in Korea. He has published more than 90 papers in reputed journals and has been awarded the IBC TOP 100 Scientists in 2012, 2013, 2015, and 2017.

Carbohydrate Based Molecular Transporters for Drug Delivery

Jungkyun Im

Soonchunhyang University, South Korea

The blood brain barrier (BBB) is composed of densely packed endothelial cells which surrounds the vessels of the brain. Endothelial cells of brain capillaries are tightly joined through tight junctions. Thus most molecules in blood plasma such as chemicals as well as pathogens are excluded from the brain. Due to this unique barrier property, brain can be effectively protected from common infectious and inflammatory processes. On the other hand, when the brain is in trouble by a certain disease, the BBB becomes the major hurdle for drug delivery to the brain. In addition, many kinds of efflux pumps are present in the endothelial cells in the brain. For these reasons, the development of CNS (central nervous drug) drugs with the BBB permeability is the major issue in pharmaceutical research.

Employing the G8 (guanidine eight) sorbitol-based molecular transporter, we have prepared AZT and 5-FU conjugates to examine their delivery to the mouse brain. The transporter has two selectively protected-primary hydroxyl groups. One hydroxyl group was conjugated to the drug of interest, while the other was used to attach a fluorophore via suitable linkers. For AZT and 5-FU conjugation, we utilized the succinate ester linker, which can be enzymatically cleaved to release the drug after successful delivery to tissues.

Dr. Jungkyun Im has obtained his Ph.D. degree in 2010 from Pohang university of science and technology in the field of bioorganic medicinal chemistry. During the Ph.D. course he has synthesized glycodendrimer, molecular transporter, stereo isomers of kinase inhibitor etc. In particular, to overcome the problems in the drug delivery across biological barriers, he prepared a series of novel molecular transporters based on carbohydrate as a scaffold. The G8 (containing eight guanidine units) sorbitol-based molecular transporter was found to be highly effective in cellular uptake as well as crossing the BBB.

Design, Synthesis and Biological Evaluation of 2-Anilinopyrimidine-Based Selective Inhibitors Against Triple Negative Breast Cancer Cell Line

Hwayoung Yun*, Young-Suk Jung, Heegyu Kim, Ji Youn Oh and Jeyun Jo

Pusan National University, South Korea

Triple negative breast cancer (TNBC) is a subtype of breast cancer that is phenotypically defined by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). This subtype accounts for about 15% to 20% of all diagnosed breast cancers. TNBC is characterized by highly aggressive and intractable subtype due to its unique molecular profile, high cell proliferation and distinct metastatic patterns. Although TNBC currently can be treated with chemotherapy, approximately 20% of patient with TNBC responds to standard chemotherapy. Until now, no approved targeted therapy is available for TNBC.

In connection with development of novel anticancer agents for TNBC, an in-house chemical library was screened in a luminal type breast cancer and an EGFR over-expressed TNBC cell lines using a dose dependent MTT assay. A hit compound was identified that exhibited anticancer activity in both cell lines equal to that of gefitinib, representative EGFR tyrosine kinase inhibitor. On the structural basis of a hit compound, a novel series of 2-anilinopyrimidines was designed and synthesized. Cell viability of newly prepared analogs was intensively evaluated and then selective and potent inhibitors against TNBC cell line were developed.

Hwayoung Yun did undergraduate and work at Seoul National University. He have intensively experienced the synthesis of complex small molecules through the studies on total synthesis of various natural products such as macrolides, alkaloids, iridoids, macrolactams and polypeptides. A range of academic training and an in-depth research experience have provided him with considerable expertise in biomedical disciplines including synthetic organic, medicinal chemistry and chemical biology. His ultimate research interests are the discovery of bioactive small molecules as selective regulators of intracellular signaling pathways and investigation of their biological mode of action.

The Ligand Binding to the Gamma-Secretase Complex

Jakub Jakowiecki*, Urszula Orzeł, Krzysztof Młynarczyk and Sławomir Filipek

Faculty of Chemistry, University of Warsaw, Poland

Alzheimerʼs disease is the most common progressive neuro degenerative disorder and is characterized by the presence of amyloid β (Aβ) plaques and neurofibrillary tangles in the brain. No treatments are yet available to cure Alzheimerʼs disease however, soluble Aβ oligomers are believed to play a crucial role in the neuro inflammation that is observed in this disease. The γ-secretase complex, which produces a β, consists of the catalytic subunit presenilin which is associated in a 1:1:1:1 stoichiometry with three subunits: PEN-2, APH-1 and nicastrin (NCT). Recently, the cryo-electron microscopy (cryo-EM) structures of the apo form of this complex [1], as well as with an inhibitor [2], were obtained. The γsecretase is an intramembrane-cleaving protease involved in Alzheimerʼs disease, cancer and other disorders. The clinical trials with the γ-secretase inhibitors have however, demonstrated that unselective inhibition of γ-secretase causes serious toxicity. Evolving insights suggest that more subtle modulations of γ-secretase proteolysis are potentially valuable approaches.

Using the refined 3.4 Å cryo-EM structure of γ-secretase we investigated unfolding and binding of substrate C99 (C-terminal fragment of amyloid precursor protein) as well as inhibitors to the membranous part of γ-secretase exploring primary and secondary binding sites. We also uncovered conformational dynamics of C99 and inhibitors which can have a great influence on mechanism of substrate cleavage by this enzymatic complex.

Jakub Jakowiecki graduated from a high school with natural profile. Afterwards he studied at the Interfaculty Individual Studies in Mathematics and Natural Sciences (MISMaP) at University of Warsaw. In 2008 he received his Masters degree in Chemistry (specialization: organic chemistry) and started his PhD studies in organic chemistry at University of Missouri (Columbia, Missouri in United States) which he has not finished because of health problems. In 2013 Jakub changed his specialization to theoretical chemistry and started a PhD research in biomodeling group directed by prof. Sławomir Filipek at the University of Warsaw. He has been studying G-Protein Coupled Receptors (GPCRs) and other membrane proteins ever since. His scientific interests focus on GPCRs binding hydrophobic ligands, especially cannabinoid and sphingosine1phopshate receptors, which are the topic of his PhD thesis. He also works in the project which aims to find a cure for Alzheimerʼs disease and participates in a development of GPCRM modeling service (a non-profit web service for GPCRs modeling). In his research Jakub uses techniques such as: Homology modeling, ab initio modeling, docking, interaction fingerprints (IFPs) and molecular dynamics simulations (MD) plus various modifications of this method such as steered molecular dynamics (SMD), supervised molecular dynamics (SuMD) and replica exchange molecular dynamics (REMD).

The Homology Modeling Service GPCRM for Construction of GPCR Models

Przemysław Miszta*, Paweł Pasznik, Jakub Jakowiecki, Agnieszka Sztyler, Dorota Latek and Sławomir Filipek

Faculty of Chemistry, University of Warsaw, Poland

G protein-coupled receptors (GPCRs) belong to a super family of cell surface signaling proteins, which are embedded in the membrane. About 800 of them is present in the human genome comprising of about 4% of the human genes. Currently, there are over 200 structures of GPCRs in Protein Data Bank (PDB). GPCRs are sensitive to variety of signals: photons, odorants, nucleotides, lipids, peptides and even small proteins. It is estimated that 30%-50% of modern drugs act by binding to GPCRs. GPCRs play a pivotal role in many physiological processes and in multiple diseases including cardiovascular and mental disorders, cancer and viral infections. Therefore, there is a need for new, high quality models of GPCRs. The updated homology modeling service GPCRM ( meets those expectations by greatly reduced time of execution of submissions (from days to hours/minutes) with nearly the same average quality of obtained models. GPCRM is continually upgraded in semiautomatic way and the number of template structures increased from 20 in 2013 to over 90. Additionally, due to three different scoring functions (Rosetta, Rosetta-MP, BCL::Score) it is possible to select accurate models for the required purposes: the structure of the binding site, the transmembrane domain or the overall shape of the receptor.

Novel Carbon Dot for Glucose Analysis Using Standard Addition Paper Device

Eduardo Luiz Rossini*, Maria Izabel Milani and Helena Redigolo Pezza

UNESP, Sao Paulo State University, Brazil

Carbon dots (CD) are fluorescent nanoparticles with wide application in biosensing, optical and bioimaging, due to its biocompatibility, low toxicity, good solubility, photo stability and simple synthesis. The integration of CD with paper platform is a very interesting application for bioanalysis, due to low cost, availability, portability, biocompatible and simplicity of paper devices. Here, we describe a new CD nanoparticle for glucose determination using standard addition paper device. The CDs were synthesized using a one-step microwave route. Briefly, an aqueous solution of citric acid and tyramine was heated in a domestic microwave for 2 min. The product was dissolved in deionized water, centrifuged and filtered to remove large particles. Corel DRAW X5 was used to design the spot test paper device. The model was printed on filter paper using a wax printer. After printing, the paper was heated at 120 °C for 120 s for formation of the hydrophobic barriers. The fluorescent reagent solution consisted of a mixture of glucose oxidase (120 UmL-1), horseradish peroxidase (30 U mL-1) and CD stock solution. In each spot of the paper device, 1.0 μL of the reagent was spotted, followed by 0.5 μL of sample and 0.5 μL of standard glucose solution (5 – 30 mM). The analysis was conducted by extrapolation of the standard addition curves of quenching by concentration. The methodology was applied in certified urine and serum samples with good accuracy and precision.

Eduardo Luiz Rossini is a PhD student at Institute of Chemistry of São Paulo State University – UNESP – Araraquara, Brazil. He received his master degree in chemistry in the same institution under the supervision of Prof. Helena Redigolo Pezza. He has experience in analytical chemistry with focus on micro fabrication, spectrometric methods and low-cost devices. His research interest is the development of paper platform for clinical analysis.

NMR-Based Methodology for Roasted Coffee Adulteration

Maria Izabel Milani1*, Eduardo L. Rossini1, Leonardo Pezza1, Helena R. Pezza1 and Aline T. Toci2

1UNESP, Sao Paulo State University, Brazil
2UNILA, Federal University for Latin American Integration, Brazil

NMR has been proved a robust and versatile technique to determine different types of food adulteration, including one of the most studied and valuable commodities: coffee. Coffee brings several benefits to human health and due to its high value unfortunately, it is frequently adulterated. For example, low-value grains such as corn, rice, soy and barley are normally found in adulterated coffee samples. In Brazil, the main producer and exporter of coffee beans, there is a limit of “different substances” that is tolerated in commercial coffee brands which corresponds to 1% of the mass of “adulterant” in relation to the total mass of roasted coffee. Due to its versatility, NMR has been proved an ideal tool to determine and quantify coffee adulteration at the lowest level permitted by Brazilian law. Along with chemo metric tools (with the appropriate processing), NMR data allow us to perfectly see the separation between pure and adulterated samples (as shown in the figure below). With the present work, it is possible to easily determine if a commercial sample is adulterated or not with a reliable methodology. The developed NMR-based methodology does not use harmful solvents and only uses deuterium oxide and centrifugation to prepare the samples to NMR analysis. Lastly, it allows us to determine surely the adulteration percentage in a coffee sample only with data processing.

Maria Izabel Milani has an academic background in Analytical Chemistry. She did her undergraduate and masterʼs degree at Institute of Chemistry of the São Paulo State University - UNESP. She is a doctoral student in the graduate program in chemistry at the same institute and the subject of her PhD research is the authentication of samples of roasted coffee and coffee oil under the supervisor of Prof. H. R. Pezza and co-supervisor of Prof. Toci. Ms. Milani has several papers published in international journals derived from her graduate research and in collaboration with her colleagues.

Efficient Nano-Catalytic Hydrogenation and Etherification of 5-Hydroxymethyl-2-Furaldehyde to 2,5-Bis(Alkoxymethyl)Furans Under Mild Conditions

Jung Won Kim

Kangwon National University, South Korea

The conversion of lingo cellulosic biomass-derived 5-hydroxymethyl-2-furaldehyde (HMF) into liquid fuels or fuel additives is quite attractive for reducing the green house gas emission a major cause of global warming. The HMF was hydrogenated to 2, 5-bis(hydroxymethyl)furan (BHMF) in various n-alcohol solvents with more than 99% yield using nano-catalyst, Ru(OH)x/ZrO2. The observed catalysis of Ru/ZrO2 was truly heterogeneous in nature and the catalyst recovered after reaction could be reused without an appreciable loss of its catalytic performance.

The etherification conditions of BHMF such as temperature, time or amount of catalyst were optimized in 1-butanol with Amberlyst-15 catalyst for high yield of BAMF. The HMF in various n-alcohols (methanol, ethanol, 1-propanol and 1-butanol) was smoothly transformed to BAMFs in more than 70 % yields by simple two-step sequential reaction process. The BHMF in the same solvents was subsequently etherified into 2, 5-bis(alkoxymethyl)furans (BAMFs, 4 examples) as potential biodiesels with moderate to good yields using Amberlyst-15.

Jung Won Kim work at Department of Chemical Engineering, Kangwon National University, as a professor. His main research interests lie in the area of heterogeneous nano-catalysis and reaction engineering, especially for the sustainable energy production and the environment protection. The desired innovation can be assisted significantly by an adequate understanding of catalytic reactions and an ability to design catalytic centers. So his research goal is to search for and develop the underlying chemical and engineering rules governing nano-catalysis, especially regarding the relationship between the active sites and product activity/selectivity.

Human Serum Albumin Nanostructures Generated by Ionizing Radiation

Karolina Radomska* and Marian Wolszczak

Institute of Applied Radiation Chemistry, Lodz University of Technology, Poland

Nanoparticles (NPs) are one of the most promising nanomaterials to be used in the biomedical field. Recently, the technology to encapsulate lipophilic drugs into nanostructures of albumin has been establish and approved by FDA (Food and Drug Administration) for the clinical treatment of breast cancer. Here we report on the fabrication of human serum albumin (HSA) nanostructures by ionizing radiation. HSA NPs were obtained in neat HSA solution or deposited on the textile materials. The synthesis does not involve any toxic compounds for instance the cross linking agents. The NPs dimensions in the solution were measured by dynamic light scattering method. The fluorescence studies have shown that two similar kinds of NPs are generated both in solution and on the textile surface. The time-resolved fluorescence measurements also indicate the presence of nanostructures on natural fibers after radiolytic procedure. The possibility of practical applications in medicine (e.g. wound dressing, drug delivery system) will be discussed.

Karolina Radomska graduated from Lodz University of Technology at Faculty of Chemistry with a master degree. Currently, She is a PhD student of the 3rd year at the same Department at Lodz University of Technology. Her specialization is radiation chemistry and She work in laboratory of laser photolysis. The main subject of her PhD thesis is the study of the influence of ionizing radiation on the proteins structure. Her scientific interests include radiation modification of human serum albumin and fabrication of albumin nanostructure.

Metallosupramolecular Architectures Derived from Aroylhydrazone Ligands

Visnja Vrdoljak*, Mirna Mandarić1, Dino Kuzman1, Mirta Rubčić1, Jana Pisk1, Marina Cindrić1 and Gordana Pavlović2

1University of Zagreb, Croatia
2Faculty of Textile Technology, University of Zagreb, Croatia

Supra molecular architectures based on coordination compounds, where the metal centres are bridged by organic ligands are continuing to be an interesting area of research. Such architectures exhibit a wide variety of properties and therefore represent attractive materials in connection with numerous possible applications. They can in principle be generated by self-assembly of a wide range of suitable building blocks in solution as well as in the solid-state. However, reports on Mo(VI) metallosupramolecular compounds are relatively rare. Recently, interest in such architectures led to formation of the molecular squares, hexagons and zigzag chains derived from isoniazid-related hydrazones. Here we present studies of coordination polymers, tetranuclear and dinuclear cyclic assemblies of the general formula[MoO2(L)]x, where x = n, 4 or 2 and L=nicotinylhydrazoate or aminobenzoylhydrazonate ligands. The study examines the formation of the self-assembled architectures and the factors that affects their formation (geometric control, substituents of the aroylhydrazone ligands, reaction conditions and choice of solvent). In all compounds the ligand is coordinated in the dianionic form to the cis-{MoO2}2+ core via the O,N,O donor atoms whereas the remaining sixth coordination site is occupied by the nitrogen atom of the nicotinoyl (or aminobenzoyl) moiety of the neighboring molecule thus forming such metallo-assemblies.

Visnja Vrdoljak obtained a Ph.D degree of Inorganic chemistry in 1996 from the Faculty of Science, University of Zagreb. Following post-doctoral fellowship at the University of Trieste, Italy. She joined the Faculty of science at the University of Zagreb. She is now Full professor. Her current research interests are focused on the development of POM based materials, metal supramolecular architectures and mononuclear complexes for applications in catalysis. Her interests include design, synthesis and characterization of novel inorganic-organic hybrid materials.

Effects of Substituents on s-Triazine Reactivity

Sedef Ozcan* and A. Ersin Acar

Bogazici University, Turkey

Triazine and its derivatives an important class of heterocyclic compounds have been intensively studied for decades. The oldest known isomer of it, s-triazine or 1,3,5 triazine is the most widely used one due to its availability in various areas such as textile, plastic rubber industries in addition to its usage as pesticides, dye-stuffs, optical bleaches polymer photo-stabilizers or antitumor agents. The most commonly preferred starting material to obtain functionalized s-triazines is cyanuric chloride which is highly reactive three chlorosubstituted s-triazine, since it provides controlled stepwise substitution through the chlorine atoms. In the study, cyanuric chloride is reacted with one and two equivalents of amine or phenol reactive nucleophiles which may contain electron donating or withdrawing groups at different positions. Besides, the further substitution of chlorines on mono- or di-amino substituted s-triazines by different hydroxyl groups are performed by nucleophilic aromatic substitution reaction. Here, the effect of each subsequent substitution of chlorine atoms on s-triazine reactivity will be clarified. It is supposed that resonance and inductive effects of reactive substituents as well as steric effect of the groups on them will change the reactivity of remaining chlorines.

Sedef Ozcan graduated from Bogazici University with a bachelorʼs degree in chemistry. She is a teaching assistant and has been doing PhD in chemistry at BogaziciUniversity. Previously, she taught in organic and physical chemistry laboratories. She is currently teaching in general chemistry laboratory for freshmen. She is experienced inorganic synthesis of varioustriazines, some acrylic monomers with theirradical polymerizations as well as purification and characterization of these materials. Besides, she has ability to analyse the compounds with different chromatographies, spectrophotometries. She likes listening to jazz and blues, playing tennis in addition tohiking and camping.

Microbial Transformation of Testosterone by Cladosporium cladosporioides

Ali Kuru* and Kudret Yildirim

Chemistry Department, Sakarya University, Turkey

Fungal steroid bio transformations have been widely used to produce more valuable and functionalized compounds such as steroid drugs and hormones due to their high regio and stereo selectivities.

Cladosporium is a large genus of the Ascomyta. Cladosporium species are mostly saprobes and also include common endophytes, plant pathogens and even hyperparasites of other fungi. Some Cladosporium species are also considered pathogenic to humans and animals.

Cladosporium cladosporioides is an endophytic fungus widely distributed around the world and it is pathogenic to some plants. This fungus is also considered pathogenic to animals and humans. As far as biotransformations by C. cladosporioides are concerned, there are no reports on steroid biotransformations.

In this work, testosterone was incubated with C. cladosporioides MRC 70282 for 5 days. Incubation of testosterone with the fungus mainly afforded some hydroxylated or oxidised metabolites at C-16. Oxidation and epimerisation of I at C-17 were also observed.

The metabolites were separated by column chromatography. Structures of the metabolites were determined by comparison of their melting points, 1H NMR, 13C NMR and IR spectra with those of the starting material.

Dr. Ali Kuru was born in 1982, in Kahramanmaras/Turkey. He graduated Yuzuncu Yıl University, Faculty of Education, Chemistry Teaching Department at 2008 and had a master degree from Yuzuncu Yıl University, Health Sciences Institute, Biochemistry branch at 2011. Same year he started his career at Chemistry Department of Sakarya University as a research assistant and at the same time started his PhD at Biochemistry branch of same university and graduated at 2017.

Investigation on In-Situ Chain End Modification of Polyesters by Succinic and Phthalic Anhydrides

Aysenur Ozdemir1,2*, Goknil Susler1,2, Kübra Kalaycı1, A.Ersin Acar1 and Recep Piyade2

1Bogazici University, Turkey
2Pulver Kimya San.Tic. A.S., Turkey

Powder Coatings are the most environmental friendly system for metal, automotive and wooden coating systems. The advantage of system comes from the absence of volatile organic compounds. A powder coating formulation contains a cross linkable resin, cross linker (hardener), flow modifiers and degassing agents. The curing reaction which creates the cross linked network carries out between resin end groups and hardener at appropriate temperatures. In this study, chain end modification of polyesters by succinic and phthalic anhydrides and their effects on polymer system are investigated.

Aysenur Ozdemir is a PhD candidate in Chemistry Department at Bogazici University, Turkey and works as a part-time chemist in R&D Department at Pulver Kimya A.S. She holds BS degree (2013) and MSc degree (2015) in chemistry at Bogazici University. Her master project was “Screening of Various Polyethylene Terephthalate Chain Extenders in a Melt Polymerization Set-Up”. She is currently studying about powder coating resins. Also, she is interested in solid state polymerization, reactive extrusion, crystallization and curing kinetics of polymer systems.

Investigation of PET Synthesis via Solution Polymerization Technique

Isil Yesil*, Aysenur Ozdemir and A. Ersin Acar

Bogazici University, Turkey

Poly (ethylene terephthalate) (PET) is a thermoplastic polyester commonly used in the industry owing to its good mechanical strength, thermal stability, high solvent resistance and low cost production. Depending on the application area, various molecular weight PETs are produced. (1)The initial step of PET synthesis is the formation of bis(hydroxyethyl) terephthalate (BHET) from the reaction between terephthalic acid (TPA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) with metal catalysts. Terephthaloyl chloride (TPC) can also be used but it is not common as DMT and TPA (2)due to the HCl formation as by-product. (3)After BHET synthesis, polycondensation reaction is carried out at high temperature at melt phase where vacuum is also applied at the end of the process to increase the molecular weight. Although melt polymerization is feasible and widely used there are disadvantages of the system such as degradation of PET due to the long reaction time at high temperature and formation of side products, diethylene glycol. The aim of the current research is to synthesize PET by the reaction between TPC and EG in one step by solution polymerization. The effect of reaction conditions on the polymerization and the polymer properties are investigated.

Isil Yesil after completing her undergraduate program in Molecular Biology and Genetics at Bogazici University, she continued a masterʼs degree in Chemistry at the same university. Since major interest areas are organic synthesis and analysis she attended a summer-term internship in R&D department at Eczacıbaşı Monrol Nuclear Products Company and continued as a part time employee for six more months. Currently she is doing solution and melt polymerization and working with polyesters in organic and polymer laboratory.

Synthesis of Polyester Networks through Ionic Interactions

Goknil Susler1,2*, Aysenur Ozdemir1,2, Recep Piyade2 and A. Ersin Acar2

1Bogazici University, Turkey
2Pulver Kimya San. Ve Tic A.S., Turkey

A supramolecular polymeric assembly originate from reversible, non-covalent interactions such as hydrogen bonding, ionic interactions, metal-ligand bond, π – π stacking between polymer chains or units on polymer chains. Supramolecular materials are sensitive to external stimuli in a different manner than traditional polymers due to their reversibility. This reversibility and low energy bonding brings extra features to material compared with covalent polymers and consequently enable materials to be reprocessed and recycled in the assistance of heat or solvent. Ionic hydrogen bonds, which are formed by a proton transfer between anions and cations are more robust and less-directional than traditional neutral hydrogen bonds. Hence, it would be beneficial to incorporate thermoreversible ionic hydrogen bonds as alternative cross-links into polymers to attain the reprocessing and recycling of crosslinked materials at elevated temperatures. Here in we report the facile synthesis of supramolecular ionic networks using a series of di- or multifunctional amines and carboxyl-terminated polyesters. A proton transfer reaction takes place between the carboxyl-terminated polyesters and the amine groups leads to the corresponding ionic carboxylate and quaternary ammonium groups. The influence of the density of ionic hydrogen bonds on the physical properties of polymers was studied. H-NMR and FTIR analyses were conducted to characterize obtained polymers. Thermal analysis was performed on DSC. Rheological measurements of the ionic networks were carried out using oscillatory tests and parallel plate geometry.

Goknil Susler graduated from Yıldız Technical University with a bachelorʼs degree in chemistry in 2016 with her thesis on “Synthesis of triazine-based macromolecules and examination of their liquid crystal properties”. She is a MSc. student in chemistry at Bogazici University. She is simultaneously works at Pulver Kimya San. ve Tic. A.S. in R&D Department as a part-time chemist. Her research areas are powder coating resins, melt polymerization.

Synthesis of Self-UV-Protective Polyesters by the Reaction of Resorcinol with Iso/Terephthaloyl Chloride

Refia Tigrak1*, Seda İkikardeşler1, Aysenur Ozdemir1,2, A. Ersin Acar1 and Recep Piyade2

1Bogazici University, Turkey
2Pulver Kimya San. Tic. A.S., Turkey

There has been a great interest towards the synthesis of weatherable polymers that provide enhanced UV-protection. The aim of this project is to synthesize polyester resins that are self-UV protecting. These polyesters are obtained by the reaction of resorcinol with various diacids. These polymers in principle should undergo Photo-Fries rearrangement that leads to the formation of hydroxy benzophenones derivatives which are known to be effective UV-absorbers. Various polyesters were synthesized by using resorcinol, terephthaloyl chloride and isophthaloyl chloride at different ratios.

Refia Tigrak is a master student in Chemistry department at Bogazici University, Turkey. In 2017, she received her bachelorʼs degree in Chemistry at Bogazici University. She has been worked on organic/drug synthesis and polymer synthesis, also their characterizations during her undergraduate researches. She is currently studied about polyester synthesis for powder coating applications by using the solution polymerization.

Synthesis of Novel Acetal-Based Formaldehyde-Free Crosslinkers

Sule Nihal Oz* and A. Ersin Acar

Bogazici University, Turkey

Binders are cross linkable polymer lattices which are used to bond fibers in textile and nonwovens. They provide to the fabric properties such as strength, flexibility, durability, resistance to washing and provide adhesion to fiber. N-Methylol acrylamide is one of the most commonly used cross linker in binder composition since it has good chemical and physical properties and selfcross linking ability. However, it emits formaldehyde to the environment during the cross linking reaction as a side product. Formaldehyde is known as a human carcinogen compound and is harmful to the human and the environment.

In this study, a novel cross linker is synthesized by the reaction of pentaerythritol with 3,4-Dihydro-2H-pyran under acidic conditions. Tetra- and tri- functional products will be used to crosslink cellulosicor amine containing polymer chains and their cross linking ability in different conditions and swelling ratios will be investigated.

Sule Nihal Oz is a graduate student in Chemistry Department at Bogazici University, Turkey and holds a BSc Degree (2015) in chemistry at Bogazici University. She worked as research student in Organic Synthesis & Polymer Chemistry Laboratory during her undergraduate study. She is currently working on organic synthesis, purification and analysis of organic products for her master thesis.

Application of Metallic Nanoparticles in LDI MS and Mass Spectrometry Imaging

Justyna Sekuła*, Tomasz Ruman and Joanna Nizioł

Rzeszow University of Technology, Poland

In the last years metallic nanoparticles, especially gold nanoparticles have attracted the attention of researchers due to their unique properties. Among the various metal nanoparticles, gold nanoparticles are the most frequently applied in LDI-MS. The advantages of using gold nanoparticles in laser desorption/ionization mass spectrometry (LDI MS) are primarily the simplicity of synthesis and modification/functionalization of AuNPs surfaces, high chemical stability and high UV absorption coefficient.

One of the most important objective of the project PRELUDIUM research is the development of new method for deposition of metallic nanoparticles onto steel target. Our research group focus on methods of preparing steel surfaces and synthesis of metallic, bimetallic and polymetallic nanoparticles. We also study of the potential and limitations of using AuNPET method in laser desorption/ionisation for the analysis of ionic and non-ionic compounds of different chemical properties.

One of the main directions of LDI-MSʼs development is the imaging mass spectrometry (MSI), enabling the visualization of surface distribution of biological samples. Our research focused on possibility of using AuNPET method in imaging of objects of biological origin. In addition, our research group analysis of a fingerprint on the steel target coated with metallic nanoparticles in order to identify and localize the endogenous and exogenous substances was described.

Justyna Sekuła received the M.Sc. degree in Biotechnology (specialization – industrial biotechnology) at Warsaw University of Technology (Poland) in 2013. She received Ph.D. title in 2017 after defending her work entitled “New matrix free system to laser mass spectrometry” at Rzeszow University of Technology (Poland). She is manager of the project PRELUDIUM financed by the National Science Centre. Her research is focused on the novel matrix-less systems used for laser desorption/ionization mass spectrometry and mass spectrometry imaging.

Spot Test Paper Platform Coupled with DLLME for Detection of Furosemide Doping

Eduardo Luiz Rossini*, Helena Redigolo Pezza and Felipe de la Rua Müzel

Instituto de Química, Universidade Estadual Paulista “Júlio de MesquitaFilho” (UNESP), Brazil

Furosemide is a diuretic widely used for treatment of hypertension, heart and renal failure. Due to its diuretic action, its use could be considered as doping, because it causes weight loss and masks other doping compounds by decreasing their concentrations in urine. Dispersive liquid-liquid microextraction (DLLME) is a novel and powerful preconcentration and extraction technique based on miniaturization. Its combination with a paper platform provides an attractive methodology that offers low cost, simplicity and portability. The spot test was designed using Corel DRAW X5. The template was printed on a filter paper, using a wax printer, followed by heating the paper to form hydrophobic barriers. The chromogenic reagent was 50mMiron nitrate. A mixture of acetonitrile (disperser solvent) and dichloromethane (extractor solvent), in a ratio of 1:9 was used as the solvent in the DLLME procedure. Samples were prepared by adding 10 mL of urine and 2mL of the mixed solvents to a tube, with vortexing and centrifugation. A 1.0 μL aliquot of the lower phase was used in the spot test. After drying, 1.0 μL of the iron solution was added and digital images of the system were acquired with analysis using ImageJ® software (blue channel). An analytical curve was constructed and the LOD and LOQ obtained were 0.95 and 3.18 mM, respectively. The matrix showed no significant influence in the analysis. Natural urine samples were analyzed by the proposed method and by HPLC-UV. The results indicated that the developed methodology wasprecise and accurate.

Eduardo Luiz Rossini is a PhD student at Institute of Chemistry of São Paulo State University – UNESP – Araraquara, Brazil. He received his master degree in chemistry in the same institution under the supervision of Prof. Helena Redigolo Pezza. He has experience in analytical chemistry with focus on micro fabrication, spectrometric methods and low-cost devices. His research interest is the development of paper platform for clinical analysis.

Interconnection of Charge Neutrality Level with Electronic Structure and P-D Hybridization and its Modification upon Electronic Excitations

Arkaprava Das1*, Subodh K. Gautam1, G. R. Umapathy1, S. Ojha1, Fouran Singh1 and D. K. Shukla2

1Inter University Accelerator Centre, India
2UGC-DAE Consortium for Scientific Research, India

Undoped and tin doped cadmium oxide (CdO) based thin films are irradiated by 84 MeV Si6+ and 120 MeV Ag9+ ions. In the present work the charge nutrality level (CNL) [1] in highly conducting CdO thin films is demonstarted by the observed variation in the band gap upon annealing and doping. The increase in crystallite size with tin doping is a signature of decrease of CdO stoichiometry by substitutional replacement of Cd with Sn. Each Cd2+ ions are substituted by Sn2+ ions with reduction of Sn4+ via creating oxygen vacancies in the lattice which also enhnaces the carrier concentration in the tin doped thin film [2]. The band gap enhancement cannot be explained by Burstein-Moss Shift (BMS) only but can be explained by formation of charge neutrality level (CNL). The level of local CNL resides at the branch point of virtual gap states (ViGS) generation of which is the consequence of tin doping in CdO lattice. Further investigations using soft x-ray absorption spectroscopy (SXAS) at Oxygen k and Cadmium M4,5 edge and the analysis of the spectral features has revealed an evidence of p-d interaction between O 2p and Cd 4d orbitals. After irradiation, the thin films exhibit an unusual band gap enhancement via generation of oxygen vacancies due to huge electronic energy deposition inside the lattice by Ag and Si ions. The observed band gap enhancement has been substantiated by an schematic block diagram.

Small-Molecule PERK Inhibitors as a Promising, Anticancer Treatment Approach

Wioletta Rozpędek1*, Alicja Nowak-Zduńczyk1, Adam Wawrzynkiewicz1, Radosław Wojtczak1, Dariusz Pytel2, J. Alan Diehl2 and Ireneusz Majsterek1

1Medical University of Lodz, Poland
2Medical Univeristy of South Carolina, USA

The newest data has reported that activation of the pro-adaptive Protein kinase RNA-like Endoplasmic Reticulum kinase (PERK)-dependent Unfolded Protein Response (UPR) signaling pathway is directly implicated in the cancer development and progression. Hypoxia evokes Endoplasmic Reticulum (ER) stress conditions, that activate PERK and Eukaryotic Initiation Factor 2α(eIF2α) phosphorylation leading to enhanced translation of pro-adaptive Activating Transcription Factor 4 (ATF4). However, upon severe, long-termed ER stress conditions the pro-adaptive UPR is switched into the pro-apoptotic resulting in apoptotic death of cancer cells. The objective of the presented study was to examine the inhibitory activity of the small-molecule PERK inhibitor NCI-A146 selected from the 150000 compounds by utilizing docking software. Evaluation of its inhibitory activity was conducted on human colon cancer cell line (HT-29), that was pretreated with NCI-A146 at a concentrations range of 3μM to 50μM for 1h, and then treated with thapsigargin (Th) for 2h to evoke ER stress conditions. Cells treated only with Th constitute a positive control; cells without any treatment a negative control. The NCI-A146 inhibitory activity was measured by the evaluation of the level of eIF2α phosphorylation using the Western blot technique. Aa a result significant inhibition of eIF2α phosphorylation was observed after treatment of HT-29 cell line via NCI-A146 ata concentration of 25μM (58%) and 50μM (70%). Thus, our results suggest small-molecule PERK inhibitors may provide a novel, targeted anti-cancer therapy.

This work was supported by grant PRELUDIUM no. 2015/19/N/NZ3/00055 from the National Science Centre, Poland.

Wioletta Rozpędek studied biology at the University of Lodz, Poland. She specialized in the field of neurophysiology and cell biology. Currently she is a PhD student at the Department of Clinical Chemistry and Biochemistry of Medical University of Lodz, Poland. She is working on molecular basis of cancer and neurodegenerative diseases associated with Endoplasmic Reticulum stress and activation of PERK-dependent signaling pathways. Her area of focus includes use of small-molecule inhibitors as a novel therapy against neurodegenerative diseases and cancer.

Investigation for Characterization of Paraffinic Deposit from Oil Production

Mariem Samcha* and Amel Boukadi

Entreprise Tunisienne dʼActivités Pétrolières, Tunisia

The presence of heavy organic compounds such as paraffins and asphaltenes in crude oil causes several problems during the petroleum production. Precipitation of these compounds causes the formation of deposit causing the clogging of installations, the blockage of pipeline and the shutdown of production. The basic maintenance method consists in sending scrapers into these pipes in order to drive out these deposits.

This is the case of an oil field in Tunisia, which produces a paraffinic crude. The exploitation of this field and the shipment of the produced oil to storage terminal, have led to the accumulation of large amounts of deposits from the regular pipeline pigging.

In this work we are interested in the characterization of the crude oil and the deposit formed by several techniques included physical-chemical analyses, chromatography, Fourier Transform Infra Red spectroscopy, Differential Thermal Analysis.

The obtained results have shown that the deposit is so rich in paraffin and characterized by higher as phaltenes contents than the original crude oil. The paraffinic fraction isolated from the deposit seems to be of two types: microcrystals and macrocrystals.

In order to remedy the deposit problem, curative solutions has been used to dissolve the deposit.

Finally, to find preventive solutions several tests were performed using two paraffin inhibitors.

The best results, for which deposit remained fluid at room temperature, were obtained by adding a dispersant to the paraffin deposit, previously mixed with a predetermined amount of the crude oil from which it is derived.

Mariem Samcha is a chemical engineer graduated from faculty of Sciences of Tunis in 2004. She obtained her master degree in analytical chemistry on molecular characterization of paraffins isolated from different Tunisian crude oils. Since 2008, she is the coordinator of the petroleum fluids Laboratory in Petroleum Services Department from ETAP. Her responsibilities included the studies on oil and gas as well as special work on crude oil such as: mixture oil compatibilities, Deposit identification, chemicals additives efficiency, emulsion formation and separation, flow assurance.

Treatment of Petroleum Drill Cuttings using Stabilization/Solidification Method and Pollutant Loading Characterisation

Sonia Barbouchi* and Anis Belhadj Mohamed

Entreprise Tunisienne dʼActivités Pétrolières, Tunisia

During the drilling phase in petroleum exploration, the cuttings of drilled rocks are transported from the well to the surface by a circulating fluid called mud. Once they have been brought to the surface, the cuttings are separated from the synthetic fluid and dried. The management of those generated solid wastes is one of the emerging problems of oil and gas companies.

The purpose of the present study is to evaluate the pollutant loading of the cuttings generated from a drilled well in a southern Tunisian oilfield and to perform treatment tests using stabilization/solidification method.

The analysis of leachates by ICP-OES revealed relatively high heavy metals concentration values especially for Zn, Cu and Pb. The concentration of TPH determined by Rock-Eval pyrolysis exceeded the pollution indicative value. A geochemical study has been conducted to identify the source of hydrocarbon contamination using GC and GC-MS.

A series of treatment tests of the drill cutting has been performed using mixes containing different ratios of cement, lime and sodium silicate. Total petroleum hydrocarbons and heavy metals content of the obtained leachates have also been determined.

The drill waste disposal strategy to be adopted in the concerned oilfield is being derived in a large part from the results of the present study.

Sonia Barbouchi is a chemical engineer graduated from INSAT (Institut National des Sciences Appliquéeset de Technologies), in March 2010. On 2014, she obtained her master degree in industrial chemicals. She joined the ETAP labs on 2010 and from June 2011, she is the coordinator of the Environmental Laboratory in the ETAP Petroleum Services Department. Her experience in ETAP allowed her to broaden the sphere of her knowledge in the Environmental sector such as pollutants analyses in petroleum rejects, environmental regulation and environmental impact assessment. On the other hand, it allowed her to deal with some problems related to produced water.

Practical Aerobic Oxidation of Alcohols: Ligand Enhanced TEMPO/Mn(NO3)2 Catalyst System

Kalle Lagerblom

University of Helsinki, Finland

A highly efficient, ligand enhanced TEMPO/Mn(NO3)2 catalyst system for the aerobic oxidation of alcohols is described. From the series of coordinating ligands studied, 2-picolinic acid (PyCOOH) remarkably improves the catalytic activity of TEMPO/Mn(NO3)2. Under ambient air, at room temperature and in acetic acid, the ligand-enhanced catalyst converts various functional group-bearing aliphatic and benzylic primary alcohols to their respective aldehydes with near quantitative conversions (Scheme 1). A change of TEMPO to sterically less demanding 9-azabicyclo[3.3.1]nonane N-oxyl (ABNO) turns the Mn-catalyst also capable for oxidation of secondary alcohols to ketones. Mechanistic studies show that alcohols are oxidized by the oxoammonium cation derived from the nitroxyl radical. The active oxidant is re-generated by Mn(NO3)2 and this process is greatly promoted by the coordination of PyCOOH to Mn.

Development of Analytical Method Based on Systematic Approach of Column Preconcentration/Determination of Toxic Metal Ions in Environmental Samples Using Graphene Oxide Based Solid Phase Extractant

Suneel Kumar1*, Amit Paul1 and Aminul Islam2

1Indian Institute of Science Education and Research, India
2Aligarh Muslim University, India

Layered graphene oxide (GO) with two-dimensional carbon lattice is linked to styrenic carbon of porous XAD polymeric resin through azo spacer arm without utilizing any oxygen containing functional group for the first time. This approach makes all the epoxy, hydroxyl, carbonyl and carboxyl groups on axial and basal plane of GO sheet available for coordination with metal ions and introduction of hydrophilic character resulting in highest preconcentration factor for Pb (500) among the GO-composites used as solid phase extractant in column operation. The analytical method developed using XAD-GO for preconcentration of Pb, Cd and Zn ions enables the use of an economically viable less sensitive AAS for their trace determination in water samples due to the improved limit of detection (0.41, 0.41, 0.13 μg L-1) and quantification limit (1.38, 1.36, 0.42 μg L-1) for Pb, Cd and Zn ions respectively. Use of polymer immobilized GO in a column sort-out the problem of escape of toxic GO into the environment and under optimized SPE conditions, quantitative desorption of metal ion involves only 5.0 mL of 2M HCl instead of any carcinogenic organic solvents. These two factors make this method ecofriendly and green one. The method was further validated analyzing standard reference materials and recovery of the spiked analyte from real water samples.

Dr. Suneel Kumar, he received his MSc in Analytical Chemistry in 2011 and Doctor of Philosophy in 2016 from Aligarh Muslim University (AMU) Aligarh, UP, India. Currently, he is associated with Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal, MP, India as a National Postdoctoral Fellow. His research work focused on development of analytical method for toxic metal determination and their removal by solid phase extractant. He also working in the field of super capacitor for energy storage.

Synthesis and Characterization of Chitosan Nanoparticles in the Pharmaceutical Application

F. Damiri*, A. Laaraibi, I. Charhouf, N. Knouzi, A.Bennamara and M. Berrada

Department of Chemistry, University Hassan II of Casablanca, Morocco

Nanoparticles have been widely studied for applications in drug release systems. To prevent a drug from rapid release, the use of biodegradable polymers, which serve as protective drug coatings, has been developed. Chitosan, as a biodegradable and biocompatible polymer, is extensively used as a carrier for encapsulation of drugs and biological substances in the pharmaceutical industry due to: its ability in a drug controlled-release system, its solubility in aqueous acidic solution which avoids the use of hazardous organic solvents while fabricating particles, its cationic nature that allows ionic to crosslink with multivalent anions, the capacity of chemical crosslink applied by its amino groups and its muco adhesive character of increasing residual time at the site of absorption. Emulsion cross linking, coacervation/precipitation, ionic gelation methods are usually used in preparing chitosan nanoparticles.

Water-soluble drugs can be loaded by using the emulsion crosslinking technique with high encapsulation efficiency. In this method, a water/oil (W/O) emulsion was prepared by emulsifying the chitosan aqueous solution in the oil phase and aqueous droplets are stabilized by using a suitable surfactant. Then the stable emulsion is solidified by an appropriate crosslinking agent.

Keywords: Nanoparticles- chitosan-emulsion crosslinking-ionic gelation.

Metal-Organic Frameworks for Luminescent Sensing and White LED

Yuanjing Cui*, Zhiyu Wang, Banglin Chen and Guodong Qian

Zhejiang University, China

Metal-organic frameworks (MOFs) are a new family of organic-inorganic hybrid materials and have received tremendous attention in the past decades due to their exceptional tunability and structural diversity. The luminescent properties of MOF materials cannot only be generated from the metal ions/clusters and organic linkers (two basic components for MOFs) but can also be tuned by guest molecules/ions and the interplay/interactions among these different components. Such unique characteristics enable the luminescent MOFs to be very promising multifunctional materials for light-emitting devices. By encapsulating the organic dyes with different emitting color into pore spaces of luminescent MOFs to form MOFs dye composites, the combination of the emissions from MOFs and the dyes can be elaborately tuned and thus realize the efficient white emission with high color quality. Furthermore, the resultant MOFs dye composite exhibits a high quantum yield because that the confinement and isolation of the MOFs efficiently restrict the aggregation-caused quenching of the dyes. Such a strategy can be easily expanded to other luminescent MOFs and dyes, thus opening a new perspective for the development of white light emitting materials.

Lipase Immobilization on Facile Synthesized Polyaniline-Coated Silver-Functionalized Graphene Oxide Nanocomposites as Novel Biocatalysts

Mohd Shamoon Asmat* and Qayyum Husain

Department of Biochemistry, Aligarh Muslim University, India

Enzymes perform an essential role in catalysing extensive reactions. Yet, their instability upon repetitive use, as well as their activity inhibition by different solvent remains a cumbersome task of concern. We present here a simple method to immobilize Aspergillus niger lipase (ANL) onto polyaniline-coated silver-functionalized graphene oxide nanocomposites (PANI/Ag/GO), involving the facile synthesis of PANI/Ag/GO and the formation of ANL@PANI/Ag/GO nanocomposites. Covalent bonding was achieved via glutaraldehyde as a cross linking agent onto these nanocomposites. The resulting ANL@PANI/Ag/GO with a nanoscale dimension has a remarkably high enzymatic activity recovery yield of 88.5% and immobilization yield upto 94%. The apparent optimum temperature and pH for ANL@PANI/Ag/GO were higher than those of free ANL. ANL@PANI/Ag/GO exhibited comparatively higher catalytic efficiency and enzyme-substrate affinity. The binding of ANL on PANI/Ag/GO-NCs was confirmed by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, dynamic light scattering and atomic force microscopy. The metal content was examined by energy-dispersive X-ray spectroscopy. ANL@PANI/Ag/GO biocatalyst retained over 86% of its initial enzyme activity after 11 repeated uses. ANL@PANI/Ag/GO displayed significantly enhanced solvent tolerance and high thermal stability compared to the free enzyme, it might be due to the increase in enzyme structure rigidity. Remarkably, the as-prepared nanobiocatalyst ANL@PANI/Ag/GO will have a deep impact on practical industrial scale uses of enzymes for the transformation of lipids into fuels.

Quantitative Determination of Heavy Metals in Some Commonly Consumed Herbal Medicines in Kano State, Nigeria

Aliyu Umar Mohammed Y1*, Saidu G2 and Muhammad2

1Kano State Polytechnic, Nigeria
2Nigeria Defense Academy, Nigeria

Evaluation of heavy metals in twelve commonly consumed herbal medicines/preparations in Kano State Nigeria was carried out. The samples comprised of five unregistered powdered medicines, namely, Zuwo (ZW); Rai Dorai, (RD); Miyar Tsanya, (MTS); Bagaruwar Makka, (BM); and Madobiya, (M); five unregistered liquid herbal medicines concussions for pile (MB), yellow fever (MS), typhoid (MT), stomach pain (MC), sexually transmitted diseases (STDs) and two registered herbal medicines; Alif powder (AP) and Champion Leaf (CL). The heavy metals evaluation was carried out using Atomic Absorption Spectrometry (AAS) and the result revealed the concentration (ppm) ranges of the heavy metals as follows: Cadmium (0.0045 – 0.1601), Chromium (0.0418 – 0.2092), Cobalt (0.0038 – 0.0760), Copper (0.0547 – 0.2465), Iron (o.1197 – 0.3952), Manganese (0.0123 – 1.4462), Nickel (0.0073 – 0.0960), Lead (0.185 - 0.0927) and Zinc (0.0244 - 0.2444). Comparing the results in this work with the standards of the World Health Organization (WHO), the food and Agricultural Organization (FAO) and the permissible limits of other countries, the concentration of heavy metals in the herbal medicine/preparations are within the allowed permissible limits range in herbal medicines and their use could be safe.

Keywords: Herbal medicines, Registered, Unregistered, Kano State

Hierarchical Supramolecular Cross-Linking of Polymers for Biomimetic Fracture Energy Dissipating Sacrificial Bonds and Defect Tolerance under Mechanical Loading

Teemu T. T. Myllymäki

University of Helsinki, Finland

Biological structural materials offer fascinating models how to synergistically increase the solid-state defect tolerance, toughness, and strength using nanocomposite structures by incorporating different levels of supramolecular sacrificial bonds to dissipate fracture energy. Inspired there of, we show how to turn a commodity acrylate polymer, characteristically showing a brittle solid-state fracture, to become defect tolerant manifesting noncatastrophic crack propagation by incorporation of different levels of fracture energy dissipating supramolecular interactions. There in poly(2-hydroxyethyl methacrylate) (pHEMA) is a feasible model polymer showing brittle solid state fracture in spite of a high maximum strain and clear yielding, where the weak hydroxyl group mediated hydrogen bonds do not suffice to dissipate fracture energy. We provide the next level stronger supramolecular interactions towards solid-state networks by post-functionalizing a minor part of the HEMA repeat units using 2-ureido-4[1H]-pyrimidone (UPy), capable of forming four strong parallel hydrogen bonds. Interestingly, such a polymer, denoted here as p(HEMA-co-UPyMA), shows toughening by suppressed catastrophic crack propagation even if the strength and stiffness are synergistically increased. At the still higher hierarchical level, colloidal level crosslinking using oxidized carbon nanotubes with hydrogen bonding surface decorations, including UPy, COOH and OH groups, leads to further increased stiffness and ultimate strength, still leading to suppressed catastrophic crack propagation. The findings suggest to incorporate a hierarchy of supramolecular groups of different interactions strengthens materials upon pursuing towards biomimetic toughening.

Teemu T. T. Myllymäki had his M.Sc. in organic chemistry from University of Helsinki in 2014, after which he started working as a Ph.D. student at Aalto University Department of Applied Physics. In his research he takes innovation from nature to develop materials with better properties than ever before. Biomimetics aims to copy the properties of the naturally occurring materials into synthetic ones. Areas of expertise include chemical analysis, supramolecular chemistry, self-assembly, nanomaterials and material characterization. Also co-founder & CEO of Measur.

Modeling of the Effective Thermal Conductivity of Natural Composite Materials

Said Sair*, O. Tanane, Y. Abboud and A. El Bouari

University Hassan II of Casablanca, Morocco

Insulation is considered one of the effective solutions to achieve energy savings in building and thermal energy storage systems. Better insulation having low thermal conductivity contributes significantly to new construction and retrofitting existing buildings. Numerous analytical expressions for estimation of effective thermal conductivity of composite materials have been proposed by several authors. Basic expressions apply to spherical filler particles but later models were developed to allow the inclusion of other particle shapes, the presence of particle coating and the interfacial thermal resistance. Models belonging to the class of effective medium approximations usually fail to predict the properties of a multiphase material close to and above the percolation threshold. In the present paper, a novel and efficient model was developed for predicting the effective thermal conductivity of the composite materials based of polymers matrix and natural fibers at different filler percentages. By introducing the relative radius as a parameter, the effective thermal conductivity can be predicted precisely when the thermal properties of filler and matrix are prescribed. The model employed the resistor network strategy to achieve a highly efficient prediction during the overall conductivity calculation. To verify this model, a wide range of composites were analyzed using lambda meter apparatus. The model-based simulation values showed good agreement with the experimental results. Moreover, a discussion on the effects of the newly-introduced parameter was given. Finally, the relationship between the fibers content percentage and the thermal conductivity of the composite was studied.

Said Sair is a PhD candidate in Chemistry research and development at Hassan II university of Casablanca Morocco. His research interest is in the field of the use of natural resources in the reinforcement of composite materials for different applications including thermal insulation, the modelling of physical behavior of composite materials is one of those interests. His other projects include the uses of fibers treatments rejects in inhibiting the corrosion of metals and alloys.

Exploration of Polyfunctional Flavonoids Based Compounds in Alzheimerʼs Disease: Design, Synthesis and Biological Evaluations

Manjinder Singh1* and Om Silakari2

1Chitkara College of Pharmacy, Chitkara University, India
2Punjabi University, India

Polyfunctional compounds comprise a novel class of therapeutic agents for the treatment of multi-factorial diseases like Alzheimerʼs disease (AD). Following this approach, a new series of flavonoids were designed, synthesized and biologically evaluated against acetylcholinesterase (AChE), advanced glycation end products formation (AGEs) with additional free radical scavenging activity. The in vitro studies showed that the majority of synthesized derivatives inhibited acetylcholinesterase (AChE) with IC50 values in the nanomolar range. Among them, inhibitors FLV-16 and FLV-32, strongly inhibited AChE and were more potent than the reference compound donepezil. Moreover, the molecular docking study displayed that most potent compounds simultaneously bind to catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. Besides, these compounds also exhibited greater ability to inhibit advanced glycation end products formation with additional radical scavenging property. Thus, flavonoids might be the promising lead compound as potential poly-functional Anti-Alzheimerʼs agents.

Investigation of Temperature Dependent Transport Characteristics of Polyaniline Films Modified with Gold Nanoparticles

Lakhwant Singh* and Sonika Thakur

Guru Nanak Dev University, India

The present work investigates the modification of the electrical properties of polyaniline with the introduction of gold nanoparticles to the polymer matrix. The nanocomposites of polyaniline and gold nanoparticles have been successfully synthesized using conventional chemical polymerization technique, where gold nanoparticles have been added in different successive weight percents. The dielectric studies as a function of temperature have been carried out on these composite samples in the frequency range 20 Hz-1 MHz. The dielectric relaxation characteristics of the synthesized samples have been examined by analyzing dielectric spectroscopy, dielectric loss and electrical conductivity spectroscopy. Perusal of the dielectric data depicts that the dielectric permittivity of the samples increases with an increase in the temperature and nanoparticles content. The frequency dependent ac conductivity has been analysed using Jonscherʼs universal power law relation. The power law exponent(s) has been observed to be composition and temperature dependent. The decrease in s with an increase in temperature suggested that the ac conduction mechanism of these samples follows the correlated barrier hopping (CBH) model. The improved dielectric constant of nanocomposite suggests its increased ability to store electric potential energy under the impact of alternating electric field.