Day 13 :
- Organic & Inorganic Chemistry
Session Introduction
Ronnell John R. Gonzales
National University College of Allied Health, Philippines
Title: Comparative Colorimetric Study on the Aqueous Extract of Areca catechu “Bunga†(Arecaceae) Fruit and Methanolic Extracts of Bixa orellana “Atsuete†(Bixaceae) Seed and Hibiscus rosa-sinensis Linn. “Gumamela†(Malvaceae) Flower as Red Colorants using UV-Vis Spectrometry
Biography:
Ronnell John R. Gonzales has completed his college degree in Pharmacy at the age of 24 years from National University - Manila. He earned his license from the Board of Pharmacy in 2018. Currently, he holds the position of Junior Safety Data Analyst at a premier clinical research company under the pharmacovigilance department. He’s a community pharmacist. He’s also the founder of a non-profit charity organization which aims to extended helping hand to the less fortunate. He has co-written 2 papers both in the Pharmacy area of practice.
Abstract:
Natural dyes are also used in the coloration of food, medicines and in leather processing. Unlike natural colorants, synthetic colors have been banned due to allergic and carcinogenic symptoms that they can cause. More eco-friendly dyes are now being developed to replace synthetic dyes which are found to be toxic and hazardous to health. Thus, the researchers wanted to study natural colorants from three botanical sources namely, Areca carechu, Bixa orellana and Hibiscus rosa-sinensis as possible alternative for the commercially used FD&C Red 40, Allura Red. UV-Vis Spectrometery was used to measure the transmittance of the samples within 380-770 nm at 10 nm interval. Using the transmittance values, CIELAB parameters were obtained and used to characterize and compare the colorants quantitatively. The results obtained in the present study revealed that the natural colorants from Areca catechu, Bixa orellana, and Hibiscus rosa-sinensis all fall within the dark, red and yellow spectra of colors based on the L*, a* and b* values respectively. Among the three natural colorants that were utilized in this study, both the natural colorants from A. catechu and B. orellana yielded p-values of 0.042 and 0.024 respectively. These are both lower than the level of significanc aforementioned colorants to that of the standard. Thus it can be inferred that they can’t be utilized as possible alternative colorant to Allura Red. Only H. rosa-sinensis yielded a p.value (0.641) that is greater than the level of significance. This means that there is no significant different between the two colorants across the combined color characteristics making it a possible alternative colorant to that of the standard in terms of color characterization alone. This means that among the three natural colorants, it can be implied that the natural colorant from H. rosa-sinensis is the closest to Allura Red in terms of combined color characteristics.
Ragab Amin El-Sakka
Faculty of Engineering, Nahda University, Egypt
Title: Spectroscopic Analysis and Antimicrobial Studies for Novel Metal Oxytetracycline Drug Complexes
Biography:
Ragab Amin El-Sakka has been working in Sana’a University. Then from 1992 to 2001 he has been working as an assistant lecturer in Qatar University. He worked as an Associate Prof. and consultant for Dean of post-graduate studies, Faculty of Science, Taif University for 5 years. From 2010 to 2012. He worked as a Vice Dean of Student Affairs for three years. Then he joined the Faculty of engineering as a Full Prof. and Head of Basic Science department in 2012. Since Nov 2016, He is working as a Vice Dean of Faculty of Engineering, Nahda University.
Abstract:
The 1:1 and 2:1 M ratio metal complexes of new Cu(II), Co(II), Fe(III), Zn(II) and Zr(II) complexes of Oxytetracycline hydrochloride have been synthesized. Attempts have been made to ascertain their probable structures on the basis of elemental analysis, spectra (IR, Electronic) and NMR studies. The ligand forms a complexes in a molar ratio 1:1 having an empirical formula (MLSO4.nH2O) and 2:1 molar ratio having an empirical formula (M2LSO4.nH2O) where M = Cu(II), Co(II), Fe(III), Zn(II) and Zr(II), L = Oxytetracycline and n = 2 – 6. The infrared spectral data and proton magnetic resonance studies were support the postulate that Oxytetracycline reacts with metal ions as an ionic bidentate ligand through its carboxylate oxygen and the amide carbonyl oxygen. Drug compounds are biologically active, these compounds have become of interest to be studied biologically, and compared their activities against four species of bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa), and two fungal species (Aspergillus flavus and Candida albicans).
Haojie Yu
Zhejiang University, China
Title: Preparation of hyperbranched polyethylene-based copolymers and their applicaitons
Biography:
Haojie Yu is an Associate Professor at the College of Chemical and Biologycal Engineering, Zhejiang University. He got his Ph.D. degree in 2006 and finished postdoctoral research in 2009 at Zhejiang University. He served as a visiting associate researcher at the University of California, Irvine, USA from Feb 2015 to Feb 2016. He is an editorial board member of Studies in Synthetic Chemistry. His research interests largely focus on functional polymers. He is the project principal of more than 20 research programs that from Natural Science Foundation of China, International Cooperative Programs, Multinational Corporations and domestic enterprises. He has published more than 100 papers in the journals such as Chemical Reviews, Prog. Polym. Sci., Angewandte Chemie-International Edition, J. Phys. Chem. B, Macromolecules, Nanotechnology and so on.
Abstract:
Hyperbranched polyethylene exhibits unique branched topology and properties. However, hyperbranched polyethylene lacks polar functionality, which limited its further application. Introduction of polar functionality into hyperbranched polyethylene via graft polymerization method can extend its application scope. Herein, a series of hyperbranched polyethylene-based polymethacrylates polymers were synthesized through a combination of coordination polymerization and atom transfer radical polymerization. The dispersibility of MWCNTs employing the obtained hyperbranched polyethylene-based polymethacrylates was evaluated via TGA, UV-vis, TEM and SEM technologys. These results indicated that MWCNTs were effectively dispersed by the hyperbranched copolymers. Then, hyperbranched polyethylene-based polymethacrylates/MWCNTs/PET composite film was fabricated and its conductivity was measured. The resultant film exhibited uniform MWCNTs networks and excellent conductivity. Moreover, the composite film showed good conductivity even it was bentand released for 1000 times. The mechanism of the dispersion of MWCNTs by hyperbranched polyethylene-based polymethacrylates was discussed. Existence of π-π stacking interactions between the hyperbranched polyethylene-based polymethacrylates and MWCNTs was proved by UV-vis results. The obtained conductive composite films might find its potential application in electronic devices.
Chioma Festus
Ignatius Ajuru University of Education, Rumuorlumeni, Rivers State, Nigeria
Title: Mixed Ligand Divalent Complexes of 2-(4,6-dimethylpyrimidin-2-ylamino)naphthalene-1,4-dione: Synthesis, investigational and hypothetical characterisation, and Biological actions.
Biography:
Festus Chioma, ia a lecturer with the Department of Chemistry. Ignatius Ajuru University of Education Rivers State, Nigeria. He completed his Ph.D at the age of 38 years specializing in Coordination/Organometallic Chemistry from the University of Ibadan, Oyo State Nigeria. He is the Head of Unit, Inorganic Chemistry at the University where he presently works. He has authored three Inorganic chemistry textbooks, co-authored two general chemistry textbooks, published thirty-two research articles in high-rated academic journals and attended several conferences with quality research papers presented.
Abstract:
A new pyrimidinyl ligand, 2-(4,6-dimethylpyrimidin-2-ylamino)naphthalene-1,4-dione (HL) and its divalent heteroleptic manganese, cobalt, nickel and copper complexes have been synthesized and characterized in the light of elemental (CHN), magnetic, conductance, infrared (IR), nuclear magnetic resonance (1H- and 13C-NMR), electronic (UV-Vis), electrospray ionization mass spectrometry (ESI-MS), thermographic analysis (TGA) and molecular docking studies. The acquired results were consistent with the adoption of the chemical formula, [M(bipy)(L)(Y)]∙nH2O (where M = Mn, Co, Ni, and Cu; L = Schiff base; bipy = 2,2’-bipyridine; Y = OAc and n = 0,1) for the metallic complexes. The magnetic susceptibility measurements and low conductivity data offer proof for monomeric and neutral nature of the heteroleptic complexes. On the basis of spectral investigations and analytical data, it was manifest that the pyrimidinyl ligand acts as bidentate chelator. The divalent heteroleptic complexes were apportioned octahedral stereochemistry on the basis of electronic and magnetic susceptibility measurement data. In order to evaluate the influence of metallic ions upon chelation, both the ligands and their complexes were appraised for their antimicrobial actions against S. aureus, P. aeruginosa, E. coli, B. cereus, P. mirabilis, K. oxytoca, A. niger, A. flevus and R. Stolonifer. The antimicrobial studies presented moderate-good actions verifying their possibilities as broad-spectrum antibacterial agents. The free radical scavenging activity of newly synthesized compounds has been determined at a different concentration range by means of their interaction with the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). Molecular docking studies on these compounds indicated significant binding attraction between the adopted drug targets and the divalent heteroleptic metallic complexes showing the potentials of the latter to be used as drugs.