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Title:	Synthesis, characterization and biological activities of bis-thiourea amino acid derivatives and their binding studies with metal ions
Authors:	Imran Fakhar (P74032)
Supervisor:	Bohari Mohammed Yamin, Prof. Dr.
Keywords:	Thiourea -- Toxicology Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	17-Sep-2019
Description:	Recently, chemistry of thiourea derivatives has retained considerable attention due to their proliferate applications. In the past decade most of the research was done on mono substituted amino acid derivatives. In the present study forty-six bis(thiourea) derivatives were synthesized by the reaction of isothiocyante with amino acid/amino ester/amino ethanol in good yield. The synthesized derivatives were characterized by microelemental analysis (CHNS), infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and the structure of seven derivatives was solved using X-ray crystallographic technique. Dicarbonyl chloride was added into ammonium thiocyanate, in slight excess to obtain isothiocyanate intermediate. Amino derivatives were then added to isothiocyanate and refluxed for 24-36 hours to obtain bisthiourea derivative. Based on the results of characterization, the experimental values are in close agreement with the scientific literature. FTIR spectra of the synthesized derivatives confirms the presence of characteristic functional groups, such as v(NH) in the range of 3200-3400 cm-1, v(C=Ocarboxylic) in the range 1700-1728 cm-1, v(C=Oamide) in the range 1658-1690 cm-1 and v(C=S) are in the range of 1009-1031 cm-1. The 1H-NMR spectra highlights the presence of two distinct characteristic amino proton peaks in the range 10.50-11.38 ppm and 11.20-11.97 ppm. The 1H-NMR spectra also reveals that the bis(thiourea) derivatives have a plane of symmetry. Moreover, all the aromatic and aliphatic proton chemical shifts are in concurrence with the scientific reported literature. Whereas, the 13C-NMR spectra shows characteristic peaks for C=S, C=Ocarboxylic, and C=O in the range of 180-181 ppm, 170-174 ppm, and 163-173 ppm, respectively. X-ray crystallographic study was used to solve the structure of seven of the derivatives and revealed that the terminal side chains adopts cis-trans configuration with respect to the central benzene ring. X-ray data also confirms that the molecules are planar with respect to the central aromatic ring stabilized by intramolecular and intermolecular H-bonding. The binding study of bis-thiourea derivatives with sixteen different metal cations reveals appreciable interaction of the ligands with only soft/mild acidic ions referring to Pearson's soft/hard scale, such as Ag+, Cu2+, Hg2+, Fe2+, Fe3+, and Pb2+. The binding study reveals the presence of two different binding sites of bis(thiourea) amino acid derivatives. Antibacterial study was performed against sixteen distinct strains of bacteria using disc diffusion method. Overall bis(thiourea) derivatives display weak antibacterial activities nevertheless, some amino acid based derivatives show moderate to good antibacterial inhibition. The cytotoxic activity against normal human colon epithelial cell line was assayed by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) method. Cytotoxic test results indicated that bis(thiourea) amino acid derivatives are safe to be used as an antimicrobial therapeutic agent due to their non-toxicity towards CCD841 Normal human colon epithelial cell line as compared to amino ethanol derivative. Binding study data for bis(thiourea) amino acid derivatives can be used as potential chemosensors.,Certification of Masters/Doctoral Thesis is not available,Ph.D.
Pages:	181
Call Number:	RA1231.T48F335 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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