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- ItemSynthesis, FT-IR Spectroscopic Studies and in vitro FRAP Assay of some Chalcone Derivatives and their Metal Complexes(ACADEMIC STAFF UNION OF UNIVERSITIES, 2022) Bale, Adebayo Tajudeen; Daramola, Kehinde Dele; Osunniran, Wahab AdesinaA variety of substituted chalcones, namely, 3”-aminochalcone, 2”,4”-dichlorochalcone, 2”-methoxychalcone, 4”-methoxychalcone and 2”-hydroxychalcone have been synthesized by Claisen-Schmidt condensation and characterised by melting point and FT-IR spectroscopic technique. The tin(II), cadmium(II) and copper(II)) complexes of the 2”-hydroxychalcone (4E2HC) with the formula [M(L)2] were subsequently prepared. The 2”-hydroxychalcone and its metal complexes were evaluated for in vitro radical scavenging activity by carrying out ferric reducing antioxidant power (FRAP) assay. In almost all cases, the metal complexes exhibited higher activities than the ligand (chalcone). Notable activity (11.63 µM) was observed for the cadmium complex of the 4-ethoxy-2”-hydroxychalcone at 10 µg/mL. Limited structure–activity relationship (SAR) was established by considering the effect of different groups attached to the aryl rings and the metal centers on varying antioxidant activity. The enhanced activity may be due to the presence of electron-rich metals and electron-releasing ethoxy (-OC2H5) and hydroxy (–OH) groups. The confirmed bioactive compounds from this study can be used as effective template in medicinal chemistry for drug discovery.
- ItemSynthesis and Biological Study of Substituted 2”-Hydoxy, 2”,4”- dichloro Chalcones and Their Co(II), Cu(II) and Ni(II) Complexes for Their Antioxidant and Antimicrobial Potentials(Sami Publishing Company, 2022-02-26) Bale, Adebayo Tajudeen; Fasina, Tolulope Mojisola; Shaibu, Rafiu Olarewaju2-methoxy-2”-hydroxychalcone (2M2HC) and 4-methoxy-2”,4”-dichlorochalcone (4M24DC) and their metal complexes were synthesized, characterized, and confirmed by melting point, FT-IR, UV-Visible, 1H-NMR, EIMS, and AAS spectroscopic techniques. The elemental analysis was done and found following the calculated values. Metal(II) complexes, [M(L1-2)2], [where M = Ni(II), Cu(II), Co(II); L=2-methoxy-2”-hydroxychalcone (2M2HC) and 4-methoxy-2”,4”-dichlorochalcone (4M24DC)] were subsequently prepared. The biological evaluation of the synthesized chalcone derivatives and their metal complexes was done. They were screened for antioxidant and antimicrobial activities. Overall, the ligands (chalcones) and metal complexes demonstrated good to moderate antioxidant and antimicrobial activities.
- ItemNuclear Magnetic Resonance and Infra Red Spectroscopic Studies of some Metal Complexes of Maleoyl-p-Aminobenzoic acid(Faculties of Life and Physical Sciences, University of Ilorin, Nigeria, 2010) Bale, Adebayo Tajudeen; Eke, Uche BasilMetal complexes of p-Aminobenzoic acid derivative of maleic anhydride were investigated. Thus, N-(4-carboxy-phenyl) maleimide and its sodium salt (sodium N-maleoylbenzoate) were prepared. The sodium salt was complexed with some transition metals (Co2+, Ni2+, Zn2+ and Cu2+). Complexes separated as precipitates from the reaction mixtures and were characterized by spectroscopic studies.
- ItemSynthesis, Characterization and α-Amylase Inhibition Study of Substituted Schiff Base and Its Metal Complexes(2023-12-31) Bale, Adebayo Tajudeen; Osunniran, Wahab Adesina; Ajiboye, Abdulfatai TemitopeMechanochemical synthesis is considered as a green and sustainable approach to chemical reactions since it requires little or no solvent, making the process more environmentally friendly by reducing waste and minimizing solvent related hazards. In this study, substituted Schiff base was synthesized from 2-aminophenol and 2- hydroxy-1-naphthaldeyde via mechanochemical synthesis method. The metal complexes were synthesized by reacting the ligand with metal(II) chlorides in ratio 2:1. The synthesized compounds were characterized by colour, melting point, molar conductivity, FT-IR, and UV-Vis spectroscopy. The ligand and its metal complexes were screened for α-amylase inhibitory activity. FT-IR results showed absorption bands in between the ranges 1628-1632 cm-1 and 1585-1597 cm-1 indicating the formation of azomethine C=N and aromatic C=C respectively. The metal complexes showed M-O absorption bands in between the range 519-579 cm-1 and M-N band in between the range 461-484 cm-1. The synthesized compounds displayed significant inhibitory activities (IC50: 2.00-8.43 mg/mL) against α-amylase comparable to the reference compound, acarbose (IC50: 9.12 mg/mL). These compounds can serve as viable templates in the formulation of new active antidiabetic drugs.
- ItemThe Studies of Antioxidant and Antimicrobial Potentials of the Leaf Extract of Bauhinia monandra Plant(Longdom Publishing SL, 2015) Bale, Adebayo Tajudeen; Ajiboye, Abdulfatai Temitope; Musa, MD; Otun, KO; Jimoh, Akeem Adebayo; Lawal, SO; Arowona, MTIn the present study, the dried leaf (144g) of B. monandra plant was extracted with 95% ethanol. The crude extract was partitioned into ethyl acetate and n-hexane layers to afford fractions with golden brown and greenish yellow colours respectively. The fractions were concentrated and coded EFBM and HFBM. The preliminary phytochemical screening conducted on the crude extract and ethyl acetate fraction (EFBM) revealed the presence of flavonoids, tannins, steroids, terpenoids, saponin, cardiac glycoside and phenols. The antioxidant activity of EFBM and HFBM was evaluated using DPPH radical scavenging assay with ascorbic acid as a reference standard. However, the result of analysis revealed that EFBM exhibited high antioxidant (IC50 µg/mL=0.010) activity than HFBM (IC50 µg/m = 5.564) and reference standard ascorbic acid (IC50 µg/mL=30). The antibacterial activity of EFBM and HFBM against three gram negative bacterial strains (Eschericha coli, Pseudomonas aeruginosa and Klebsillia oxytoca) was also evaluated and it was found that EFBM exhibited highest antibacterial potential. In contrast to this, HFBM showed negligible or zero activity against all the bacteria strains. The results of the GC-MS analyses of EFBM and HFBM showed the presence of nine different phytochemicals. In EFBM, oleic acid which is classified as monounsaturated omega-9-fatty acid with percentage concentration, (40.76%) was the major compound as identified by the GC-MS and 4-hydroxy-5-methyl-3-propyl-2-hexanone with percentage concentration, (42.70%) was identified as the major compound in HFBM. The results of this studies demonstrated that folk medicine can be as effective as modern medicine to combat pathogenic microorganisms. The millenarian use of the leaf of this plant in folk medicine suggests that it represents an economic and safe alternative to treat infectious diseases.