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CURATOR

Postdoc Researcher and Lecturer, Medicinal Chemistry Division, Department of Chemistry, University of Ilorin, Ilorin

PINBOARD SUMMARY

Chemoinformatics and Medicinal Chemsitry

I am a Natural Products/Medicinal Chemist with few years teaching and research experience in the University system. My current research interest is in Chemoinformatic application for drug discovery and development for cancer, malaria and diabetes. His attention was drawn to cancer and malarial as a result of the global burden and excessive impact in the developing countries especially Africa.

Obviously, cancer is the second leading causes of morbidity and death worldwide (WHO, 2017). Approximately 14 million new cases were reported in 2012 and 8.8 million deaths in 2015. Globally, nearly 1 in 6 deaths is due to cancer (Ferlay et al., 2012). Unfortunately, a whopping 70% of deaths resulting from cancer occur in low- and middle-income countries where western therapy is either meager or unaffordable.

On the other hand, malaria is a disease that has plagued the tropical countries for the past decades. Malaria is one of three major infectious diseases in the world, and a main cause of death in the tropical areas. The disease can be found in 107 countries, and 40 percent of the world population is at risk of getting the disease. Every 30 seconds an African child dies from it. Unfortunately, the mainstream drug used to combat malaria, artemisin combination therapy has suffered major setback as major resistances in some regions of the world has been reported. The entire world population will be endangered if the resistance should spread rapidly to other regions.

I am currently making use of extensive modern tools such as Chemoinformatics as well as 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopies with various techniques of low resolution and high resolution, mass spectrometries for elucidation and drug development for cancer and malaria. Some of our discovered candidates have passed through pre-clinical testings and waiting for the next cycles of trials. In collaboration with Charité University of Medicine, Berlin, Germany, we currently apply Chemoinformatics tools for drug discovery and development through SARs studies, drug repurposing, scaffold hopping, fragment-based substructure techniques and molecular docking for cancer and malarial drug discovery.

Currently, my particular strength lies in capacity building and mentoring of younger academics and researchers in these line of researches. I am a mentor to numerous undergraduates and Master’s candidates so that we can collectively combat cancer and malarial.

6 ITEMS PINNED

Phytochemicals from Kigelia pinnata leaves show antioxidant and anticancer potential on human cancer cell line.

Abstract: Studies suggest that the traditional applications of Kigelia pinnata leaves have beneficial effects against oxidative stress-mediated diseases and cancers. The pulverized dried leaves of K. pinnata were extracted with hexane, ethyl acetate, and methanol sequentially, and the crude extracts were fractionated by silica gel column chromatography with solvent gradient of increasing polarity. 3-hydro-4,8-phytene, trans-phytol, (9Z,12Z)-methyl octadeca-9,12-dienoate, and two oil fractions were obtained. The chemical compositions of chromatographic fractions were determined using gas chromatography-mass spectroscopy. The structure elucidations of the isolated compounds were based on FTIR, MS, and NMR spectral data analyses. These along with the crude extracts were examined for their antioxidant activities using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) assays. Total phenolic contents were also determined. The crude extracts and purified compounds were evaluated on the rhabdomyosarcoma human cancer cell for their cytotoxicity using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assays. The methanol extract was richer in phenolics and was most potent as antioxidant and cytotoxic agent among all the substances tested. Among the fractions and pure compounds, the two oil fractions showed more cytotoxicity potency, with IC50s of 143.4±0.5 and 147.9±1.3 ng/mL, which is more significant than the reference standard, cyclophosphamide (165.6±1.0 ng/mL). 3-hydro-4,8-phytene showed lower antioxidant and cytotoxicity potential (IC50=1818±5.2 μg/mL and 171.7±0.8 ng/mL, respectively). Trans-phytol did not show a high cytotoxic power (IC50=769.8±4.3 ng/mL). The comparatively high cytotoxicity index of (9Z, 12Z)-methyl octadeca-9,12-dienoate (IC50=153.3±0.1 ng/mL) indicated that it may be one of the principal cytotoxic agent in the ethyl acetate extract. These results suggest that the leaves of K. pinnata possess tumor cytotoxic potential and could be part of a drug combination for future cancer chemotherapy.

Pub.: 27 Sep '13, Pinned: 04 Aug '17

Phytochemical, sub-acute toxicity, and antibacterial evaluation of Cordia sebestena leaf extracts.

Abstract: In Nigeria, Cordia sebestena (Boraginaceae), an understudied medicinal plant, is used in traditional medicine for the treatment of gastrointestinal disorders. In this study, we investigated the chemical composition, antibacterial potential, and sub-acute toxicity of C. sebestena leaves.Ethyl acetate extracts were analyzed using thin layer chromatography (TLC) and Fourier transform infrared (FTIR) spectrophotometry. The antibacterial potential of the extracts was tested against five standard bacteria, namely Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Clinical observations and blood parameters were used to evaluate the possible toxicity of C. sebestena.The TLC profile yielded 39 fractions, which were pooled to nine combined sub-fractions (A-I). The FTIR spectrum of sub-fraction H indicated the presence of aliphatic C-H stretching vibration at 2922 and 2850 cm-1, C=O stretch at 1734 and 1708 cm-1, and C=C stretch of aromatics and aliphatics at 1464 and (shoulder) 1618 cm-1, respectively. The fractions of the C. sebestena ethyl acetate leaf extract showed antibacterial potential across board, but fraction H had the highest antibacterial activity against B. cereus and S. aureus. The study also indicated the relatively low toxicity profile of the ethyl acetate leaf extract of C. sebestena in the liver of rats.The study showed that C. sebestena leaves have strong antibacterial potential and low toxicity, thereby underlying the scientific basis for their folkloric use in the management of microbial infections and its associated complications.

Pub.: 27 Oct '15, Pinned: 04 Aug '17

Pectolinarigenin from the leaves of Clerodendrum volubile shows potent immunomodulatory activity by inhibiting T - cell proliferation and modulating respiratory oxidative burst in phagocytes.

Abstract: There have been increasing interest in the use of plant-derived substance as immunomodulators for the treatment and management of inflammatory ailments. Clerodendrum volubile, a leafy vegetable is known for its folkloric applications in the treatments of several inflammatory related ailments, but with little scientific evidence. This study reports the isolation, structure elucidation and in vitro immunomodulatory potentials of pectolinarigenin from C. volubile leaves. The immunomodulatory potentials of the crude methanolic extract and fractions [n-hexane (Hex), dichloromethane (DCM), ethyl acetate (EtOAc) and n - butanol (BuOH)] were investigated on whole blood, neutrophil and macrophage phagocytic respiratory burst using luminol-amplified chemiluminescence technique. DCM fraction showed higher inhibitory activity on respiratory burst, indicating high suppressive immunomodulatory potency. The DCM fraction was further fractionated using a gravity column chromatography loaded with silica gel. The column was eluted with mixtures of Hex and DCM (92.5:7.5) in increasing order of polarity up to Hex: DCM (88:12) to afford 5,7-Dihydroxy-6,4'-dimethoxyflavone (pectolinarigenin). The structure of the compound was established using data obtained from (1)H- and (13)C NMR spectroscopies and mass spectrometry. The isolated flavone was investigated for its inhibitory activity of neutrophil phagocytes respiratory burst as well as T - Cell proliferation. The compound exhibited significant activities (at p <0.05) indicating high suppressive immunomodulatory potency. The potent suppressive effect of pectolinarigenin on polymorphonuclear neutrophils (PMNs) respiratory oxidative burst and T - cell proliferation suggests an immunomodulatory potential and pathway of the flavonoid.

Pub.: 08 Jul '17, Pinned: 04 Aug '17