Nutritional Content, Antimicrobial Study and Isolation of Quercetin from Ziziphus spina-Christi Leaf

Plant has been the major source of medicinal globally. This study aimed at determining the nutritional composition, antimicrobial activity and isolation of phytochemical from the leaf of Ziziphus spina-Christi. Proximate composition, elemental (Ca, Na, Mg, K, P, Cu, Cd, Fe, Ni, Zn) concentrations, phytochemical screening and antimicrobial activity were carried out using standard protocols. Column chromatographic elution process was used to fractionate the methanol extract and Preparative TLC was used to isolate a compound. The result of the proximate composition and elemental concentration levels showed that the leaf is nutritious. Phytochemical screening showed the presence of alkaloids, cardiac glycosides, flavonoids, saponins and tannins. The methanol extract inhibited the growth of Escherichia coli, Salmonella typhi, Staphyloccocus aureus and Bacillus subtilis significantly at extract concentrations of 100, 200, 300, 400 and 500mg/mL was used, thus having antimicrobial activity. The compound isolated has 114-116^oC melting point (uncorrected) with a single banding pattern confirmed by TLC study. Physical and chemical tests of isolated compound were conducted. By using IR,¹H-NMR and ¹³C-NMR spectra of the isolated compound was confirmed as Quercetin – a flavonoid.   Keywords: Ziziphus spina-Christi; Phytochemical; Quercetin; Antimicrobial; Elements