A New Biflavonoid Glycoside from the Leaves of Ziziphus mucronata Willd. (Rhamnaceae)

Abstract

and structure elucidation of bis (quercetin 3-O-β-D-glucopyranoside) from the n-butanol fraction of the crude methanol leaf extract of Z. mucronata. Materials and Methods General experimental procedures The solvents used were of high quality (analytical grade) and include: methanol, n-hexane, chloroform, ethyl acetate and n-butanol purchased from Sigma Co. USA; silica gel 60-120 µm (Qualikems, India) was used for column chromatography, sephadex LH-20 (GE Healthcare) was used for purification of isolated compound, thin layer chromatography (TLC) was carried out on aluminum-backed Kieselgel 60 F254 TLC plate (Merck no. 5554, Darmstadt, Germany) and a Gallenkhamp electro thermal melting point apparatus was used to determine the melting point of isolated compound. The UV was recorded on Thermo scientific biomate 6 UV-Visible spectrophotometer; the IR was recorded on Agilent Technologies Cary 6030 Fourier Transform Infrared Spectrophotometer; 1 H __ NMR (500 MHz, MeOD) and 13 C __ NMR (125 MHz, MeOD) spectra were recorded on a Bruker AVANCE-500 spectrophotometer (Japan). The chemical shift values (δ) were reported in parts per million (ppm) relative to internal standard TMS and coupling constants (J values) were given in Hertz. Collection and identification of the plant material The leaves of Z. mucronata were collected from Kudingi village, Giwa Local Government Area of Kaduna State, Nigeria in 2015. It was authenticated by taxonomist Musa Muhammad in the Herbarium Unit, Department of Biological Sciences, Ahmadu Bello University, Zaria by comparison with the existing herbarium specimen, voucher number 900328. Preparation of the extract The leaves of the plant were dried under shade at room temperature until a constant weight was obtained and size-reduced manually using mortar and pestle. About 1 kg of the pulverized leaf material was extracted with methanol by cold maceration for 72 hours with occasional shaking and concentrated in vacuo using rotary evaporator at 40 o C. This yielded a dark green gummy (134 g) crude extract; 100 g of the extract was suspended in 500 mL of distilled water and filtered using Whatman No. 1 filter paper.

Hepatoprotective role of myricitrin isolated from Mimusops elengi Linn. leaves extract on γ‐radiation‐induced liver damage in rats: Phyto‐biochemical investigations

“…Identification of isolated phytoconstituentsPhytochemical analysis of the EtOAC fraction of M. elengi leaf extract led to the isolation and characterization of nine compounds (Figure1), including four triterpenes α,β-amyrin (2a, b), ursolic acid (3), and lupeol (1),[38][39][40][41] and three flavonol glycosides myricetin 3-O-rahmnopyranoside (myricitrin) (4), myricetin 3-O-galactoside (5), and myricetin 3-O-rahmnopyranoside…”