Etude phytochimique de l’extrait au méthanol des écorces du tronc de sapium cornutum pax (euphorbiaceae)

Abstract

The present work report the phytochemical study of the methanolic extract of the stem barks of Sapium cornutum, a Cameroonian medicinal plant, belonging to the Euphorbiaceae family, widely used in traditional pharmacopoeia.The stem barks of Sapium cornutum (Euphorbiaceae) was harvested at Soa, a locality in the Centre region of Cameroon, The stem barks were cut, dried and then pulverized to give a powder of 2.4 kg, which was extracted by maceration in methanol at room temperature for 48 hours. After filtration and evaporation, a crude extract 240.8 g was obtained. 3 g was reserved for biological tests and 237.8 g was subjected to liquid-liquid partition extraction using ethyl acetate and n -butanol as solvent. This extraction afforded two (2) fractions indexed F1 and F2 respectively. Fraction F1 was purified using usual column chromatography on a silica gel column and a solvent system of n - Hex/AcOEt in an increasing polarity.The purification of this fraction of this fraction F1, led to the isolation of five (05) compounds. Three (03) of which were fully characterized and identified as derivatives of ellagic acid, more specifically, these are 3,3′-di-O-methyl-ellagic-4′-O-α-L-rhamnose acid 75 (SCE5); 3,3′-di-O-methylellagic acid 54 (SCE4) and ellagic acid 53 (SCE3).The structures of these compounds have been elucidated with the help of spectroscopic techniques that is, one-dimensional ( H and C) and two-dimensional (COSY, HSQC and HMBC) nuclear magnetic resonance (NMR), and spectrometry technique using high-resolution (ESI) methods, and by comparison of their spectral data with relevant date from the literature