A Novel Acylated Flavonoidic Glycoside from the Wood of Cultivated Acacia Nilotica (l.) Willd. Ex. Delile

Acacia is a fast-growing plant that has high potential in commercial plantations in tropical areas. It is already being grown as a plantation crop for building and industrial raw materials, as well as for reforestation of difficult sites. Extensive cultivation of this promising tree would enrich the natural resources besides being useful for industrial raw material, waste land management, and afforestation. In addition, Acacia exhibits extensive medicinal values. In view of the medicinal importance of Acacia nilotica and the therapeutic utility of flavonoids, an attempt has been made to isolate novel flavonoids from the wood of cultivated A. nilotica. The extraction of crude ethanol extract from the A. nilotica wood was followed by fractionation with chloroform, ethyl acetate, and methanol in increasing order of polarity of the solvent. The mixed ethyl acetate and methanol extract afforded three pure compounds through column chromtomatography and fractional crystallization. Among the isolated phenolic compounds, a new acylated flavonoidic glycoside, tricin-4′-O-β-(6′′-hydroxycinnamic)-glucoside (1) was isolated from the wood of A. nilotica together with two known compounds, gallic acid and apigenin. Their structures were established by chemical evidence, spectroscopic techniques (FT-IR, H-NMR, C-NMR, HSQC, HMBC, and ESI-MS), and by comparison with already existing spectroscopic data. The yield of novel tricin glucoside showed that it make up to 0.0786% of mixed ethyl acetate and acetone extract.