Antibacterial Stilbene Derivative from the Leaves of Combretum paniculatum

Abstract

Combretaceae family comprises 20 genera with 600 species of which the genus Combretum and Terminalia contain the largest number of species, 370 and 200 species, respectively. The genus Combretum is used in folk medicine for the treatment of various diseases such as stomach pain and diarrhea. Silica gel column fractionation of the leaf extract of the leaves of C. paniculatum led to the isolation of two compounds; myristic acid and a new stilbene derivative (1-(2’,6’-dihyroxphenyl-2-(4”-hdroxyphenyl))-1,2-ethane-diol). The structures of these compounds were determined with the help of spectroscopic methods (UV-Vis, IR, and NMR). Phytochemical screening tests revealed the presence of terpenoids, tannins, saponins, alkaloids and phenols. Antibacterial analysis of the hexane, EtOAc and methanol extracts using paper disc diffusion method against Staphylococcus aureus, Escherichia coli, Klebsella preumanin and Proteus mirabilis revealed the n-hexane and ethyl acetate extracts were active against S. aureus, E. coli and P. mirabilis at concentration of 1.5mg/mL each. On the other hand, the methanol extract is not active against E. coli but showed activity against K. preumanin. The stilbene derivative (2) was found to be active against all bacterial strains tested.

Keywords: Phytochemical, antibacterial, C. paniculatum, Myristic acid, stilbene derivative