Aiza Harun

Bioactive Terpenoids from the Stem Bark of Entada spiralis Ridl. (Sintok)

The application of the Entada spiralis Ridl. (Leguminosae) stem bark containing saponin in the treatment of scalp and as body soap is well known for generations. Our previous investigation revealed that E. spiralis stem bark contains several terpenoid compounds and is responsible for the inhibitory effect against bacteria Staphylococcus epidermidis ATCC 12228 and skin disease dermatophytes, Microsporum gypseum ATCC 24102, Trichophyton mentagrophytes ATCC 9533 and Trichophyton tonsurans ATCC 28942. The aim of this work is to isolate and identify the chemical structures of terpenoid compounds from active fraction of E. spiralis stem bark. The isolation of active compounds was conducted by chromatographical separation, and the structure characterization was done based on 1D and 2D NMR analysis (1H,13C NMR, HMQC, HMBC and DEPT135) and comparison with those of the literature. We managed to isolate two terpenoid compounds known as ester saponin (1) and terpene benzoate (2). These compounds were elucidated as 16-β-D-arabinofuranosyl-15-β-D-xylopyranosyl-5,8,9,10-tetrahydroxyl-17,18,19,20-tetramethyl diterpene ester (1) and 4-(β-D-glucopyranosyl)-1-hydroxybenzene-(20-hydroxyl-18,19-dimethylcyclotetradecanol) benzoate (2). The finding is hoped to provide an alternative of new search for natural antimicrobial drug.