BIOLOGICAL INVESTIGATION OF ENTADA RHEEDII SPRENG. AND ISOLATION OF ENTADAMIDE A FROM ITS SEED

Abstract

The methanolic extracts of bark, leaf and seed of E. rheedii and their Kupchan partitionates were investigated for in vitro cytotoxic, antioxidant, thrombolytic, membrane stabilizing and antimicrobial activities. In the brine shrimp lethality bioassay, the chloroform soluble extractive from seed showed significant cytotoxicity (LC50 = 1.95 mug/ml and LC90 = 3x10-4 mug/ml) as compared to vincristine sulfate (LC50 = 0.45 mug/ml and LC90 = 9x10-6 mug/ml). Antioxidant activity was screened using DPPH assay and ethyl acetate soluble partitionate of bark revealed the highest free radical scavenging activity with IC50 values of 33.68 mug/ml as compared to standard, ascorbic acid (IC50 4.05 mug/ml) and butylated hydroxyl toluene (IC50 27.50 mug/ml). Significant membrane stabilizing activities were observed for aqueous and ethyl acetate soluble fractions of bark in hypotonic solution-induced haemolysis (94.94%) and in heat induced condition (97.39%), respectively. No significant antimicrobial and thrombolytic activities were observed for any extractive from this plant. Chemical investigation of the seed extract of E. rheedii provided entadamide A (1) for the first time from this plant, which was isolated previously from E. phaseoloides. This is the also the first report of the bioactivities of this plant.