Pure form bulk isolation of rare and bioactive triterpenoid 3-o-(4- hydroxy cinnamoyl)-taraxerol from mangrove plant rhizophora mucronata through classical chemistry, and biological activities of rhizophora mucronata

摘要

Biological and phytochemical investigations on Rhizophora mucronata revealed its remarkable pharmacological significance due to the presence of important secondary plant metabolites in its various parts. In the present studies various extracts and fractions of different parts of R. mucronata were subjected to bioassay directed isolation studies for the evaluation of antioxidant, cytotoxic and antifungal activities. The ethyl acetate extract of fruits showed moderately good antioxidant activity, with IC_(50) value of 26.28 μg/mL (87.8 %). The methanol extract of fruits, ethyl acetate extract of leaves and ethyl acetate extract of stem and twigs showed low antioxidant activity, with IC_(50) values of 62.30 (83.2 %), 66.87 (8.6.1 %) and 79.53 ug/mL (87.8 %), respectively. Antioxidant activity from the fruits of this plant is reported for the first time in present studies. The lower layer of dichloromethane extract of stem and twigs showed cytotoxic activity against nauplii of brine shrimp (Artemia salind), with LD_(50) value of 556.92 μg/mL (60 % mortality) at higher dose level of 1000 μg/ mL. Extraction and fractionation with polar and non polar solvents resulted in the isolation of bulk quantity of pure 3-O-(4-hydroxy cinnamoyl)-taraxerol (I) (6.13 % of wet plant material) from the petroleum ether insoluble fraction of leaves of R. mucronata through classical chemistry, without applying any chromatographic technique.