Bioactive Compounds from Medicinal Plants and their Semi Synthetic derivatives

Abstract

A majority of available drugs are either obtained from medicinal plants or are synthetically or semi-synthetically derived from natural resources. Investigations are based on traditional and ethnopharmacological knowledge of the indigenous people. The medicinal plants are screened to validate the traditional claim by right scientific parameters. Sometimes, bioactive fractions are identified, or active compounds therein are obtained in this process. In the present study, 10 virgin orchids of AP were selected based on the literature search for phytochemical and pharmacological properties of the plants. Out of ten orchids, two relatively unexplored plants viz. Tropidia curculioides and Satyrium nepalense were selected for novel phytochemicals and pharmacological investigation including antimycobacterial, leishmanicidal and antibacterial activities. Extraction of the plant material using MeOH: H2O afforded organic extract for each part of plant. Further, fractionation of the extract afforded 21 fractions from two orchids. All these fractions were evaluated by qualitative phytochemical analysis to get a preliminary idea about the presence or absence of different chemical groups. Thereafter, the fractions were evaluated against Mycobacterium, Leishmania and bacterial strains. Based on the screening results of antimycobacterial, leishmanicidal and antibacterial activity along with low cell cytotoxicity, the diethyl ether (Et2O) fraction of T. curculioides, ethyl acetate (EtOAc) and dichloromethane fractions of S. nepalense was further used for isolation of marker compounds to identify potential leads. The most significant antimycobacterial activity (MIC 15.62 µg/mL) was observed with C9 against both H37Rv strain and MDR clinical isolates. The highest leishmanicidal activity was also noted with C9 showing IC50 31.25 and#956;g/mL for promastigotes and intracellular amastigotes.The encouraging results could further be investigated through in-vivo studies to develop new antimycobacterial as well as leishmanicidal agents in future.