The present study investigates the phytochemical constituents, the antimicrobial, antioxidant activity, the functional groups by FT-IR and the presence of bioactive compounds by GC-MS analyses of leaves of Solanum torvum, rhizome of Acorus calamus and whole plant of Mollugo pentaphylla. The preliminary phytochemical analysis of the solvent extracts revealed the presence of alkaloids, flavonoids, steroids, proteins, carbohydrates, phenols, saponins, glycosides, coumarins, quinines. The solvent extracts showed antibacterial activity against E.faecalis, E.coli S.aureus, B.subtilis. K.pneumonia and C.albicans. The total phenolic content was 0.3430 GAE/g DW whereas, the total flavonoid content varied between 4.928 - 7.751mgQE/g DW. DPPH free radical scavenging activity of the diethyl ether extract of S. torvum recorded the IC50 at a concentration of 7.23µg/ml. In the hydrogen peroxide assay of the M. pentaphylla aqueous extract the IC50 value at a concentration of 3.295µg/ml was recorded. FT-IR studies showed the major functional groups alcohols, alkane, amines, aldehydes, alkyl halide and GC-MS studies showed 20 compounds with phytol being the major constituent.