227PRELIMINARY PHYTOCHEMICAL SCREENING AND ANTIMICROBIAL POTENTIAL OF PTEROSPERMUM CANESCENS ROXB., (STERCULIACEAE) BARKIn the present investigation, preliminary phytochemical screening and antimicrobial potential of the petroleum ether, chloroform and methanolic bark extracts (100, 50, 25 mg/ml) of Pterospermum canescens Roxb., (Sterculiaceae) were carried out against certain gram-positive (Bacillus subtilis, Staphylococcus aureus, Streptococcus pneumoniae) and gram-negative (Proteus vulgaris, Escherichia coli, Vibrio vulnificus) bacteria and fungi (Aspergillus niger, Candida albicans) by detecting the zone of inhibition using agar well-diffusion method. Preliminary phytochemical screening showed the presence of alkaloids, flavonoids, phenolic compounds and steroids. Petroleum ether, chloroform and methanolic bark extracts (100, 50, 25 mg/ml) exhibited significant antimicrobial activity against the various bacteria and fungi using the respective standard drugs (10 µg/ml).kpjaiyaganesh@gmail.comResearch432013Pterospermum canescens,Phytochemistry,Antimicrobial activityK.P.Jaiganesh,G.Arunachalam,K.P.JaiganeshDivision of Pharmacognosy & Phytochemistry Research Laboratory, Thanthai Roever College of Pharmacy, Perambalur, Tamil Nadu, India.,PGP College of Pharmaceutical Science and Research Institute, Namakkal, Tamil Nadu, India,Centre for Research and Development, PRIST University, Thanjavur, Tamil Nadu, India.