570DETECTION OF VARIOUS PHYTOCHEMICAL COMPOUNDS FROM SEEDS OF A. AURICULIFORMIS FOR POSSIBILITIES OF OBTAINING POTENT ANTIMICROBIAL AGENTSAcacia auriculiformis belonging to the family Fabaceae (Leguminosae), is a plant of medicinal importance having antibacterial, anthelmintic, antifilarial and microbicidal activities. Earlier studies have revealed the spermicidal activity of the seeds of the plant. Phytochemical analyses of the methanolic and ethanolic extracts of A.auriculiformis were performed with the help of TLC, HPLC and HPTLC. Several different phytoconstituents were found to be present in both the extracts. These included alkaloids, flavonoids, tannin and phenolic compounds, steroid, triterpenoids, saponins, fats and oils. The flavonoid was characterized further and was found to be quercetin. Quercetin being known for providing antimicrobial activity, the extracts was both tested to determine such an activity in an in vitro system with the help of agar dilution technique following International Guidelines. A total of 13 strains belonging to both Gram positive and Gram negative types were included in this study. The extracts were incorporated into gradually increasing amounts in standard nutrient agar media. The test organisms were grown in nutrient broth for 18hr, standardized to contain 105 colony forming units and spot inoculated on agar media. Results were noted after 24hr. Most of the Gram positive and Gram negative bacteria were sensitive to the seed pod extracts of A.auriculiformis. However, 4 organisms were found to be resistant; these included Listeria monocytogenes MTCC 659, Klebsiella pneumoniae 1, Pseudomonas aeruginosa ATCC 27853 and Acinetobacter boumanii 530. It may be pointed out here that all these 4 bacteria were simultaneously resistant to a large number of known commonly used antibiotics. Ethanolic extract was found to be more active than the methanolic extract against both Gram positive and Gram negative bacteriajumicrobiol@yahoo.co.inResearch622015A.auriculiformis,Phytoconstituents,Flavonoids,Quercetin,Antimicrobial activityShaswati Chaki,Bidisha Ghosh,Smarak Bandyopadyhay,Musfiqua Mookerjee,Sukhen Das,Sujata G. Dastidar Department of Microbiology, Herbicure Healthcare Bio-Herbal Research Foundation, Saral Dighi (E), Boral, Kolkata 700154, India,Department of Microbiology, NSHM College of Pharmaceutical Technology, NSHM Knowledge campus, Kolkata 700063, India,Department of Microbiology, Herbicure Healthcare Bio-Herbal Research Foundation, Saral Dighi (E), Boral, Kolkata 700154, India,Department of Microbiology, NSHM College of Pharmaceutical Technology, NSHM Knowledge campus, Kolkata 700063, India, Department of Physics, Jadavpur University, Kolkata 700032, India. # Institute of Serology (Govt. of India), 3, Kyd Street, Kolkata 700016, India,Department of Microbiology, Herbicure Healthcare Bio-Herbal Research Foundation, Saral Dighi (E), Boral, Kolkata 700154, India