PHYTOCHEMICAL INVESTIGATION AND ANTIMICROBIAL ACTIVITY OF LEAF EXTRACTS OF STEREOSPERMUM KUNTHIANUM

Abstract

Natural products have been a source of drugs for centuries. The decoction or infusion of the stem-bark of Stereospermum kunthianum which is used to cure bronchitis, pneumonia, cough, and dysentery. The present study was carried out to study the phytochemicals of leave extracts and esterified oil of Stereospermum kunthianum and evaluates their antimicrobial screening. Phytochemical analysis of the crude extracts showed the presence of saponins, tannins, alkaloids, terpenoids, flavonoids and higher fatty acids. The oil was analysed by GC-MS technique. This analysis revealed that the esterified oil of S. kunthianum leaves were contains Estragole (6.5%), Merpholine, 4,4’,4’’-borylidynetris- (2.34%), Benzaldehyde, 4-[[(4-methyl) phenyl amino] carbonyl methoxy]- (2.85%), 2,7-diphenylindole (7.88%), Beta-bisabolene (14.97%), Humulene (8.81%),Pyridine-3-carboxamide, 2,4,6-trichloro-5-nitro-(0.95%), Monomethyl-3- phenylcyclobutane-1,1-dicarboxylate (2.32%), Cumylphenol (2.04%), Methylhexadecanoate (13.74%), Fluoxetine(2.91%), Methyl-10-trans, 12-cisoctadecadienoate (7.96%), Methylstearate(2.10%), Methyl - 9, 12, 15-octadecatrienoate (8.69%, Benzo[h]quinoline, 2,4-dimethyl-(1.32%), Tetrasiloxane, decamethyl (12.78%) and Cyclotrisiloxane, hexamethyl-(1.83%). The presence of some of these constituents in the plant extract provides the scientific evidences for the antimicrobial properties of the plant. The plant extracts were found to be more effective on bacteria than fungi. The bioassay has indicated that the inhibition effect of the extracts was proportional to the concentration applied. The maximum antibacterial activity was shown by the methanol crude extract against S.aureus with an inhibition zone of 32 mm at 30 µg/mL concentration. The maximum antifungal activity was shown by methanol crude extract against A. niger with an inhibition zone of 26 mm at 30 µg/mL concentration.