Phytochemical Investigation And Antimicrobial Activities Onthe Leaves Extract Of Croton Macrostachyus (Bisana)

Abstract

Croton macrostachyus Hocsht. ex Del. (Euphorbiaceae) leaves is one of the 1200 species of Croton have been described with biological activities, mainly due to diterpenes, alkaloids and/or other secondary metabolites. These activities account for the traditional use of Croton species to treat certain diseases in South America, Asia and Western Africa. Hence the aim of the present study was to investigate phytochemicals of the plant leaves and evaluate the antimicrobial activity of its extracts against bacteria and fungi. The leaf powder Croton macrostachyus was successively extracted with n-Hexane, chloroform, ethyle acetate and methanol. The crude chloroform, ethyle acetate and methanol extracts obtained from leaves of Croton macrostachyus were subjected to phytochemical tests for the presence of secondary metabolites, tannins, cardiac glycoside, alkaloids and flavonoids.etc. In all extracts studied, Flavonoids, tannin, terpenoid, saponins, steroids, cardiac glycoside and alkaloids, were present in the, methanol and chloroform extracts while terpenoid and steroid were detected in chloroform crude extracts and essential oil. The antimicrobial activity of extracts was studied using the disk diffusion method and determination of minimal inhibitory concentration (MIC) value. The antimicrobial activity of C.macrostachyus leaves extracts and essential oil was tested against pathogenic bacteria like gram positive bacteria Staphylococcus aureus, Salmonella typhimurium, and gram negative bacteria Klebsiella pneumoniae, Escherichia coli and fungi like Candida albican. The highest antibacterial inhibition against S.aureus (14mm) and E. coli (12mm) were revealed by chloroform and methanol extracts reaspectively. While the least inhibition zone (8mm) has shown against S.aures by ethyle acetates. The antimicrobial assay showed that volatile oil was generally more active on E. coli (9 mm) than S. aureus (6 mm); whereas higher antifungal activity was observed on C.albicans (inhibition diameter (24.20 mm). Repeated use of solvent extraction followed by CC, leaf extract of C.macrostachyus yielded two compounds and only one characterized as tetrahydro-2-hydroxymethyl) -6- (tetrahydro-3, 4,5trihydroxy -6(hydroxymethyl)-2H-pyran-2-yloxy) -2H-pyran-3,4,5 -triol, whose structure was elucidated based on its 1H-NMR, 13C-NMR,FT-IR and DEPT data. Crude extracts and essential oil exhibited reasonable antimicrobial activities. These showed potential as antimicrobial agents and might be used to improve therapeutic efficiency to overcome, rising bacterial and fungal resistance of existing drugs.This study provides some scientific base for the folkloric medicinal use of this plant as remedy for ailments whose causative agents are the pathogens studied. The activities observed could also be attributed to the phytochemicals detected, some of which have been associated with antimicrobial activity.