Phytochemical profile and antimicrobial potential of methanolic extracts of bark and leaf of Quassia indica (Gaertn.) Nooteb.

The study comprises the results of phytochemical analysis and antimicrobial evaluation of extracts from bark and leaf of Quassia indica (Gaertn). Nooteb. – a medicinal plant used in traditional healing owing to its analgestic, antiinflammatory, antifeedant and antimicrobial properties. A preliminary qualitative analysis was carried out successively in five different solvents with increasing order of polarity-Petroleum ether, Chloroform, Ethyl acetate, Methanol and Water to document the nature and yield of phytochemicals. The extracts were evaluated for antimicrobial effect using two strains of bacteria – Escherichia coli and Staphylococcus aureus and fungi – Aspergillus niger and Candida albicans. Among solvents methanol and water were found as effective extractants in which most of the secondary metabolites - alkaloids, flavonoids, terpenoids, phenolics, tannins, phytosterols were released. Quantitative analysis of the methanolic and aqueous extracts was carried out to estimate the quantity (mg/g tissue) of the phytoconstituents. The alkaloid content was much higher in leaf extract (5.7 mg/g) than in bark (3.5 mg/g). The phenolic content expressed as mg/ g GAE was determined in the methanolic extract, bark (24.38) > leaf (10.44) and the aqueous extract does not show much phenolic content. Flavonoid were maximum in methanolic leaf extract (1.085 mg/g) and minimum in aqueous bark extract (0.305 mg/g) and the terpenoid content was detected in methanolic extracts of leaf (0.4016 mg/g) and bark (0.4224 mg/g). The leaf extract indicated more tannin content (1.536 mg/g) than bark (1.328 mg/g). Evaluation of antimicrobial activity suggested leaf extract as an effective antibacterial and antifungal agent at a concentration of 1000 g/ml with inhibition zones- 24 mm (S.aureus), 22 mm (E.coli) and 14 mm (A.niger), 14 mm(C. albicans). The bark extract was comparatively lesser efficient in resisting microbial growth (E. coli – 20 mm; S. aureus – 22 mm; A. niger – 12 mm; C. albicans – 10 mm).