Phytochemical Investigation and Antimicrobial Evaluation of Solvent Extracts and Essential Oils From Piper Capense L.F.

Abstract

Medicinal plants are good resources of Lead compounds for drug development. Thus, the aim of this study was to obtain essential oil and crude extracts from different part of P. capense and characterize compounds isolated from the crude extracts. The antimicrobial activities of essential oils, crude extracts and isolated compounds were also evaluated against selected bacteria (S. aureus, E. coli, S. typhi, B. cereu) and fungi (C. albicans) using the disk diffusion method. Gradient extracts (with solvents Pet-ether, chloroform, acetone and methanol sequentially), crude chloroform extracts (only from fruits) and essential oils were obtained using soxhlet, maceration and hydro-distillation methods respectively. Identification of compounds was made using GC/MS data (for essential oils) and spectral methods (NMR for the isolated compounds).The crude chloroform extracts of fruit had a yield of 106 g (13.42%) while the oils yields were 0.5% - 3% from different parts of the plant.35 - 88 compounds were identified in essential oil of different parts of P. capense. Oxygenated sesquiterpenes were the most abundant components in all the oils analyzed accounting to 33.76 - 48.53%. Column chromatographic analysis gave 54 fractions, which upon decantation offered two crystalline compounds characterized as Capentin (Compound 1) and 5-hydroxy-7,4’-dimethoxyflavone (compound-2). The antimicrobial activities of essential oil and crude extracts were in the range of 12 mm (fruit chloroform extracts) to 7 mm (in some parts of extract) with the highest and lowest results for bacterial and fungal strains respectively. The essential oils of fresh fruit, dry leaf and fresh root of P.capense and methanol extracts of stem bark are responsible for the antifungal activity. The antimicrobial activity of compound-1was found to be 9 mm for both (S. typhi and B. cereus)while that of compound-2 was found to be 7 mm for S. typhi. The present study indicates that fresh fruit, dry leaf and fresh root of P.capense Can be a source of antibiotic agents. The study provides scientific support for the ethno-medical use of different parts of P. capense as an antimicrobial agent.