ABSTRACT
The essential oil was extracted from the seeds of Heracleum rigens by hydrodistillation and a total of twenty compounds accounting for 98.5% of the total oil composition were identified. Physicochemical properties and chemical composition of the oil was determined by a combination GC/FID and GC/MS analysis. The major compounds identified were bornyl acetate (51.2%), alpha-pinene (22.6%), limonene (9.62%), octyl acetate (3.94%), rho-cymene (2.85%) and gamma-terpinene (1.93%). The antimicrobial activity of the oil was screened by the disc diffusion method against nine pathogenic bacterial strains. Maximum antimicrobial activity was noted against Klebsiella pneumonia and Bacillus subtillis. This investigation corroborates the traditional claim of H. rigens as an effective antimicrobial agent.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Heracleum/chemistry , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Bacillus subtilis/drug effects , Bicyclic Monoterpenes , Cyclohexane Monoterpenes , Cyclohexenes/chemistry , Gas Chromatography-Mass Spectrometry , Klebsiella pneumoniae/drug effects , Limonene , Microbial Sensitivity Tests , Monoterpenes/chemistry , Terpenes/chemistryABSTRACT
The essential oil from the leaves of Didymocarpus tomentosa was extracted by hydrodistillation and analyzed by GC/FID and GC/MS. Twenty five constituents amounting to 81.6% of the oil were identified. The leaf oil contained 78.7% sesquiterpenes and 2.9% monoterpenes. The leaf essential oil of D. tomentosa is a unique caryophyllene-rich natural source containing beta-caryophyllene, caryophyllene oxide, a-humulene and humulene oxide. The cytotoxic activity of the oil was determined by the BSLT using shrimp larva and the MTT assay using HeLa tumor cell line. The oil showed significant cytotoxic activity with LC50 and IC50 values of 12.26 and 11.4 microg/mL, respectively. This is the first report on the chemical composition and cytotoxic activity of the essential oil of D. tomentosa.
