ESSENTIAL OIL CONSTITUENTS AND ANTIMICROBIAL ACTIVITY OF THE SEEDS OF ZANTHOXYLUM ARMATUM DC. FROM CHAMOLI, UTTRAKHAND

R. Ramchandram, Mohammed Ali*, Showkat Rasool Mir and Shahnaz Sultana

ABSTRACT

Zanthoxylum armatum DC. (Rutaceae) is a thorny shrub or small tree found in south eathern Asia. Its seeds are used to treat arthritis, asthma, blood diseases, bronchitis, bruises, cancer, cholera, diabetes, depression, digestive impairment, dyspepsia, earache, fever, fibrositis, headache, heart diseases, microbial infections, piles, roundworms, skin diseases, swellings, toothache and worms. The present study was carried out to analyse an essential oil from the seeds of Z. armatum and to evaluate its antimicrobial activity. The seeds were hydrodistilled to get the essential oil which was analysed by GC and GC-MS techniques. The oil was evaluated for antimicrobial activity by disc diffusion method. The seed essential oil was characterized by high percentage of linalool (86.93%) followed by limonene (1.74 %), β-caryophyllene (1.53%) and β-phellandrene (1.32%). Oxygenated monoterpenes (91.4%) comprised major profile of chromatogram of the essential oil including eight monoterpenic alcohols (89.66%), two ketones (0.80%) and one oxide (0.94%) whereas seven monoterpenic hydrocarbons occurred up to 4.64%. There were only two sesquiterpene hydrocarbons (1.91%) identified as β-caryophyllene and alloaramadendrene. Three esters, viz., (E)-methyl cinnamate, ethyl 9-hexadecenoate and ethyl palmitate were positively identified. The chloroform, acetone and ethanolic extract and the essential oil of the seeds showed significant antimicrobial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus when compared with standard antibiotics by using cup and plate method. The essential oil mainly contained a large number of monoterpenes and exhibited significant antimicrobial activity against pathogenic microorganisms.

Keywords: Zanthoxylum alatum, seeds, essential oil, GC-MS analysis, antimicrobial activity.