Chemical Composition, Antioxidant and Antimicrobial Activities of the Essential Oil of Nepeta hindostana (Roth) Haines from India

Aerial parts of Nepeta hindostana (Roth) Haines collected from Gorakhpur Division, U. P., India possessed an essential oil in 0.42% yield. GC and GC-MS analysis of the oil revealed recognition of thirty three compounds, representing 91.0% (area percent) of the total oil composition. Oil was rich in sesquiterpene hydrocarbons, exhibited higher percentage of (E) β - farnesene (10.4%) followed by ageratochromene (9.7%), spiro [4.5] decan-1-one, 6-hydroxy (9.5%), b -caryophyllene (8.6%) and spiro [4.5] decan-6-ol, 6-methyl (8.2%). At 60 µL, oil showed 80.7% antioxidant activity by β-carotene bioassay (IC 50 = 8 µL) and 73.4% by DPPH free radical scavenging bioassay (IC 50 = 8.5 µL). Furthermore, the oil was tested for its antimicrobial activity in opposition to five plant and human pathogenic bacteria namely Bacillus subtilis, Erwinia herbicola, Escherichia coli, Pseudomonas putida, Salmonella typhi and six post-harvest fungi such as Aspergillus flavus Link., A. niger van Tieghem, A. ochraceus Wilhelm, A. terreus Thom, Fusarium nivale (Fries) Cesati and F. oxysporum Schlecht. The oil was found to be more efficacious for E. coli, Erw. herbicola and A. ochraceus.