Antimicrobial activity and chemical composition of essential oils of Stachys lavandulifolia Vahl. from Mazandaran , Iran

Abstract

Stachys lavandulifolia vahl. or Chaye Koohi is a native plant, which has been used as an anxiolytic and sedative in Iranian folk medicine which belongs to the Lamiaceae family. In this study, S. lavandulifolia vahl. were collected from mountain of Baladeh area in Mazandaran province, Iran. Chemical constituents of essential oil of S. lavandulifolia vahl. were determined. Aerial parts were subjected to hydrodistillation (HD) in a Clevenger – type apparatus until there was no significant increase in the volume of the oil collected (3 h). The yield of the oil was 0.69% (w/w). The essential oil was analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). Identification of the components was based on GC retention indices computer matching with Wiley GC-MS library, and by comparison of the fragmentation patterns of the mass spectra with those reported in the literature. 59 components were identified constituting more than 99.1% of the oil. Hexadecanoic acid (13.9%), α-pinene (13.7%), germacrene-D (8.9%), β-pinene (7.0%), myrcene (4.5%), β-phellandrene (5.7%), Z-ocimene (3.4%), spathulenol (3.5%), δ-cadinene (2.0%) and α-cadinol (2.6%) were major components in S. lavandulifolia vahl. oil. The oil was tested against two strains of bacteria (Gram-positive and Gram-negative). In vitro antimicrobial activity of essential oil of S. lavandulifolia vahl. were investigated by disc diffusion method and the minimum inhibitory concentration (MIC) and also minimal bactericidal concentration (MBC) determination. The studied sample was active against gram-positive and Gram-negative microbial strains. The oil exhibited higher activities against the Gram-negative tested bacterial strain. Key words: Stachys lavandulifolia vahl., essential oil composition, antimicrobial activity, α-pinene.