Background: The genus lagochilus, family Lamiaceae consists of 44 species, 33 of which grow in central Asia. Only one report on the analysis of essential oil of Lagochilus species has been published. Objective: Aim of this study is to determine the chemical composition and antimicrobial activities of the hydrodistilled oil of flower and leaves of Lagochilus kotschyanus Boiss. of Iranian origin for the first time. Methods: The essential oils obtained by hydrodistillation from the flower and leaves of L. kotschyanus were analyzed by GC and GC/MS. The antimicrobial activities were determined by measuring the growth inhibitory zones (well diffusion assay). Results: The major constituents of the flower and leaf oils appeared to be myrcene (28.2% and 36.6%), α-pinene (25.9% and 29.8%) and β-caryophyllene (10.3% and 9.4%), respectively. Conclusion: In L. kotschyanus we identified 34 components representing 95.2% and 18 constituents representing 96.3% of the flower and leaf oils, respectively. Both oils were rich in regard to monoterpene hydrocarbons (72.7% and 79.7%) respectively. The sesquiterpene fraction was relatively small, representing 19.4% and 14.1%, respectively. Antibacterial activity was measured using the growth inhibitory zones. It was found that oil from leaves and flowers of L. kotschyanus, and especially that of flowers, exhibited interesting antibacterial activity.

Background: Basil (Ocimum basillicum L.) is one of the most important medicinal plants belong to Lamiaceae family. Basil essential oil contains important terpenoid compounds, including monoterpanes and sesquiterpanes widely used in drug industries. Objective: In the current investigation, a completely randomized design-based experiment was conducted in greenhouse with three replications and treatments to study the effect of drought stress on the expression of some genes involved in monoterpanes and sesquiterpenes biosynthesis including selinene synthase (SES), beta-myrcene synthase (MYS), gamma-cadinene synthase (CDS), alpha-zingeberene synthase (ZIS) and geraniol synthase (GES), and the compounds produced by these genes in O. basilicum c.v. Keshkeni luvelou. Methods: Drought stress was applied at three levels of 100, 75 and 50% of field capacity (FC) at 6-8 leaf stages. Results: Analysis of gene expression data revealed that treatments 75% and 50% of FC increase the GES expression two and 3.8 times, MYS expression 16 and 17.4 times, and expression of the ZIS 1.31 and 1.41 times, respectively. The expression of SES gene was almost constant and the CDS expression was declined. Conclusion: the results of essential oil analysis showed that drought stress reduced the geraniol content, but increased beta-myrcene and gamma-cadinene contents. The results also showed that changes in MYS expression was consistent with the beta-myrcene content under drought stress conditions.