Nasim Milani Kalkhorani - Department of Applied Chemistry, Faculty of Science, Islamic Azad University, South Tehran Branch, Tehran, Iran
Mohsen Dadgar - Department of Applied Chemistry, Faculty of Science, Islamic Azad University, South Tehran Branch, Tehran, Iran
Mohammad Bagher Rezaee - Department of Medicinal Plants, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization, Tehran, Iran
Arash Mahboubi - Pharmaceutical Department, School of Pharmacy, Shahid Beheshti University, Tehran, Iran
Fatemeh HeroAbadi - Faculty of Science and New Technology, Chemistry Department, Islamic Azad University, South Tehran Branch, Tehran, Iran

There are distinct varieties of basil types in the genus Ocimum L. which makes them very special. Genus Ocimum L. is widespread over Asia, Africa, Central and Southern America. All basils are member of the Lamiaceae family. The colors of the leaves vary from bright green to purple-green and sometimes almost black. Fresh basil leaves have a strong and characteristic aroma, plant which is used in several traditional medicine systems to cure various diseases. The Ocimum basilicum var. purpurascens where green cultivated and collected from three different locations (Alborze, Shahr-e-Rey and Golestan provience) in Iran. The essential oils were extracted by water distillation, and then injected to Gas Chromatography (GC) and Gas Chromatography coupled with mass spectrometry (GC/MS). Main chemical composition of essential oils of leaf sample of Alborz were chavicol ۸۱.۴۱%, methyl acetate ۲.۸۹%, and sample of Shahr-e-Rey were chavicol ۵۷.۶۹%, linalool ۱۶.۴۳%, and sample of Gorgan city were chavicol ۶۳.۵۱%, and linalool ۱۹.۸۰% yield. In this study, extracted essential oil was investigated on bacterial with definition of MIC and MBC. essential oil of Alborz sample was examined on Gram-positive bacteria: Staphylococcus aureus, Basilus subtilis and Gram-negative bacteria Pseudomonas aeruginosa, Escherichia coli, which it has growth inhibitory effect (MIC) and bactericidal (MBC), with a concentration of ۵% and it has a stronger effect on Basilus subtilis (MBC = ۵%, MIC = ۲.۵ %) too. Essential oil of Shahr-e-Rey was examined on the same bacterias which it has growth inhibitory effect (MIC) and bactericidal (MBC), with a concentration of ۵% and it has a Stronger effect on Basilus subtilis (MBC = ۵%, MIC = ۲.۵ %) too. Essential oil of Gorgan city was examined on the same bacterias which it has growth inhibitory effect (MIC) and bactericidal (MBC) with a concentration of ۵% and it has a Stronger effect on Basilus subtilis (MBC = ۵%, MIC = ۲.۵ %) too.

Hydro distillation, Ocimum, Gram- bacteria, Chavicol, linalool