Chemical composition and antibacterial activity of nepeta cataria l. essential oil against some pathogenic bacteria

الملخص EN

Catnip (Nepeta cataria) is hardy perennial plant native in Syria.

However, this plant is not investigated.

So the current research aimed to study the volatile component profiles and the antibacterial activity of N.

cataria grown in Draykish-Tartous (Syria), and was carried out in National Commission for Biotechnology (NCBT) in the period of March 2019 to October 2020.

Essential oil of catnip was obtained by hydrodistillation of dry aerial parts (leaves and flowers) of plant.

The chemical composition of N.

cataria EO was identified using Gas chromatography–mass spectrometry (GC/MS) technique, and antibacterial activity against three Gram-positive bacteria (Staphylococcus aureus, S.

epidermidis and Bacillus subtilis), and three negative bacteria (Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae) was determined by macrodilution minimal bactericidal concentration (MBC) method.

The analysis of the EOs indicated that 4a-α,7-β,7a-α-β-Nepetalactone (71.28%) and 4a-α,7-α,7a-β-Nepetalactone (18.06%) were the major compounds of the EOs developmental stages.

Other important compounds were Berbenol, β–Myrcene, 3-Carene, Isoterpinolene, 1-Phellandrene, Trans-Caryophylene, β–Pinene and α–Pinene (1.57, 1.30, 0.92, 0.71, 0.61, 0.45, 0.43 and 0.40%, respectively).

The most resistant bacterium towards N.

cataria EO was Staphylococcus epidermidis, followed by Staphylococcus aureus (MBC values were 32 and 16 µg.ml1, respectively), while Bacillus cereus, Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae were relatively sensitive with MBC value of 8 µg.ml-1).