Chemical Composition, Antimicrobial and Antioxidant Activities of the Essential Oil of Nepeta deflersiana Growing in Yemen

In the course of our phytochemical studies of essential oils, the oil obtained from the aerial part of Nepeta deflersiana (Lamiaceae) was analyzed by GC and GC/MS. In parallel to that, evaluation of the antimicrobial and antioxidant activities was also carried out. The investigation led to the identification of 51 components. The oil was rich in oxygenated monoterpenes (31.4%). The oil contained as well a high content of oxygenated sesquiterpenes (28.2%). Hexadecanoic acid (8.0%), caryophyllene oxide (6.4%), 2-methoxy-p-cresol (5.6%), camphor (4.7%) and eugenol (4.7%) were the most abundant constituents. In antimicrobial investigation, the essential oil has shown strong activity for Gram-positive bacteria with MIC-value of 0.4 mg/mL. Moreover, the DPPH-radical scavenging assay exhibited a moderate antioxidant activity (38%) at 1.0 mg/mL.