A Novel Isopimarane Diterpenoid with Acetylcholinesterase Inhibitory Activity from Nepeta sorgerae, an Endemic Species to the Nemrut Mountain

From the dichloromethane extract of Nepeta sorgerae, the isolation and structure elucidation are now reported of a new isopimarane diterpenoid, named sorgerolone, and two known triterpenoids, oleanolic acid and ursolic acid. Antioxidant activity of the extracts and the isolated terpenoids was determined by the DPPH free radical scavenging and lipid peroxidation inhibition (β-carotene bleaching) methods. Anticholinesterase activity of the extracts and isolates was investigated by Ellman's method against AChE and BChE enzymes. Although the antioxidant activity results were low, the AChE enzyme inhibition of the extracts and terpenoids was very promising.

Nepetalactone Content and Antibacterial Activity of the Essential Oils from Different Parts of Nepeta persica

The essential oils from the flower, leaf, stem and root of Nepeta persica Boiss., analyzed by GC and GC/MS, were shown to contain 4aβ,7α,7aβ-nepetalactone (58.5%, 62.3%, 66.2% and 27.1%, respectively), and 4aα,7α,7aβ-nepetalactone (33.0%, 28.3%, 24.9% and 7.6%, respectively). The other main component of the flower and stem oils was α-pinene (3.6% and 4.4%) and of the leaf oil β-ocimene (3.6%). In the root oil, other main constituents were α-pinene (40.4%), α-amorphene (5.3%), γ-cadinene (2.9%), and cis-calamenene (2.5%). Nepetalactone was the major component of the flower, leaf and stem oils, which are thus important sources of nepetalactone. Antibacterial activities of the flower, leaf, stem and root oils were evaluated using the microdilution broth method. Inhibitory effects on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Enterococcus faecalis were recorded. The flower, leaf, stem, and root oils had difference activities against the test microorganisms. The antibacterial property of the essential oils might be ascribed to their high content of nepetalactone isomers.

Antibacterial Activity and Composition of the Essential Oil of Nepeta Menthoides from Iran

The antibacterial activity and chemical composition of the essential oil obtained from the aerial flowering parts of Nepeta menthoides were analyzed by GC and GC-MS. Twenty-nine compounds representing 97.6% of the total oil were identified. Oxygenated monoterpenes (71.9%) were the principal fraction of the oil with 1,8-cineole (33.8%) and 4aα-7α-7aα-nepetalactone (23.2%) as the main constituents. The antibacterial activity of the oil and its two main constituents were tested against seven bacteria. High activity of the oil and its two main constituents was demonstrated against all the tested bacteria with MIC values in the range of 1.8 - 7.2, 0.9 - 7.2 and 1.8 - 15 mg/mL, respectively.