Analgesic, anti-inflammatory, and CNS depressant activities of new constituents of Nepeta clarkei

Two new pentacyclic triterpenes named kirmanoic acid (1) and kurramanoic acid (2) have been isolated from the chloroform-soluble portion of the whole plant of Nepeta clarkei Hook. The structures of the two new compounds were assigned on the basis of their 1H and 13C NMR spectra including two-dimensional NMR techniques such as COSY, HMQC, and HMBC experiments. Kirmanoic acid (1) was investigated for analgesic, anti-inflammatory, and CNS depressant activities. Interestingly kirmanoic acid (1) showed strong analgesic activity than standard drug in acetic induced writhing and formalin tests. Similarly kirmanoic acid (1) also showed strong anti-inflammatory activity than its standard drug. The gross behavioral study of kirmanoic acid (1) revealed that it exhibited mild CNS stimulant and muscle relaxant in the mice. Compound 1 showed a slight increase in Locomotor activity and possesses the antidepressant effect.