New 2-acetoxy fatty acid methyl esters from Nepeta parnassica

The genus Nepeta (Lamiaceae) comprises approximately 250 species of annual or perennial herbs distributed in temperate Europe, Asia and Africa [1]. Nepetalactones, iridoids and their glucosides, diterpenes and triterpenes are reported in the literature as major constituents of Nepeta species. Their extracts and essential oils have exhibited analgesic, anti-inflammatory, antiviral, antioxidant and antimicrobial activities. Nepeta parnassica Heldr. & Sart. is an aromatic perennial herb, endemic to Greece and South Albania [2].

The dichloromethane extract of the aerial parts of wild N. parnassica populations collected from Mt. Parnassos (Greece) was subjected to a series of chromatographic separations to yield three new fatty acid methyl esters bearing an acetoxy group at C-2 (1-3), in addition to the new nepetalactone dimer, nepetaparnone, and the new pimarane derivative, parnapimarol [3]. The structure elucidation of 1-3 was based on analyses of their spectroscopic data (1D and 2D NMR, IR, MS).

References: 1. Mabberley, D.J. (1997) The Plant Book: A Portable Dictionary of the Vascular Plants. Cambridge University Press. Cambridge.

2. Turner, C. (1972) Flora Europaea, Vol. 3 (Tutin, T.G.; Heywood, V.H.; Burges, N.A.; Moore, D.M.; Valentine, D.H.; Walters, S.M.; Webb, D.A., Eds.). Cambridge University Press. Cambridge.

3. Gkinis, G. et al. (2008)J. Nat Prod. In press.