|Can Baser, K. Husnu|
Submitted to: Chemistry and Biodiversity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2004
Publication Date: 2/17/2005
Citation: Tabanca, N., Bedir, E., Ferreira, D., Slade, D., Wedge, D.E., Jacob, M.R., Khan, S.I., Kirimer, N., Can Baser, K., Khan, I.A. 2005. Bioactive constituents from turkish pimpinella species. Chemistry and Biodiversity. 2:221-232. Interpretive Summary: Essential oils from several Turkish medicinal herbs (Pimpinella species) were found to have two new and eight known chemical constituents. In this paper the structure and absolute configuration of the two newly isolated compounds was determined. All 10 compounds were evaluated for antifungal activity against several plant pathogenic fungi and marked activity was determined for some of the isolated compounds. Other biological activities were also evaluated and presented in the paper.
Technical Abstract: A new phenylpropanoid, 4-(3-methyloxiran-2-yl)phenyl 2-methylbutyrate (1), one new trinorsesquiterpene, 4-(6-methylbicyclo[4.1.0]hept-2-en-7-yl)butan-2-one (2), and eight known compounds (3-10) were isolated from the essential oils of several Pimpinella species grown in Turkey. Structures of the new compounds were determined from 1D- and 2D-NMR analysis. The absolute configuration of 1 was established via comparison of its optical rotation with that of epoxypseudoisoeugenyl 2-methylbutyrate (11), the absolute configuration of which was determined by chemical degradation and an appropriate Mosher's ester protocol. Direct bioautography on silica gel TLC plates revealed antifungal activity of 1-3 and 11 against Collectotrichum acutatum, C. fragariae, and C. gloesporioides. Subsequent evaluation of antifungal compounds in a 96-well microtiter assay showed that compounds 1 and 11 produced the most significant growth inhibition in Phomopsis spp., Colletotrichum spp and Botrytis cinerea. Compounds 1 and 6 had antimicrobial activity against Mycobacterium intracellulare with IC50 values of 2.78 uM and 1.29 uM, respectively.