Gymnasterkoreayne G, a new inhibitory polyacetylene against NFAT transcription factor from Gymnaster koraiensis.

A new polyacetylene, gymnasterkoreayne G (1) and seven known (2--8) constituents were isolated from the leaves of Gymnaster koraiensis. Base on extensive 1D and 2D NMR spectroscopic data, the structure of the new compound was identified as erythro-8(S)-9(Z),16-heptadecadiene-4,6-diyne-2,3,8-triol. Isolated compounds were evaluated for their ability to inhibit NFAT transcription factor. While other components did not show activity, most of polyacetylene components markedly inhibit NFAT transcription factor. Of these compounds, gymnasterkoreayne B (3) was the most potent (IC(50) 1.44+/-0.59 microM). In term of the isomers, compound 1 (IC(50) 43.9+/-2.24 microM) with an erythro-configuration showed less inhibition than 2 (IC(50) 7.24+/-0.42 microM) with a threo-configuration.