Monoterpene pyridine alkaloids and phenolics from Scrophularia ningpoensis and their cardioprotective effect.

Scrophularianines A-C (1-3), three new unusual monoterpene pyridine alkaloids with cyclopenta [c] pyridine skeleton reported from the genus Scrophularia for the first time, together with 15 known compounds (4-18), were isolated from the extract of Scrophularia ningpoensis. Their structures were elucidated on the basis of extensive analyses of spectroscopic evidences. The biogenetic relationship between monoterpene pyridine alkaloids and iridoids was proposed preliminarily. The myocardial protective bioassay indicated that compounds 13 and 14 with a concentration of 10(-4)M exhibited significantly protective effect against H2O2-induced apoptosis in cardiomyocytes.