Three new monoterpene alkaloids and a new caffeic acid ester from Incarvillea mairei var. multifoliolata

Three new monoterpene alkaloids, mairine A (1), mairine B (2), and mairine C (3), and a new caffeic acid ester, 2-(1-hydroxy-4,4-dimethoxycyclohexyl)ethyl caffeate (4), were isolated from the EtOH extract of the whole plants of Incarvillea mairei var. multifoliolata. The structures of these compounds were established on the basis of 1D- and 2D-NMR and HR-ESI-MS analysis.