Alkaloid constituents from Viola tianschanica

Abstract Eighteen previously undescribed alkaloids, tishaviolamines A−J, including eight pairs of enantiomers, together with two known benzylisoquinoline alkaloids, (−)-bicuculline and (−)-corlumine, were isolated from Viola tianschanica . Among them, tishaviolamine A−E were demonstrated to possess three types of unpresented skeletons. The structures of these alkaloids were established by comprehensive analyses of the 1D, 2D-NMR and (+)HRESIMS data. The absolute configurations of enantiomers were determined by comparing their calculated ECD spectra with the experimental ones. The menin−mixed lineage leukemia 1 protein−protein interaction inhibitory effect of the isolated compounds were also measured.