Glycolipid ester-type heterodimers from Ipomoea tyrianthina and their pharmacological activity

Tyrianthins A (1) and B (2), two partially acylated glycolipid ester-type heterodimers were isolated from a methanol-soluble extract of Ipomoea tyrianthina. Scammonic acid A was determined as the glycosidic acid in both monomeric units. Tyrianthin A (1) (IC50 0.24 ± 0.09 μM and Emax 81.80 ± 0.98%), and tyrianthin B (2) (IC50 0.14 ± 0.08 μM and Emax 87.68 ± 0.72%) showed significant in vitro relaxant effect on aortic rat rings, in endothelium- and concentration-dependent manners. Also, these compounds were able to increase the release of GABA and glutamic acid in brain cortex, and displayed weak antimycobacterial activity.