Four new resin glycosides, murasakimasarins I-IV, from the tuber of Ipomoea batatas

Four new resin glycosides having macrolactone structures (jalapins), murasakimasarins I–IV, were isolated from the tubers of Ipomoea batatas (L.) Lam. (‘Murasakimasari’, Convolvulaceae), along with three known glycosides. Their structures were determined on the basis of spectroscopic data as well as chemical evidence. Murasakimasarin III is the first representative of a resin glycoside with 10-methylundecanoic acid as the component organic acid.