Four novel pyrrolizidine alkaloids were isolated from Ipomoea hederifolia. It could be shown by spectroscopic methods that the compounds represent two pairs of isomeric turneforcidine diesters with either erythro- or threo-2,3-dihydroxy-2-methyl-butyric acid as the acyl moiety at C-9 OH. One pair (ipanguline A/isoipanguline A) is characterized by phenylacetic acid as the second acyl component (at C-7 OH), the other (ipanguline B/isoipanguline B) includes a salicylic acid moiety in this position. The distribution pattern shows the occurrence of the A compounds in the seeds and of the B compounds in the roots, respectively, with all four alkaloids in the aerial parts. © 1993.