Chemical Compositions of Eupatorium heterophyllum Leaf Samples from Yunnan and Sichuan Provinces of China-Isolation of 13 New Sesquiterpene Lactones

Eight samples of Eupatorium heterophyllum leaves were collected at different locations in Yunnan and Sichuan provinces in China, and their chemical constituents were investigated. Thirteen previously undescribed sesquiterpene lactones-seven germacranolides, three eudesmanolides, two guaianolides, and a 2-norelemanolide-were isolated, and their structures were elucidated based on extensive spectroscopic analyses. The major constituents in the six samples from northwestern Yunnan and Sichuan are hiyodorilactones A and B, whereas that in the two samples from the region near Kunming, Yunnan is eupatoriopicrin. These results and previously reported results suggest the presence of locality-dependent intra-specific diversity in the chemical constituents of E. heterophyllum leaves.

Automated summary

In this study, eight samples of Eupatorium heterophyllum leaves were collected from different locations in Yunnan and Sichuan provinces in China, and their chemical constituents were investigated. Thirteen previously undescribed sesquiterpene lactones were isolated and their structures were elucidated. The major constituents varied depending on the location, suggesting the presence of locality-dependent intra-specific diversity in the chemical constituents of E. heterophyllum leaves.