A new ingol diterpenoid from the seeds of Euphorbia marginata Pursh

A new ingol diterpenoid, namely 3-de-O-acetyleuphornan R (1), along with two known analogues, euphornans E (2) and N (3) were isolated from the seeds of Euphorbia marginata Pursh. The structure of 1 was elucidated by extensive 1H NMR, 13C NMR, HSQC, HMBC, and 1H-1H COSY, and HR-MS spectroscopic analyses.