Abstract
Three novel oxazoline alkaloids, 1-oxa-3-azaspiro [4.5] dec-2-ene-8-one (1), 1-oxa-3-azaspiro [4.5] dec-2, 6-diene-8-one (2), and 1-oxa-3-azaspiro [4.5] dec-10-methoxy-2, 6-diene-8-one (3) were isolated from the methanol extract of the whole plant of Gymnotheca chinensis. The chemical structures were established by means of spectroscopic analysis including one- and two-dimensional NMR spectroscopy.