Two germacrane sesquiterpenes from Pulicaria glutinosa

Abstract The aerial parts of Pulicaria glutinosa yielded two new germacrane sesquiterpenes, named puliglene and epoxypuliglene. The room temperature 1 H and 13 C NMR spectra of these compounds indicated that they were conformationally mobile, but those of epoxypuliglene showed one major conformer in spectra recorded at 95°; the NMR peaks of puliglene remained broad and ambiguous at temperatures up to 95°. Single-crystal X-ray analysis established the structure and relative stereochemistry of each compound.