Cyclic Peptides, Acyclic Diterpene Glycosides and Other Compounds from Lycium chinense MILL

Abstract

The chemical structures of four cyclic peptides, lyciumins A-D (1-4), three acyclic diterpene glycosides, lyciumosides I-III (5-7) and other three compounds, a tryptophan derivative glycoside (8), a monoterpene glycoside (9) and a steroidal glycoside (10) isolated from Lycium chinense, have been elucidated by a combination of chemical, ¹H- and ¹³C-NMR, and mass spectrometric studies. Lyciumins are interesting because of their monocyclic octapeptides containing a novel C-N linkage between tryptophan N₁ and glycine C_α.