Gypsins A-D from Gypsophila arabica

Four new cyclopeptides, named gypsins A-D (1-4). together with one known oleanane saponin, were isolated from the roots of Gypsophila arabica. The structures of cyclo(-Leu(1)-Pro(2)-Leu(3)-Trp(4)-Pro(5)-Gly(6)-) (1), cyclo(-Leu(1)-Pro(2)-Tyr(3)-Phe(4)-Pro(5)-Gly(6)-) (2), cyclo(-Ala(1)-Pro(2)-Tyr(3)-Leu(4)-Leu(5)-Pro(6)-Pro(7)-Ala(8)-) (3), and cyclo(-Leu(1)-Trp(2)-Pro(3)-Gly(4)-Gly(5)-Ser(6)-Ser(7)-) (4) were elucidated by 1D and 2D NMR spectroscopy including 1D-TOCSY, DQF-COSY, 2D-ROESY, HSQC, and HMBC experiments, as well as ESI tandem mass spectrometric fragmentation analysis and chemical evidence.