Two new cyclopeptides from Stachys geobombycis C. Y. Wu.

Two new cyclic peptides, named as cyclogeobomptides A ( 1 ) and B ( 2 ) were isolated from the roots of Stachys geobombycis C. Y. Wu. Compounds 1 and 2 are both made up of eight amino acids. The structures of them were established on the basis of the spectral data, including mass spectrometry, 2D NMR, and X-ray crystallography. Cyclogeobomptides A and B were proved to have obvious inhibitory activities against α -glucosidase with the IC ₅₀ values of 26.00 and 19.16  μ M, respectively.