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 IC₅₀ values of 26.00 and 19.16 μM, respectively.