New Iridoid Glucosides from Caryopteris incana (Thunb.) Miq. and Their α-Glucosidase Inhibitory Activities

摘要

In our continued investigations of the plant Caryopteris incana , five new iridoid glucosides 1 – 5 , including two cis-trans -isomers, 3 and 4 , along with six known compounds 6 – 11 , were isolated from the n -butyl alcohol ( n -BuOH) soluble fraction of whole dried material of Caryopteris incana . Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α-glucosidase inhibitory effects. Among these compounds, 4 – 8 and 10 exhibited potent inhibition of α-glucosidase.