Iridoids and bis-iridoids from Patrinia scabiosaefolia

Abstract

Ten new iridoids, patriscabioins A–J (1–10), and three unique bis-iridoids, patriscabiobisins A–C (11–13), together with seven known analogues, have been identified from whole plants of Patrinia scabiosaefolia. Compounds 1 to 8 are a series of 5,6-dihydrovaltrate hydrins with unique substituent groups in the Valerianaceae family such as isovaleryl and 3-methylcrotonyl. Furthermore, compounds 11 and 12 are the first reported bis-iridoids with two units connected by a 1,3-dioxane group, whereas compound 13 is linked by an ether bond between two units. The structures of all the compounds were established on the basis of extensive spectroscopic analysis as well as experimental and calculated ECD spectra. Compounds 1 and 3 showed moderate inhibitory activities on AChE with IC₅₀ values of 37.6 and 10.5 µM, respectively. Moreover, compounds 1, 3, and 5 also showed moderate cytotoxic activity against HL-60, with IC₅₀ values ranging from 1.2 to 27.6 µM.