Iridoids and sfingolipids from Hedyotis diffusa

Abstract Seven new compounds were isolated from the aerial part of Hedyotis diffusa , including three iridoid glycosides, hedyoiridoidside A – C ( 1 – 3 ), two cerebrosides, hedyocerenoside F ( 4 ) and G ( 5 ), and two new ceramides, hedyoceramide A ( 6 ) and B ( 7 ). And six known iridoid glycosides ( 8– 13 ) were also obtained. Their structures were established by their physico-chemical constants and spectroscopic analysis. The cytotoxicity of all compounds against tumor cell lines of human cervical cancer HeLa, human leukemia HL-60, human lung cancer A459, human hepatoma HepG2, human gastric gland carcinoma BCG-823, human nasopharyngeal cancer CNE-2, human colon cancer HCT15, and human prostate cancer PC-3 were also evaluated in vitro . As a result, new compound 1 exhibited evident cytotoxicity to all tumor cell lines, and the IC 50 values are from 9.5 μM to 28.2 μM, while new compound 2 exhibited evident cytotoxicity to Hela, HL-60, A459, HepG2, BGC-823, CNE-2, and HCT15, and the IC 50 values are from 15.8 μM to 26.2 μM. Known compound 11 also exhibited evident cytotoxicity to HL-60, A459, HepG2, BGC-823, CNE-2, and HCT15, and the IC 50 values are from 16.5 μM to 40.4 μM. New compounds 4 – 7 and known compounds 12 and 13 showed moderate cytotoxicity to some tumor cell lines.