Structures and biological activities of the triterpenoids and sesquiterpenoids from Alisma orientale

Sixteen triterpenoids and nine sesquiterpenoids were isolated from the rhizome of Alisma orientate. Structures of 16-oxo-11-anhydroalisol A 24-acetate, 13 beta,17 beta-epoxy-24,25,26,27-tetranor-alisol A 23-oic acid, 1 alpha H,5 alpha H-guaia-6-ene-4 beta,10 beta-diol, and alisguaiaone were elucidated by comprehensive spectroscopic data analysis. The cytotoxic, antibacterial, antifungal, anti-inflammatory, and alpha-glucosidase inhibitory activities of isolated terpenoids were evaluated. Triterpenoids alisol A, alisol A 24-acetate, 25-O-ethylalisol A, 11-deoxyalisol A, alisol E 24-acetate, alisol G, alisol B 23-acetate and sesquiterpenoids 10-hydroxy-7,10-epoxysalvialane exhibited cytotoxicities against the three tested human cancer cell lines with IC50 values ranging from 11.5 +/- 1.7 mu M to 76.7 +/- 1.4 mu M. Triterpenoids alisol A, 25-O-ethylalisol A, 11-deoxyalisol A, alisol E 24-acetate, alisol G, and 25-anhydroalisol F showed antibacterial activities against the Gram-positive strains Bacillus subtilis and Staphylococcus aureus with MIC values of 12.5-100 mu g/mL. Sesquiterpenoid 4 beta,10 beta-dihydroxy-1 alpha H,5 beta H-guaia-6-ene exhibited antibacterial activity against B. subtilis with an MIC value of 50 mu g/mL, and 10-hydroxy-7,10-epoxysalvialane exhibited activity against S. aureus with an MIC value of 100 Compounds 16-oxo-il-anhydroalisol A 24-acetate, alisol F, 25-anhydroalisol F, and alisguaiaone exhibited inhibitory effects on lipopolysaccharide-induced NO production in RAW 264.7 macrophage cells. None of the compounds showed obvious inhibitory activity against alpha-glucosidase. (C) 2016 Elsevier Ltd. All rights reserved.