Alisol C monoacetate

Arch. Pharm. Res., 2012, 35(11):1919-26.

A new triterpenoid from Alisma orientale and their antibacterial effect.[Pubmed: 23212633 ]

A new triterpenoid, named alisol Q 23-acetate, as well as fourteen known terpenes, alisol B 23-acetate (2), alisol B (3), alismol (4), 10-O-methyl-alismoxide (5), alismoxide (6), 11-deoxyalisol C (7), 13β,17β-epoxyalisol B 23-acetate (8), 4β,12-dihydroxyguaian-6,10-diene (9), alisol C 23-acetate (Alisol C monoacetate,10), alisolide (11), 16β-methoxyalisol B monoacetate (12), alisol A (13), 16β-hydroxyalisol B 23-acetate (14), alisol A 24-acetate (15) were isolated from the rhizomes of Alisma orientale.
METHODS AND RESULTS:
The structures of compounds (1-15) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Among these isolates, antibacterial effect of compounds 2, 3, 10, and 15, major constituents of A. orientale was examined. The MIC values of compounds 2, 10, and 15 were 5-10 βg/mL against eight antibiotic resistant strains, which were lower than those from the positive controls (MICs of chloramphenicol and ampicillin were 5-80 μg/mL).
CONCLUSIONS:
Therefore, compounds 2, 10 and 15 exhibited the potent antibacterial activity.

Chem.Pharm. Bull.,1970,18(7):1369-84.

Biological-Active Triterpenes of Alismatis Rhizoma. IV. The Structures of Alisol B, Alisol B Monoacetate and Alisol C Monoacetate-Some Reactions of the α-Hydroxy Epoxide of the Alisol B Derivatives[Reference: WebLink]

Studies on the structures of alisol B, alisol B monoacetate and Alisol C monoacetate, the new biological-active triterpenes of Alismatis Rhizoma, are reported.
METHODS AND RESULTS:
The former two compounds have been correlated to alisol A (1) establishing their structures as shown 2 and 4,respectively. The structure of Alisol C monoacetate has been clarified to be 16-oxoalisol B 23-monoacetate (21) on the basis of correlation of the compound with 4. Stereochemical courses and mechanisms of some epoxide cleavage reactions of 2,4 and alisol B diacetate (8) are also described.