2a-Hydroxy ursolic acid

Studies of the CHCI3 extract of E.japonica resulted in the isolation of a new derivative 3p, 6a, 19a trihydroxy-urs-12-en-28-oic acid, 5, besides the already reported maslinic acid 6, 2a-hydroxy-ursolic acid 7, 2a, 3a, 19a-trihydroxy-urs-12-en-28 oic acid or tormentic acid 8, 2a, 3p,19a, 23-tetrahydroxy-urs-12-en-28-oic acid 9 and ursolic acid 10 ( Fig.l). 

Triterpenic Acids. The following pentacyclic mono- and dihydroxy triterpenic acids are present in virgin olive oil (35, 43, 44) 3p-hydroxy-17-carboxy-5-12-olea-nene (oleanolic acid) 3 3,2a-dihydroxy-17-carboxy-5-12-oleanene (maslinic acid) 3p-hydroxy-17-carboxy-8-12-ursene (ursolic acid) 2a,3p-dihydroxy-17-carboxy-5-12-ursene (2a-hydroxyursolic acid) and deoxyursolic acid (structure not fully elucidated). 

Y. Wang, L. Xiang, M. Chen, Z.-X. Zhang, X. He, Substrate specificity for the 2a-hydroxy-lation of ursolic acid by Altemaria alternata and the antitumor activities of those metabolites, /. Mol. Catal. B Enzym. 2012. 83,51-56. 

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