The leaves of rose-bay willow-herb (Chamaenerion angustifolium) are shown to contain ursolic acid, oleanolic acid, maslinic acid, and a hitherto unknown acid, 2a-hydroxyursolic acid. A partial synthesis of the new acid is described and some of its derivatives are compared with the corresponding derivatives of the isomeric maslinic acid.* The compound described by Aplin and co-workers as 2-hydroxyursolic acid (see ref. 6b) was later shown to be maslinic acid.
Reaction of L-tartaric acid with thiocarbohydcrazide afforded (1R, 2S)-1,2-bis(4-amino-5-mercapto-1,2,4-triazol-3-yl)-ethane-1,2-diol (3). The functional groups in 3 allowed the construction of fused heterocycles on the 1,2,4-triazole rings, mainly of the 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine type as in 4, 5, 7, 10, 13 and 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole type as in 14.
The ether as well as the
methanol extracts of the defatted leaves of Hibiscus sabdariffa
yielded a new glycoside, the structure of which has been determined, by mass
and N.M.R. spectra and by synthesis, as β- sitosteryl β-D-galactoside.
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