A chemical analysis of the alcoholic extract of the fresh cortical (pulp) portion of the Organ Pipe cactus (Lemaireocereus thurberi) affords, besides thurberogenin (I), two more triterpenes, betulin (11) and a new tritepne, thurberin (111), hitherto unidentified in this species. The new triterpene belongs to the lupeol class and is an is+ mer of betulin. Based on the mass, nmr, spectral, and optical rotatory dispersion (ORD) data, the hydroxyl ...
[Wijeratne, Dharmassree B. T.; Kumar, Vijaya; Sultanbawa, M. Uvais S. Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1981 , p. 2724 - 2726]