Triptocallic acid

The only example of this type of skeleton found was triptocallic acid B (28), isolated from tissue cultures of T. wilfordii by Nakano and coworkers [47]. The compound showed a molecular formula of C30H48O3, according with its HREIMS. Its El-mass fragmentation pattern were consistent with that of a D C-friedoolean-7-en pentacyclic triterpene [40, 48]. The l3C NMR data of (28) were similar to those of wilforic acid C [49] for C-15 to C-22 and C-28 to C-30, and swertenol [50] for C-l to C-14 and C-23 to C-25. Thus, triptocallic acid B was shown to be 3P-hydroxymultiflor-7-en-29-oic acid, Fig. (19). 

From callus cultures of T. wilfordii, triptocallic acid A was isolated (29), [47]. Based on its spectroscopic data (FAB-MS, IR, H, 13C and 2D NMR) and of that from its diacetate derivative (obtained from acetylation of (29) with acetic anhydride-pyridine), the structure of the compound was determined to be as shown in fig. (20). 

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