Plant growth triterpenoids

Fasciculol G (13) is a further member of the series of plant growth inhibitors from Neamatoloma fasciculare (see Vol. 9, p. 188). Structure (14) has been proposed for fasciculatol from Veronia fasciculata Extraction of a fossil plant from the Ningyo-Toge uranium deposit afforded the nortriterpenoid ketones (15) and (16). The structure (17) of a new tetracyclic triterpenoid from Pertya robusta was confirmed by partial synthesis of its dihydro-derivative from 24-methyl-enecycloartenol. "... 

Many of these terpenoids have been reported to be biologically active as indicated in Table 1, although such work has occurred on these compounds when isolated as constituents of plant families other than the Dipterocarpaceae [68-81]. For example, the common triterpenoid, betulinic acid (21), was reported as having selective cytotoxic activity for several human melanoma cell lines, and also demonstrated highly effective tumor growth inhibition in athymic (nude) mice with human melanoma cells at non-toxic doses [72]. 

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