Any one of a class of tetracyclic triterpenoids, formally derived from the triterpene hydrocarbon cucurbitane, developed by some plants (especially those of the family Cucurbitaceaeas) as a defence mechanism against herbivores.
| Member | Definition | Role |
|---|
| cucurbitacin b | A cucurbitacin in which a lanostane skeleton is multi-substituted with hydroxy, methyl and oxo substituents, with unsaturation at positions 5 and 23; a hydroxy function at C-25 is acetylated. | cucurbitacin B |
| cucurbitacin c | | Cucurbitacin C |
| cucurbitacin d | A cucurbitacin in which a lanostane skeleton is multi-substituted with hydroxy, methyl and oxo substituents, with unsaturation at positions 5 and 23. | cucurbitacin D |
| cucurbitacin i | A cucurbitacin that is 9,10,14-trimethyl-4,9-cyclo-9,10-secocholesta-2,5,23-triene substituted by hydroxy groups at positions 2, 16, 20 and 25 and oxo groups at positions 1, 11 and 22. | cucurbitacin I |
| cucurbitacin I 2-O-beta-D-glucopyranoside | A triterpenoid saponin that is cucurbitacin I attached to a beta-D-glucopyranosyl residue at position 2 via a glycosidic linkage. It has been isolated from Machilus yaoshansis. | cucurbitacin I 2-O-beta-D-glucopyranoside |
| nsc 106399 | A cucurbitacin in which a lanostane skeleton is multi-substituted with hydroxy, methyl and oxo substituents, with unsaturation at positions 1, 5 and 23. | cucurbitacin E |