cucurbitacin
Cucurbitacin refers to a group of highly oxidized tetracyclic triterpenoids produced by plants in the family Cucurbitaceae. These compounds are best known for their intensely bitter taste and are widely distributed in cucumber, melon, squash, gourd and related species. In plants they function primarily as defense chemicals against herbivores and pathogens.
Cucurbitacins occur in various tissues, including fruits, seeds, and roots, with concentrations influenced by species, cultivar,
Chemically, cucurbitacins are derived from a cucurbitane skeleton (C30 pentacyclic triterpenoid). They include aglycones and glycosides;
Biosynthesis proceeds from squalene to 2,3-oxidosqualene, cyclization to cucurbitadienol/cucurbitane skeleton, followed by oxidative tailoring by cytochrome