Limonoids arephytochemicals of thetriterpenoid class which are abundant in sweet or sour-scentedcitrus fruit and other plants of the familiesCucurbitaceae,Rutaceae, andMeliaceae.[1] Certain limonoids areantifeedants such asazadirachtin from theneem tree.[2]
Chemically, the limonoids consist of variations of thefuranolactone core structure. The prototypical structure consists of four six-membered rings and afuran ring. Limonoids are classed astetranortriterpenes.
Citrus fruits contain the limonoidslimonin,nomilin andnomilinic acid, while both neem seeds and leaves contain the limonoidazadirachtin, although higher concentrations are present in the former.
Eight previously unknown limonoids were identified viaspectroscopy in the fruits ofChisocheton erythrocarpus gathered in Malaysia. These compounds were dubbed erythrocarpines after the species epithet.The same study tested several preparations ofC. erythrocarpus extract aslarvicidal agent againstAedes aegypti mosquitoes; they found that 1000 ppm ofDCM extract resulted in 100% mortality of larva 24 hours after exposure.[3]