Limonoid

Limonoids are phytochemicals, abundant in citrus fruit and other plants of the classes Rutaceae and Meliaceae. They account for the scent of fresh lemon or orange peel. Many of the plants used in traditional healing, such as Neem, are rich in limonoids. Currently limonoids are under investigation for a wide variety of therapeutic effects such as antiviral, antifungal, antibacterial, antineoplastic and antimalarial. They also show effectiveness as insecticides both in traditional farming cultures and modern biochemistry labs.

Chemically the limonoids are varied but the prototypical structure consists of 4 benzene rings and a furan ring. Limonoids are classed as tetranortriterpenes.