The chief ingredient of the medicinal value of the bael is

The chief ingredient of the medicinal value of the bael is Marmelosin.
Marmelosin is believed to be the therapeutically active principle of bael fruit. It has shown antihelminthic and antibacterial activities. It can also be used as a laxative and for diuretic treatment.
The fruits, bark, leaves, seeds and roots of bael contain various bioactive compounds such as coumarin, xanthotoxol, imperatorin, aegeline and marmeline. These compounds can provide antidiabetic, anticancerous, antifertility, antimicrobial, immunogenic and insecticidal activities.