An immunomodulatory C-glucosylated propelargonidin from the unripe fruit of Aegle marmelos

A C-glucosylated propelargonidin has been isolated from the aqueous extract of the pulp of the unripe fruit ofA. marmelos. Structure determination was based on chemical degradation and 13 C-NMR. The compound exhibited moderate inhibition of the classical pathway of complement activation and of luminol enhanced chemiluminescence by zymosan activated polymorphonuclear leucocytes. It had no effect on the alternative pathway of complement activation.