Are anthocyanidins the immediate products of anthocyanidin synthase?

Turnbull JJ, Sobey WJ, Aplin RT, Hassan A, Firmin JL, Schofield CJ, Prescott AG

Anthocyanidin synthase catalyses the in vitro conversion of its natural substrate, leucocyanidin, to cis- and transdihydroquercetin, quercetin and a small amount of cyanidin; incubation of trans-dihydroquercetin gave quercetin.