and flavanone 3-hydroxylase to form dihydrokaempferol. The compound then reacts with NADPH and dihydroflavinol 4-reductase to form leucopelargonidin, which is further oxidized with oxygen, alpha-Ketogluteratic acid, and anthocyanidin synthase. This compound spontaneously loses a water molecule and a hydroxide ion to form cyanidin (figure 3). Activation Among many anthocyanidins studied, cyanidin most potently stimulated activity of the sirtuin 6 enzyme. References Anthocyanidins