ID 1.1.1.366 DE L-idonate 5-dehydrogenase (NAD(+)). CA L-idonate + NAD(+) = 5-dehydro-D-gluconate + H(+) + NADH. CC -!- Involved in the catabolism of ascorbate (vitamin C) to tartrate. CC -!- No activity is observed with NADP(+) (cf. EC 1.1.1.264). CC -!- Formerly EC 1.1.1.n8. DR Q1PSI9, IDND_VITVI ; //