alditol:NADP+ 1-oxidoreductase activity MetaCyc:ALDEHYDE-REDUCTASE-RXN molecular_function aldose reductase activity polyol dehydrogenase (NADP(+)) activity Reactome:REACT_112358 Reactome:REACT_32715 EC:1.1.1.21 Catalysis of the reaction: an alditol + NADP+ = an aldose + NADPH + H+. Reactome:REACT_92726 KEGG:R02820 Reactome:REACT_114284 Reactome:REACT_91048 Reactome:REACT_94458 Reactome:REACT_110163 Reactome:REACT_32005 GO:0004032 Reactome:REACT_32567 Reactome:REACT_112305 Reactome:REACT_31934 Reactome:REACT_105330 Reactome:REACT_107111 Reactome:REACT_9986 alcohol dehydrogenase (NADP+) activity