Aldo/keto reductase with broad substrate spectrum. Catalyzes the NADPH-dependent reduction of aldehyde- and ketone-groups of different classes of carbonyl compounds to the corresponding alcohols. Highest enzymatic efficiency is observed with 4-oxonon-2-enal (4-ONE) and 4-hydroxynon-2-enal (4-HNE), that are lipid peroxidation products, and 9,10-phenanthrenequinone (9,10-PQ), a photoproduct of phenanthrene that is one of the most prevalent polycyclic aromatic hydrocarbons in the environment. Is also active on sugar-derived reactive carbonyls such as methylglyoxal (MG), glyoxal and 3-deoxyglucosone (3-DG), and on other lipid-derived carbonyls such as acrolein. May be involved in the detoxification of the toxic lipid peroxidation products 4-ONE and 4-HNE besides many other exo- and endogenic reactive carbonyl compounds (RCs) that may lead to photoinhibition or other cell damages. a secondary alcohol + NADP(+) = a ketone + H(+) + NADPH Curcumin non-competitively inhibits the enzyme with respect to furfural. To a lesser extent, enzyme activity is also inhibited by indomethacin, coumarate, coumarin, and alrestatin. kcat is 351 min(-1) with methylglyoxal as substrate. kcat is 1049 min(-1) with glyoxal as substrate. kcat is 226 min(-1) with 3-deoxyglucosone as substrate. kcat is 1078 min(-1) with acrolein as substrate. kcat is 1.75 sec(-1) with hexanal as substrate. kcat is 1.17 sec(-1) with 4-pyridinecarboxaldehyde as substrate. kcat is 0.3 sec(-1) with 4-nitrobenzaldehyde as substrate. kcat is 2.23 sec(-1) with 9,10-phenanthrenequinone as substrate. kcat is 4.06 sec(-1) with 2,3-pentanedione as substrate. kcat is 2.63 sec(-1) with 4-oxonon-2-enal as substrate. kcat is 1.57 sec(-1) with 4-hydroxynon-2-enal as substrate. kcat is 8.52 sec(-1) with furfural as substrate. Optimum pH is 5 for the reduction of methylglyoxal. Optimum temperature is 60 degrees Celsius for the reduction of methylglyoxal. Monomer. Belongs to the aldo/keto reductase family.