Reaction catalyzed by thioredoxin glutathione reductase (1.8.1.B1), thioredoxin-disulfide reductase (1.8.1.9)

		+		NADPH	=			+		NADP+
	5,5'-dithiobis(2-nitrobenzoic acid)	+		NADPH	=		2-nitro-5-thiobenzoate	+		NADP+