Theoretical prediction: In mammals an aldehyde dehydrogenase oxidizes 3-nitrobenzaldehyde (1) to 3-nitrobenzoic acid (2). This metabolite can be excreted as a glycine conjugate (3) or as glucuronic acid ester (4). Also 3-nitrobenzaldehyde (1) can be metabolized by cytochrome P450 with hydroxylation of the aromatic ring and subsequent oxidation to the corresponding benzoic acid derivates (5). A possible reduction to the aromatic amine (3-aminobenzaldehyde (6)) which generates toxic intermediates is probably less important, but cannot be excluded totally.