N-Formylanthranilic acid

Amino-2-hydroxy[4- C]butyric acid (the corresponding aldehyde has been condensed with o-aminobenzaldehyde to give vasicine 4-hydroxy-[2- C]glutamic acid (found with vasicine in Linaria yw/garis ), N-methyl-anthranilic acid, and N-formylanthranilic acid have been tested as vasicine precursors in A. vasica, without success. 

Irradiation of both soluble and fibrous proteins with ultraviolet light leads to considerable destruction of cystine and aromatic acid residues, in particular tryptophan. However, apart from a small degree of conversion to formylkynurenine and/or kynurenine residues, all attempts to ascertain the nature of the tryptophan photoproducts have so far been unsuccessful (72, 63, 303, 304). Pirie and Dilley 304) have proposed that photo-oxidation of tryptophan to formylkynurenine is followed by splitting out of N-formylanthranilic acid (60). Rivett s... 

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