... 20 04, accepted 18 June 20 04) Eur. J. Biochem. 271, 32 48 32 54 (20 04) Ó FEBS 20 04 doi:10.1111/j.1 43 2 -1 033 .20 04. 042 58.x6-semialdehyde as a substrate. Insights into the metabolicfate of 4- amino -3- hydroxybenzoic ... 100%), 43 6 (M+-CH 3 · 2, 0. 53% ), 42 1 (M+-CH 3 · 3, 0. 53% ), 37 7 [M+-OSi(CH 3 ) 3 , 0. 64% ], 36 3 [M+-Si(CH 3 ) 3 -CH 3 · 2, 4. 8%], 299 (M+-C6F5, 65.1%),195 ([C6F5N2]+, 8.7%), 147 ... {[(CH 3 )2¼O-OSi(CH 3 ) 3 ]+, 24 .3% }, 73 {[Si(CH 3 ) 3 ]+, 98 .4% }V: 2,5-pyridine-dicarboxylic acidb 31 1 (M+, 30 .6%), 296 (M+-CH 3 , 100%), 266 (M+-CH 3 · 3, 39 .3% ), 238 [M+-Si(CH 3 ) 3 ,...