TABLE 11.1 Common biotransformations and the corresponding elemental composition and
m
/z
changes.
Metabolic reactionDescriptionMolecular formulachangem
/zchangeR–CHC 2H 6! 5R–HDebenzylation–CH 7690.0468R
79
Br!RHReductive debromination–Br + H77.9104R–CF! 3R–HTrifluoromethyl loss–CF+H 367.98742R35
Cl!2R
H2reductive dechlorination–Cl+H 2267.9222R
79Br!ROHOxidative debromination–Br + OH61.9156R–C(CH) 3! 3R–HTert–butyl dealkylation–CH 4856.0624R–ONO! 2R–OHHydrolysis of nitrate ester–NO+H 244.9851R–COOH!R–HDecarboxylation–CO243.9898R–CH(CH) 3! 2R–HIsopropyl dealkylation–CH 3642.0468R–CHCOCH 2CH 2CH 23
!R–COOHPropyl ketone to acid–CH 4+O 840.0675R–C(CH) 3! 3R–OHTert-butyl to alcohol–CH 4+O 840.06752R–F!2R–H2reductive defluorination–F+H 2235.9811R
35Cl!RHReductive dechlorination–Cl + H33.9611R–CHOH 2!R–HHydroxymethylene loss–CHO 230.0106R–NO! 2R–NH2Nitro reduction–O+H 2229.9742R–CHOCH 2CH 2CH 2! 3R–COOHPropyl ether to acid–CH 3+O 828.0675R–CH 2! 5R–HDeethylation–CH 2428.0312R–CO–R0!R–R0Decarboxylation–CO27.9949R–CHCOCH 2CH 2! 3R–COOHEthyl ketone to acid–CH 3+O 626.0519R–CH(CH) 3! 2R–OHIsopropyl to alcohol–CH 3+O 626.0519R–CH–CH 2OH 2!R–CH = CH2Alcohols dehydration–HO 218.0105R–CH = N–OH!R–CNDehydration of oximes–HO 218.0105R–F!R–HReductive defluorination–F + H17.9906R
35Cl!ROHOxidative dechlorination–Cl + OH17.9662RR0 S=O!R–S–R0Sulfoxide to thioether–O15.9949R–NHNHR0 C=S!R–NHNHR0 C = OThioureas to ureas–S + O15.9772
(continued)
331