Reactions of Hydroxybenzoates and Related Compounds

Hydroxybenzoates can nndergo hydroxylation with or withont concomitant loss of CO2. For example, salicylate — catechol + CO2 (salicylate-l-hydroxylase) (Fignre 3.9a) (White-Stevens et al. 1972) and 4-hydroxybenzoate — 1,4-dihydroxybenzene + CO2 [(4-hydroxy-benzoate 1-hydroxylase (decarboxylating)] in Candida parapsilosis (Fignre 3.9b) (Eppink etal. 1997). 

Hydroxylation withont elimination of CO2 is illnstrated in the following examples  

FIGURE 3.10 Monooxygenation of (a) salicylate, (b,c) 2-aminobenzoate, (d) 3-aminobenzoate, and (e) 2-hydroxyquinoline. 

Environmental Degradation and Transformation of Organic Chemicals OH HO2C. 

FIGURE 3.12 Biodegradation of 3,4-dihydroxybenzoate mediated by (a) 4,5-dioxygenase in Pseudomonas acidovorans and (b) 2,3-dioxygenase in Bacillus macerans. 

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