Salicylic acid, biodegradation

Hydroxyl groups, 9 390-391 in salicylic acid reactions, 22 4 biodegradability of compounds with, 25 826... 

In pond water, carbaryl degraded very rapidly to 1-naphthol. The latter degraded, presumably by Flavobacterium sp., into hydroxycinnamic acid, salicylic acid, and an unidentified compound (HSDB, 1989). Four d after carbaryl (30 mg/L and 300 ng/L) was added to Fall Creek water, >60% was mineralized to carbon dioxide. At pH 3, however, <10% was converted to carbon dioxide (Boethling and Alexander, 1979). Under these conditions, hydrolysis of carbaryl to 1-naphthol was rapid. The authors could not determine how much carbon dioxide was attributed to biodegradation of carbaryl and how much was due to the biodegradation of 1-naphthol (Boethling and Alexander, 1979). Hydrolysis half-lives of carbaryl in filtered and sterilized Hickory Hills (pH 6.7) and U.S. Department of Agriculture Number 1 pond water (pH 7.2) were 30 and 12 d, respectively (Wolfe et al., 1978). 

In a static-culture-flask screening test, naphthalene (5 and 10 mg/L) was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. After 7 d, 100% biodegradation with rapid adaptation was observed (Tabak et al, 1981). In freshwater sediments, naphthalene biodegraded to c/5-1,2-dihydroxy-1,2-dihydronaphthalene, 1-naphthol, salicylic acid, and catechol. 

It is more difficult to decide whether chelation plays any part in the activity of salicylic acid which is released in the biodegradation of aspirin and, especially in cases of abuse of this drug and in the therapy of rheumatic disease, may be present in appreciable quantities in the body. 

Wastewaters contaming aromatic organic compounds must be pre-treated be re they are discharged into conventional waste treatment systems. A variety of these compounds are reftactory, toxic and. inhibitory in nature. The purpose of the pretreatment is to remove or reduce these compounds to less toxic or more biodegradable mtermediate products which can be treated by conventional biological methods (6). Examples of organic compounds that are toxic in nature are resorcmol, vanillin and salicylic acid. 

Details are given of the preparation of new biodegradable polyurethanes containing azo-linked polymeric prodrugs of amino salicylic acid in the main chain. Polymers were characterised by FTIR and proton NMR. Hydrolysis measurements were carried out. The hydrolysis product was detected using UV spectroscopy. 30 refs. 

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