漆酶转化对氨基苯胂酸的研究

为全面了解对氨基苯胂酸(ARS)在环境中的归趋,研究了ARS在漆酶与邻苯二酚或丁香酸两种腐植酸模型化合物共同存在时的转化过程及产物鉴定。结果发现在漆酶-ARS单一体系中,漆酶并不能降解ARS;当体系中加入邻苯二酚或者丁香酸时,ARS的降解效果显著,且漆酶-邻苯二酚体系中ARS的转化更加彻底。在反应过程中,邻苯二酚和丁香酸首先在漆酶的作用下氧化成为1,2-醌和1,4-醌,然后分别和ARS发生亲核加成反应,形成聚合物,产物中均没有发现砷酸基团的脱落,始终以有机胂形态存在。

Transformation of p-arsanilic acid by laccase catalyzed oxidation process

p- Arsanilic acid(ARS), a veterinary feed additive promoting growth, may contaminate the environment. In the present study, transformation of ARS by laccase catalyzed oxidation process was investigated in the presence of catechol and syringic acid as representative humic constituents. Laccase alone could not decompose ARS. However, the presence of catechol or syringic acid facilitated ARS transfor-mation. Fourier transform infred spectra(FTIR)and mass spectra(MS)analysis revealed that ARS was degraded via the formation of cova-lent bonds with quinone intermediates upon oxidation of catechol and syringic acid by laccase. In general, the reaction was a nucleophilic addition process with the aniline N acting as necleophile attacking the α-carbon of the carbonyl group in the quinone molecules. The pre-sent findings suggest a transformation pathway of ARS in environment in addition to biodegradation and photolysis.