Oxidation of pharmaceutically active compounds by a ligninolytic fungal peroxidase

Abstract

Pharmaceuticals are an important group of emerging pollutants with increasing interest due to their rising consumption and the evidence for ecotoxicological effects associated to trace amounts in aquatic environments. In this paper, we assessed the potential degradation of a series of pharmaceuticals: antibiotics (sulfamethoxazole), antidepressives (citalopram hydrobromide and fluoxetine hydrochloride), antiepileptics (carbamazepine), anti-inflammatory drugs (diclofenac and naproxen) and estrogen hormones (estrone, 17β-estradiol, 17α-ethinylestradiol) by means of a versatile peroxidase (VP) from the ligninolytic fungus Bjerkandera adusta. The effects of the reaction conditions: VP activity, organic acid concentration and H(2)O(2) addition rate, on the kinetics of the VP based oxidation system were evaluated. Diclofenac and estrogens were completely degraded after only 5-25 min even with a very low VP activity (10 U l(-1)). High degradation percentages (80%) were achieved for sulfamethoxazole and naproxen. Low or undetectable removal yields were observed for citalopram (up to 18%), fluoxetine (lower than 10%) and carbamazepine (not degraded).

Biodegradation of sulfamethoxazole: current knowledge and perspectives

“…The results demonstrated that 64 to 80 % of the initial SMX (2.5 mg/L) was degraded after 7 h. In addition, experiments conducted at a higher SMX concentration (25 mg/L) resulted in the detection of a metabolite identified and confirmed using an authentic standard as 3-amino-5-methylisoxazole (Eibes et al 2011).…”

Biodegradation of sulfamethoxazole and other sulfonamides by Achromobacter denitrificans PR1

“…[21][22][23]. Also a versatile peroxidase from the ligninolytic fungus Bjerkandera adusta showed SMX breakdown activity [32]. The accumulation of 3A5MI, resultant of aerobic SMX degradation, seems to be common, being observed also in Microbacterium sp.…”

“…The accumulation of 3A5MI, resultant of aerobic SMX degradation, seems to be common, being observed also in Microbacterium sp. BR1 [28], activated sludge [18] or produced by the above mentioned per-oxidase [32]. Nevertheless, different reaction mechanisms may be involved on SMX breakdown with accumulation of this metabolite.…”

Enzyme Initiated Radical Polymerizations

“…Phenothiazenes, for example, have been used to initiate the polymerization of sterically demanding phenols, [32,33] or ABTS to facilitate pyrrole polymerization [34,35]. Also transition metals (e.g., Mn 2+/3+ ) [36] or polyoxometallates [37] have been reported. Second, the mediator radical itself can initiate chain growth thereby being incorporated into the polymer (see Section 2.4).…”

“…Likewise halophenols [178][179][180][181][182] bisphenol A, [183][184][185] various hormones and so-called endocrine disrupting compounds [186][187][188] or even TNT [189,190] have been reported. Non-phenolic compounds may be ‗inactivated' using the LMS or PMS strategy [36,[191][192][193][194][195][196][197][198].…”