4340-44-7

Upstream product

• 1173-88-2 Bristopen 
• 66-79-5 oxacillin 
• 1136-45-4 5-methyl-3-phenylisoxazol-4-carboxylic acid 
• 16883-16-2 5-methyl-3-phenylisoxazole-4-carbonyl chloride 

Downstream Products

• 24400-67-7 5-methyl-3-phenylisoxazole-4-carbonitrile 
• 21169-65-3 5-methyl-3-phenyl-1,2-oxazole-4-amine 
• 21169-67-5 [4-(5-methyl-3-phenyl-isoxazol-4-ylsulfamoyl)-phenyl]-carbamic acid methyl ester 
• 21169-62-0 4-amino-N-(5-methyl-3-phenyl-isoxazol-4-yl)-benzenesulfonamide 
• 24380-48-1 3-phenyl-5-styrylisoxazole-4-carbonitrile 
• 21169-66-4 N-(5-methyl-3-phenyl-isoxazol-4-yl)-acetamide 

Relevant academic research and scientific papers

TiO2 photocatalysis applied to the degradation and antimicrobial activity removal of oxacillin: Evaluation of matrix components, experimental parameters, degradation pathways and identification of organics by-products

The TiO2 photocatalytic degradation of oxacillin (OXA) in synthetic and natural waters was studied. The matrix effects, in terms of antibiotic and antimicrobial activity removal, were evaluated in the presence of iron ions, natural mineral water and additives contained in commercial formulations of the antibiotic. A slight improvement in degradation was observed in the presence of iron ions. On the other hand, the presence of excipients in a commercial formulation or inorganic ions in natural mineral water slightly inhibited the efficiency of the system. An experimental design using pH, catalyst load and light intensity as variables was also evaluated. The best performances were achieved at natural pH (～6.0) using 2.0 g L-1 of TiO2 with 150 W of applied power. The evaluation of OXA concentration indicated that the photodegradation process showed a Langmiur-Hinshewoold kinetic model. The extent of the process was evaluated following the evolution of chemical oxygen demand (COD) and dissolved organic carbon (DOC). Total removal of both, the antibiotic and its antimicrobial activity, was achieved after 120 min; while 100% of mineralization was observed within 480 min of treatment. Finally, five by-products were identified, the degradation routes were elucidated and a schema of the antibiotic degradation was proposed.

High frequency ultrasound as a selective advanced oxidation process to remove penicillinic antibiotics and eliminate its antimicrobial activity from water

This work studies the sonochemical degradation of a penicillinic antibiotic (oxacillin) in simulated pharmaceutical wastewater. High frequency ultrasound was applied to water containing the antibiotic combined with mannitol or calcium carbonate. In the presence of additives, oxacillin was efficiently removed through sonochemical action. For comparative purposes, the photo-Fenton, TiO2 photocatalysis and electrochemical oxidation processes were also tested. Therefore, the evolution of the antibiotic and its associated antimicrobial activity (AA) were monitored. A high inhibition was found for the other three oxidation processes in the elimination of the antimicrobial activity caused by the additives; while for the ultrasonic treatment, a negligible effect was observed. The sonochemical process was able to completely degrade the antibiotic, generating solutions without AA. In fact, the elimination of antimicrobial activity showed an excellent performance adjusted to exponential kinetic-type decay. The main sonogenerated organic by-products were determined by means of HPLC-MS. Four intermediaries were identified and they have modified the penicillinic structure, which is the moiety responsible for the antimicrobial activity. Additionally, the possible oxacillin sonodegradation mechanism was proposed based on the evolution of the by-products and their chemical structure. Furthermore, the high-frequency ultrasound action over 120 min readily removed oxacillin and eliminated its antimicrobial activity. However, the pollutant was not mineralized even after a long period of ultrasonic irradiation (360 min). Interestingly, the previously sonicated water containing oxacillin and both additives was completely mineralized using non-adapted microorganisms from a municipal wastewater treatment plant. These results show that the sonochemical treatment transformed the initial pollutant into substances that are biotreatable with a typical aerobic biological system.

Identification of a series of highly potent activators of the Nurr1 signaling pathway

The nuclear receptor Nurr1 (NR4A2) is critically involved in the development and maintenance of midbrain dopaminergic neurons and is believed to function independently of endogenous activation. The hit identification and SAR studies leading to isoxazolo-pyridinone 7e, a highly potent, brain penetrable activator of the Nurr1 signaling pathway, are described.