Kinetic Analysis of Penicillin Degradation in Acidic Media

Determination of penicillin G and its degradation products in a penicillin production wastewater treatment plant and the receiving river

“…Compared with its degradation products, such a low concentration of PEN G in raw wastewater indicated that before entering the WWTP, most of the PEN G had undergone chemical degradation processes at 75 1C and a pH of 3.970.3 during solvent recovery (Table S1). Penilloic acid, which was reported to be easily transformed from penicilloic acid under acidic conditions (Clarke et al, 1949), was found to be the dominant compound, with the molar concentration (1263732 mmol/L) accounting for 70.7% of the total molar concentration in raw wastewater, and this result was in accordance with that obtained by Blaha et al (1976) in which penilloic acid was also the main a Raw wastewater, the effluent of the WWTP and river water taken from R2 were kept at 4 1C in the dark in the laboratory for 2 days to determine the degradations of the analytes during storage. PEN G had been only spiked to the river water sample at 20 mg/L because of its low concentration in river samples.…”

“…Additionally, it was reported that penicilloaldehyde could be formed from penilloic acid as the end hydrolytic degradation product of PEN G (Hou and Poole, 1971;Blaha et al, 1976), and this was partly supported by the fact that penicilloaldehyde was the second most abundant product in raw wastewater, with the molar concentration (42573 mmol/L) accounting for more than 23% of the total molar concentration. On the other hand, the existence of penillic acid in raw wastewater, whose molar concentration (70.476.0 mmol/L) ranged up to 3.94% of the total concentration of all the analytes, was also in accordance with the report that a low percent of PEN G would also convert to penillic acid as the other degradation pathway of PEN G in acidic media simultaneously with the transformation to penilloic acid (Blaha et al, 1976). During the treatment of wastewater, it should be noted that the load of isopenillic acid increased significantly by 46.676.1% during the anaerobic treatment process as shown in Table 3.…”

“…However, in most surveys until (Hirsch et al, 1999;Sacher et al, 2001), mainly due to the chemically unstable b-lactam ring, which is highly sensitive to pH, heat and b-lactamase enzymes (Clarke et al, 1949;Hou and Poole, 1971;Bush et al, 1995). Laboratory experiments have shown that with the opening of the b-lactam ring through an intermediate of penicillenic acid in weak acidic or neutral solutions (Blaha et al, 1976), PEN G quickly transforms to penicilloic acid, which is also the degradation product of PEN G in alkaline media (Clarke et al, 1949) and can easily convert to penilloic acid under acidic conditions (Clarke et al, 1949;Blaha et al, 1976), or penillic acid, which could be formed from PEN G in strong acid and convert to isopenillic acid in alkaline media (Clarke et al, 1949), depending on the pH of the solutions. The end hydrolytic degradation products of PEN G are reported to be penicilloaldehyde and penicillamine (Hou and Poole, 1971;Blaha et al, 1976).…”

“…Laboratory experiments have shown that with the opening of the b-lactam ring through an intermediate of penicillenic acid in weak acidic or neutral solutions (Blaha et al, 1976), PEN G quickly transforms to penicilloic acid, which is also the degradation product of PEN G in alkaline media (Clarke et al, 1949) and can easily convert to penilloic acid under acidic conditions (Clarke et al, 1949;Blaha et al, 1976), or penillic acid, which could be formed from PEN G in strong acid and convert to isopenillic acid in alkaline media (Clarke et al, 1949), depending on the pH of the solutions. The end hydrolytic degradation products of PEN G are reported to be penicilloaldehyde and penicillamine (Hou and Poole, 1971;Blaha et al, 1976). Besides the chemical degradation process, b-lactamase enzymes released from resistant bacteria can also transform PEN G to penicilloic acid by opening the b-lactam ring (Bush et al, 1995), and some products like penicilloic acid have been detected in human bodies as the metabolites of PEN G after taking medicine (Pcole et al, 1973).…”

“…Besides the chemical degradation process, b-lactamase enzymes released from resistant bacteria can also transform PEN G to penicilloic acid by opening the b-lactam ring (Bush et al, 1995), and some products like penicilloic acid have been detected in human bodies as the metabolites of PEN G after taking medicine (Pcole et al, 1973). These PEN G degradation products have not been detected in the environment until now, and most of theirantibiotic abilities have been lost as the b-lactam ring is opened (Hou and Poole, 1971); however, it has been reported that penicillin allergic reactions in 3-5% of patients are linked with these compounds to some extent (Blaha et al, 1976), with their environmental influence still unknown.…”