title: Enzymatic synthesis of amoxicillin via a one-pot enzymatic hydrolysis and condensation cascade process in the presence of organic co-solvents.
abstract: A cascade reaction combining the enzymatic hydrolysis of Penicillin G potassium salt (PGK) with the kinetically controlled enzymatic coupling of in situ formed 6-aminopenicillanic acid (6-APA) with p-hydroxyphenylglycine methyl ester (D-HPGM) to give amoxicillin as the final product by using a single enzyme has been demonstrated successfully. Ethylene glycol (EG) was employed as a component of reaction buffer to improve the synthesis yield. Reaction parameters, including different cosolvents, EG content, the loading of immobilized penicillin G acylase (IPA), and reaction temperature and time were studied to evaluate their effects on the reaction. The best result of 55.2% yield was obtained from the reaction which was carried out in the mixed media containing 40% sodium dihydrogen phosphate buffer (apparent pH 6.0) and 60% EG (v/v), with the initial concentration 150 mM and 450 mM of PGK and D-HPGM, respectively, catalyzed by 50 IU/mL IPA at 25 degrees C for 10 h. The IPA could be recycled for nine batches without obviously losing of catalytic activity. The important strategy will have potential application in the beta-lactam antibiotics industry due to the advantages of saving the effort of isolating 6-APA, reducing usual enzymatic steps and the industrial cost of amoxicillin synthesis.
authors: Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors: Qi
authors: Q
authors: Wu
authors: Chun-Xiu
authors: CX
authors: Chen
authors: Li-Li
authors: LL
authors: Du
authors: Xian-Fu
authors: XF
authors: Lin
mesh_terms: D000658:Amoxicillin / Q000138:chemical synthesis* / Q000737:chemistry; D055162:Biocatalysis; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D019855:Ethylene Glycol / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D006868:Hydrolysis; D010399:Penicillin Amidase / Q000737:chemistry* / Q000378:metabolism; D010400:Penicillin G / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D010756:Phosphoric Acids; D012997:Solvents; C473951:p-hydroxyphenylglycine methyl ester; D000658:Amoxicillin; C030242:phosphoric acid; D010399:Penicillin Amidase; D019855:Ethylene Glycol; D010400:Penicillin G; D005998:Glycine