Phenoxymethylpenicillin

The most commonly prescribed penicillins are phenoxymethylpenicillin, ampicillin, and penicillin G. 

Certain factors and product precursors are occasionally added to various fermentation media to iacrease product formation rates, the amount of product formed, or the type of product formed. Examples iaclude the addition of cobalt salts ia the vitamin fermentation, and phenylacetic acid and phenoxyacetic acid for the penicillin G (hen ylpenicillin) and penicillin V (phenoxymethylpenicillin) fermentations, respectively. Biotin is often added to the citric acid fermentation to enhance productivity and the addition of P-ionone vastly iacreases beta-carotene fermentation yields. Also, iaducers play an important role ia some enzyme production fermentations, and specific metaboHc inhibitors often block certain enzymatic steps that result in product accumulation. 

Potassium salt of benzyl and phenoxymethylpenicillin. Peed grade. ... 

The only penicillins used in their natural form are benzylpenicillin (penicillin G) and phenoxymethylpenicillin (penicillin V). The remainder of penicillins in clinical use are derived from 6-APA and most penicillins having useful biological properties have resulted from acylation of 6-APA using standard procedures. 

The acylation of 6-APA (Scheme 59) has been a very versatile way in which to generate new penicillin derivatives which differ from fermentation-produced penicillins in the 6-side chain. As will be discussed in Section 5.11.5.1, this approach has led to significant improvements in the therapeutic properties of penicillins, and, in fact, of the penicillins in medical use today, only benzylpenicillin and phenoxymethylpenicillin are produced directly by fermentation. 

Scheme 68 shows the conversion of the phenoxymethylpenicillin-derived disulfide (see Scheme 10) to penem derivative (91) (78JA8214). Of particular interest in this sequence is the reductive acylation step to afford (89) and the Wittig ring closure to give (90). The rate of the latter reaction was found to be greatly infiuenced by the steric and electronic character of both the thiol ester and the carboxyl blocking group. 

Following the realization that the presence of phenylacetic acid in the fermentation led to a simplification of the mixture of penicillins produced by the fungus due to preferential uptake of this acid and its incorporation into benzylpenicillin (4), a wide variety of other acids were added to the growing culture. Inclusion of the appropriate acids in the culture medium thus afforded, respectively, phenoxymethylpenicillin (5, penicillin V), phenethicillin propicillin (7), and phehbencillin... 

Conceptually closely related, cefroxadi ne (40) can be prepared by several routes, including one in which the enol (33) is imethylated with diazomethane as a key step. A rather more involved route starts with comparatively readily available phenoxymethylpenicillin sulfoxide benzhydryl ester (36). This undergoes fragmentation when treated with benzothiazole-2-thiol to give Ozonolysis (reductive work-up) cleaves the... 

Common Name 6-phenoxyacetamidopenicillanic acid phenoxymethylpenicillin Structural Formula ... 

Approximately 1,000 g of phenoxymethylpenicillin acid (Penicillin V) is dissolved directly in about 5 liters of ethyl acetate to a concentration of 20% w/v. The resulting solution Is fil-... 

Benzyl- and Phenoxymethylpenicillins, Ampidllin, Carbenicillin Cephalosporin C Cephaloglycine, Cephaloridine, Cephalothin Hydrolysis Corresponding p-lactam ring cleavage products Escherichia coli Streptomyces aibus Pseudomonas aeruginosa Enterobacter cloacae Streptomyces sp. 

No single product can exemplify all the important features of antibiotie manufaeture. Benzylpenicillin is a /Mactam. Brief aeeounts are given of the manufaeture of two other /3-lactams, penicillin V (phenoxymethylpenicillin) and cephalosporin C, to illustrate further key points. 

The same test conditions used for the pure drug powder can now be used to compare formulations. The dissolution characteristics of potassium phenoxymethylpenicillin and several IR formulations of this drug that are available on the German market were compared, along with the dissolution of the pure drug powder (Fig. 2) at both low and almost neutral pH. The results show that dissolution is formulation-dependent. For the formulations tested, dissolution from some was virtually... 

In addition to potassium phenoxymethylpenicillin (aqueous solubility >10 mg/mL except at low pH), which just fails to meet the BCS criteria for highly soluble at higher doses, there are numerous other examples of compounds which are unable to meet the criteria at low pH but which fall well within the required D S range at typical pH in the small intestine. Notable examples include ibuprofen and indomethacin,... 

Penicillinacylase is used industrially to catalyze the hydrolytic removal of the side chain in naturally occurring penicillins such as benzylpenicillin (4.49) and phenoxymethylpenicillin (4.50). The nucleus 6-aminopenicillic acid (4.48) is then used as the starting material for the preparation of semisynthetic penicillins. Appropriate acylation of the 6-NH2 group leads to )3-lactamase-stable and broad-spectrum penicillins. 

Dolezalova, M., Capova, H., and Jobanek, R. (2003). Determination of the purity of phenoxymethylpenicillin by micellar electrokinetic chromatography and reversed phase liquid chromatography on a monolithic silica column.. Sep. Sci. 26, 701—708. 

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