Methyl penicillin

Chemical Name Q-Carboxy-Q-(3-thienyl)methyl penicillin disodium salt Common Neme —... 

I Brand Name(s) PenicillinV (Phenoxy-methyl Penicillin), DeepenVK, Pen-V, Pen-Vee K, Truxcillin VK, Veetids... 

Cleavage of penieiUins Reaction of a methyl penicillinate 1-oxide (1) with a carboxylic acid and trimethyl phosphite in benzene or benzene-THF gives an azetidinone (2) in 65-86% yield. The reaction involves replacement of sulfur with an acyloxy group with inversion at C4. The 6-epimer (3) of 1 under the same conditions gives two epimeric azetidinones, 4 and 5. 

Poet and Keeler 81 extracted phenoxy-methyl penicillin from formulations and distinguished the drug from ampicillin, penicillin G and dicloxacillin by infrared. Bands at 6.7 and 9.45 (j. are particularly useful for identifying penicillin V (acid). 

Many penicillins, including penicillin V, are metabolized in the human body to other active compounds. Rolinson and Batchelor 140 administered the drugs orally or by intramuscular injection and evaluated both blood and urine samples by paper chromatography. Active metabolites were detected by bioautographic plates. Vanderhaeghe, Parmentier and Evrard 141 identified the major metabolite of penicillin V as p-hydroxyphenoxy-methyl penicillin. It represented about 10% of the microbiological activity in the urine. A small amount of o-hydroxyphenoxymethyl penicillin was also observed while in the urine of some patients another metabolite was detected. They speculated this might be the dihydroxy derivative. 

In 1948, Brotzu reported on the biological activity of a crude extract from a Cephalosporium sp. that subsequently led to the identification in the late 1950s of another -lactam series, the basis for which was cephalosporin C (19a). Very soon after the identification of this molecule, workers at Lilly were able to convert methyl penicillin V via its sulphoxide into a cephalosporin. Further work then led to... 

Discuss the synthesis of phenoxy methyl penicillin from tert- 3uty -a ] a-phthalimidom-alonalhydate and D-penicillamine. 

On the other hand methyl penicillinate which lacks the side-chain was readily transformed into the corresponding azetidine 110 diborane reduction gave 109 which cyclised under acidic conditions with diethyl diazodicarboxylate and triphenylphosphine [66] (Scheme 36). The carboxylate 111 is a very weak p-lactamase inhibitor. 

Solvent Benzyl-penicillin methyl ether Phenoxy-methyl-penicillin methyl ether... 

Pruess and Johnson (274) partially purified an enzyme from P. chrysogenum which catalysed acyl-transfer from a number of P -S]-penicillins (penicillins V, G, K, X and dihydro-F) to 6-APA. The side-chains of penicillin N, methyl penicillin and phenylpenicillin were not transferred by this enzyme. The enzyme showed no penicillin amidase activity i. e. no 6-APA was generated when penicillin and enzyme were mixed in the absence of added 6-APA. Other compounds, such as esters of glycine, could act as acyl acceptors but not efficiently as 6-APA. 

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