Penilloic acid

Degradation. Penicillins are rapidly hydroly2ed by aqueous alkaU to the corresponding peniciEoic acids (30) which are stable as salts, but which decarboxylate on acidification to yield penilloic acids (31). 

Penicillin V—see Penicillin, phenoxymethyl-, 7, 300 Penicilloate, benzyl-, 7, 303 Penicilloate, D-a-benzyl-a-methyl ester, 7, 303 Penillamine, benzyl-, 7, 303 Penillic acid, benzyl-, 7, 303 Penilloaldehyde, benzyl-, 7, 303 Penilloic acid, benzyl-, 7, 303 Penillonic acid, benzyl-methyl ester, 7, 303 1,2,3,4,6-Pentaazaindene nomenclature, 1, 18 Pentadeca-5,10-dienols synthesis, 1, 428 Pentadienol, tetrachloro-2H-pyran synthesis from, 3, 740 Pentadienonitrile, 5-(l,2-benzoselenazol-3-yl)-X-ray diffraction, 6, 334 Penta-2,4-dienonitrile, 5-(dimethylamino)-2-(2-thienyl)-... 

Salts of penicilloic acid (III) are stable. However, on acidification, the resulting free penicilloic acids readily lose carbon dioxide to form the corresponding penilloic acid (IV). 

Drug stability studies (i) in aged solutions of potassium penicillin G Potassium penicillin G in the presence of five of its degradation products, DL-penicillamine, benzyl penilloic acid (two isomers), benzylpenamaldic acid, benzylpenicilloic acid and benzylpenillic acid Partition Bondapak AX/ Corasil pH 3.8 buffer... 

It has been observed that the hydrolysis of penicillin with dilute alkali or with the enzyme penicillinase) yields penicilloic acid (a diearboxylie acid), which readily eliminates a molecule of carbon dioxide to form penilloic acid, thereby suggesting that a carboxyl group is present in the P-position with regard to a negative group. 

It has been established experimentally that penilloic acid upon hydrolysis with aqueous mercuric chloride yields penicillamine and penilloaldehyde respectively. This type of hydrolysis is characteristic of compounds containing a thiazolidine ring, i.e.,... 

Hence, penilloic acid coidd be (I), because this particular structure would give the above required products. Thus... 

Therefore, if (I) is penilloic acid, then penicilloic acid would be (II)... 

Benzylpenicilloic acid, the main hydrolysis product of benzylpenicillin, elicits wheal and flare skin reactions in some patients and was considered to be one of the so-called minor (in a quantitative sense) determinants by Levine. Decarboxylation of penicilloic acid gives rise to penilloic acid, another of the minor determinants... 

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