Kinetics of the Hydrolysis of Cephalosporin C

Konecny, J.; Felber, Eugen; Gruner, J.

doi:10.7164/antibiotics.26.135

Cited by 73 publications

(33 citation statements)

References 6 publications

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“…11-15) and for a discussion of the relative stabilities. From the present results and previous discussions (8,9,16) of analytical methods for the cephalosporin stability tests, it appears that UV spectrophotometric and chemical methods such as iodometry and colorimetry are acceptable for good estimations of the &lactam opening rate of the starting cephalosporins. However, HPLC seems to be the most desirable analytical method.…”

Section: Resultsmentioning

confidence: 81%

“…This site is the ester group of the acetoxy side chain. In fact, acidic and alkaline degradations of cephalosporin C (8,21), cephalothin (12,22), and cephaloglycin (23) lead to the formation of the corresponding deacetyl derivatives and their lactones as the hydrolytic intermediates. However, except for cephalosporin C (81, no quantification of these hydrolytic reactions has appeared.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Comparative Stability of Cephalosporins in Aqueous Solution: Kinetics and Mechanisms of Degradation

Yamana¹,

Tsuji²

1976

Journal of Pharmaceutical Sciences

261

108

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Section: Resultsmentioning

confidence: 81%

Section: Resultsmentioning

confidence: 99%

Comparative Stability of Cephalosporins in Aqueous Solution: Kinetics and Mechanisms of Degradation

Yamana¹,

Tsuji²

1976

Journal of Pharmaceutical Sciences

261

108

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“…In the HPLC (Fig.3) of the hydrolysis products from ceftriaxone (lc), the peak of 2c overlapped with that of l c as its high polarity hindered separation; however, the 'H-NMR technique confirmed the presence of Zc by the s at 4.9 ppm (H-C (6)) and that at 6.97 pprn (H-C(5') of the thiazolyl group).…”

mentioning

confidence: 99%

HPLC and ¹H‐NMR Studies of Alkaline Hydrolysis of Some 7‐(Oxyiminoacyl)cephalosporins

Vilanova

Muñoz

Donoso

et al. 1993

Helvetica Chimica Acta

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Alkaline hydrolysis (pH 10.5) of the three 7-(oxyiminoacyl)cephalosporins la+ (cefuroxime, ceftazidime, and ceftriaxone) was studied at 37O using HPLC and 'H-NMR techniques. The 7-epicephalosporin 2, the 3-methylidene compound 3, and the 6-epimer 4 of the 3-methylidene compound 3 were identified for each cephalosporin as the major degradation products under the conditions used; ceftazidime (lb) yielded also the d2-isomer 5b (Scheme I ) . A kinetic scheme was developed to account for the production of these compounds, and the different kinetic constants involved in the process were calculated. The experimental results show that the presence of a pyridinio group at position C-C(3) favours the appearance of the A*-isomer, which was detected mainly in cephalosporins bearing an ester function at C(4). The presence of an oxyimino group at C-CONH-C(7) facilitates epimerization at C(7) (+ 2), whereas that of an electron-withdrawing group at C-C(3) results in a increased formation constant for the 3-methylidene compound 3. The 3-methylidene compounds 3a-c produced by the three cephalosporins on cleavage of the p-lactam ring all underwent epimerization at C(6) to yield the corresponding 6-epimer 4.1. introduction. -The first cephalosporin, cephalosporin C, was isolated over 40 years ago by Abraham and Newton from a Cephalosporium acremoniurn culture from Sardinia [l]. By introducing appropriate substituents at position 7 of the original compound, a number of substances -the first of which was cephalothin-were obtained that improved on the antibacterial potency of the parent compound. However, the new cephalosporins were scarcely resistant to p-lactamases which are enzymes produced by bacteria that hydrolyse the p-lactam ring. This problem was solved in two ways, viz. by isolating cephamycins (cephalosporins with an tl -oriented M e 0 group at C(7)) and by synthesizing 7-(oxyiminoacyl)cephalosporins. Both groups of substances are highly resistant to most p-lactamases [2].The alkaline hydrolysis of cephalosporins was found to resemble the enzymatic acylation involved in transpeptidation at the bacterial cell wall [3]. Such a similarity has fostered studies on the reactions of the P-lactam ring in basic media aimed at determining a potential relationship between the ring cleavage and antibacterial activity [4-131. Many of such studies involved UV spectroscopy, although HPLC and 'H-NMR spectroscopy have proved to be more effective, since the former provides information on the number of hydrolysis products and the latter supplies valuable evidence of their structures.

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“…8,9 However, in aqueous solution under certain condition, the CS degree of degradation is very low, and still be able to meet the clinical needs of the administration. But, not everyone knows that and there are no literatures on the stability of CS currently.…”

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confidence: 99%

A New Kinetic Approach. Stability of Cefquinome Sulfate under Variable pH and Temperature

Liu¹,

Fu²,

Fu³

et al. 2014

IJPER

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Object: This study was evaluation of Cefquinome Sulfate (CS) long-term stability under different conditions of pH and temperature, so as to suggest the best conditions to perform its clinical application. Method: The CS stability was investigated at different values of pH (2.0-9.0) and temperature (4-37 0 C). Kinetic parameters of CS degradation in alkaline environment were calculated adopting a new model that took into consideration the equilibrium between the active and a reversibly inactivated form of CS after long-time degradation. Result: All temperatures show increased CS instability,and this effect decreased in following sequence: 37

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Kinetics of the Hydrolysis of Cephalosporin C

Cited by 73 publications

References 6 publications

Comparative Stability of Cephalosporins in Aqueous Solution: Kinetics and Mechanisms of Degradation

Comparative Stability of Cephalosporins in Aqueous Solution: Kinetics and Mechanisms of Degradation

HPLC and ¹H‐NMR Studies of Alkaline Hydrolysis of Some 7‐(Oxyiminoacyl)cephalosporins

A New Kinetic Approach. Stability of Cefquinome Sulfate under Variable pH and Temperature

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Kinetics of the Hydrolysis of Cephalosporin C

Cited by 73 publications

References 6 publications

Comparative Stability of Cephalosporins in Aqueous Solution: Kinetics and Mechanisms of Degradation

Comparative Stability of Cephalosporins in Aqueous Solution: Kinetics and Mechanisms of Degradation

HPLC and 1H‐NMR Studies of Alkaline Hydrolysis of Some 7‐(Oxyiminoacyl)cephalosporins

A New Kinetic Approach. Stability of Cefquinome Sulfate under Variable pH and Temperature

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HPLC and ¹H‐NMR Studies of Alkaline Hydrolysis of Some 7‐(Oxyiminoacyl)cephalosporins