FarFaR - Pharmacy Repository
University of Belgrade, Faculty of Pharmacy
    • English
    • Српски
    • Српски (Serbia)
  • English 
    • English
    • Serbian (Cyrillic)
    • Serbian (Latin)
  • Login
View Item 
  •   FarFaR
  • Pharmacy
  • Radovi istraživača / Researchers’ publications
  • View Item
  •   FarFaR
  • Pharmacy
  • Radovi istraživača / Researchers’ publications
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position

Authorized Users Only
2005
Authors
Aleksić, Mara
Savić, Vladimir
Popović, Gordana
Burić, Nikola
Kapetanović, Vera
Article (Published version)
Metadata
Show full item record
Abstract
Ionization constants of three cephalosporin antibiotics, cefetamet (CEF), cefotaxime (CFX) and ceftriaxone (CFTR) are determined using pH-potentiometric titrations at I= 0.1 M (NaCl) and t = 25 degrees C. Cefetarnet and cefotaxime have three ionization groups: carboxylic, amide and aminothiazole. Besides those three, ceftriaxone possesses an hydroxytriazi none group as new and additional ionization center. In acid medium two overlapping acid-base processes are occuring with acidity constants being: pK(1) 2.93 (COOH) and PK2 3.07 (amin nothiazole) for cefetamet, and pK(1) 2.21 (COOH) and pK(2) 3.15 (aminothiazole) for cefotaxime. In the case of ceftriaxone the situation is even more complicated, three overlapping processes coexist with pK(1) 2.37 (COOH), pK(2) 3.03 (aminothiazole) and pK(3) 4.21 (hydroxytriazinone). Protolysis of amide group is happening in the alkaline medium as completely separated process from those in acid medium. The acidity constants which correspond to amide grou...p are pK(3) 10.65 (CEF), pK(3) 10.87 (CFX) and pK(4) 10.74 (CFTR). The influence of the C3 substituent on the dissociation process of the neighboring ionization group, particularly carboxylic group, was considered. The differences in acidity of CEF, CFX and CFFR pK(1): 2.93, 2.21 and 2.37, respectively) are likely to be caused by the stereoelectronic properties of substituents in the P-position to the carboxylic group due to the combined inductive, hyperconjugative and resonance effects.

Keywords:
cephalosporins / cefetamet / ceftriaxone / cefotaxime / acidity constants / potentiometry
Source:
Journal of Pharmaceutical and Biomedical Analysis, 2005, 39, 3-4, 752-756
Publisher:
  • Elsevier Science BV, Amsterdam

DOI: 10.1016/j.jpba.2005.04.033

ISSN: 0731-7085

PubMed: 15967622

WoS: 000232209700057

Scopus: 2-s2.0-23944515541
[ Google Scholar ]
30
19
URI
https://farfar.pharmacy.bg.ac.rs/handle/123456789/616
Collections
  • Radovi istraživača / Researchers’ publications
Institution/Community
Pharmacy
TY  - JOUR
AU  - Aleksić, Mara
AU  - Savić, Vladimir
AU  - Popović, Gordana
AU  - Burić, Nikola
AU  - Kapetanović, Vera
PY  - 2005
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/616
AB  - Ionization constants of three cephalosporin antibiotics, cefetamet (CEF), cefotaxime (CFX) and ceftriaxone (CFTR) are determined using pH-potentiometric titrations at I= 0.1 M (NaCl) and t = 25 degrees C. Cefetarnet and cefotaxime have three ionization groups: carboxylic, amide and aminothiazole. Besides those three, ceftriaxone possesses an hydroxytriazi none group as new and additional ionization center. In acid medium two overlapping acid-base processes are occuring with acidity constants being: pK(1) 2.93 (COOH) and PK2 3.07 (amin nothiazole) for cefetamet, and pK(1) 2.21 (COOH) and pK(2) 3.15 (aminothiazole) for cefotaxime. In the case of ceftriaxone the situation is even more complicated, three overlapping processes coexist with pK(1) 2.37 (COOH), pK(2) 3.03 (aminothiazole) and pK(3) 4.21 (hydroxytriazinone). Protolysis of amide group is happening in the alkaline medium as completely separated process from those in acid medium. The acidity constants which correspond to amide group are pK(3) 10.65 (CEF), pK(3) 10.87 (CFX) and pK(4) 10.74 (CFTR). The influence of the C3 substituent on the dissociation process of the neighboring ionization group, particularly carboxylic group, was considered. The differences in acidity of CEF, CFX and CFFR pK(1): 2.93, 2.21 and 2.37, respectively) are likely to be caused by the stereoelectronic properties of substituents in the P-position to the carboxylic group due to the combined inductive, hyperconjugative and resonance effects.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position
VL  - 39
IS  - 3-4
SP  - 752
EP  - 756
DO  - 10.1016/j.jpba.2005.04.033
ER  - 
@article{
author = "Aleksić, Mara and Savić, Vladimir and Popović, Gordana and Burić, Nikola and Kapetanović, Vera",
year = "2005",
abstract = "Ionization constants of three cephalosporin antibiotics, cefetamet (CEF), cefotaxime (CFX) and ceftriaxone (CFTR) are determined using pH-potentiometric titrations at I= 0.1 M (NaCl) and t = 25 degrees C. Cefetarnet and cefotaxime have three ionization groups: carboxylic, amide and aminothiazole. Besides those three, ceftriaxone possesses an hydroxytriazi none group as new and additional ionization center. In acid medium two overlapping acid-base processes are occuring with acidity constants being: pK(1) 2.93 (COOH) and PK2 3.07 (amin nothiazole) for cefetamet, and pK(1) 2.21 (COOH) and pK(2) 3.15 (aminothiazole) for cefotaxime. In the case of ceftriaxone the situation is even more complicated, three overlapping processes coexist with pK(1) 2.37 (COOH), pK(2) 3.03 (aminothiazole) and pK(3) 4.21 (hydroxytriazinone). Protolysis of amide group is happening in the alkaline medium as completely separated process from those in acid medium. The acidity constants which correspond to amide group are pK(3) 10.65 (CEF), pK(3) 10.87 (CFX) and pK(4) 10.74 (CFTR). The influence of the C3 substituent on the dissociation process of the neighboring ionization group, particularly carboxylic group, was considered. The differences in acidity of CEF, CFX and CFFR pK(1): 2.93, 2.21 and 2.37, respectively) are likely to be caused by the stereoelectronic properties of substituents in the P-position to the carboxylic group due to the combined inductive, hyperconjugative and resonance effects.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position",
volume = "39",
number = "3-4",
pages = "752-756",
doi = "10.1016/j.jpba.2005.04.033"
}
Aleksić, M., Savić, V., Popović, G., Burić, N.,& Kapetanović, V.. (2005). Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 39(3-4), 752-756.
https://doi.org/10.1016/j.jpba.2005.04.033
Aleksić M, Savić V, Popović G, Burić N, Kapetanović V. Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position. in Journal of Pharmaceutical and Biomedical Analysis. 2005;39(3-4):752-756.
doi:10.1016/j.jpba.2005.04.033 .
Aleksić, Mara, Savić, Vladimir, Popović, Gordana, Burić, Nikola, Kapetanović, Vera, "Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position" in Journal of Pharmaceutical and Biomedical Analysis, 39, no. 3-4 (2005):752-756,
https://doi.org/10.1016/j.jpba.2005.04.033 . .

DSpace software copyright © 2002-2015  DuraSpace
About FarFaR - Pharmacy Repository | Send Feedback

OpenAIRERCUB
 

 

All of DSpaceCommunitiesAuthorsTitlesSubjectsThis institutionAuthorsTitlesSubjects

Statistics

View Usage Statistics

DSpace software copyright © 2002-2015  DuraSpace
About FarFaR - Pharmacy Repository | Send Feedback

OpenAIRERCUB