Naslov
STRUCTURAL CHARACTERIZATION OF AZITHROMYCIN BY ESI-MSn AND H/D EXCHANGE

Autori
Gembarovski, Dubravka ; Gabelica Marković, Vesna ; Galić, Nives

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts / Matković-Čalogović, Dubravka - Zagreb, 2010

Skup
10th International Symposium and Summer School on Bioanalysis

Mjesto i datum
Zagreb, Hrvatska, 07.07.2010. - 14.07.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
mass spectrometry; H/D exchange; azithromycin

Sažetak
Macrolides are a group of antibiotics that have been widely used in human medical and veterinary practices. Analysis of macrolides and related compounds in food, biological, and environmental matrices continue to be the focus of scientists for the reasons of food safety, pharmacokinetic studies, and environmental concerns. Azithromycin is a semi-synthetic macrolide antibiotic derived from erythromycin A (EA). It consists of a 15-membered macrocyclic lactone ring onto which two sugar moieties are linked. An aminosugar, D-desosamine, is attached through a ß-glycosidic bond to the C5 position of the lactone ring. A neutral sugar, L-cladinose, is attached via a α-glycosidic linkage to the C3 position of the lactone ring. Azithromycin exhibits a more extensive spectrum of activity, greater acid stability and more favorable pharmacokinetic parameters than erythromycin. , It is an effective antibiotic for the treatment of sexually transmitted diseases, upper and lower respiratory tract infections, and skin structure infections. In the last two decades, mass spectrometry has become increasingly popular for a large variety of applications. ESI-MS recently emerged as a leading technology in drug discovery for structural confirmation or identification of newly synthesized compounds. In order to get a better insight into behavior of macrolides under ESI-MS conditions, a detailed fragmentation study of azithromycin was performed on ion trap and Q-ToF mass analyzers. Based on MSn data of protonated molecular ion [M+H]+ at m/z 749, as well as MSn data of deuterated molecular ion [MD+D]+ at m/z 755, a fragmentation pathway of azithromycin was proposed. In addition, a fragmentations of alkali metal adducts, e.g. [M+Na]+ and [M+K]+ were also performed, since a compounds such as a macromolecules can undergo a different fragmentation routes under the influence of alkali-metal interactions with aglycone ring. The influence of collision energy on in-source fragmentation was also examined and break-down curves were calculated. Additionally, the influence of solvents used during the analysis (CH3OH and CH3CN) will be discussed since the chosen solvent has the impact on the intensities of [M+H]+, [M+2H]2+ and [M+Na]+ signals in MS spectrum. We believe that this comprehensive study of fragmentation of azithromycin will be very useful in characterization of newly synthesized azithromycin derivatives, related compounds and metabolites, but also in analyzing residual amounts of azithromycin in different matrices, such as food, water and sewage plants.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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