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2024-11-22 2:07

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Conference: Bucharest University Faculty of Physics 2018 Meeting

Section: Biophysics; Medical Physics

Title:

Spectral studies of quinazoline derivatives designed as EPI’s

Authors:

Andra DINACHE (1), Mihail-Lucian PASCU (1,2)

Affiliation:

1) National Institute for Laser, Plasma and Radiation Physics, Magurele, Romania

2) Faculty of Physics, University of Bucharest, Magurele, Romania

E-mail

andra.dinache@inflpr.ro

Keywords:

quinazoline derivatives, stability, FTIR spectroscopy, UV-Vis absorption spectroscopy

Abstract:

Several quinazoline derivatives were designed as efflux pump inhibitors (EPI’s), to increase the antibiotic susceptibility of multidrug resistant (MDR) bacteria. Among them, several compounds increased the activity of chloramphenicol against a panel of MDR Gram-negative isolates [1]. Spectral studies of two selected quinazoline derivatives, labeled BG1189 and BG1190, were performed to analyze their stability. The stability of new designed compounds is an important factor in approval for biomedical applications. Stability studies take into consideration factors like solvent, temperature, time, and illumination conditions. The concentration of studied solutions was 10-3 M, chosen in the interval tested for antimicrobial activity. FTIR spectra of BG1189 and BG1190 were recorded and vibrations of their functional groups were identified and compared to the theoretical ones calculated with Gaussian 09 simulation software. The stability of BG1189 and BG1190 in different solvents was studied by UV-Vis absorption. UV-Vis absorption spectra recorded immediately after the preparation of solutions and at different periods of time, were compared for analyzing the time stability of quinazoline derivatives in ultrapure de-ionized water; this is important for shelf life of medicines. Influence of temperature on stability of BG1189 and BG1190 solutions was studied considering three usual temperatures for medicines storage and applications: 4 °C (refrigerator), 22 °C (room) and 37 °C (human body). The photostability of quinazoline derivatives solutions was tested at different illumination conditions: a set of samples were kept in dark, one was exposed to ambient room light and other were exposed to a laser beam emitted as the fourth harmonic of a Nd:YAG laser fascicle (λ = 266 nm).The photostability studies are needed to determine the maximum radiation dose (ambient light or laser radiation) to which a compound can be exposed without modifying its initial properties.

References:

[1] Chevalier, J. et al., Quinazoline derivatives are efficient chemosensitizers of antibioticactivity in Enterobacter aerogenes, Klebsiella pneumoniae and Pseudomonas aeruginosa resistant strains, Int. J. Antimicrob. Agents, 36, 164-168 (2010)

Acknowledgement:

This work was supported by: Romanian National Authority for Scientific Research and Innovation, CNCS/CCCDI- UEFISCDI, project numbers PN-III-P2-2.1-PED-2016-0420 and MCI through Nucleu program PN 1813/2018.