Faculty of Physics - University of Bucharest

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FACULTY OF PHYSICS

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2024-11-22 2:17

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Conference: Bucharest University Faculty of Physics 2013 Meeting

Section: Optics, Spectroscopy, Plasma and Lasers

Title:

Studies of the interaction of UV laser radiation whit non-antibiotics using optical and non-optical

Authors:

T. Alexandru (1,2), V. Nastasa(1), A. Staicu (1), E. Radu (3), A. Stoicu (1,4), M. L. Pascu (1,2)

Affiliation:

(1)National Institute for Laser, Plasma and Radiation Physics, Laser Department, 077125, Magurele, Romania

(2)Faculty of Physics, University of Bucharest, 077125, Magurele, Romania

(3)National Institute for Research & Development in Chemistry & Petrochemistry, 060021 Bucharest, Romania

(4)Faculty of Chemistry, University of Bucharest, 4-12 Regina Elisabeta Blv., Sector 3, 030018, Bucharest, Romania

E-mail

tatiana.alexandru@inflpr.ro

Keywords:

phenothiazines,FTIR spectra, chlorpromazine

Abstract:

Phenothiazines are compounds related to the thiazine-class of heterocyclic compounds and they are used in treating mental disorders and as a particular case, Chlorpromazine is used in the treatment of schizophrenia and mania. Exposed to the UV laser radiation they undergo different reactions, generating new photoproducts. The obtained mixture, containing the photoproducts, presents an increase antimicrobial activity against some Gram-positive and Gram-negative bacteria. Chlorpromazine Hydrochloride (dissolved in ultrapure water) having a concentration of 2 mg/mL was exposed to 266 nm laser beam, emitted by a YAG:Nd laser, for 1, 5, 15, 30, 60, 120 and 240 min. The compounds were analyzed using different optical and non-optical techniques: spectrophotometry measurements between 200-1500 nm, Thin Layer Chromatography (TLC), pH analysis, Fourier Transform Infrared Spectroscopy (FTIR) measurements and laser induced fluorescence (LIF) spectroscopy. The 2 mg/mL uniradiated CPZ showed in the UV-Vis absorption spectra four absorptions peaks: 254, 307, 1158 and 1411 nm. From these wavelengths only the 254 and 307 nm characterize the CPZ, the other two are related to the absorption of the water. In the same time after 15 min after irradiation , the second peak , at 307 nm, starts to disappear and is accompanied by the apparition of two other peaks at 503 and 540 nm.The Laser induced fluorescence spectra of 2 mg/mL CPZ show the presence of a peak at 500 nm and the intensity increased for exposure times up to 8-10 min, following which it starts decreasing. Analyzing the TLC plates it can be seen that by the end of the 240 min the “complete conversion” of CPZ resulted. Also the FTIR spectra confirm the presence of the compounds identified via TOF LC/MS. All the techniques presented above, were used for a better understanding of the processes and the photodegradation pathways that take place during the interaction of a 266 nm laser beam and Chlorpromazine. Acknowledgements: The authors from NILPRP acknowledge the financing of the research by Program LAPLAS 3, PN 09 39/2009 and CNCS – UEFISCDI by project number PN-II-ID-PCE-2011-3-0922 and PN-II-PT-PCCA-2011-3.1-1350. Authors would like also to acknowledge the COST BM1003 and the COST MP1106 networks.