The protonation/deprotonation equilibrium of thymidine and azidothymidine studied by UV spectra and multivariate curve resolution

TRNKOVÁ, Libue and Jana TOPINKOVÁ. The protonation/deprotonation equilibrium of thymidine and azidothymidine studied by UV spectra and multivariate curve resolution. In sborník- XLVII Zjazd PTchem i SITPChem Wroclaw 2004. Wroclaw, Polsko,2004: Polskie Towarystwo Chemiczne, 2004, p. 1232.

Basic information

• Original name: The protonation/deprotonation equilibrium of thymidine and azidothymidine studied by UV spectra and multivariate curve resolution
• Name in Czech: Protonaní/deprotonaní rovnováhy thymidinu a azidothymidinu studované pomocí UV spektrometrie a chemometrie
• Authors: TRNKOVÁ, Libue (203 Czech Republic, guarantor) and Jana TOPINKOVÁ (203 Czech Republic).
• Edition: Wroclaw, Polsko,2004, sborník- XLVII Zjazd PTchem i SITPChem Wroclaw 2004, p. 1232-1232, 2004.
• Publisher: Polskie Towarystwo Chemiczne

Other information

• Original language: English
• Type of outcome: Proceedings paper
• Field of Study: 10403 Physical chemistry
• Country of publisher: Czech Republic
• Confidentiality degree: is not subject to a state or trade secret
• RIV identification code: RIV/00216224:14310/04:00011238
• Organization unit: Faculty of Science
• Keywords in English: Thymidine; Azidothymidine; UV spectra;Multivariate Curve Resolution
• Tags: azidothymidine, Multivariate Curve Resolution, Thymidine, UV spectra

Abstract

The aim of our work was to study of protonation/deprotonation equilibrium of AZT and AZU in aqueous solutions with different concentrations of NaCl by using UV spectra connected with chemometrics. Calibration and correct function of pH meter (electrode) was performed by acido-basic potenciometric titration (HCl and NaOH), of which parameters were calculated by means of GranLs method. Correct way how to determine ionization constants was verified using thymidine and uridine for which the pKa value was known. The absorption spectra were measured from 240 to 320 nm at temperature 25C and various ionic strength from 0.05M to 0.25M. The absorption maxima of thymidine and AZT are very close and have values of 267 and 266.5 nm for pH 8, respectively. The wavelength of maxima of uridine and AZU were identical 262nm, but the absorbance of AZU has hypochromical shift. Firstly, from non-smoothed spectra the system of matrices (É, A.U., pH) was made (Fig. a), that were the input data for Multivariate Curve Resolution (MCR, Matlab) [6,7]. The data were processed on a Pentium PC computer using software package MATLAB (version 6) from Mathworks Inc. (Natick, MA) routines codes are freely available at URL: www.ub.es/gesq/mcr/mcr.htm).

Abstract (in Czech)

Usilím naší práce bylo získat pK hodnoty u thymidinu a azidothymidinu z vodných roztoků změřených pomocí UV spektroskopie.K vyhodnocování spekter thymidinu a azidothymidinu bylo použito chemometrické metody; Multivariate Curve Resolution MCR.

Links

• GA203/02/0422, research and development project: Name: Nové směry v elektrochemii nukleových kyselin a jejich aplikace v chemii životního prostředí

Investor: Czech Science Foundation, New trends in electrochemistry of nucleic acids and their applications in enviromental chemistry

• IAA1163201, research and development project: Name: Využití adsorptivní přenosové a eliminační techniky pro elektrochemickou analýzu oligonukleotidů a nukleových kyselin

Investor: Academy of Sciences of the Czech Republic, Application of adsorptive transfer and elemination techniques in oligonucleotides and nucleic acids analysis.