Determination of 5-aminolevulinic acid (ALA) by HPLC method.

5-Aminolevulinic acid is at present most popular precursor of photosensitizer for photodynamic therapy and diagnostics. The effect of accumulation of PpIX induced by exogenous ALA is based on the avoidance of feedback control in the pathway of heme biosynthesis. For use ALA in medicine, development of analytical methods that will enable precise determination of content and purity is necessary. The ALA content is determined i. a. by titration with perchloric acid. Much greater problems are connected with purity determination by HPLC method. There are rather scarce literature data concerning purity determination of ALA by HPLC.

Selective hydrolysis of nucleotides to nucleosides and free bases.

The kinetics of the hydrolysis of 2'-deoxyadenosine-5'-monophosphoric acid (dAMP), 2'-deoxycytidine-5'-monophosphoric acid (dCMP), 2'-deoxyguanosine-5'-monophosphoric acid (dGMP) and tymidine-5'-monophosphoric acid (dTMP) was studied in the presence of Xanthomonas maltophilia [1]. The reaction products are nucleosides: 2'-deoxyadenosine (dA), 2'-deoxycytidine (dC), 2'-deoxyguanosine (dG) and tymidine (dT), respectively, or the respective free bases. Hydrolysis of dTMP and dGMP proceeded stepwise according to the sequence: nucleotide-->nucleoside-->free base, whereas no accumulation of the free base was observed during the hydrolysis of dAMP and dCMP.