PREPARATION OF CU(II) COMPLEXES OF OXIDIZED CHLOROPHYLLS AND THEIR DETERMINATION BY THIN-LAYER AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Different allomerization products of pheophytins a and b have been obt ained by alkaline treatment in the presence of atmospheric oxygen and isolated by normal phase thin-layer chromatography (NP-TLC) and semi-p reparative high-performance liquid chromatography (HPLC). 15(1)-hydrox y-15(1)-hydroxy-rhodochlorin-15-acetic acid delta-lactone-15(2)-methyl -17(3)-phytyl ester (a and b) and 3(1),3(2)-Didehydro-rhodochlorin-15- glyoxylic acid-17(3)-phytyl ester (a and b) have been identified as pr incipal products. Identification was based on UV-Vis and mass spectra, retention times and R(F) values. The molecular mass of allomerized ph eophytins was confirmed by positive-ion fast-atom bombardment mass spe ctrometry and positive/negative ion electrospray mass spectrometry. Th e corresponding Cu(II) complexes of these compounds were prepared by c helation reaction with CuCl2 and separated by reversed-phase ion-pair high-performance liquid chromatography (RP-IP-HPLC) using a gradient o f water and ion suppressor-methanol-acetone. The chromatographic chara cteristics in NP-TLC and RP-IP-HPLC of the Cu(II) complexes are report ed. The corresponding UV-Vis spectra obtained with an on-line diode-ar ray detector have been included.