Peter M. Schaber

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC STUDY OF THE CHLOROPHYLL ALLOMERIZATION REACTION*

Abstract The allomerization of chlorophyll has been investigated by reversed-phase HPLC. Four major product peaks (two sets of doublets) are observed in the HPLC chromatogram. These are shown to be pairs of stereoisomers of two major components. Similar results have been obtained from the allomerization of fully deuterated chlorophyll a. Attempts to characterize the reaction products and to delineate the reaction mechanism were initially studied by the oxidation of chlorophyll in the absence of extraneous nucleophiles. The structure of the reaction products of chlorophyll allomerization were conclusively identified as 10-hydroxychlorophyll and the 10-methoxylactone by co-chromatography, NMR, and 252Cf plasma-desorption mass spectroscopy. Exploratory studies on the allomerization products of bacteriochlorophyll have also been carried out.