Polystyrene‐Divinylbenzene (PS‐DVB), a Mild Stationary Phase for the Chromatographic Purification of the Unstable 13², 17³‐Cyclopheophorbide a‐Enol

Abstract

One of the most abundant pigments in certain recent sediments (Black Sea, Mediterranean Sea, Peru margin, Florida Bay) is an unstable derivative of chlorophylla known as 13 2 , 17 3 -cyclopheophorbide a-enol (aka CPP, CYCLO, CPP516). To date, the purification of synthetic or natural samples of this compound has always been challenging, since it is readily converted to a 1:1 mixture of (13 2 R/S) chlorophyllones a (Chlone), 15 1 -hydroxychlorophyllonelactone-a, and/or other derivatives when chromatographed over silica gel or alumina supports in normal or reversed phase modes. In this study, Polystyrene-Divinylbenzene (PS-DVB) support (aka Polymeric Reversed Phase, or PRP) is introduced as an efficient stationary phase for the flash column chromatographic purification of CPP with little oxidation/conversion to artifacts. Similarly, PRP-1 in analytical sized columns is shown to be highly useful for purity verification prior to UV/Vis, FTIR, and NMR characterizations.