Structural characterization of 132-hydroxy-(132-S)-phaeophytin-a from leaves and stems of Amaranthus tricolor isolated by high-speed countercurrent chromatography

Amaranthus tricolor (Amaranthaceae) is a popular vegetable in China. Separation of lipophilic extracts of the aerial parts of A. tricolor by means of preparative ‘High-speed Countercurrent Chromatography’ (HSCCC) led to the isolation of two chlorophyll breakdown products which were characterized as 132-hydroxy-(132-S)-phaeophytin-a (1) and chlorophyll b methoxylactone (2).The structure of 1 was established using a combination of 1D- and 2D-NMR spectroscopic and mass spectrometric techniques. Component 2 was identified by means of ESI-MS/MS analysis.Industrial relevanceChlorophylls and their degradation products are natural pigments of interesting bioactivities. For industry, recovery of these pigments from waste materials of fruit and vegetable processings could be a promising by-product line. Here we present the isolation of a pure chlorophyll breakdown product which is in principle suited as a nutraceutical ingredient. Large-scale isolation procedures using countercurrent chromatography techniques for chlorophyll related pigments are currently under development.