Identification of astaxanthin diglucoside diesters from snow alga Chlamydomonas nivalis by liquid chromatography–atmospheric pressure chemical ionization mass spectrometry

Abstract

A method is described for the identification of astaxanthin glucoside esters from snow alga Chlamydomonas nivalis by means of liquid chromatography–mass spectrometry with atmospheric pressure chemical ionization (LC–MS/APCI). The method is based on the use of preparative HPLC and subsequent identification of astaxanthin diglucoside diesters by microbore LC–MS/APCI. The combination of these two techniques was used to identify more than 100 molecular species. The astaxanthin diglucoside diester, i.e. (all- E)-[di-(6- O-oleoyl-β- d-glucopyranosyloxy)]-astaxanthin, was also synthesized to unambiguously confirm its structure.