Technical Study On Converting Native Lutein Into Zeaxanthin And Astaxanthin

The lutein which is isolated from the extracts of marigold flowers is used as the raw material to synthesize zeaxanthin and astaxanthin,by rearrangement and oxidation reaction.This thesis includes the following two parts.This first part describes the process for preparing zeaxanthin from lutein,by the base-catalyzed isomerization.The influential factors of this reaction were analyzed.The results show that the optimal reaction condition is as follows: using 1,2-Propanediol as solvent,using potassium hydroxide as catalyst,using PEG600 as phase transfer catalyst,reaction temperature at 110 ? and reaction time for 60 h.The conversion rate of zeaxanthin from lutein can reach the highest 92% under the optimal condition.This second part describes the process for preparing astaxanthin from zeaxanthin l,by the oxidation reaction.The influential factors of this reaction were analyzed.The results show that the optimal reaction condition is as follows: using chloroform as solvent,using sodium bromate as oxidant,using NBS as halogenating agent,the PH of the reaction solution at 9,reaction temperature at 30 ? and reaction time for 2.5 h.The yield of astaxanthin can reach 27% under the optimal condition.The final substrates was identified by HPLC and HPLC-MS...