Optimization On Synthesis Route Of Canthaxanthin

Canthaxanthin is also known as ?-carotene-4,4'-diketone,which is one of the five major carotenoids,has similar antioxidant effect with the other carotenoid compounds,and has good capability of coloring.Now,canthaxanthin has been widely used in the field of food,nutrition,cosmetics and feed additives etc.Presently canthaxanthin can be got by three ways: extraction from natural animal and plant,extraction by fermentation,and chemical synthesis.But by far canthaxanthin is the only compound in the five major carotenoids which is still mainly rely on chemical synthesis for mass production.So it is necessary to study the chemical synthesis of canthaxanthin,and many synthetic routes have been reported in the literature and patents.This paper also introduces several relatively mature chemical synthesis route,and one of the more popular chemical synthesis routes of the canthaxanthin is the oxidation of ?-carotene.The advantage of this route is that the route is short,and the reaction conditions is mild,but it's product compared to the synthesis route by carbon chain growth has more impurities.This will directly affect the application of canthaxanthin for feeds and health.Therefore,this paper considered both the literature and the company's actual situation,and studied the chemical synthesis route of canthaxanthin by carbon chain growth.In this paper,the research route is divided into four main steps.First of all,with acetone as starting materials for the synthesis of isophorone,experiment emphasizes on the performance of the catalyst.And studied use isophorone through isomerization reaction,oxidation reaction,reduction reaction and condensation reaction to prepare etherate.And then studied the condensation reaction by the product of C6 enynols reacted with trimethylchlorosilane with the Grignard reagent which prepare by etherate,the product through hydrolysis,reduction,bromide and condensation with triphenylphosphine,then obtain C15 quaternary phosphonium salt.Finally the quaternary phosphonium salt condense with C10 dialdehyde prepared canthaxanthin,the product through purification processing,up to the high content of standard.In the process of experiments,one or more react conditions have been optimized for each reaction step,such as temperature,time,and ratio and so on.The product was characterized by UV,IR,NMR,MS,and others advanced analytical instruments,and its structure was confirmed as canthaxanthin.In this paper,the studies of the preparation route for canthaxanthin from a fundamental point of view is C15+C10+C15 route,but the choice of reaction raw material is different,such as the ?-isophorone,?-isophorone,keto-isophorone,C6 enynols and C10 dialdehyde and other raw materials which are the important intermediates for the preparation of VA,VE,astaxanthin etc.Therefore,it's reduced the challenge of the implementation in this chemical synthesis route.In this paper,the chemical synthesis route is a really feasible preparation method for canthaxanthin.Due to this chemical synthesis route has so many reaction processes,this study focuses on the chemical synthesis route how to get the right product.Thus for the optimization of reaction conditions is to be done in the future work.