摘要

 

目的：虾青素(astaxanthin)，是一种类胡萝卜素，也是类胡萝卜素合成的最高级别产物，在自然界，虾青素具有最强的抗氧化性。而雨声红球藻中提取虾青素是常见的方法，本文采用新的提取工艺来提高虾青素的提取率。但由于提取率低，本着找到更好的工艺条件为目的，又进行了实验室的合成虾青素来实现大规模的应用，本文在已知的化学合成路线基础上，对在合成反应中，尤其是在多个烯烃存在下，如何进行选择性合成，进行了化学反应本质的探讨。我们从化学内禀属性出发，对相关化合物进行了量子化学计算，以净亲电指数作为量子化学反应性指数，定量地描述和预测多烯化合物中选择性环氧化过程，并指出了反应过程中反应条件的控制，以期达到其减少副反应，实现提高产率，优化合成路线的目的。

 

方法：本文用雨声红球藻提取虾青素以及与全合成比较为目的采用国内已用的合成方法，采用微波化学法进行路线优化提高其反应效率并降低反应时间，来完成虾青素的全合成。主要工作如下：

 

关键词：虾青素 雨声红球藻 选择性环氧化 量子化学

 

Abstract

 

Objective: Astaxanthin is a carotenoid and the highest grade product of carotenoid synthesis.In nature, astaxanthin has the strongest antioxidant activity.In this paper, a new extraction technology was used to improve the extraction rate of astaxanthin.But because of the low extraction rate,according to find a better process conditions for the purpose,and the synthesis of shrimp green have implemented large-scale application of laboratory, this article on the basis of known chemical synthetic route, in synthetic reaction, especially in the presence of multiple olefins, how to carry out selective synthesis, discussed the nature of the chemical reaction. We set off from the chemical intrinsic attributes,the quantum chemistry calculation of related compounds, with net electrophilic as quantum chemical reactivity index, quantitatively describe and predictpolyene compounds in selective epoxidation process, and points out the reaction conditions of process control, in order to reach its to reduce side effects, improve production rate, the purpose of optimizing the synthetic route.

 

Methods: In order to complete the total synthesis of astaxanthin,we extracted astaxanthin from Yusheng Chlorella and compared it with the total synthesis. We used the domestic synthesis methods,and optimized the route by microwave chemistry method to improve the reaction efficiency and reduce the reaction time. The main work is as follows:

 

f from the chemical intrinsic attributes,the quantum chemistry calculation of related compounds,with net electrophilic as quantum chemical reactivity index, quantitatively describe and predict polyene compounds in selective epoxidation process, and points out the reaction conditions of process control, in order to reach its to reduce side effects, improve production rate, the purpose of optimizing the synthetic route.

 

Methods: In order to complete the total synthesis of astaxanthin,we extracted astaxanthin from Yusheng Chlorella and compared it with the total synthesis. We used the domestic synthesis methods,and optimized the route by microwave chemistry method to improve the reaction efficiency and reduce the reaction time. The main work is as follows:

 

1.Extraction: Astaxanthin was extracted from Chlorophylla urensis (astaxanthin content was 3%).After wall breaking by ultrasonic method,astaxanthin was refluxed with ethanol under pressure at 70℃ for 30 minutes, filtered, and the residue was retained for next extraction. After six times of extraction,the extraction solution was combined to obtain the astaxanthin.

 

2.Synthesis :(1) Taking E-1, 4-dibromo-2-butene as raw material,bisphosphonate esterification was obtained through Abrozov rearrangement reaction, and then C10 dialdehyde compound was obtained by Wittig-Hoorner reaction with pyruval dimethanol and deprotection group

 

(2)Alpha - ionone was the starting material, chlorine acid peroxide between epoxidation,then under the alkali catalytic isomerization form 4 - (2,6,6-3 - methyl - 3 - hydroxy - 1 cyclohexene - 1 - base) - 3 -butene - 2 - keto crude products,after purification of the microwave extraction technology, reaction with vinyl chloride grignard reagent diol compounds, isopropanol aluminum after selective oxidation, after using trimethylchlorosilane protection, again with chlorine acid peroxide between selective epoxidation reaction with triphenylphosphine after get C15 compounds, reacts with C10 double aldehyde by astaxanthin finished products.

 

The innovation of this paper lies in:

 

1.Extraction: for Chlorella spp.extraction using decompression reflux mode, because at 70℃,ethanol is very volatile,extraction using -20℃ intelligent temperature control low temperature ultrasonic extraction instrument to strictly control the reaction temperature of ethanol reflux large circulation way to improve the extraction rate of Chlorella spp..

 

2.Synthesis: (1) 4 - (2,6,6-3 - methyl - 3 - hydroxy - 1 cyclohexene - 1 - base) - 3 - butene - 2 -ketone products purification using the microwave reaction method, using toluene as solvent,with succinic anhydride esterification,using DMAP (4 - dimethyl aminopyridine) as catalyst, the purification method for hydrolysis, greatly shorten the reaction time, improve the reaction efficiency.

 

(2) By the method of computational chemistry 4 - (2,6,6 - trimethyl - 2,3 - epoxy - 1 - cyclohexyl) - 3 - ketone of butene - 2-2,3 a selective epoxidation and 5 - (2,6,6 - three epoxy - 3 - methyl - 3, 4-3-1,3 - methyl silicon oxygen radicals ring diallyl - 1 - base) - 3 - methyl - 3-3-1, 4 - methyl silicon oxygen radicals pentadiene 3, 4 a selective epoxidation of quantum chemistry analysis, the charge distribution for selective epoxidation with more clear explanation.

 

Key words: astaxanthin,Red Chlorella of Rain Sound ,selective epoxidation, quantum chemistry