DFT and Raman study of all-trans astaxanthin optical isomers

Guohua Yao; Shuju Guo; Wenjie Yu; Muhammad Muhammad; Jianguo Liu; Qing Huang

doi:10.1016/j.saa.2021.120143

DFT and Raman study of all-trans astaxanthin optical isomers

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Dec 5:262:120143. doi: 10.1016/j.saa.2021.120143. Epub 2021 Jul 7.

Authors

Guohua Yao¹, Shuju Guo², Wenjie Yu³, Muhammad Muhammad⁴, Jianguo Liu⁵, Qing Huang⁶

Affiliations

¹ CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
² CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
³ CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China.
⁵ CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China. Electronic address: jgliu@scsio.ac.cn.
⁶ CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China. Electronic address: huangq@ipp.ac.cn.

PMID: 34271237
DOI: 10.1016/j.saa.2021.120143

Abstract

Astaxanthin (AST) is a xanthophyll carotenoid widely distributed in aquatic animals, which has many physiological functions such as antioxidant, anti-inflammatory, anti-hypertensive and anti-diabetic activities. AST has three optical isomers, including a pair of enantiomers (3S,3'S and 3R,3'R) and a meso form (3R,3'S). Different optical isomers have differences in a variety of physiological functions. Traditionally, High Performance Liquid Chromatography (HPLC) has been used to distinguish these isomers. In this work, it was found that Raman spectroscopy can be employed to distinguish the three optical isomers. The intensities of two Raman bands at 1190 and 1215 cm^-1 of three isomers are different. Density Functional Theory (DFT) calculations are performed to analyze the spectral differences. The mainly occupied conformers of these three optical isomers are speculated and identified.

Keywords: All-trans astaxanthin; Chiral; DFT; Optical isomers; Raman spectroscopy.

MeSH terms

Animals
Carotenoids
Isomerism
Lutein*
Stereoisomerism
Xanthophylls*

Substances

Xanthophylls
Carotenoids
astaxanthine
Lutein