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ID 11132
Eprint ID
11132
FullText URL
Title Alternative
A Spectroscopic Behavior of Zeaxanthin Molecular Aggregate and Its From
Author
Takagi, Shigeaki
Itani, Junko
Kimura, Yoshinobu Kaken ID
Takeda, Kunio
Abstract
Lutein, one of the xanthophylls, can be dispersed in various aqueous solutions, for example, protein solution, dilute acetone solution, dilute sodium dodecyl sulfate (SDS) solution, dodecyl trimethylammonium bromide solution, hen egg yolk phosphatidyl-choline (PC) liposome, or digalactosyldiglyceride liposome, to from chiral helical aggregates which acquire an optical activity in the visible region, and have a left handed helical structure. In this report, zeaxanthin, a structural isomer of lutein, was subjected to investigation as to whether zeaxanthin formed the chiral helical aggregate. When zeaxanthin was dispersed in SDS solution, some differences from lutein were obserbed. (1) CD spectrum of positive Cotten effect was shown, which was the reverse of lutein. (2) SDS concentration giving the reversion of the CD spectrum pattern was higher (3.5mM) than that of lutein (0.6mM). IN spite of these differences, however, the results showed that zeaxanthin molecules also associated to from molecular aggregate in such a manner performing π*-π*interaction at conjjugated polyene sites. zeaxanthin dispersed in PC liposome gave both left and right-handed helical structure under presence of Ca2+ at alkaline condition in comparison with lutein's left-handed structure. This result may depend on the fact that synthesized racemic zeaxanthin is subjected to this experiment. Those results gave the general conclusion that xanthophylls had the same basic types of behavior for making molecular aggregate in aqueous dispersion.
Abstract Alternative
我々はxanthophyllの一つであるluteinが種々の水溶液例えばたんぱく質溶液、うすいアセトン溶液、うすい界面活性剤水溶液、卵黄レシチン製リポソーム、あるいはホウレンソウdigalactosyl diglyceride製リポソームに分散溶解してキラルならせん状集合体を形成し、可視領域に光学活性を示すと同時に左巻きのらせん構造体を作ることを既に明らかにしている。本報告ではluteinの構造異性体であるzeaxanthinを用いて同様に分子集合体を形成するかどうかを検討した。zeaxanthinをsodiumdodecylsulfate (SDS)に分散させると、円2色性(CD)スペクトルが逆のCotton効果を与え、またそのスペクトルパターンが逆転するSDS濃度がluteinのとき0.6mMであったのに対して約3.51mMと高く、またそのときのSDS結合量も多いという相異はあるが水系においてπ*-π*相互作用行わせるような分子集合体を形成するという基本的挙動を示した。PCリポソームに分散させたときアルカリ性でCa2+存在下らせん構造を与える点もluteinと同じであった。しかし、用いたzeaxanthinが合成された光学異性体混合物であったためか左巻きと右巻きらせんの両方とも観察されたホウレンソウlutein Aの左巻きらせんだけの結果と異なった。以上の結果からzeaxanthinもluteinと同じく水系で分子集合体を形成するという基本的分子挙動をとることが明らかとなった。
Keywords
zeaxanthin
molecular aggregate
chiral helical structure liposome
Published Date
1996-02-01
Publication Title
岡山大学農学部学術報告
Publication Title Alternative
Scientific reports of the Faculty of Agriculture, Okayama University
Volume
volume85
Issue
issue1
Publisher
岡山大学農学部
Publisher Alternative
Faculty of Agriculture,Okayama University
Start Page
7
End Page
13
ISSN
0474-0254
NCID
AN00033029
Content Type
Departmental Bulletin Paper
language
日本語
File Version
publisher
Refereed
False
Eprints Journal Name
srfa