Total Synthesis of Gobiusxanthin Stereoisomers and Their Application to Determination of Absolute Configurations of Natural Products: Revision of Reported Absolute Configuration of Epigobiusxanthin

Marine Drugs

Yumiko Yamano²  Kotaro Ematsu²  Hiromasa Kurimoto²  Takashi Maoka¹  Akimori Wada² 

[1] Research Institute for Production Development, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto 606-0805, Japan; E-Mail:;Department of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Motoyamakita-machi, Higashinada-ku, Kobe 658-8558, Japan; E-Mails:

关键词: carotenoid;    gobiusxanthin;    epigobiusxanthin;    total synthesis;    chiral HPLC separation;    absolute configuration;   

DOI  :  10.3390/md13010159

来源: mdpi

【 摘 要 】

(3R)-Gobiusxanthin stereoisomers (1a–d) were synthesized by stereoselective Wittig reaction of the (3R)-C₁₅-acetylenic tri-n-butylphosphonium salt 7 with C₂₅-apocarotenal stereoisomers 5a,b and 14a,b bearing four kinds of 3,6-dihydroxy-ε-end groups. The validity of the reported stereochemistry of gobiusxanthin was demonstrated by the fact that the reported spectral data of natural gobiusxanthin were in agreement with those of synthetic (3R,3'S,6'R)-gobiusxanthin (1a). On the other hand, the reported CD spectral data of natural epigobiusxanthin, which has been assigned as (3R,3'R,6'R)-isomer (3'-epigobiusxanthin), were identical with those of synthetic (3R,3'S,6'S)-isomer 1d (6'-epigobiusxanthin) rather than those of the corresponding synthetic 3'-epi-isomer 1b. It was found that the stereochemistry at C3-position has little effect on the shape of their CD spectra. Thus, in order to reinforce the validity of the absolute configurations at C3-position of natural specimens, (3S,3'S,6'R)- and (3S,3'S,6'S)-stereoisomers 1e and 1f were also synthesized and a HPLC analytical method for four stereoisomers was established by using a column carrying a chiral stationary phase. The HPLC analysis has proven that the stereochemistry of the natural epigobiusxanthin is 3R,3'S,6'S.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.