Synthesis of (3S,3′S)- and meso-Stereoisomers of Alloxanthin and Determination of Absolute Configuration of Alloxanthin Isolated from Aquatic Animals
نویسندگان
چکیده
In order to determine the absolute configuration of naturally occurring alloxanthin, a HPLC analytical method for three stereoisomers 1a-c was established by using a chiral column. Two authentic samples, (3S,3'S)- and meso-stereoisomers 1b and 1c, were chemically synthesized according to the method previously developed for (3R,3'R)-alloxanthin (1a). Application of this method to various alloxanthin specimens of aquatic animals demonstrated that those isolated from shellfishes, tunicates, and crucian carp are identical with (3R,3'R)-stereoisomer 1a, and unexpectedly those from lake shrimp, catfish, biwa goby, and biwa trout are mixtures of three stereoisomers of 1a-c.
منابع مشابه
Carotenoids in Marine Animals
Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals p...
متن کاملTotal Synthesis of Gobiusxanthin Stereoisomers and Their Application to Determination of Absolute Configurations of Natural Products: Revision of Reported Absolute Configuration of Epigobiusxanthin
(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...
متن کاملSuppressive effects of alloxanthin and diatoxanthin from Halocynthia roretzi on LPS-induced expression of pro-inflammatory genes in RAW264.7 cells.
To investigate anti-inflammatory effects of carotenoids from Halocynthia roretzi, gene expression levels were measured for pro-inflammatory cytokines and enzymes in the murine macrophage-like cell line, RAW264.7, stimulated with lipopolysaccharide (LPS). All-trans alloxanthin, all-trans diatoxanthin, and their 9-cis isomers isolated from H. roretzi significantly suppressed expression of IL-1bet...
متن کاملSome recent advances in the synthesis of carotenoids.
A route to unsymmetrical polyene dialdehydes is described. The utility of these intermediates is illustrated by a synthesis of okenone. The stereochemistry assigned to methyl natural bixin has been confirmed by preparation of the cis-4 isomer. Support has been obtained for the cis-6 formulation of natural cis-crocetin. Oxidation of astacene with manganese dioxide yields violaxanthin. The synthe...
متن کاملAbsolute Stereochemistry of the β-Hydroxy Acid Unit in Hantupeptins and Trungapeptins.
The β-hydroxy/amino acid unit is a common structural feature of many bioactive marine cyanobacterial depsipeptides. In this study, the absolute stereochemistry of the β-hydroxy acid moieties in hantupeptins and trungapeptins were determined through their synthesis and HPLC analysis of the Mosher ester derivatives. Synthesis of two3-hydroxy-2-methyloctanoic acid (Hmoa) stereoisomers, (2S,3R)-Hmo...
متن کامل