Neurosporaxanthin

Because most natural carotenoids are present at very low abundance and are difficult to purify, metabolic engineering provides a powerful alternative, and various carotenoids, such as lycopene, /3-carotene, canthaxanthin, zeaxanthin, torulene, neurosporaxanthin, and astaxanthin, have been successfully synthesized in non-carotenogenic microbes, such as E. coli, Saccharomyces cerevisiae, and Neurospora crassa. This research is summarized in several of reviews [65,108,110]. 

Apocarotenoids. The natural occurrence of neurosporaxanthin methyl ester [methyl 4 -apo-/3-caroten-4 -oate (33)] in the fungus Verticillium agaricinum has been reported. ... 

The methyl ester of neurosporaxanthin has been isolated from Nectria cin-naborina. ... 

Amongst the apocarotenoids with less than 40 carbon atoms in the skeleton there are several examples of naturally occurring carotenoid mono- and dicarboxylic acids [7]. These include crocetin (31) from saffron, bixin (32) from Bixa orellana, azafrin (33) from roots of Escobedria scabrifolia and neurosporaxanthin (4) from yeasts (Neuro-spora sp.), Fig. 13. 

As described for neurosporaxanthin (4) [75], exhibit carotenoid carboxylic acids acidic properties, and may therefore be converted to the methyl esters with diazomethane, Fig. 14. The polar carboxylate anion is obtained upon base treatment. Thus neurosporaxanthin (4) becomes completely hypophasic when distributed between petroleum ether and 1 % NaOH in methanol-water (9 1) [75]. 

Correspondingly, neurosporaxanthin from the microorganisms Neurospora crassa and N. sitophila is denoted as 4 -apo-p, /-caroten-4 -oic acid. 

Aasen, A.J., and S. Liaaen-Jensen Fungal Carotenoids II. The Structure of the Carotenoid Acid Neurosporaxanthin. Acta Chem. Scand. 19, 1843 (1965). 

Presence de I Ester Methylique de la Neurosporaxanthine chez TAscomycete Nectria cinnabarina. Phytochem. 9, 1133 (1970). 

At present, very few species of fungi have been taken from the sea surface an undetermined species of the genus Fusarium (strain T-1) has been isolated in Japanese waters, and its culture has led to the extraction of a group of carotenoid pigments containing neurosporaxanthin and its glucosylated ester, which is the first known example of such a glucoside (Sakaki et al, 2002). 

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