Refine
Document Type
- Article (3)
- Doctoral Thesis (1)
Has Fulltext
- yes (4)
Is part of the Bibliography
- no (4)
Keywords
- 4,4’-dihydroxy-nostoxanthin (1)
- 4,4’-diketo-nostoxanthin (1)
- Carotene Isomerase (1)
- Gene sll0033 (1)
- HPLC separation (1)
- MS-MS spectra (1)
- Paprika ; Desaturasen ; Genexpression ; Paprika (1)
- Phaeodactylum tricornutum (1)
- Xanthophyllomyces dendrorhous (1)
- all-E Lycopene (1)
- carotenogenic genes (1)
- carotenoid biosynthesis (1)
- complementation (1)
- diadinoxanthin (1)
- fucoxanthin (1)
- genetic engineering (1)
- genetic pathway (1)
- neoxanthin (1)
Institute
The biosynthesis pathway to diadinoxanthin and fucoxanthin was elucidated in Phaeodactylum tricornutum by a combined approach involving metabolite analysis identification of gene function. For the initial steps leading to β-carotene, putative genes were selected from the genomic database and the function of several of them identified by genetic pathway complementation in Escherichia coli. They included genes encoding a phytoene synthase, a phytoene desaturase, a ζ-carotene desaturase, and a lycopene β-cyclase. Intermediates of the pathway beyond β-carotene, present in trace amounts, were separated by TLC and identified as violaxanthin and neoxanthin in the enriched fraction. Neoxanthin is a branching point for the synthesis of both diadinoxanthin and fucoxanthin and the mechanisms for their formation were proposed. A single isomerization of one of the allenic double bounds in neoxanthin yields diadinoxanhin. Two reactions, hydroxylation at C8 in combination with a keto-enol tautomerization and acetylation of the 3′-HO group results in the formation of fucoxanthin.