1. Fast cleavage of phycocyanobilin from phycocyanin for use in food colouring
- Author
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Rime Bahij El-Houri, Xavier Fretté, Lars Porskjær Christensen, Knud Villy Christensen, and Maria Cinta Roda-Serrat
- Subjects
0106 biological sciences ,0301 basic medicine ,Food Coloring Agents/isolation & purification ,Natural blue colourant ,Cyanobacteria ,Photochemistry ,01 natural sciences ,Analytical Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Elimination reaction ,Chromophore ,Phycocyanobilin ,Phycobilins ,Phycocyanin ,Nucleophilic substitution ,Solvolysis ,Reaction mechanism ,Phycocyanin/chemistry ,Methanolysis ,Food Coloring Agents ,General Medicine ,030104 developmental biology ,chemistry ,Phycobilins/isolation & purification ,Yield (chemistry) ,Reagent ,SN2 reaction ,010606 plant biology & botany ,Food Science - Abstract
Phycocyanins from cyanobacteria are possible sources for new natural blue colourants. Their chromophore, phycocyanobilin (PCB), was cleaved from the apoprotein by solvolysis in alcohols and alcoholic aqueous solutions. In all cases two PCB isomers were obtained, while different solvent adducts were formed upon the use of different reagents. The reaction is believed to take place via two competing pathways, a concerted E2 elimination and a S N2 nucleophilic substitution. Three cleavage methods were compared in terms of yield and purity: conventional reflux, sealed vessel heated in an oil bath, and microwave assisted reaction. The sealed vessel method is a new approach for fast cleavage of PCB from phycocyanin and gave at 120 °C the same yield within 30 min compared to 16 h by the conventional reflux method (P
- Published
- 2018
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