Carotenoid Surfactants and Transfection Agents: The Colourful Chemistry of Polyenes

Abstract

Synthetic procedures have been developed for efficient preparation of caroteinoid choline-ester analogues and phospholipids. One series of choline-esters and one series of phospholipids were based on β-apo-8’-carotenic acid, whereas another series of phospholipids was based on retinoic acid. The final products generally had good surfactant properties.

In addition, hydrophilic carotenoids derived from sodium and potassium β-apocarotenoates, carotenoid-oxime salts, and norbixin and its potassium salts were prepared and examined for their surfactant properties.

Selected carotenoid choline-ester analogues and phospholipids were examined for their potential use as transfection agents. The carotenoid compounds were as effective as commercial standards concerning complexation and protection of nucleic acids. Preliminary biological confirm the transfection activity of the new carotenoid lipids.

A novel method for radical induction was examined. Stable radicals were observed at room temperature upon addition of small amounts of base to DMF or DMSO, contradicting earlier claims of their inertness.

The reaction of radicals with polyene-carbonyl compounds resulted in electrontransfer to the polyenes, forming reduced anions or radical anions. The synthetic potential of this reaction was also demonstrated.

Pyran-groups operate as strong auxochromes in polyene-dyes. A new method for the synthesis of pyranocarotenoids has been developed, by reacting different polyene dicarbonyl compounds with Lewis acids.