D. G. Roux

Chromatographic behaviour of some stereochemically interrelated flavonoid compounds in aqueous medium

Abstract Factors affecting the chromatographic behaviour of some flavonoid compounds in aqueous medium may be evaluated more accurately now that their stereochemical interrelationships have been established. The effect of the following factors on RF have been examined: (a) the separation of enantiomorphous flavan-3-ols, flavan-3,4-diols and 2,3-dihydroflavonols; (b) the cis- trans relationship of substituents in the heterocyclic ring of flavan-3-ols, (c) the introduction of a carbonyl group in the 4-position, hydroxyl groups in the 4, 5 and 5′-positions, and a galloyl group in the 3-position. The zero RF of flavonoid compounds of planar structure is likely to be due to their low solubility in water. Solubility appears to be one of the predominant factors affecting the RF of flavonoid compounds in aqueous medium.

CORRELATIONS OF ELECTROPHORETIC MOBILITIES IN BORATE BUFFER WITH STRUCTURAL FACTORS OF SOME FLAVONOID COMPOUNDS.

Abstract Comparison of the electrophoretic mobilities of flavonoid compounds in sodium borate-boric acid buffer has shown that co-ordination of borate with phenolic ortho-hydroxyls and ionization of the 7-hydroxyl correlate with large increases in mobility, whereas overall planarity strongly reduces mobility. The effects of hydroxyl, carbonyl and galloyl substituents, and of cis- and trans-arrangements in the2,3- and 4-positions are related to smaller differences in mobility. These differences in mobility are of diagnostic value.

Structural and chromatographic correlations of some flavonoid compounds

The chromatographic behaviour of flavan, flavan-3-ol, flavan-4-ol, flavan-3,4-diol, flavanone, flavanonol, flavonol and chalcone analogues of robinetinidin and fisetinidin chlorides in 2% acetic acid, water-saturated butan-1-ol, and in butan-1-ol-acetic acid—water (6:1:2, v/v), is discussed. Similarly, the diagnostic value of quinonechloroimides, Erlichs reagent, and p-toluenesulphonic acid as spray reagents for flavonoids is examined.