Enantiomeric Separation of Racemic Neolignans on Chiralcel OD and Determination of Their Absolute Configuration with Online Circular Dichroism

• Published in: Journal of chromatographic science Vol. 42; no. 9; pp. 478 - 483
• Main Authors: Kónya, Krisztina, Kiss-Szikszai, Attila, Kurtán, Tibor, Antus, Sándor
• Format: Journal Article
• Language: English
• Published: Niles, IL Oxford University Press 01.10.2004; Preston Publications
• Subjects: Analytical chemistry; Biological and medical sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - methods; Circular Dichroism - methods; Exact sciences and technology; General pharmacology; Lignans - chemistry; Lignans - isolation & purification; Medical sciences; Other chromatographic methods; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Stereoisomerism; Separation; Optical resolution; Enantiomer; Cellulose derivatives; Absolute configuration; HPLC chromatography; Lignan; Chiral stationary phase; Organic carbamate; Circular dichroism
• ISSN: 0021-9665; 1945-239X
• DOI: 10.1093/chromsci/42.9.478

Effective enantiomeric separations of erythro- and threo-8.O.4′-neolignans with different aromatic substitution pattern (1a-i, 2a-i) are achieved on the commercially available chiral stationary phase cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD). It is shown that the chiral recognition of the stationary phase is significantly dependent on the substitution pattern of the racemic compounds. Online liquid chromatography (LC)-circular dichroism (CD) analysis allows for the establishment of a correlation between the absolute configuration of the separated erythro-8.O.4′-neolignans and their characteristic CD transitions, which could be used to determine or revise the configuration of previously isolated erythro-8.O.4′-neolignans. Although the absolute configurations of threo-isomers is not determined unambiguously from the LC-CD analysis, it is proven that both their elution order and chiroptical properties are significantly influenced by the substitution pattern of the aromatic rings.