Enantiomeric Mixtures in Natural Product Chemistry: Separation and Absolute Configuration Assignment

Autor(es)

Batista, Andrea N. L. ^[1] ; dos Santos, Jr., Fernando M. ^[1] ; Batista, Jr., Joao M. ^{[1, 2]} ; Cass, Quezia B. ^[1]

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos UFSCar, Dept Chem, Rod Washington Luis S-N, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Fed Univ Sao Paulo UNIFESP, Inst Sci & Technol, R Talim 330, BR-12231280 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo de Revisão
• Fonte: Molecules; v. 23, n. 2 FEB 2018.
• Citações Web of Science: 15

Resumo

Chiral natural product molecules are generally assumed to be biosynthesized in an enantiomerically pure or enriched fashion. Nevertheless, a significant amount of racemates or enantiomerically enriched mixtures has been reported from natural sources. This number is estimated to be even larger since the enantiomeric purity of secondary metabolites is rarely checked in the natural product isolation pipeline. This latter fact may have drastic effects on the evaluation of the biological activity of chiral natural products. A second bottleneck is the determination of their absolute configurations. Despite the widespread use of optical rotation and electronic circular dichroism, most of the stereochemical assignments are based on empirical correlations with similar compounds reported in the literature. As an alternative, the combination of vibrational circular dichroism and quantum chemical calculations has emerged as a powerful and reliable tool for both conformational and configurational analysis of natural products, even for those lacking UV-Vis chromophores. In this review, we aim to provide the reader with a critical overview of the occurrence of enantiomeric mixtures of secondary metabolites in nature as well the best practices for their detection, enantioselective separation using liquid chromatography, and determination of absolute configuration by means of vibrational circular dichroism and density functional theory calculations. (AU)

• Processo FAPESP: 13/01710-1 - Ligantes enzimáticos: novos modelos de triagem
• Beneficiário: Quezia Bezerra Cass
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/23794-0 - Estereoquímica de substâncias naturais complexas por atividade óptica vibracional: acetogeninas
• Beneficiário: Fernando Martins dos Santos Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/25222-9 - Espectroscopia quiróptica vibracional na caracterização estereoquímica de pequenas moléculas e macromoléculas
• Beneficiário: João Marcos Batista Junior
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 15/07089-2 - Espectroscopia quiróptica vibracional na caracterização estereoquímica de pequenas moléculas e macromoléculas
• Beneficiário: João Marcos Batista Junior
• Modalidade de apoio: Bolsas no Brasil - Jovens Pesquisadores