Bovine serum albumin-catalysed cross aldol condensation: Influence of ketone structure. (November 2019)

• Record Type: Journal Article
• Authors: Ardanaz, Sebastián M.; Borucki, Estefanía L.; Velez Rueda, Ana J.; Parisi, Gustavo; Iribarren, Adolfo M.; Iglesias, Luis E.
• Is Part Of: Process biochemistry. Volume 86(2019)
• Page Start: 50
• Page End: 57
• Publication Date: 2019-11
• Subjects: Aldol condensation -- Biocatalysis -- Bovine serum albumin -- Catalytic promiscuity -- Enones; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2019.08.003
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: Bovine serum albumin (BSA) catalyses the cross aldol condensation of a set of ketones. BSA is active at mild temperature and in ethanol, a cheap and green solvent. Bis-enone is formed only from cyclohexanone and in low amount. An ordered bi-bi mechanism for BSA-catalysed enone formation is proposed. Abstract: Bovine serum albumin (BSA) catalyses the cross aldol condensation and proved to be catalytically active at mild temperature and in ethanol, a cheap and green solvent, contrasting with the strong or expensive reaction media usually employed for this reaction. We herein report the reaction of a set of ketones (butanone, 3-pentanone, cyclopentanone and cyclohexanone) with benzaldehyde and p -nitrobenzaldehyde which provided high conversions (77–95%) of the corresponding enones (isolated in a range of yields from 19% to 74%). Parameters assayed to achieve these conversion values were solvent, ketone/aldehyde molar ratio and temperature. In this procedure only cyclohexanone gave the bis- enone, by-product of the conventional aldol condensation, in low amount even at high benzaldehyde/cyclohexanone molar excess. Under the assayed conditions null or low ketol amounts were observed, except for the reaction of cyclopentanone and p -nitrobenzaldehyde. Moreover, kinetic data of BSA-catalysed aldol condensation of cyclohexanone and p -nitrobenzaldehyde suggest an ordered bi bi mechanism for enone formation; an enamine mechanism involving residues of the catalytic cavity exhibiting abnormal pKa values is also proposed.