Biotransformation of Hydroxychalcones as a Method of Obtaining Novel and Unpredictable Products Using Whole Cells of Bacteria

• Main Authors: Joanna Kozłowska, Bartłomiej Potaniec, Mirosław Anioł
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Catalysts
• Subjects: biotransformation; biologically active compounds; chalcone; dihydrochalcone
• Online Access: https://www.mdpi.com/2073-4344/10/10/1167

The aim of our study was the evaluation of the biotransformation capacity of hydroxychalcones—2-hydroxy-4′-methylchalcone (<b>1</b>) and 4-hydroxy-4′-methylchalcone (<b>4</b>) using two strains of aerobic bacteria. The microbial reduction of the α,β-unsaturated bond of 2-hydroxy-4′-methylchalcone (<b>1</b>) in <i>Gordonia</i> sp. DSM 44456 and <i>Rhodococcus</i> sp. DSM 364 cultures resulted in isolation the 2-hydroxy-4′-methyldihydrochalcone (<b>2</b>) as a main product with yields of up to 35%. Additionally, both bacterial strains transformed compound <b>1</b> to the second, unexpected product of reduction and simultaneous hydroxylation at C-4 position—2,4-dihydroxy-4′-methyldihydrochalcone (<b>3</b>) (isolated yields 12.7–16.4%). During biotransformation of 4-hydroxy-4′-methylchalcone (<b>4</b>) we observed the formation of three products: reduction of C=C bond—4-hydroxy-4′-methyldihydrochalcone (<b>5</b>), reduction of C=C bond and carbonyl group—3-(4-hydroxyphenyl)-1-(4-methylphenyl)propan-1-ol (<b>6</b>) and also unpredictable 3-(4-hydroxyphenyl)-1,5-di-(4-methylphenyl)pentane-1,5-dione (<b>7</b>). As far as our knowledge is concerned, compounds <b>3</b>, <b>6</b> and <b>7</b> have never been described in the scientific literature.