Biotransformation of Natural and Synthetic Isoflavonoids by Two Recombinant Microbial Enzymes

Abstract

Isolation and synthesis of isoflavonoids has become a frequent endeavor, due to their interesting biological activities. The introduction of hydroxyl groups into isoflavonoids by the use of enzymes represents an attractive alternative to conventional chemical synthesis. In this study, the capabilities of biphenyl-2,3-dioxygenase (BphA) and biphenyl-2,3-dihydrodiol 2,3-dehydrogenase (BphB) of Burkholderia sp. strain LB400 to biotransform 14 isoflavonoids synthesized in the laboratory were investigated by using recombinant Escherichia coli strains containing plasmid vectors expressing the bphA1A2A3A4 or bphA1A2A3A4B genes of strain LB400. The use of BphA and BphB allowed us to biotransform 7-hydroxy-8-methylisoflavone and 7-hydroxyisoflavone into 7,2,3-trihydroxy-8-methylisoflavone and 7,3,4-trihydroxyisoflavone, respectively. The compound 2-fluoro-7-hydroxy-8-methylisoflavone was dihydroxylated by BphA at ortho-fluorinated and meta positions of ring B, with concomitant dehalogenation leading to 7,2,3,-trihydroxy-8-methylisoflavone. Daidzein (7,4-dihydroxyisoflavone) was biotransformed by BphA, generating 7,2,4-trihydroxyisoflavone after dehydration. Biotransformation products were analyzed by gas chromatography-mass spectrometry and nuclear magnetic resonance techniques.

A Lux-like Quorum Sensing System in the Extreme Acidophile Acidithiobacillus ferrooxidans

“…Helium served as carrier gas. The mass spectrometer was operated in the electron impact ionization mode at 70 eV as described (Seeger et al, 2001(Seeger et al, , 2003. The following AHL standards were purchased from Fluka: N-hexanoyl-DL-homoserine lactone (AHL-C 6 ), N-octanoyl-DLhomoserine lactone (AHL-C 8 ) and Ntetradecanoyl-DL-homoserine lactone (AHL-C 14 ).…”

Synthesis, Characterization, and Antioxidant Activities of Genistein, Biochanin A, and Their Analogues

“…Isoflavonoids ( ) are one of the main subclasses of flavonoids ( ) which contain C6-C3-C6 carbon skeleton based on 3-phenylchroman [1]. They are widely distributed in many plants [2,3] and in various common foods which are particularly abundant in seeds and other parts of leguminous plants [4,5].…”

Remarkable Ability of Pandoraea pnomenusa B356 Biphenyl Dioxygenase To Metabolize Simple Flavonoids

“…The ␣ subunit is the one involved in the catalytic activity. It comprises two domains; the Rieske domain containing a 2Fe-2S Rieske cluster receives the electrons from BphF and transfers them to the catalytic mononuclear iron center of the catalytic domain (7).Several investigations have shown that BPDO can metabolize flavonoids (4,15,29,30). These plant secondary metabolites (PSMs) are regarded as very promising for the prevention and treatment of cancers (26) and cardiovascular diseases (35).…”