Leuconostoc mesenteroides glucansucrase synthesis of flavonoid glucosides by acceptor reactions in aqueous-organic solvents.
The enzymatic glucosylation of luteolin was attempted using two glucansucrases: the dextransucrase from Leuconostoc mesenteroides NRRL B-512F and the alternansucrase from L. mesenteroides NRRL B-23192. Reactions were carried out in aqueous-organic solvents to improve luteolin solubility. A molar conversion of 44% was achieved after 24h of reaction catalysed by dextransucrase from L. mesenteroides NRRL B-512F in a mixture of acetate buffer (70%)/bis(2-methoxyethyl) ether (30%). Two products were characterised by nuclear magnetic resonance (NMR) spectroscopy: luteolin-3'-O-alpha-d-glucopyranoside and luteolin-4'-O-alpha-d-glucopyranoside. In the presence of alternansucrase from L. mesenteroides NRRL B-23192, three additional products were obtained with a luteolin conversion of 8%. Both enzymes were also able to glucosylate quercetin and myricetin with conversion of 4% and 49%, respectively.
Bertrand
Anne
A
Laboratoire Biotechnologie-Bioprocédés UMR CNRS 5504, UMR INRA 792, INSA DGBA, 135 avenue de Rangueil, 31077 Toulouse Cedex 04, France.
Morel
Sandrine
S
Lefoulon
François
F
Rolland
Yves
Y
Monsan
Pierre
P
Remaud-Simeon
Magali
M
D002021:Buffers; D005960:Glucosides / Q000737:chemistry*; D016695:Glycosyltransferases / Q000096:biosynthesis*; D007934:Leuconostoc / Q000201:enzymology*; D008968:Molecular Conformation; D019906:Nuclear Magnetic Resonance, Biomolecular; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013379:Substrate Specificity; D014867:Water / Q000737:chemistry*
D002021:Buffers; D005960:Glucosides; D012997:Solvents; D014867:Water; D016695:Glycosyltransferases; C033837:alternansucrase