Synthesis of guaiacol-alpha-D: -glucoside and curcumin-bis-alpha-D: -glucoside by an amyloglucosidase from Rhizopus.
Guaiacol (2-methoxyphenol) and curcumin [1E,6E-1,7-di(4-hydroxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione] were converted into their corresponding glucosides using glucose and an amyloglucosidase from Rhizopus. Guaiacol-alpha-D: -glucoside yields ranged from 3 to 52% with the highest at pH 7.0. Curcumin-bis-alpha-D: -glucoside yields ranged from 3 to 48% with the highest at pH 4.0 with 50% (w/w D: -glucose) of enzyme. The phenolic hydroxyl group of guaiacol and both phenolic hydroxyl groups of curcumin were glucosylated at the C1 carbon of alpha-D: -glucose indicating that the enzymatic reaction is stereospecific. Both guaiacol-alpha-D: -glucoside and curcumin-bis-alpha-D: -glucosides had antioxidant activities.
R Vijayakumar
Giriyapura
G
Fermentation Technology and Bioengineering, Central Food Technological Research Institute, 570020, Mysore, India.
Divakar
Soundar
S
D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism; D001713:Biphenyl Compounds / Q000737:chemistry / Q000378:metabolism; D002021:Buffers; D002851:Chromatography, High Pressure Liquid; D003474:Curcumin / Q000737:chemistry; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry* / Q000378:metabolism; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D006139:Guaiacol / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015394:Molecular Structure; D010851:Picrates; D012233:Rhizopus / Q000201:enzymology*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D000975:Antioxidants; D001713:Biphenyl Compounds; D002021:Buffers; D005960:Glucosides; D006834:Hydrazines; D010851:Picrates; D006139:Guaiacol; C004931:1,1-diphenyl-2-picrylhydrazyl; D005087:Glucan 1,4-alpha-Glucosidase; D003474:Curcumin