In vitro enzymatic modification of puerarin to puerarin glycosides by maltogenic amylase.
Puerarin (daidzein 8-C-glucoside), the most abundant isoflavone in Puerariae radix, is prescribed to treat coronary heart disease, cardiac infarction, problems in ocular blood flow, sudden deafness, and alcoholism. However, puerarin cannot be given by injection due to its low solubility in water. To increase its solubility, puerarin was transglycosylated using various enzymes. Bacillus stearothermophilus maltogenic amylase (BSMA) was the most effective transferase used compared with Thermotoga maritima maltosyl transferase (TMMT), Thermus scotoductus 4-alpha-glucanotransferase (TS4alphaGTase), and Bacillus sp. I-5 cyclodextrin glucanotransferase (BSCGTase). TMMT and TS4alphaGTase lacked acceptor specificity for puerarin, which lacks an O-glucoside linkage between D-glucose and 7-OH-daidzein. The yield exceeded 70% when reacting 1% puerarin (acceptor), 3.0% soluble starch (donor), and 5U/100 microL BSMA at 55 degrees C for 45 min. The two major transfer products of the BSMA reaction were purified using C(18) and GPC chromatography. Their structures were identified as alpha-d-glucosyl-(1-->6)-puerarin and alpha-D-maltosyl-(1-->6)-puerarin using ESI+ TOF MS-MS and 13C NMR spectroscopy. The solubility of the transfer products was 14 and 168 times higher than that of puerarin, respectively.
Li
Dan
D
National Laboratory for Functional Food Carbohydrate and Center for Agricultural Biomaterials, School of Agricultural Biotechnology, Seoul National University, Shillim-dong, Kwanak-gu, Seoul 151-742, Korea.
Park
Sung-Hoon
SH
Shim
Jae-Hoon
JH
Lee
Hee-Seob
HS
Tang
Shuang-Yan
SY
Park
Cheon-Seok
CS
Park
Kwan-Hwa
KH
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D001411:Geobacillus stearothermophilus / Q000201:enzymology; D006026:Glycoside Hydrolases / Q000737:chemistry*; D006027:Glycosides / Q000138:chemical synthesis*; D006031:Glycosylation; D007529:Isoflavones / Q000138:chemical synthesis / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012995:Solubility
D006027:Glycosides; D007529:Isoflavones; D006026:Glycoside Hydrolases; C120909:glucan 1,4-alpha-maltohydrolase; C033607:puerarin