calycosin-7-o-beta-d-glucopyranoside and daidzin

Hydrolysis by lactase-phloridzin hydrolase (LPH) is the first and critical step in the absorption of isoflavonoid glucosides. However, the absorption characteristics of calycosin-7-O-β-d-glucoside (CG) slightly differ from other isoflavonoid glucosides. In this study, we used the rat intestinal perfusion model and performed pharmacokinetic studies and in vitro experiments to determine the factors influencing CG absorption and disposition. After oral administration of isoflavonoid glucosides, LPH was found to play minimal or no role on the hydrolysis of CG, in contrast to that of daidzin. CG was mainly transported into the small intestinal cells by sodium-dependent glucose transporter 1 (SGLT-1) as intact. This pathway could be the main mechanism underlying the high permeability of CG in the small intestine. CG was likely to be hydrolyzed in enterocytes to its aglycone calycosin by broad-specific β-glucuronides (BSβG) and glucocerebrosidase or rapidly metabolized. Calycosin was also rapidly and extensively metabolized to 3'-glucuronide in the enterocytes and liver, and the glucuronidation rates of calycosin and CG were much higher in the former. The metabolites were also transported into lumen by breast cancer resistance protein and multidrug resistance-associated protein 2. In conclusion, the enterocytes could be an important site for CG absorption, deglycosylation, and metabolism in rats. This study could contribute to the theoretical foundation and mechanism of absorption and disposition of flavonoid compounds.

Topics: Animals; Caco-2 Cells; Cell Line, Tumor; Enterocytes; Glucosides; Glucosylceramidase; Glucuronides; Glycosylation; Humans; Intestinal Absorption; Intestine, Small; Isoflavones; Male; Permeability; Protein Transport; Rats; Rats, Sprague-Dawley; Sodium-Glucose Transporter 1

A new flavonoid glycoside, hesperetin-7-O-[β-D-glucopyranosyl-(1 → 3)]-β-D-glucopyranosyl (1), was isolated from the n-BuOH extract of Smilax scobinicaulis, together with four known flavonoid glycosides, clematine (2), ononin (3), daidzin (4) and puerarin (5). All of the five compounds were reported from this material for the first time. Their structures were determined on the basis of spectroscopic and spectrometric methods.

Topics: Drugs, Chinese Herbal; Flavonoids; Glucosides; Glycosides; Hesperidin; Isoflavones; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Plant Roots; Rhizome; Smilax

A novel isoflavone 7- O -glucosyltransferase PlUGT1 was isolated from Pueraria lobata . PlUGT1 could convert daidzein to daidzin, genistein to genistin as well as formononetin to ononin. Pueraria lobata roots are traditionally consumed as a rich source of isoflavone glycosides that have various human health benefits. However, to date, the genes encoding isoflavone UDP-glycosyltransferases (UGTs) have only been isolated from the roots of soybean seedlings (GmIF7GT), soybean seeds (UGT73F2) and Glycyrrhiza echinata cell suspension cultures (GeIF7GT). To investigate the isoflavone metabolism in P. lobata, 40 types of partial UGT cDNAs were isolated from P. lobata, and seven full-length UGT candidates with preferential expression in roots were identified. Functional assays in yeast (Saccharomyces cerevisiae) revealed that one of these UGT candidates, designated PlUGT1 (official UGT designation UGT88E12), efficiently glycosylated isoflavone aglycones at the 7-hydroxy group. Recombinant PlUGT1 purified from Escherichia coli cells was characterized and shown to be relatively specific for isoflavone aglycones, while flavonoid substrates were poorly accepted. The biochemical results suggested that PlUGT1 was an isoflavone 7-O-glucosyltransferase. The deduced amino acid sequence of PlUGT1 shared only 26 % identity with GeIF7GT, 27 % with UGT73F2 and 63 % with GmIF7GT. The PlUGT1 gene was highly expressed in P. lobata roots relative to other organs and strongly induced by methyl jasmonate signal in P. lobata cell suspension culture. The transcript abundance of PlUGT1 was correlated with the accumulation pattern of isoflavone glycosides such as daidzin in P. lobata plants or in cell suspension culture. The biochemical properties and gene expression profile supported the idea that PlUGT1 could play a role in isoflavone glycosylation in P. lobata.

Topics: Acetates; Cloning, Molecular; Cyclopentanes; Glucosides; Glucosyltransferases; Isoflavones; Molecular Sequence Data; Oxylipins; Phylogeny; Plant Proteins; Plant Roots; Pueraria

To investigate the isoflavones from the vines of Pueraria lobata.. The compounds were isolated by column chromatography over silica gel and RP-C18, and purified by Sephadex LH-20 column chromatography and preparative TLC. The structures were elucidated on the basis of physico-chemical properties and spectral data.. Twelve compounds were isolated and identified as: 3'-methoxydaidzein (1), formononetin (2), genistein (3), daidzein (4), daidzin (5), genistin (6), ononin (7), 5-hydroxyl ononin (8), calycosin (9), 6"-O-acetyl genistein (10), 6"-O-acetyl daidzin (11), puerarin (12).. For the first time, compounds 9-11 were isolated from the genus Pueraria plant, and compounds 1, 3, 6-8 were obtained from the vines of this plant.

Topics: Genistein; Glucosides; Isoflavones; Magnetic Resonance Spectroscopy; Plant Stems; Pueraria