Silymarin, an extract from milk thistle (Silybum marianum) fruits, is consumed in various food supplements. The metabolism of silymarin flavonolignans in mammals is complex, the exact structure of their metabolites still remains partly unclear and standards are not commercially available. This work is focused on the preparation of sulfated metabolites of silymarin flavonolignans. Sulfated flavonolignans were prepared using aryl sulfotransferase from Desulfitobacterium hafniense and p-nitrophenyl sulfate as a sulfate donor and characterized by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). Their 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and N,N-dimethyl-p-phenylenediamine (DMPD) radical scavenging; ferric (FRAP) and Folin⁻Ciocalteu reagent (FCR) reducing activity; anti-lipoperoxidant potential; and effect on the nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway were examined. Pure silybin A 20-O-sulfate, silybin B 20-O-sulfate, 2,3-dehydrosilybin-20-O-sulfate, 2,3-dehydrosilybin-7,20-di-O-sulfate, silychristin-19-O-sulfate, 2,3-dehydrosilychristin-19-O-sulfate, and silydianin-19-O-sulfate were prepared and fully characterized. Sulfated 2,3-dehydroderivatives were more active in FCR and FRAP assays than the parent compounds, and remaining sulfates were less active chemoprotectants. The sulfated flavonolignans obtained can be now used as authentic standards for in vivo metabolic experiments and for further research on their biological activity.
- Klíčová slova
- Silybum marianum, activity, biotransformation, metabolites, sulfate, sulfotransferase,
- MeSH
- antioxidancia chemie MeSH
- flavonolignany chemie MeSH
- hmotnostní spektrometrie MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární struktura MeSH
- ostropestřec mariánský chemie MeSH
- ovoce chemie MeSH
- potravní doplňky MeSH
- rostliny chemie ultrastruktura MeSH
- scavengery volných radikálů chemie MeSH
- sírany chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antioxidancia MeSH
- flavonolignany MeSH
- scavengery volných radikálů MeSH
- sírany MeSH
Quercetin 3'-O-sulfate is one of the main metabolites of the natural flavonoid quercetin in humans. This study was designed to prepare quercetin 3'-O-sulfate (1), isoquercitrin 4'-O-sulfate (2) and taxifolin 4'-O-sulfate (3) by the sulfation of quercetin, isoquercitrin (quercetin 3-O-glucoside) and taxifolin (2,3-dihydroquercetin) using the arylsulfate sulfotransferase from Desulfitobacterium hafniense, and to examine the effect of sulfation on selected biological properties of the flavonoids tested. We found that flavonoid sulfates 1-3 were weaker DPPH radical scavengers than the corresponding nonsulfated flavonoids, and that 1-3, unlike quercetin, did not induce the expression of either heme oxygenase-1 in RAW264.7 cells or cytochrome P450 1A1 in HepG2 cells. In both cell types, the cell uptake of compounds 1-3 was much lower than that of quercetin, but comparable to that of the glycoside isoquercitrin. Moreover, HPLC/MS metabolic profiling in HepG2 cells showed that flavonoid sulfates 1-3 were metabolized to a limited extent compared to the nonsulfated compounds. We conclude that sulfation of the tested flavonoids reduces their antiradical activity, and affects their cell uptake and biological activity in vitro.
- Klíčová slova
- Antiradical activity, Arylsulfate sulfotransferase, Flavonoids, Gene expression, Metabolism, Sulfate,
- MeSH
- buněčné linie MeSH
- buňky Hep G2 MeSH
- cytochrom P-450 CYP1A1 genetika MeSH
- hemoxygenasa-1 genetika MeSH
- lidé MeSH
- myši MeSH
- quercetin analogy a deriváty chemie metabolismus farmakokinetika farmakologie MeSH
- regulace genové exprese účinky léků MeSH
- scavengery volných radikálů chemie metabolismus farmakokinetika farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- CYP1A1 protein, human MeSH Prohlížeč
- cytochrom P-450 CYP1A1 MeSH
- hemoxygenasa-1 MeSH
- isoquercitrin MeSH Prohlížeč
- quercetin 3'-sulfate MeSH Prohlížeč
- quercetin MeSH
- scavengery volných radikálů MeSH
- taxifolin MeSH Prohlížeč
A panel of lipases was screened for the selective acetylation and alcoholysis of silychristin and silychristin peracetate, respectively. Acetylation at primary alcoholic group (C-22) of silychristin was accomplished by lipase PS (Pseudomonas cepacia) immobilized on diatomite using vinyl acetate as an acetyl donor, whereas selective deacetylation of 22-O-acetyl silychristin was accomplished by Novozym 435 in methyl tert-butyl ether/ n-butanol. Both of these reactions occurred without diastereomeric discrimination of silychristin A and B. Both of these enzymes were found to be capable to regioselective deacetylation of hexaacetyl silychristin to afford penta-, tetra- and tri-acetyl derivatives, which could be obtained as pure synthons for further selective modifications of the parent molecule.
- Klíčová slova
- acetylation, alcoholysis, lipase, silychristin, silymarin,
- MeSH
- acetáty chemická syntéza MeSH
- acetylace MeSH
- bakteriální proteiny metabolismus MeSH
- biokatalýza MeSH
- Burkholderia cepacia enzymologie MeSH
- enzymy imobilizované metabolismus MeSH
- lipasa metabolismus MeSH
- molekulární struktura MeSH
- registrace MeSH
- silymarin chemie MeSH
- stereoizomerie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- acetáty MeSH
- bakteriální proteiny MeSH
- enzymy imobilizované MeSH
- lipasa MeSH
- silychristin MeSH Prohlížeč
- silymarin MeSH
Aryl sulfotransferase IV (AstIV) from rat liver was overexpressed in Escherichia coli and purified to homogeneity. Using the produced mammalian liver enzyme, sulfation-the Phase II conjugation reaction-of optically pure silybin diastereoisomers (silybin A and B) was tested. As a result, silybin B was sulfated yielding 20-O-silybin B sulfate, whereas silybin A was completely resistant to the sulfation reaction. Milligram-scale sulfation of silybin B was optimized employing resting E. coli cells producing AstIV, thus avoiding the use of expensive 3'-phosphoadenosine-5'-phosphate cofactor and laborious enzyme purification. Using this approach, we were able to reach 48 % conversion of silybin B into its 20-sulfate within 24 h. The sulfated product was isolated by solid phase extraction and its structure was characterized by HRMS and NMR. Sulfation reaction of silybin appeared strictly stereoselective; only silybin B was sulfated by AstIV.
- MeSH
- antioxidancia metabolismus MeSH
- arylsulfotransferasa genetika izolace a purifikace metabolismus MeSH
- Escherichia coli genetika MeSH
- játra enzymologie MeSH
- krysa rodu Rattus MeSH
- rekombinantní proteiny genetika izolace a purifikace metabolismus MeSH
- silibinin MeSH
- silymarin metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- arylsulfotransferasa MeSH
- rekombinantní proteiny MeSH
- silibinin MeSH
- silymarin MeSH
Silybin and its congeners belong to a group of flavonolignans with strong biological activities. These compounds are potentially applicable in human medicine, e. g. due to their cytoprotective activity. As a part of herbal preparations available on the open market, they face the risk of potential negative drug-drug interactions. This review aims to evaluate current knowledge on the metabolism of these compounds by biotransformation enzymes, interactions with other drugs, their pharmacokinetics, and bioavailability. While silybin and its derivatives interact with cytochrome P450s, only metabolism of silybin by cytochrome P450 2C8 poses a risk of adverse effects. The main biotransformation route of silybin and derivatives was identified as conjugation, which is stereospecific in case of silybin. Studies of the metabolism, pharmacokinetics, potentional drug--drug interactions and increasing bioavailability of these flavonolignans play an important facet of possible therapeutical use of these compounds. The goal of our review is to aid future developments in the area of silybin research.
- MeSH
- antioxidancia chemie metabolismus farmakokinetika MeSH
- biologická dostupnost MeSH
- biotransformace MeSH
- glukuronidy metabolismus MeSH
- lidé MeSH
- silibinin MeSH
- silymarin analogy a deriváty chemie metabolismus farmakokinetika MeSH
- stereoizomerie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- antioxidancia MeSH
- glukuronidy MeSH
- silibinin MeSH
- silymarin MeSH
Two selective acylation methods for silybin esterification with long-chain fatty acids were developed, yielding a series of silybin 7-O- and 23-O-acyl-derivatives of varying acyl chain lengths. These compounds were tested for their antioxidant (inhibition of lipid peroxidation and DPPH-scavenging) and anti-influenza virus activities. The acyl chain length is an important prerequisite for both biological activities, as they improved with increasing length of the acyl moiety.
- MeSH
- acylace MeSH
- antioxidancia farmakologie MeSH
- antivirové látky farmakologie MeSH
- buněčné linie MeSH
- esterifikace MeSH
- magnetická rezonanční spektroskopie MeSH
- mastné kyseliny farmakologie MeSH
- molekulární struktura MeSH
- Orthomyxoviridae účinky léků MeSH
- psi MeSH
- silibinin MeSH
- silymarin farmakologie MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- antivirové látky MeSH
- mastné kyseliny MeSH
- silibinin MeSH
- silymarin MeSH
