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1.
Nat Commun ; 11(1): 4864, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978392

RESUMO

The synthesis of customized glycoconjugates constitutes a major goal for biocatalysis. To this end, engineered glycosidases have received great attention and, among them, thioglycoligases have proved useful to connect carbohydrates to non-sugar acceptors. However, hitherto the scope of these biocatalysts was considered limited to strong nucleophilic acceptors. Based on the particularities of the GH3 glycosidase family active site, we hypothesized that converting a suitable member into a thioglycoligase could boost the acceptor range. Herein we show the engineering of an acidophilic fungal ß-xylosidase into a thioglycoligase with broad acceptor promiscuity. The mutant enzyme displays the ability to form O-, N-, S- and Se- glycosides together with sugar esters and phosphoesters with conversion yields from moderate to high. Analyses also indicate that the pKa of the target compound was the main factor to determine its suitability as glycosylation acceptor. These results expand on the glycoconjugate portfolio attainable through biocatalysis.


Assuntos
Tolerância a Medicamentos/fisiologia , Fungos/enzimologia , Fungos/metabolismo , Xilosidases/química , Xilosidases/metabolismo , Biocatálise , Domínio Catalítico , Fungos/efeitos dos fármacos , Glicoconjugados/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosídeos/química , Glicosilação , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Mutagênese , Especificidade por Substrato , Talaromyces/enzimologia , Talaromyces/genética , Xilosidases/genética
2.
Chemistry ; 26(45): 10222-10225, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32567165

RESUMO

The first total synthesis of terpioside B (1) has been accomplished. Key steps include the stereoselective installments of a set of challenging 1,2-cis-glycosidic linkages. Thus, α(1,4)-linked d-galactoside was effectively constructed from a 1,2-anhydrogalactose donor and an unprotected 1,6-anhydrogalactose acceptor by using a boron-mediated aglycon delivery (BMAD) method. In addition, α-l-fucofuranosides were stereoselectively and simultaneously constructed by remote group-assisted 1,2-cis-α-stereoselective glycosylations.


Assuntos
Boro/química , Glicolipídeos/síntese química , Glicosídeos/química , Glicolipídeos/química , Glicosilação
3.
Int J Biol Macromol ; 161: 936-938, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32534094

RESUMO

This short report is dedicated to the description of the wide antiviral and antibacterial activity of the immune-modulating agent Panavir®. Panavir® is a high-molecular-weight fraction of the polysaccharides extracted from the shoots of the Solanum tuberosum. It demonstrates activity against many types of viruses, including animal coronavirus and also against bacterial infections. These properties look very promising considering the COVID-19 epidemy and allow propose that Panavir® would be effective in the therapy of the SARS-CoV-2 infection.


Assuntos
Antivirais/farmacologia , Glicosídeos/farmacologia , Herpes Genital/tratamento farmacológico , Adulto , Animais , Antivirais/química , Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Disenteria Bacilar/tratamento farmacológico , Feminino , Glicosídeos/química , Glicosídeos/uso terapêutico , Humanos , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Camundongos , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Shigella flexneri/efeitos dos fármacos , Adulto Jovem
4.
Food Chem ; 324: 126871, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32344346

RESUMO

Flavones are important bioactive flavonoids in cereal grains, but are poorly characterized. This study investigated rye flavone profile as influenced by phenotype (grain color), sourdough fermentation, and subsequent heat processing. Twelve rye varieties belonging to 4 phenotypes were characterized using UPLC-tandem quadrupole MS before and after fermentation and baking. Antioxidant properties were also assessed. Rye flavones (range 57-137 µg/g) were dominated by O-glycosides (50-68%), present as derivatives of tricin (exclusively O-glycosides), chrysoeriol (O-/C-glycosides), and apigenin (exclusively C-glycosides). Phenotype did not influence flavone content. Fermentation partially hydrolyzed O-glycosides to their aglycones, but did not affect C-glycosides. Extractable phenols and antioxidants increased 1.9-3.6X after 96-h fermentation; baking further increased these components by 36-96% in fermented samples, likely via enhanced cell wall disruption. The high proportion of flavone-O-glycosides in rye is of interest due to their known higher bioavailability relative to typical cereal grain C-glycosides.


Assuntos
Antioxidantes/química , Flavonas/química , Flavonoides/química , Secale/química , Cromatografia Líquida de Alta Pressão , Flavonas/análise , Flavonoides/análise , Glicosídeos/análise , Glicosídeos/química , Temperatura Alta , Espectrometria de Massas , Fenóis/análise , Fenóis/química , Secale/metabolismo
5.
Zhongguo Zhong Yao Za Zhi ; 45(5): 1114-1119, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32237454

RESUMO

Polygonflavanol B(1), a new flavonostilbene glycoside, was isolated from the roots of Polygonum multiforum(Polygonaceae) by various column chromatography methods including macroporous resin HP-20, silica gel, Sephadex LH-20, and preparative HPLC. The structure with absolute configuration of the new compound was identified by its physicochemical properties, spectroscopic data, ECD calculation, and chemical method.


Assuntos
Fallopia multiflora/química , Flavonóis/química , Glicosídeos/química , Raízes de Plantas/química , Estilbenos/química , Flavonóis/isolamento & purificação , Glicosídeos/isolamento & purificação , Estilbenos/isolamento & purificação
6.
Z Naturforsch C J Biosci ; 75(3-4): 121-128, 2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32267249

RESUMO

Plants of the Plantago genus are widely used in Turkish folk medicine especially for the treatment of wound, abscess, and inflammation. The aqueous extract and five phenylethanoid glycosides acteoside (1), arenarioside (2), echinacoside (3), isoacteoside (4), and leucosceptoside A (5) isolated from the aerial parts and roots of Plantago holosteum Scop. (Plantaginaceae) were tested for their possible inhibitory activity against hyaluronidase, elastase, and collagenase, related to wound pathogenesis. Even though the aqueous extract prepared from the aerial parts (36.26%) and roots (47.01%) and the isolated compounds acteoside (29.13%), echinacoside (28.73%), and isoacteoside (31.69%) exerted a notable inhibition, arenarioside and leucosceptoside A were found inactive in the hyaluronidase enzyme inhibition test. Similar results were obtained from the collagenase enzyme inhibition test. The aqueous extract prepared from the aerial parts (31.09%) and roots (35.17%), echinacoside (25.13%), and isoacteoside (23.85%) exerted a notable inhibition in this test. However, none of the extracts and isolated compounds displayed elastase enzyme inhibitory activity. The experimental data demonstrated that P. holosteum displayed a remarkable enzyme inhibitory activity against hyaluronidase and collagenase. This paper is the first report regarding the in vitro enzyme inhibitory activity of P. holosteum.


Assuntos
Colagenases/metabolismo , Glicosídeos/farmacologia , Hialuronoglucosaminidase/antagonistas & inibidores , Elastase Pancreática/antagonistas & inibidores , Plantago/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Glicosídeos/química , Humanos , Medicina Tradicional , Estrutura Molecular , Fenóis/química , Fenóis/farmacologia , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Raízes de Plantas/química , Turquia
7.
Food Chem ; 321: 126644, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247886

RESUMO

Genetics and environment both influence the content of hop (Humulus lupulus L.) aroma compounds. The effects of these two factors on aroma glycosides, which can change the aroma profile of beer over time, were examined in a preliminary study. Twenty-three hop cultivars were grown in the northwestern United States in two locations with distinct terroirs. UPLC-MS/MS analysis of hop cone extracts revealed that growing location had a large effect on hexyl glucoside levels but only a negligible effect on levels of linalyl, raspberry ketone, and 2-phenylethyl glucoside, which were mostly affected by genetic differences. The large terroir effect on hexyl glucoside, which releases a green leaf volatile with a grassy aroma when hydrolyzed, but not on the other aroma glucosides, which have more desirable aromas when hydrolyzed, could have an impact on beer aroma profiles.


Assuntos
Glucosídeos/análise , Glicosídeos/química , Humulus/química , Odorantes/análise , Cromatografia Líquida de Alta Pressão , Cor , Glucosídeos/química , Glicosilação , Estrutura Molecular , Folhas de Planta/química , Espectrometria de Massas em Tandem
8.
Org Biomol Chem ; 18(12): 2242-2251, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-32159571

RESUMO

An efficient palladium(ii) mediated C-glycosylation of glycals with diaryliodonium salts is described, providing a new strategy for the synthesis of 2,3-dideoxy C-aryl glycosides with excellent stereoselectivity. The C-glycosylation of a diverse range of glycals, including d-glucal, d-galactal, d-allal, l-rhamnal, l-fucal, l-arabinal, d-maltal, and d-lactal, occurred effectively and the corresponding C-glycosides were obtained in moderate to good yields. This protocol is commended as a significant addition to the field of carbohydrate chemistry due to the rich functional group compatibility, broad range of substrate scope and exceptional α-stereoselectivity.


Assuntos
Éteres Cíclicos/química , Glicosídeos/síntese química , Paládio/química , Catálise , Glicosídeos/química , Glicosilação , Polissacarídeos/química , Sais/química , Estereoisomerismo
9.
Org Biomol Chem ; 18(14): 2696-2701, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32206767

RESUMO

S-Glycosides are important tools for the elucidation of specific protein-carbohydrate interactions and can significantly aid structural and functional studies of carbohydrate-active enzymes, as they are often inert or act as enzyme inhibitors. In this context, this work focuses on the introduction of an S-linkage into arabinoxylan oligosaccharides (AXs) in order to obtain a small collection of synthetic tools for the study of AXs degrading enzymes. The key step for the introduction of the S-glycosidic linkage involved anomeric thiol S-alkylation of an orthogonally protected l-arabinopyranoside triflate. The resulting S-linked disaccharide was subsequently employed in a series of glycosylation reactions to obtain a selectively protected tetrasaccharide. This could be further elaborated through chemoselective deprotection and glycosylation reactions to introduce branching l-arabinofuranosides.


Assuntos
Glicosídeos/química , Oligossacarídeos/química , Xilanos/química , Arabinose/análogos & derivados , Arabinose/química , Reagentes para Ligações Cruzadas/química , Dissacarídeos/síntese química , Glicosilação , Compostos de Sulfidrila/química
10.
J Chromatogr A ; 1620: 461036, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32201039

RESUMO

Leaves, flowers, fruits and stems (44 sample groups) were collected from mature Camptotheca acuminate during 2017.3-2018.3 and classified by ultra-high performance liquid chromatography coupled with quadrupole-time of flight-mass spectrometry based metabolomics. One hundred metabolites including forty-seven alkaloids, fifteen terpenes, thirty-two polyphenols and six other metabolites were rapidly identified through the in-house database alignment at first glance. Thirty-three alkaloids classified into five groups including camptothecin group (CG1-13), pumiloside group (PG1-5), strictosidinic acid group (SG1-3), vincosamide group (VG1-7), and a new hybrid group, vincosamide-camptothecin group (VC1-5) were mined and further characterized by MS/MS analyses. The identification of two untapped biosynthetic precursors, 2-hydroxypumiloside (PG2) and 16­hydroxy­15, 16-dihydrocamptothecoside (CG3), along with sixteen new alkaloids enables us for a better understanding of camptothecin biogenetic reasoning. The underlying enzymes involved in camptothecin biosynthesis were also proposed according to the guiding metabolic map, thus purposefully mining of enzymes involved in the downstream biosynthetic pathway of camptothecin could be initiated with the help of this map.


Assuntos
Alcaloides/análise , Vias Biossintéticas , Camptotheca/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Camptotecina/análogos & derivados , Camptotecina/análise , Camptotecina/química , Camptotecina/metabolismo , Carbolinas/análise , Carbolinas/química , Bases de Dados como Assunto , Análise Discriminante , Glicosídeos/análise , Glicosídeos/química , Alcaloides Indólicos/análise , Alcaloides Indólicos/química , Análise dos Mínimos Quadrados , Redes e Vias Metabólicas , Metaboloma , Metabolômica , Análise Multivariada , Análise de Componente Principal
11.
Chem Pharm Bull (Tokyo) ; 68(3): 273-287, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32115535

RESUMO

Phytochemical analysis of the whole Helleborus foetidus plants identified 28 steroidal glycosides (1-28), including 20 novel spirostanol glycosides (1-20) and a novel furostanol glycoside (21). The structures of the newly identified compounds were elucidated by two-dimensional NMR spectroscopy and hydrolytic cleavage. Compounds 12, 13, and 15 were determined to be spirostanol trisdesmosides bearing sugar moieties at the C-1, -21, and -24 hydroxy groups of the aglycone unit. The isolated compounds were subsequently evaluated for cytotoxic activity against HL-60 human promyelocytic leukemia cells and A549 human lung carcinoma cells. In particular, 7 showed cytotoxic activity against the HL-60 and A549 cells, with IC50 values of 5.9 and 6.6 µM, respectively, whereas 19 was selectively cytotoxic to A549 cells with an IC50 value of 5.5 µM.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Glicosídeos/farmacologia , Helleborus/química , Compostos Fitoquímicos/farmacologia , Esteroides/farmacologia , Células A549 , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glicosídeos/química , Glicosídeos/isolamento & purificação , Células HL-60 , Humanos , Conformação Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Esteroides/química , Esteroides/isolamento & purificação , Relação Estrutura-Atividade
12.
Org Biomol Chem ; 18(7): 1343-1348, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-32003394

RESUMO

Reported herein is a practical route to access synthetically challenging and chemoselective α,α'-diarylmethyl N-glycosides via Sc(OTf)3-catalyzed 1,6-conjugate addition of amino sugars with para-quinone methides (p-QMs). The reactions proceed smoothly without a base and under mild reaction conditions with a broad substrate scope and moderate to good yields.


Assuntos
Aminas/química , Benzoquinonas/química , Carboidratos/química , Glicosídeos/síntese química , Glicosídeos/química , Estrutura Molecular , Estereoisomerismo
13.
Carbohydr Res ; 488: 107905, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32004953

RESUMO

A series of 19 synthetic alkyl and thioalkyl glycosides derived from d-mannose, d-glucose and d-galactose and having C10-C16 aglycone were investigated for cytotoxic activity against 7 human cancer and 2 non-tumor cell lines as well as for antimicrobial potential on 12 bacterial and yeast strains. The most potent compounds were found to be tetradecyl and hexadecyl ß-d-galactopyranosides (18, 19), which showed the best cytotoxicity and therapeutic index against CCRF-CEM cancer cell line. Similar cytotoxic activity showed hexadecyl α-d-mannopyranoside (5) but it also inhibited non-tumor cell lines. Because these two galactosides (18, 19) were inactive against all tested bacteria and yeast strains, they could be a target-specific for eukaryotic cells. On the other hand, ß-D-glucopyranosides with tetradecyl (11) and hexadecyl (12) aglycone inhibited only Gram-positive bacterial strain Enterococcus faecalis. The studied glycosides induce changes in the lipid bilayer thickness and lateral phase separation at high concentration, as derived from SAXS experiments on POPC model membranes. In general, glucosides and galactosides exhibit more specific properties. Those with longer aglycone show high cytotoxicity and therefore, they are more promising candidates for cancer cell line targeted inhibition.


Assuntos
Antibacterianos/síntese química , Antineoplásicos/síntese química , Enterococcus faecalis/efeitos dos fármacos , Glicosídeos/síntese química , Bicamadas Lipídicas/química , Células A549 , Antibacterianos/química , Antibacterianos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Sequência de Carboidratos , Linhagem Celular , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Galactose/síntese química , Galactose/química , Galactose/farmacologia , Glicosídeos/química , Glicosídeos/farmacologia , Células HCT116 , Humanos , Células K562 , Testes de Sensibilidade Microbiana , Estrutura Molecular , Espalhamento a Baixo Ângulo , Difração de Raios X
14.
Z Naturforsch C J Biosci ; 75(1-2): 51-56, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32053496

RESUMO

The leaves of Garcinia epunctata Stapf have furnished two new phenolic glucosides, epunctosides A and B, along with 13 known secondary metabolites identified as lanceoloside A, betulinic acid, lupeol, stigmasterol, ß-sitosterol, ß-sitosterol-3-O-ß-d-glucopyranoside, stigmasterol-3-O-ß-d-glucopyranoside, luteolin-7-O-glucoside, quercitin-7-O-glucoside, amentoflavone, robustaflavone, 4'-O-methyl-amentoflavone and 4'-O-methyl-robustaflavone. All structures were established from chemical and spectroscopic evidence including 1D and 2D NMR data as well as by comparing the obtained spectroscopic data with literature. This is the first report of the presence of phenolic glucosides in the genus Garcinia.


Assuntos
Garcinia/química , Glicosídeos/química , Fenóis/química , Folhas de Planta/química , Biflavonoides/química , Glicosídeos/isolamento & purificação , Triterpenos Pentacíclicos/química , Fenóis/isolamento & purificação , Metabolismo Secundário/genética , Sitosteroides/química , Estigmasterol/química , Triterpenos/química
15.
Biomed Chromatogr ; 34(4): e4807, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32020626

RESUMO

Periplocae Cortex, named Xiang-Jia-Pi in China, has been widely used to treat autoimmune diseases, especially rheumatoid arthritis. However, the in vivo substances of Periplocae Cortex remain unknown yet. In this study, an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used for profiling the chemical components and related metabolites of Periplocae Cortex. A total of 98 constituents were identified or tentatively characterized in Periplocae Cortex: 42 C21 steroidal glycosides, 10 cardiac glycosides, 23 organic acids, 4 aldehydes, 7 triterpenes, and 12 other types. Among them, 18 components were unambiguously identified by comparison with reference standards. In addition, 176 related xenobiotics (34 prototypes and 142 metabolites) were screened out and characterized in rats' biosamples (plasma, urine, bile, and feces) after the oral administration of Periplocae Cortex. Moreover, the metabolic fate of periplocoside S-4a, a C21 steroidal glycoside, was proposed for the first time. In summary, phase II reactions (methylation, glucuronidation, and sulfation), phase I reactions (hydrolysis reactions, oxygenation, and reduction), and their combinations were the predominant metabolic reactions of Periplocae Cortex in rat. It is the first report to reveal the in vivo substances and metabolism feature of Periplocae Cortex. This study also provided meaningful information for further pharmacodynamics study of Periplocae Cortex, as well as its quality control research.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/análise , Medicamentos de Ervas Chinesas/metabolismo , Espectrometria de Massas/métodos , Periploca/química , Administração Oral , Aldeídos/análise , Aldeídos/química , Animais , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/química , Glicosídeos/análise , Glicosídeos/química , Masculino , Casca de Planta/química , Raízes de Plantas/química , Ratos , Ratos Sprague-Dawley , Triterpenos/análise , Triterpenos/química
16.
Nutrients ; 12(1)2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31936273

RESUMO

Wikstroemia indica (L.) C.A. Mey. is used in traditional Chinese medicine to treat inflammatory diseases such as arthritis and bronchitis. In this study, we aimed to investigate the effects of an ethanolic extract of W. indica on cutaneous inflammation in mice with 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD). Dermal administration of W. indica ethanolic extract to DNCB-sensitized hairless mice with dermatitis, for two weeks, reduced erythema, scaling, and edema. Skin hydration was improved and transepidermal water loss was reduced at a W. indica concentration of 1%. Furthermore, W. indica also significantly reduced serum IgE and IL-4 concentrations in our mouse model. These results suggest that W. indica has potential as a topical treatment for AD and as an adjunctive agent to control AD.


Assuntos
Dermatite Atópica/tratamento farmacológico , Dinitroclorobenzeno/toxicidade , Extratos Vegetais/uso terapêutico , Wikstroemia/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Citocinas/genética , Citocinas/metabolismo , Dermatite Atópica/induzido quimicamente , Regulação da Expressão Gênica/efeitos dos fármacos , Glicosídeos/química , Camundongos , Extratos Vegetais/química , Baço/citologia
17.
J Steroid Biochem Mol Biol ; 199: 105592, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31953168

RESUMO

In the plant kingdom, steroidal lactones occur as glycosides, compounds consisting of a sugar moiety linked to a steroid aglycone. Steroidal lactones consist of five fused rings, with a total of 22 carbon atoms. Numerous methods for the preparation of steroidal lactones take advantage of the fact that steroid spirostanes may be degraded from six- to a five-rings structure. One of the most striking features common to reactions of steroid sapogenins is the C22-lactone formation. In the review, different methods for the preparation of steroidal lactones are presented with consideration of the structure of starting material. In addition, examples of lactones used in the synthesis of biologically active compounds and their analogues are described.


Assuntos
Glicosídeos/química , Lactonas/química , Esteroides/química , Radioisótopos de Carbono/química , Estrutura Molecular , Sapogeninas/química , Espirostanos/química , Esteroides/biossíntese
18.
Carbohydr Res ; 488: 107901, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31911361

RESUMO

Synthesis of novel mono- and di-O-protected l-arabinofuranoside derivatives was described via regioselective base-catalyzed acylations of methyl α- and ß-l-arabinofuranosides with acyl chlorides. A new method for selective 3(2)-O-acylation of 5-O-silyl (trityl) l-arabinofuranosides was investigated based upon generation of organoboron compounds using l-Selectride and subsequent reaction of salt carbohydrate species with pivaloyl or 4-chlorobenzoyl chloride as the electrophile. Syntheses of methyl 2,3-anhydro-l-furanosides were accomplished from selectively protected methyl l-arabinofuranosides. 2(3)-Deoxy-l-pentofuranosides, including 2-deoxy-l-ribofuranoside, and their 5-O-blocked derivatives were prepared by stereoselective reductions of 2,3-anhydro-l-furanosides with l-Selectride.


Assuntos
Arabinose/análogos & derivados , Glicosídeos/síntese química , Acilação , Arabinose/química , Catálise , Cromatografia em Camada Delgada , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Estereoisomerismo
19.
Carbohydr Res ; 488: 107908, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31927345

RESUMO

Three new triacetic acid lactone (TAL) glycosides, forsyphensides A-C (1-3) were isolated from the fruits of Forsythia suspensa. Their structures were elucidated by comprehensive spectroscopic techniques. The absolute configurations of their monosaccharides were determined by GC analysis. Notably, forsyphensides A-C were relatively rare TAL glycosides identified from plants. Compound 1 exhibited inhibitory activity against the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in microglia BV2 cells with the inhibition rate of 69.40%.


Assuntos
Forsythia/química , Glicosídeos/química , Microglia/metabolismo , Pironas/química , Animais , Sequência de Carboidratos , Linhagem Celular , Glicosídeos/farmacologia , Lipopolissacarídeos/efeitos adversos , Camundongos , Microglia/citologia , Microglia/efeitos dos fármacos , Estrutura Molecular , Óxido Nítrico/metabolismo , Extratos Vegetais/química , Pironas/farmacologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-31931331

RESUMO

Ptaquiloside (PTA) is an illudane glycoside partly responsible for the carcinogenicity of bracken ferns (Pteridium sp.). The PTA analogues ptesculentoside (PTE) and caudatoside (CAU) have similar biochemical reactivity. However, both compounds are highly under-investigated due to the lack of analytical standards and appropriate methods. This study presents a robust method for preparation of analytical standards of PTE, CAU, PTA, the corresponding hydrolysis products: pterosins G, A and B, and an LC-MS based method for simultaneous quantification of the six compounds in bracken. The chromatographic separation of analytes takes 5 min. The observed linear range of quantification was 20-500 µg/L for PTA and pterosin B, and 10-250 µg/L for the remaining compounds (r > 0.999). The limits of detection were 0.08-0.26 µg/L for PTE, CAU and PTA and 0.01-0.03 µg/L for the pterosins, equivalent to 2.0-6.5 µg/g and 0.25-0.75 µg/g in dry weight, respectively. The method was applied on 18 samples of dried fern leaves from 6 continents. Results demonstrated high variation in concentrations of PTE, CAU and PTA with levels prior to hydrolysis up to 3,900, 2,200 and 2,100 µg/g respectively. This is the first analytical method for simultaneous and direct measurement of all six compounds. Its application demonstrated that bracken ferns contain significant amounts of PTE and CAU relative to PTA.


Assuntos
Cromatografia Líquida/métodos , Glicosídeos , Indanos , Pteridium/química , Sesquiterpenos , Glicosídeos/análise , Glicosídeos/química , Indanos/análise , Indanos/química , Limite de Detecção , Modelos Lineares , Espectrometria de Massas/métodos , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Extratos Vegetais/química , Sesquiterpenos Policíclicos/análise , Sesquiterpenos Policíclicos/química , Reprodutibilidade dos Testes , Sesquiterpenos/análise , Sesquiterpenos/química
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