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1.
J Agric Food Chem ; 72(13): 7203-7218, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38518258

RESUMO

Diabetes complications are associated with aldose reductase (AR) and advanced glycation end products (AGEs). Using bioassay-guided isolation by column chromatography, 10 flavonoids and one coumarin were isolated from Poncirus trifoliata Rafin and tested in vitro for an inhibitory effect against human recombinant AR (HRAR) and rat lens AR (RLAR). Prunin, narirutin, and naringin inhibited RLAR (IC50 0.48-2.84 µM) and HRAR (IC50 0.68-4.88 µM). Docking simulations predicted negative binding energies and interactions with the RLAR and HRAR binding pocket residues. Prunin (0.1 and 12.5 µM) prevented the formation of fluorescent AGEs and nonfluorescent Nε-(carboxymethyl) lysine (CML), as well as the fructose-glucose-mediated protein glycation and oxidation of human serum albumin (HSA). Prunin suppressed the formation of the ß-cross-amyloid structure of HSA. These results indicate that prunin inhibits oxidation-dependent protein damage, AGE formation, and AR, which may help prevent diabetes complications.


Assuntos
Complicações do Diabetes , Cristalino , Florizina/análogos & derivados , Poncirus , Ratos , Humanos , Animais , Glucose/farmacologia , Poncirus/metabolismo , Reação de Maillard , Produtos Finais de Glicação Avançada/metabolismo , Albumina Sérica Humana , Aldeído Redutase/metabolismo , Frutose
2.
Enzyme Microb Technol ; 175: 110410, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38340378

RESUMO

Prunin of desirable bioactivity and bioavailability can be transformed from plant-derived naringin by the key enzyme α-L-rhamnosidase. However, the production was limited by unsatisfactory properties of α-L-rhamnosidase such as thermostability and organic solvent tolerance. In this study, biochemical characteristics, and hydrolysis capacity of a novel α-L-rhamnosidase from Spirochaeta thermophila (St-Rha) were investigated, which was the first characterized α-L-rhamnosidase for Spirochaeta genus. St-Rha showed a higher substrate specificity towards naringin and exhibited excellent thermostability and methanol tolerance. The Km of St-Rha in the methanol cosolvent system was decreased 7.2-fold comparing that in the aqueous phase system, while kcat/Km value of St-Rha was enhanced 9.3-fold. Meanwhile, a preliminary conformational study was implemented through comparative molecular dynamics simulation analysis to explore the mechanism underlying the methanol tolerance of St-Rha for the first time. Furthermore, the catalytic ability of St-Rha for prunin preparation in the 20% methanol cosolvent system was explored, and 200 g/L naringin was transformed into 125.5 g/L prunin for 24 h reaction with a corresponding space-time yield of 5.2 g/L/h. These results indicated that St-Rha was a novel α-L-rhamnosidase suitable for hydrolyzing naringin in the methanol cosolvent system and provided a better alternative for improving the efficient production yield of prunin.


Assuntos
Florizina/análogos & derivados , Spirochaeta , Metanol , Glicosídeo Hidrolases/química , Solventes
3.
J Microbiol Biotechnol ; 31(3): 419-428, 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32627762

RESUMO

To efficiently recycle GH78 thermostable rhamnosidase (TpeRha) and easily separate it from the reaction mixture and furtherly improve the enzyme properties, the magnetic particle Fe3O4-SiO2-NH2-Cellu-ZIF8 (FSNcZ8) was prepared by modifying Fe3O4-NH2 with tetraethyl silicate (TEOS), microcrystalline cellulose and zinc nitrate hexahydrate. FSNcZ8 displayed better magnetic stability and higher-temperature stability than unmodified Fe3O4-NH2 (FN), and it was used to adsorb and immobilize TpeRha from Thermotoga petrophilea 13995. As for properties, FSNcZ8-TpeRha showed optimal reaction temperature and pH of 90°C and 5.0, while its highest activity approached 714 U/g. In addition, FSNcZ8-TpeRha had better higher-temperature stability than FN. After incubation at 80°C for 3 h, the residual enzyme activities of FSNcZ8-TpeRha, FN-TpeRha and free enzyme were 93.5%, 63.32%, and 62.77%, respectively. The organic solvent tolerance and the monosaccharides tolerance of FSNcZ8-TpeRha, compared with free TpeRha, were greatly improved. Using naringin (1 mmol/l) as the substrate, the optimal conversion conditions were as follows: FSNcZ8-TpeRha concentration was 6 U/ml; induction temperature was 80°C; the pH was 5.5; induction time was 30 min, and the yield of products was the same as free enzyme. After repeating the reaction 10 times, the conversion of naringin remained above 80%, showing great improvement of the catalytic efficiency and repeated utilization of the immobilized α-L-rhamnosidase.


Assuntos
Enzimas Imobilizadas/química , Flavanonas/metabolismo , Glicosídeo Hidrolases/química , Nanopartículas de Magnetita/química , Florizina/análogos & derivados , Adsorção , Proteínas de Bactérias/química , Biocatálise , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio , Fenômenos Magnéticos , Florizina/biossíntese , Proteínas Recombinantes/química , Thermotoga/enzimologia
4.
Sci Transl Med ; 11(516)2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666401

RESUMO

Human enterovirus A71 (HEVA71) causes hand, foot, and mouth disease (HFMD) in young children and is considered a major neurotropic pathogen but lacks effective antivirals. To identify potential therapeutic agents against HFMD, we screened a 502-compound flavonoid library for compounds targeting the HEVA71 internal ribosome entry site (IRES) that facilitates translation of the HEVA71 genome and is vital for the production of HEVA71 viral particles. We validated hits using cell viability and viral plaque assays and found that prunin was the most potent inhibitor of HEVA71. Downstream assays affirmed that prunin disrupted viral protein and RNA synthesis and acted as a narrow-spectrum antiviral against enteroviruses A and B, but not enterovirus C, rhinovirus A, herpes simplex 1, or chikungunya virus. Continuous HEVA71 passaging with prunin yielded HEVA71-resistant mutants with five mutations that mapped to the viral IRES. Knockdown studies showed that the mutations allowed HEVA71 to overcome treatment-induced suppression by differentially regulating recruitment of the IRES trans-acting factors Sam68 and hnRNPK without affecting the hnRNPA1-IRES interaction required for IRES translation. Furthermore, prunin effectively reduced HEVA71-associated clinical symptoms and mortality in HEVA71-infected BALB/c mice and suppressed hepatitis C virus at higher concentrations, suggesting a similar mechanism of prunin-mediated IRES inhibition for both viruses. These studies establish prunin as a candidate for further development as a HEVA71 therapeutic agent.


Assuntos
Enterovirus Humano A/fisiologia , Infecções por Enterovirus/tratamento farmacológico , Infecções por Enterovirus/virologia , Sítios Internos de Entrada Ribossomal , Florizina/análogos & derivados , Animais , Antibacterianos/farmacologia , Morte Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Avaliação Pré-Clínica de Medicamentos , Farmacorresistência Viral/efeitos dos fármacos , Farmacorresistência Viral/genética , Flavonoides/farmacologia , Genes Reporter , Hepacivirus/efeitos dos fármacos , Ribonucleoproteína Nuclear Heterogênea A1/metabolismo , Humanos , Sítios Internos de Entrada Ribossomal/genética , Luciferases/metabolismo , Camundongos Endogâmicos BALB C , Mutação/genética , Florizina/farmacologia , Florizina/uso terapêutico , Reprodutibilidade dos Testes , Replicação Viral/efeitos dos fármacos
5.
Pharmacol Res Perspect ; 7(4): e00504, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31384471

RESUMO

Selective analogs of the natural glycoside phloridzin are marketed drugs that reduce hyperglycemia in diabetes by inhibiting the active sodium glucose cotransporter SGLT2 in the kidneys. In addition, intestinal SGLT1 is now recognized as a target for glycemic control. To expand available type 2 diabetes remedies, we aimed to find novel SGLT1 inhibitors beyond the chemical space of glycosides. We screened a bioactive compound library for SGLT1 inhibitors and tested primary hits and additional structurally similar molecules on SGLT1 and SGLT2 (SGLT1/2). Novel SGLT1/2 inhibitors were discovered in separate chemical clusters of natural and synthetic compounds. These have IC50-values in the 10-100 µmol/L range. The most potent identified novel inhibitors from different chemical clusters are (SGLT1-IC50 Mean ± SD, SGLT2-IC50 Mean ± SD): (+)-pteryxin (12 ± 2 µmol/L, 9 ± 4 µmol/L), (+)-ε-viniferin (58 ± 18 µmol/L, 110 µmol/L), quinidine (62 µmol/L, 56 µmol/L), cloperastine (9 ± 3 µmol/L, 9 ± 7 µmol/L), bepridil (10 ± 5 µmol/L, 14 ± 12 µmol/L), trihexyphenidyl (12 ± 1 µmol/L, 20 ± 13 µmol/L) and bupivacaine (23 ± 14 µmol/L, 43 ± 29 µmol/L). The discovered natural inhibitors may be further investigated as new potential (prophylactic) agents for controlling dietary glucose uptake. The new diverse structure activity data can provide a starting point for the optimization of novel SGLT1/2 inhibitors and support the development of virtual SGLT1/2 inhibitor screening models.


Assuntos
Produtos Biológicos/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia , Transportador 1 de Glucose-Sódio/metabolismo , Transportador 2 de Glucose-Sódio/metabolismo , Animais , Produtos Biológicos/química , Células CHO , Células CACO-2 , Cumarínicos/química , Cumarínicos/farmacologia , Cricetulus , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Concentração Inibidora 50 , Florizina/análogos & derivados , Quinidina/química , Quinidina/farmacologia , Bibliotecas de Moléculas Pequenas/química , Transportador 1 de Glucose-Sódio/química , Transportador 2 de Glucose-Sódio/química
6.
Biosci Biotechnol Biochem ; 82(9): 1463-1467, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29865928

RESUMO

Trilobatin [4'-(ß-D-glucopyranosyloxy)-2',4",6'-trihydroxydihydrochalcone] was synthesized from commercially available naringin in three steps with an overall yield of 30%. The key step was the acid-catalyzed site-selective hydrolysis of terminal α-rhamnopyranosidic linkage in neohesperidose involved in naringin under controlled conditions, by applying a high-pressure steam sterilizer.


Assuntos
Flavanonas/química , Flavonoides/síntese química , Glicosídeo Hidrolases/química , Florizina/análogos & derivados , Polifenóis/síntese química , Ácidos/química , Catálise , Chalconas/química , Flavonoides/química , Hidrólise , Estrutura Molecular , Florizina/química , Polifenóis/química
7.
Arch Pharm Res ; 40(1): 37-48, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27798765

RESUMO

Prunin is the main flavonoid in Prunus davidiana stems and improves hyperglycemia and hyperlipidemia in streptozotocin-induced diabetic rats. The aim of this study was to investigate the in vitro anti-diabetic potential of prunin via the inhibition of protein tyrosine phosphatase 1B (PTP1B), α-glucosidase, peroxynitrite (ONOO-)-mediated tyrosine nitration, and stimulation of glucose uptake in insulin-resistant hepatocytes. In addition, a molecular docking simulation was performed to predict specific prunin binding modes during PTP1B inhibition. Prunin showed strong inhibitory activity against PTP1B, with an IC50 value of 5.5 ± 0.29 µM, and significant inhibitory activity against α-glucosidase, with an IC50 value of 317 ± 2.12 µM. Moreover, a kinetics study revealed that prunin inhibited PTP1B (K i = 8.66) and α-glucosidase (K i = 189.56) with characteristics typical of competitive and mixed type inhibitors, respectively. Docking simulations showed that prunin selectively inhibited PTP1B by targeting its active site and exhibited good binding affinity, with a docking score of -9 kcal/mol. Furthermore, prunin exhibited dose-dependent inhibitory activity against ONOO--mediated tyrosine nitration and stimulated glucose uptake by decreasing PTP1B expression level in insulin-resistant HepG2 cells. These results indicate that prunin has significant potential as a selective PTP1B inhibitor and may possess anti-diabetic properties by improving insulin resistance.


Assuntos
Flavonoides/farmacologia , Glucose/metabolismo , Resistência à Insulina/fisiologia , Florizina/análogos & derivados , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Prunus , Relação Dose-Resposta a Droga , Flavonoides/química , Flavonoides/isolamento & purificação , Células Hep G2 , Humanos , Florizina/química , Florizina/isolamento & purificação , Florizina/farmacologia , Caules de Planta , Estrutura Secundária de Proteína , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo
8.
J Sci Food Agric ; 96(5): 1440-50, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-25914106

RESUMO

BACKGROUND: Malus domestica is the most widely cultivated fruit tree and is well known for its therapeutic value. Apple leaves are known to contain phenolic compounds but the nature of these has not been explored to the same extent as in apple fruit. A simple, rapid and sensitive ultra-performance liquid chromatography-diode array detection (UPLC-DAD) quantification method has been developed. Total polyphenol and flavonoid contents, as well as the antioxidant activity of golden and royal apple leaves were evaluated. RESULTS: Four compounds, namely rutin, 3-hydroxyphloridzin, phloridzin and quercetin-3-O-arabinoside were identified by UPLC. The separation was achieved in less than 7 min. Total polyphenol and flavonoid contents were found to be slightly higher in apple golden variety than royal variety. The IC50 values determined by the DPPH assay were 49.94 µg mL(-1) for golden apple leaves and 43.89 µg mL(-1) for royal apple leaves. IC50 values determined by the ABTS assay were 47.10 and 66.53 µg mL(-1) for golden and royal apple leaves, respectively. Antioxidant activity was determined as 24.45 and 21.15 mg ascorbic acid g(-1) for golden and royal apple leaves, respectively, by using the FRAP assay. CONCLUSION: This study showed that apple leaves (both varieties) contain considerable amounts of polyphenols and flavonoids and are also a promising source of phloridzin.


Assuntos
Antioxidantes/análise , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Malus/química , Folhas de Planta/química , Polifenóis/análise , Florizina/análogos & derivados , Florizina/análise , Quercetina/análogos & derivados , Quercetina/análise , Rutina/análise , Especificidade da Espécie
9.
Eur J Pharm Sci ; 78: 225-33, 2015 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-26209880

RESUMO

Cystic Fibrosis (CF) is the most diffuse autosomal recessive genetic disease affecting Caucasians. A persistent recruitment of neutrophils in the bronchi of CF patients contributes to exacerbate the airway tissue damage, suggesting that modulation of chemokine expression may be an important target for the patient's well being thus the identification of innovative anti-inflammatory drugs is considered a longterm goal to prevent progressive tissue deterioration. Phloridzin, isolated from Malus domestica by a selective molecular imprinting extraction, and its structural analogues, Phloridzin heptapropionate (F1) and Phloridzin tetrapropionate (F2), were initially investigated because of their ability to reduce IL-6 and IL-8 expression in human CF bronchial epithelial cells (IB3-1) stimulated with TNF-α. Release of these cytokines by CF cells was shown to be controlled by the Transcription Factor (TF) NF-kB. The results of the present investigation show that of all the derivatives tested, Phloridzin tetrapropionate (F2) is the most interesting and has greatest potential as it demonstrates inhibitory effects on the expression and production of different cytokines involved in CF inflammation processes, including RANTES, VEGF, GM-CSF, IL-12, G-CSF, MIP-1b, IL-17, IL-10 and IP-10, without any correlated anti-proliferative and pro-apoptotic effects.


Assuntos
Citocinas/antagonistas & inibidores , Florizina/análogos & derivados , Florizina/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fibrose Cística/metabolismo , Citocinas/genética , Citocinas/metabolismo , DNA/metabolismo , Frutas , Humanos , Malus , NF-kappa B/metabolismo , Florizina/isolamento & purificação , Extratos Vegetais/química , RNA Mensageiro/metabolismo
10.
Med Chem ; 11(4): 317-28, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25557661

RESUMO

A brief history of the design of sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors is reviewed. The design of O-glucoside SGLT2 inhibitors by structural modification of phlorizin, a naturally occurring O-glucoside, in the early stage was a process mainly driven by biology with anticipation of improving SGLT2/SGLT1 selectivity and increasing metabolic stability. Discovery of dapagliflozin, a pioneering C-glucoside SGLT2 inhibitor developed by Bristol-Myers Squibb, represents an important milestone in this history. In the second stage, the design of C-glycoside SGLT2 inhibitors by modifications of the aglycone and glucose moiety of dapagliflozin, an original structural template for almost all C-glycoside SGLT2 inhibitors, was mainly driven by synthetic organic chemistry due to the challenge of designing dapagliflozin derivatives that are patentable, biologically active and synthetically accessible. Structure-activity relationships (SAR) of the SGLT2 inhibitors are also discussed.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Descoberta de Drogas/história , Hipoglicemiantes/síntese química , Hipoglicemiantes/história , Inibidores do Transportador 2 de Sódio-Glicose , Compostos Benzidrílicos/síntese química , Compostos Benzidrílicos/história , Compostos Benzidrílicos/uso terapêutico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Desenho de Fármacos , Glucosídeos/síntese química , Glucosídeos/história , Glucosídeos/uso terapêutico , Glicosídeos , História do Século XX , História do Século XXI , Humanos , Hipoglicemiantes/uso terapêutico , Monossacarídeos/síntese química , Monossacarídeos/história , Monossacarídeos/uso terapêutico , Florizina/análogos & derivados , Florizina/síntese química , Florizina/história , Florizina/uso terapêutico , Transportador 2 de Glucose-Sódio/química , Transportador 2 de Glucose-Sódio/metabolismo , Relação Estrutura-Atividade
11.
Nat Prod Res ; 28(1): 41-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24404954

RESUMO

Phytochemical investigation of the ethyl acetate extract of Cycas revoluta Thunb. leaflets afforded five compounds including two new dihydroamentoflavone glucosides, (2S)-I-(2,3)-dihydro-I-7-O-ß-D-glucopyranosylamentoflavone (1) and (2S)-I-(2,3)-dihydro-I-7,II-7-di-O-ß-D-glucopyranosylamentoflavone (2), in addition to the known compounds prunin (3), vitexin-2″-rhamnoside (4) and protocatechuic acid (5). Compounds (3) and (4) being reported for the first time in this plant. The structures of these compounds were established by the detailed analysis of their spectroscopic data, mainly 1D NMR, 2D NMR, CD and HR-MSD-TOF. The ethyl acetate extract showed weak cytotoxicity against HepG2 (IC50 = 207.6 µg/mL) and RAW 264.2 cells (IC50 = 160.8 µg/mL). Compound 4 showed significant activity towards Leishmania donavani (IC50 = 13.8 µM, IC90 = 34.6 µM). The isolated compounds showed weak antimicrobial activity (IC50>10 µg/mL).


Assuntos
Antiprotozoários/isolamento & purificação , Apigenina/isolamento & purificação , Cycas/química , Flavonas/isolamento & purificação , Glucosídeos/isolamento & purificação , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Apigenina/química , Aspergillus fumigatus/efeitos dos fármacos , Candida/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Flavonas/química , Flavonas/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Células Hep G2 , Humanos , Hidroxibenzoatos , Leishmania donovani/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Complexo Mycobacterium avium/efeitos dos fármacos , Ressonância Magnética Nuclear Biomolecular , Florizina/análogos & derivados , Florizina/química , Florizina/isolamento & purificação , Pseudomonas aeruginosa/efeitos dos fármacos
12.
J Agric Food Chem ; 61(42): 10026-32, 2013 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-24070201

RESUMO

An HPLC method that can separate naringin, prunin, and naringenin was used to help accurately measure the activities of naringinase and its subunits (α-L-rhamnosidase and ß-D-glucosidase). The activities of the naringinase and ß-d-glucosidase were determined through an indirect calculation of the naringenin concentration to avoid interference from its poor solubility. The measured enzymatic activities of the naringinase complex, α-L-rhamnosidase, and ß-D-glucosidase were the as same as their theoretical activities when the substrates' (i.e., naringin or prunin) concentrations were 200 µg/mL, and the enzyme concentrations were within the range of 0.06-0.43, 0.067-0.53, and 0.15-1.13 U/mL, respectively. The ß-D-glucosidase had a much higher Vmax than either naringinase or α-L-rhamnosidase, implying the hydrolysis of naringin to prunin was the limiting step of the enzyme reaction. The reliability of the method was finally validated through the repeatability test, indicating its feasibility for the determinations of the naringinase complex.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ensaios Enzimáticos/métodos , Complexos Multienzimáticos/química , beta-Glucosidase/química , Flavanonas/química , Hidrólise , Cinética , Florizina/análogos & derivados , Florizina/química
13.
Food Chem Toxicol ; 55: 411-23, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23354392

RESUMO

Prunin (P)- and hesperetin glucoside (HG)-alkyl esters are lipid-soluble compounds with antimicrobial and antioxidant capacities in vitro. The effects of P- and HG-alkyl (C4-C18) esters (0.1-100µM) on human leukemia T (Jurkat) cells viability and plasma membrane fluidity were evaluated. After 1h of exposure, cell viability was not affected in the range 0.1-10µM. The decrease of cell viability found at 100µM concentration depended on the length of the alkyl chain and reached a maximum with C6-C12 derivatives. At this concentration, cell hyperpolarization and shrinkage were also observed. Cell plasma membrane fluidity was not affected, regardless the depths of the membrane level evaluated, but mild changes in plasma membrane hydration were found. Esterification did not affect the antioxidant capacity of P and HG (0.1-10µM) against 1mM H2O2. When exposed to 1mM AAPH, P-alkyl esters retained P antioxidant capacity, but HG-derivatives acted as pro-oxidants. Together, present experimental evidences suggest that short term exposures to 0.1-10µM concentrations of P- and HG-alkyl (C4-C18) esters can be considered safe for cultured human cells, and further studies are required to investigate their long term effects, as well their safety for human consumption.


Assuntos
Antioxidantes/farmacologia , Membrana Celular/efeitos dos fármacos , Hesperidina/farmacologia , Florizina/análogos & derivados , Ésteres , Hesperidina/química , Humanos , Células Jurkat , Florizina/química , Florizina/farmacologia
14.
Zhong Yao Cai ; 36(11): 1860-3, 2013 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-24956830

RESUMO

OBJECTIVE: To establish a method of quality assurance for mass-screening (QAMS) for simultaneously determining six flavonoids in Hongzhu Capsules. METHODS: An HPLC (high performance liquid chromatography) method was developed as QAMS to determine neoeriocitrin, prunin, naringin, rhoifolin, miliditin and naringenin in Hongzhu Capsules. Using naringin as the internal reference substance, relative correction factors (RCF) of the five flavonoids were determined and given as follows (1.05, 0.782, 1.89, 1.27, 0.532). The contents of the flavonoids in Hongzhu Capsules were determined by QAMS and validated by the external standard method. RESULTS: RCF values were determined by HPLC with good reproducibility. No significant difference between the quantitative results of QAMS and external standard method was observed. CONCLUSION: The present-developed method is convenient and accurate to determine multiple components when some standard substances are unavailable, thus considered as a potential method for quality control of Hongzhu Capsules.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Flavonoides/química , Plantas Medicinais/química , Cápsulas , Dissacarídeos/química , Medicamentos de Ervas Chinesas/normas , Flavanonas/química , Glicosídeos/química , Florizina/análogos & derivados , Florizina/química , Controle de Qualidade , Reprodutibilidade dos Testes
15.
Carbohydr Res ; 365: 46-51, 2013 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-23202537

RESUMO

Naringenin-7-O-glucoside [Prunin (Pru)] was isolated from the fruit shell of Bixa orellana L. The binding of Pru with calf thymus DNA (ctDNA) and the influence of cyclomaltoheptaose (ß-cyclodextrin, ß-CD) on the binding were studied by absorption and fluorescence spectroscopic techniques. The comparison of the binding modes of Pru/ß-CD and ctDNA-Pru/ß-CD suggested that ß-CD extracted Pru from DNA for forming inclusion complex. Molecular modeling gave added support to the above results. Fluorescence microscopy was used to visualize the effect of ß-CD on the bindings.


Assuntos
Ligação Competitiva , Bixaceae/química , DNA/química , Frutas/química , Florizina/análogos & derivados , beta-Ciclodextrinas/química , Animais , Sítios de Ligação , Indicadores e Reagentes/química , Substâncias Macromoleculares/química , Azul de Metileno/química , Microscopia de Fluorescência/métodos , Modelos Moleculares , Florizina/química , Florizina/isolamento & purificação , Plantas Medicinais/química , Espectrometria de Fluorescência
16.
Molecules ; 17(11): 13275-89, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23135632

RESUMO

The phenolic compound phloridzin (phloretin 2′-O-glucoside, variously named phlorizin, phlorrhizin, phlorhizin or phlorizoside) is a prominent member of the chemical class of dihydrochalcones, which are phenylpropanoids. Phloridzin is specifically found in apple and apple juice and known for its biological properties. In particular we were attracted by potential dermo-cosmetic applications. Here we report the synthesis, stability studies and antimicrobial activity of compound F2, a new semi-synthetic derivative of phloridzin. The new derivative was also included in finished formulations to evaluate its stability with a view to a potential topical use. Stability studies were performed by HPLC; PCL assay and ORAC tests were used to determine the antioxidant activity. F2 presented an antioxidant activity very close to that of the parent phloridzin, but, unlike the latter, was more stable in formulations. To further explore potential health claims, antifungal activity of phloridzin and its derivative F2 were determined; the results, however, were rather low; the highest value was 31,6% of inhibition reached by F2 on Microsporum canis at the highest dose.


Assuntos
Antifúngicos/síntese química , Antioxidantes/síntese química , Cosméticos/síntese química , Microsporum/efeitos dos fármacos , Florizina/análogos & derivados , Florizina/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Química Farmacêutica , Cosméticos/química , Cosméticos/farmacologia , Estabilidade de Medicamentos , Etanol/química , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Octanóis/química , Florizina/química , Florizina/farmacologia , Solventes/química , Água/química
17.
J Appl Microbiol ; 111(3): 731-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21672094

RESUMO

AIMS: To study the antimicrobial activity of naringin (NAR), a flavonoid extracted from citrus industry waste, and NAR derivatives [naringenin (NGE), prunin and alkyl prunin esters] against pathogenic bacteria such as L. monocytogenes, E. coli O157:H7 and S. aureus. The relationship between the structure of the chemical compounds and their antagonistic effect was also analysed. METHODS AND RESULTS: The agar dilution technique and direct contact assaying were applied. NGE, prunin and NAR showed no antimicrobial activity at a concentration of 0.25 mmol l(-1). Similarly, fatty acids with a chain length between C2 and C18 showed no antimicrobial activity at the same concentration. However, prunin-6″-O-acyl esters presented high antibacterial activity, mainly against Gram-positive strains. This activity increased with increasing chain length (up to 10-12 carbon atoms). Alkyl prunin esters with 10-12 carbon atoms diminished viability of L. monocytogenes by about 3 log orders and S. aureus by 6 log orders after 2 h of contact at 37°C and at a concentration of 0.25 mmol l(-1). The compounds examined were not effective against any of the Gram-negative strains assayed, even at the highest concentration. CONCLUSIONS: Addition of sugars to the aglycone did not enhance its antimicrobial activity. Attachment of a saturated aliphatic chain with 10-12 carbon atoms to the A ring of the flavonoid (or to sugars attached to this ring), seems to be the most promising modification. In conclusion, alkyl prunin esters with a chain length of C10-C12 have promising features as antimicrobial agents because of their high antilisterial and antistaphylococcal activity. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that it is possible to obtain NAR derivatives with important antimicrobial activity, especially against Gram-positive pathogenic bacteria. It also provides guidelines on the structural modifications in similar molecules to enhance the antimicrobial activity.


Assuntos
Antibacterianos/farmacologia , Escherichia coli O157/efeitos dos fármacos , Flavanonas/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Florizina/análogos & derivados , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Citrus/química , Flavanonas/química , Testes de Sensibilidade Microbiana , Florizina/química , Florizina/farmacologia , Extratos Vegetais/farmacologia , Relação Estrutura-Atividade
18.
Handb Exp Pharmacol ; (203): 105-26, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21484569

RESUMO

Recently, the idea has been developed to lower blood glucose blood glucose levels in diabetes by inhibiting sugar reabsorption sugar reabsorption in the kidney kidney . The main target is thereby the early proximal tubule proximal tubule where secondary active transport secondary active transport of the sugar is mediated by the sodium-D: -glucose D-glucose cotransporter SGLT2 SGLT2 . A model substance for the inhibitors inhibitors is the O-glucoside O-glucoside phlorizin phlorizin which inhibits transport transport competitively. Its binding to the transporter involves at least two different domains: an aglucone binding aglucone binding site at the transporter surface, involving extramembranous loops extramembraneous loops , and the sugar binding sugar binding /translocation site buried in a hydrophilic pocket of the transporter. The properties of these binding sites differ between SGLT2 and SGLT1 SGLT1 , which mediates sugar absorption sugar absorption in the intestine intestine . Various O-, C-, N- and S-glucosides have been synthesized with high affinity affinity and high specificity specificity for SGLT2 SGLT2 . Some of these glucosides are in clinical trials clinical trials and have been proven to successfully increase urinary glucose excretion urinary glucose excretion and to decrease blood sugar blood sugar levels without the danger of hypoglycaemia hypoglycaemia during fasting fasting in type 2 diabetes type 2 diabetes .


Assuntos
Diabetes Mellitus/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Proteínas de Transporte de Sódio-Glucose/antagonistas & inibidores , Animais , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/síntese química , Florizina/análogos & derivados , Florizina/síntese química , Florizina/farmacologia , Relação Estrutura-Atividade
19.
Bioorg Med Chem ; 19(3): 1167-71, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21256757

RESUMO

In our research, 14 benzyl benzoates with hydroxyl(s) (3-16) were synthesized and their inhibitory activity on mushroom tyrosinase was tested. Results indicated that among these compounds, 4-hydroxybenzyl 3,5-dihydroxybenzoate (3), 4-hydroxybenzyl 2,4-dihydroxybenzoate (5), 4-hydroxybenzyl 2,4,6-dihydroxybenzoate (7), 3-hydroxybenzyl 3,5-dihydroxybenzoate (8), 3-hydroxybenzyl 2,4-dihydroxybenzoate (10) exhibited inhibitory activity with their IC(50) less than 10µM. Further studies showed these five compounds were competitive inhibitors of tyrosinase and their structure-activity relationships were investigated in this article.


Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Florizina/análogos & derivados , Salicilatos/síntese química , Salicilatos/farmacologia , Agaricales/enzimologia , Cosméticos , Inibidores Enzimáticos/química , Conservação de Alimentos , Concentração Inibidora 50 , Cinética , Monofenol Mono-Oxigenase/metabolismo , Salicilatos/química , Relação Estrutura-Atividade
20.
J Biotechnol ; 152(4): 147-58, 2011 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-20727919

RESUMO

Novel ionic liquid (IL) sol-gel materials development, for enzyme immobilization, was the goal of this work. The deglycosylation of natural glycosides were performed with α-l-rhamnosidase and ß-d-glucosidase activities expressed by naringinase. To attain that goal ILs with different structures were incorporated in TMOS/Glycerol sol-gel matrices and used on naringinase immobilization. The most striking feature of ILs incorporation on TMOS/Glycerol matrices was the positive impact on the enzyme activity and stability, which were evaluated in fifty consecutive runs. The efficiency of α-rhamnosidase expressed by naringinase TMOS/Glycerol@ILs matrices increased with cation hydrophobicity as follows: [OMIM]>[BMIM]>[EMIM]>[C(2)OHMIM]>[BIM] and [OMIM]≈[E(2)-MPy]≫[E(3)-MPy]. Regarding the imidazolium family, the hydrophobic nature of the cation resulted in higher α-rhamnosidase efficiencies: [BMIM]BF(4)≫[C(2)OHMIM]BF(4)≫[BIM]BF(4). Small differences in the IL cation structure resulted in important differences in the enzyme activity and stability, namely [E(3)-MPy] and [E(2)-MPy] allowed an impressive difference in the α-rhamnosidase activity and stability of almost 150%. The hydrophobic nature of the anion influenced positively α-rhamnosidase activity and stability. In the BMIM series the more hydrophobic anions (PF(6)(-), BF(4)(-) and Tf(2)N(-)) led to higher activities than TFA. SEM analysis showed that the matrices are shaped lens with a film structure which varies within the lens, depending on the presence and the nature of the IL. The kinetics parameters, using naringin and prunin as substrates, were evaluated with free and naringinase encapsulated, respectively on TMOS/Glycerol@[OMIM][Tf(2)N] and TMOS/Glycerol@[C(2)OHMIM][PF(6)] and on TMOS/Glycerol. An improved stability and efficiency of α-l-rhamnosidase and ß-glucosidase expressed by encapsulated naringinase on TMOS/Glycerol@[OMIM][Tf(2)N] and TMOS/Glycerol@[C(2)OHMIM][PF(6)] were achieved. In addition to these advantageous, with ILs as sol-gel templates, environmental friendly processes can be implemented.


Assuntos
Enzimas Imobilizadas/metabolismo , Glicerol/química , Glicosídeo Hidrolases/metabolismo , Líquidos Iônicos/química , Complexos Multienzimáticos/metabolismo , beta-Glucosidase/metabolismo , Cinética , Microscopia Eletrônica de Varredura , Estrutura Molecular , Florizina/análogos & derivados , Espectrometria de Fluorescência , Espectrofotometria
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