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1.
Biosci Biotechnol Biochem ; 84(4): 780-788, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31868104

RESUMO

Sesquiterpenoids are one of the most diverse groups in natural compounds with various chemical structures and bioactivities. In our previous work, we developed the chemoenzymatic oxygenation method based on the combination of Fe(II)-EDTA and ferric-chelate reductase that could synthesize (-)-rotundone, a key aroma sesquiterpenoid of black pepper. Fe(II)-EDTA catalyzed the oxygenation of sesquiterpene to sesquiterpenoid, and ferric-chelate reductase catalyzed the supply and regeneration of Fe(II)-EDTA in this system. We then investigated the effect of various Fe2+-chelates on the catalytic oxygenation of sesquiterpene and applied this system to the synthesis of odor sesquiterpenoids. We determined Fe(II)-NTA to be an efficient oxygenation catalyst by the screening approach focusing on ligand structures and coordination atoms of Fe2+-chelates. Valuable odor sesquiterpenoids such as (+)-nootkatone, (-)-isolongifolenone, and (-)-ß-caryophyllene oxide were oxygenatively synthesized from each precursor sesquiterpene by 66%, 82%, and 67% of the molar conversion rate, respectively.Abbreviations: EDTA: ethylenediaminetetraacetate; NTA: nitrilotriacetate; DTPA: diethylenetriaminepentaacetate; phen: o-phenanthroline; cyclam: 1,4,8,11-tetraazacyclotetradecane; TPA: tris(2-pyridylmethyl)amine; GlcDH: glucose dehydrogenase; HP-ß-CD: hydroxypropyl-ß-cyclodextrin.


Assuntos
FMN Redutase/metabolismo , Quelantes de Ferro/química , Oxigênio/metabolismo , Sesquiterpenos/síntese química , Catálise , Ciclodextrinas/metabolismo , Glucose 1-Desidrogenase/metabolismo , Ligantes
2.
J Oleo Sci ; 68(12): 1279-1285, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31787676

RESUMO

The free radical scavenging activities of black and white sesame seed hulls and the powder of black and white sesame seed cakes were investigated using noninvasive continuous wave electron paramagnetic resonance (EPR) and antioxidant assays. With black sesame seed hulls and the powder of black sesame seed cakes, EPR detected the very strong single-line signal intensities that correspond to the stable organic radicals, while the spectrum of the white sesame seed hulls and the white sesame seed cakes showed no signal. The in vitro antioxidant activities of black and white sesame seed cake extract were evaluated by DPPH free radical scavenging activity, hydrogen peroxide scavenging activity, and ferric reducing antioxidant power (FRAP) assay. The results indicated that the extract from black sesame seed cake possessed a greater DPPH radical inhibitory activity and hydrogen peroxide inhibitory activity than white sesame seed cake extract, with IC50 values of 0.847 ± 0.011 mg/mL and 0.338 ± 0.007 mg/mL, respectively. Black sesame seed cake extract also showed a strong reducing power with a FRAP value of 1.307 ± 0.037 mM Fe (II)/g of extract weight and an EC1 value of 0.683 ± 0.002 mg/mL. The main compounds from the black and white sesame seed cake extracts were analysed using high-performance liquid chromatography (HPLC). The results revealed that the main compounds in black and white sesame seed cake extracts were in a group of water-soluble lignans, mainly sesaminol triglucoside and sesaminol diglucoside. However, sesaminol diglucoside was found in large amounts in the black sesame seed cake extract, while it was found in a very small amount in the white sesame seed cake extract. Therefore, these results demonstrated considerable antioxidant capacity of the sesame seed, especially in the black strain.


Assuntos
Depuradores de Radicais Livres/química , Preparações de Plantas/química , Sementes/química , Sesamum/química , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância de Spin Eletrônica , Quelantes de Ferro/química , Oxirredução
3.
Nat Commun ; 10(1): 5134, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31723130

RESUMO

Iron chelators have been widely used to remove excess toxic iron from patients with secondary iron overload. However, small molecule-based iron chelators can cause adverse side effects such as infection, gastrointestinal bleeding, kidney failure, and liver fibrosis. Here we report renal clearable nanochelators for iron overload disorders. First, after a singledose intravenous injection, the nanochelator shows favorable pharmacokinetic properties, such as kidney-specific biodistribution and rapid renal excretion (>80% injected dose in 4 h), compared to native deferoxamine (DFO). Second, subcutaneous (SC) administration of nanochelators improves pharmacodynamics, as evidenced by a 7-fold increase in efficiency of urinary iron excretion compared to intravenous injection. Third, daily SC injections of the nanochelator for 5 days to iron overload mice and rats decrease iron levels in serum and liver. Furthermore, the nanochelator significantly reduces kidney damage caused by iron overload without demonstrating DFO's own nephrotoxicity. This renal clearable nanochelator provides enhanced efficacy and safety.


Assuntos
Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Rim/patologia , Nanopartículas/química , Animais , Desferroxamina/farmacocinética , Desferroxamina/uso terapêutico , Desferroxamina/toxicidade , Quelantes de Ferro/química , Quelantes de Ferro/farmacologia , Masculino , Camundongos , Nanopartículas/toxicidade , Nanopartículas/ultraestrutura , Distribuição Tecidual
4.
Chem Biodivers ; 16(11): e1900420, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31529756

RESUMO

The widespread use of Deverra scoparia Coss. & Durieu in Algerian folk-medicine as a remedy can be relatively attributed to its total phenolic compounds. The current study aimed to provide a scientific basis for optimal collection and usage of Deverra scoparia Coss. & Durieu plant. Hence, 37 samples were gathered from nine sites in Algeria during two seasons 2016 and 2017, then exposed to a green extraction. Total phenolic (TPC), flavonoid (FC) and condensed tannins (CTC) content were estimated spectrophotometrically. The antioxidant activity was measured using five different methods, DPPH. , ABTS.+ , FRAP, CUPRAC and Fe2+ -chelating. The results have revealed considerable amounts of TPC varied from 804 to 1544 mg GAE/100 g dry matter, FC started from 187 up to 410 mg QE/100 g dry matter and CTC varied from 111 to 394 mg CE/100 g dry matter. The best IC50 values (µg/mL) of DPPH. , ABTS•+ , FRAP, CUPRAC and Fe2+ -chelating tests were 56.62, 5.41, 21.26, 52.93 and 78.10, respectively. Moreover, high correlations were found between CTC and most of the antioxidant tests. Hence, CTC are suggested to be the principal group of antioxidant activity in Deverra scoparia Coss. & Durieu extracts.


Assuntos
Antioxidantes/análise , Flores/química , Metanol/química , Fenóis/análise , Extratos Vegetais/análise , Sementes/química , Argélia , Antioxidantes/farmacologia , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Cobre/química , Quelantes de Ferro/química , Fenóis/farmacologia , Picratos/antagonistas & inibidores , Extratos Vegetais/farmacologia , Análise de Componente Principal , Estações do Ano , Ácidos Sulfônicos/antagonistas & inibidores
5.
Food Funct ; 10(10): 6711-6719, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31560353

RESUMO

Food-borne nanoparticles (FNs) produced during thermal processing of food may have potential as nanocarriers for Fe(ii) supplements. In this paper, the FNs in beef patties roasted for different times (15, 30, and 45 minutes) and the binding between FNs and ferrous ions were studied. The size of FNs decreased from 7.5 to 3.0 nm with the increase of baking time, and the FNs emitted bright blue fluorescence under ultraviolet light irradiation. The combination of FNs with ferrous ions was by means of the amino, hydroxyl and carboxyl functional groups on the particles. Cell viability study showed that the Fe(ii)-FNs increased the apoptotic rate, but significantly decreased the necrosis rate, which led to an increase in the number of living cells. In addition, the Fe(ii)-FNs can easily enter the Caco-2 cytoplasm, but not the cellular nucleus. The FNs derived from beef patties with an ultra-small size, high water solubility and plenty of functional groups might be good candidates as nanocarriers for Fe(ii) delivery.


Assuntos
Ferro/metabolismo , Produtos da Carne/análise , Nanopartículas/química , Carne Vermelha/análise , Animais , Células CACO-2 , Bovinos , Humanos , Quelantes de Ferro/química , Espectroscopia de Ressonância Magnética , Tamanho da Partícula , Solubilidade
6.
J Enzyme Inhib Med Chem ; 34(1): 1489-1497, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31416364

RESUMO

MAO-B leads to an increase in the levels of hydrogen peroxide and oxidative free radicals, which contribute to the aetiology of the AD. Thus, both iron ion chelators and MAO-B inhibitors can be used to treat AD. Taking the coumarin derivatives and hydroxypyridinones as the lead compounds, a series of dual-target hybrids were designed and synthesised by Click Chemistry. The compounds were biologically evaluated for their iron ion chelating and MAO-B inhibitory activity. Most of the compounds displayed excellent iron ion chelating activity and moderate to good anti-MAO-B activity. Compounds 27b and 27j exhibited the most potent MAO-B inhibitory activity, with IC50 values of 0.68 and 0.86 µM, respectively. In summary, these dual-target compounds have the potential anti-AD activity.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Cumarínicos/farmacologia , Quelantes de Ferro/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Piridonas/farmacologia , Doença de Alzheimer/metabolismo , Cumarínicos/síntese química , Cumarínicos/química , Relação Dose-Resposta a Droga , Humanos , Quelantes de Ferro/síntese química , Quelantes de Ferro/química , Estrutura Molecular , Inibidores da Monoaminoxidase/síntese química , Inibidores da Monoaminoxidase/química , Piridonas/síntese química , Piridonas/química , Relação Estrutura-Atividade
7.
mBio ; 10(4)2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409675

RESUMO

Biosynthetic gene clusters (BGCs) are organized groups of genes involved in the production of specialized metabolites. Typically, one BGC is responsible for the production of one or several similar compounds with bioactivities that usually only vary in terms of strength and/or specificity. Here we show that the previously described ferroverdins and bagremycins, which are families of metabolites with different bioactivities, are produced from the same BGC, whereby the fate of the biosynthetic pathway depends on iron availability. Under conditions of iron depletion, the monomeric bagremycins are formed, representing amino-aromatic antibiotics resulting from the condensation of 3-amino-4-hydroxybenzoic acid with p-vinylphenol. Conversely, when iron is abundantly available, the biosynthetic pathway additionally produces a molecule based on p-vinylphenyl-3-nitroso-4-hydroxybenzoate, which complexes iron to form the trimeric ferroverdins that have anticholesterol activity. Thus, our work shows a unique exception to the concept that BGCs should only produce a single family of molecules with one type of bioactivity and that in fact different bioactive molecules may be produced depending on the environmental conditions.IMPORTANCE Access to whole-genome sequences has exposed the general incidence of the so-called cryptic biosynthetic gene clusters (BGCs), thereby renewing their interest for natural product discovery. As a consequence, genome mining is the often first approach implemented to assess the potential of a microorganism for producing novel bioactive metabolites. By revealing a new level of complexity of natural product biosynthesis, we further illustrate the difficulty of estimation of the panel of molecules associated with a BGC based on genomic information alone. Indeed, we found that the same gene cluster is responsible for the production of compounds which differ in terms of structure and bioactivity. The production of these different compounds responds to different environmental triggers, which suggests that multiplication of culture conditions is essential for revealing the entire panel of molecules made by a single BGC.


Assuntos
Aminobenzoatos/metabolismo , Antibacterianos/metabolismo , Vias Biossintéticas/genética , Compostos Ferrosos/metabolismo , Quelantes de Ferro/metabolismo , Família Multigênica , Compostos Nitrosos/metabolismo , Aminobenzoatos/química , Antibacterianos/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Compostos Ferrosos/química , Genoma Bacteriano/genética , Ferro/metabolismo , Quelantes de Ferro/química , Estrutura Molecular , Compostos Nitrosos/química , Filogenia , Streptomyces/classificação , Streptomyces/genética , Streptomyces/metabolismo
8.
Elife ; 82019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31385808

RESUMO

Many microbes and fungi acquire the essential ion Fe3+ through the synthesis and secretion of high-affinity chelators termed siderophores. In Gram-negative bacteria, these ferric-siderophore complexes are actively taken up using highly specific TonB-dependent transporters (TBDTs) located in the outer bacterial membrane (OM). However, the detailed mechanism of how the inner-membrane protein TonB connects to the transporters in the OM as well as the interplay between siderophore- and TonB-binding to the transporter is still poorly understood. Here, we present three crystal structures of the TBDT FoxA from Pseudomonas aeruginosa (containing a signalling domain) in complex with the siderophore ferrioxamine B and TonB and combine them with a detailed analysis of binding constants. The structures show that both siderophore and TonB-binding is required to form a translocation-competent state of the FoxA transporter in a two-step TonB-binding mechanism. The complex structure also indicates how TonB-binding influences the orientation of the signalling domain.


Assuntos
Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Desferroxamina/química , Desferroxamina/metabolismo , Compostos Férricos/química , Compostos Férricos/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Pseudomonas aeruginosa/enzimologia , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo , Transporte Biológico , Quelantes de Ferro/química , Quelantes de Ferro/metabolismo , Estrutura Quaternária de Proteína
9.
Eur J Med Chem ; 180: 367-382, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325784

RESUMO

A series of hybrids of hydroxypyridinone and coumarin were rationally designed, synthesized and biologically evaluated for their iron ion chelating and MAO-B inhibitory activities. Most of the compounds displayed excellent iron ion chelating effects and moderate to good anti-MAO-B activities. Compound 27a exhibited the most potent activity against MAO-B, with an IC50 value of 14.7 nM. Importantly, 27a showed good U251 cell protective effect and significantly ameliorated the cognitive dysfunction of scopolamine-induced AD mice. Moreover, molecular docking was performed to elucidate the probable ligand-receptor interaction, and the structure-activity relationships were also summarized.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Cumarínicos/farmacologia , Quelantes de Ferro/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Piridinas/farmacologia , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/metabolismo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/química , Relação Dose-Resposta a Droga , Desenho de Fármacos , Humanos , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/farmacologia , Quelantes de Ferro/síntese química , Quelantes de Ferro/química , Camundongos , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Estrutura Molecular , Inibidores da Monoaminoxidase/síntese química , Inibidores da Monoaminoxidase/química , Piridinas/química , Escopolamina , Relação Estrutura-Atividade
10.
Int J Biol Macromol ; 138: 49-56, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31301396

RESUMO

Polysaccharides with different structures have been reported to regulate iron uptake in opposite direction. The present study investigated the interaction between a sulfated polysaccharide (AGSP) from marine shellfishes and Fe(III)/Fe(II) in order to reveal the mechanism for the effect of AGSP on iron bioavailability. The Fe(III) chelating activity and resulting Fe(III)-chelates of AGSP and its desulfated derivative (dS-AGSP) were studied, their ferric reducing activity and Fe(II) chelating activity were compared, and their inhibition effects on the Fe absorption were evaluated by using Caco-2 cell models treated with Fe(III) and Fe(II). As indicated by the results, polysaccharides could chelate Fe(III) with the sulfate and carboxyl groups via FeO bond along with conformation change, resulting in unstable particles. Both AGSP and dS-AGSP inhibited the iron uptake in a dose-dependent manner. Notably, the chelating property of polysaccharides showed a negative correlation with the iron bioavailability while their reducing capability demonstrated a positive correlation. Moreover, sulfate substitution enhanced the chelating and reducing capabilities so to regulate the effects of AGSP on Fe absorption in contradictory ways. Thus, the present study elucidated the mechanism of the influence of AGSP on bioavailability of non-heme iron.


Assuntos
Gastrópodes/química , Quelantes de Ferro/química , Quelantes de Ferro/farmacologia , Ferro/metabolismo , Polissacarídeos/química , Polissacarídeos/farmacologia , Sulfatos/química , Animais , Células CACO-2 , Sequência de Carboidratos , Humanos , Quelantes de Ferro/metabolismo , Oxirredução/efeitos dos fármacos , Polissacarídeos/metabolismo
11.
Biosci Biotechnol Biochem ; 83(10): 1875-1883, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31161886

RESUMO

(-)-Rotundone, a sesquiterpenoid that has a characteristic woody and peppery odor, is a key aroma component of spicy foodstuffs, such as black pepper and Australian Shiraz wine. (-)-Rotundone shows the lowest level of odor threshold in natural compounds and remarkably improves the quality of various fruit flavors. To develop a method for the synthesis of (-)-rotundone, we focused on non-heme Fe2+-chelates, which are biomimetic catalysts of the active center of oxygenases and enzymatic supply and regeneration of those catalysts. That is, we constructed a unique combination system composed of the oxidative synthesis of (-)-rotundone using the non-heme Fe2+-chelate catalyst, Fe(II)-EDTA, and the enzymatic supply and regeneration of Fe2+-chelate by ferric-chelate reductase, YqjH, from Escherichia coli. In addition, we improved the yield of (-)-rotundone by the application of cyclodextrin and glucose dehydrogenase to this system, and thus established a platform for efficient (-)-rotundone production.


Assuntos
FMN Redutase/química , Quelantes de Ferro/química , Odorantes , Sesquiterpenos/síntese química , Catálise , Ciclodextrinas/química , Glucose 1-Desidrogenase/química , Vinho/análise
12.
Food Funct ; 10(6): 3150-3160, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31166348

RESUMO

Mulberry fruit polysaccharide (MFP) was obtained from Morus alba L. by a hot water extraction method, and mulberry polysaccharide fractions named MFP1, MFP2 and MFP3 were isolated by DEAE cellulose-52 column chromatography. Monosaccharide analysis of MFP1, MFP2 and MFP3 showed that the three components had the same monosaccharide compositions with different ratios, and galacturonic acid was the main monosaccharide component. Molecular weight measurements showed that MFP1 and MFP2 are heteropolysaccharides and MFP3 is a homogeneous polysaccharide. In addition, the chelate mechanism of iron(iii) and polysaccharide is proposed in which iron(iii) as a core is enwrapped by the polysaccharide as a ligand by hydroxyl and carboxyl groups, which induces a morphology change from flat sheets to rods and increases the size. Furthermore, the polysaccharides showed strong antioxidant activity to eliminate hydroxyl radicals and inhibit MDA production in healthy mouse liver homogenate. Also, the polysaccharide-iron(iii) chelates exhibited stronger superoxide radical scavenging ability than the polysaccharides. These results suggest that the polysaccharides derived from Morus alba L. are promising candidates for fabricating organic iron supplements with good antioxidant activity.


Assuntos
Antioxidantes/química , Quelantes de Ferro/química , Ferro/química , Morus/química , Extratos Vegetais/química , Polissacarídeos/química , Antioxidantes/isolamento & purificação , Frutas/química , Quelantes de Ferro/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Polissacarídeos/isolamento & purificação
13.
Molecules ; 24(11)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151328

RESUMO

It has recently been shown that chitosan (Chit) induces the formation of calcium oxalate (CaOx) crystals, which are mainly responsible for the appearance of kidney stones, and this might limit the use of Chit in vivo. Here, Chit was conjugated with gallic acid (Chit-Gal) to decrease the formation of CaOx crystal. This conjugation was confirmed by FTIR and NMR analyses. Chit-Gal contains 10.2 ± 1.5 mg GA per g of Chit. Compared to the control group, Chit increased the number of crystals by six-fold, mainly in the number of monohydrated CaOx crystals, which are the most harmful CaOx crystals. In addition, Chit increased the zeta potential (ζ) of CaOx crystals by three-fold, indicating that Chit was associated with the crystals. These alterations were abolished when Chit-gal was used in these tests. As oxidative stress is related to renal calculus formation, Chit and Chit-Gal were also evaluated as antioxidants using total antioxidant Capacity (TAC), reducing power, ferrous chelation, and copper chelation tests. Chit-gal was more efficient antioxidant agent in TAC (2 times), in ferrous chelation (90 times), and in reducing Power (5 times) than Chit. Overall, Chit-gal has higher antioxidant activity than Chit, does not induce the formation of CaOx crystals. Thus, Chit-Gal has potential to be used as a chit substitute.


Assuntos
Oxalato de Cálcio/química , Quitosana/química , Ácido Gálico/química , Antioxidantes/química , Cristalização , Quelantes de Ferro/química , Cálculos Renais/química , Espectroscopia de Ressonância Magnética , Peso Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Biometals ; 32(4): 707-715, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31152280

RESUMO

The hydroxamate class of compounds is well known for its pharmacological applications, especially in the context of chelation therapy. In this work we investigate the performance of the fungal hydroxamates pyridoxatin (PYR), desferriastechrome (DAC) and desferricoprogen (DCO) as mitigators of stress caused by iron overload (IO) both in buffered medium and in cells. Desferrioxamine (DFO), the gold standard for IO treatment, was used as comparison. It was observed that all the fungal chelators (in aqueous medium) or PYR and DAC (in cells) are powerful iron scavengers. However only PYR and DCO (in aqueous medium) or PYR (in cells) were also antioxidant against two forms of iron-dependent oxidative stress (ascorbate or peroxide oxidation). These findings reveal that PYR is an interesting alternative to DFO for iron chelation therapy, since it has the advantage of being cell permeable and thus potentially orally active.


Assuntos
Antioxidantes/química , Dicetopiperazinas/química , Ácidos Hidroxâmicos/química , Cicloexanos/química , Quelantes de Ferro/química , Sobrecarga de Ferro/metabolismo
15.
Chem Res Toxicol ; 32(6): 1082-1086, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31088072

RESUMO

Hydrolyzable tannins are a class of polyphenolic compounds commonly found in natural products. In this work, we studied the in vitro inhibitory mechanism of six molecules in this class on ALKBH2, an Fe(II)/α-ketoglutarate-dependent DNA repair enzyme in the AlkB family. We determined the IC50 values of these compounds on the repair of 3-methylcytosine and 1-methyladenine, the prototypical substrates of ALKBH2. A structure-activity relationship was also observed between the strength of inhibition and the number of galloyl moieties in a molecule. In addition, we found that the inhibition by this class of polyphenolic compounds on ALKBH2 is through an iron-chelating mechanism.


Assuntos
Homólogo AlkB 2 da Dioxigenase Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Reparo do DNA , Inibidores Enzimáticos/farmacologia , Taninos Hidrolisáveis/farmacologia , Quelantes de Ferro/farmacologia , Homólogo AlkB 2 da Dioxigenase Dependente de alfa-Cetoglutarato/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Humanos , Taninos Hidrolisáveis/química , Quelantes de Ferro/química , Estrutura Molecular , Relação Estrutura-Atividade
16.
Pak J Pharm Sci ; 32(2): 491-498, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31081757

RESUMO

Engleromyces sinensis, as rare macro-ascomycetes and traditional ethnomedicine in the southeast part of China, have been applied in anti-infection, anti-inflammatory and anti-tumor for a long time. In this study, the antioxidant activities of ethyl acetate crude extract (EACE), acetone crude extract (ACE), 95% ethanol crude extract (ECE), methanol crude extract (MCE) and water crude extract (WCE) from E. sinensis fruiting body were investigated using conventional antioxidant assays in vitro for the first time. As results, it was noteworthy that WCE showed the greatest 2,2-diphenyl-1-picrylhydrazil (DPPH) radicals-scavenging activity and reducing power, with EC50 values of 3.56 and 19.28mg/mL. MCE and EACE exhibited higher hydroxyl radicals-scavenging activity and ferrous ion-chelating activity significantly, with EC50 values of 2.16 and 0.47mg/mL. The total phenolics and total polysaccharides content results revealed that WCE had the highest phenolics and polysaccharides contents with 1.19 mg GAEs/g extracts and 40.07 mg D-glucose/g extracts. The antimicrobial activity of the WCE, ECE, ACE, EACE was assessed in final and two of them, ACE and EACE showed a strong ability to inhibit the microbial growth. The research work demonstrated that E. sinensis fruiting body can present a promising source of antioxidant and antimicrobial agents.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Ascomicetos/química , Carpóforos/química , Anti-Infecciosos/química , Antioxidantes/química , Fracionamento Químico/métodos , Avaliação Pré-Clínica de Medicamentos , Polissacarídeos Fúngicos/análise , Quelantes de Ferro/química , Quelantes de Ferro/farmacologia , Medicina Tradicional Chinesa , Testes de Sensibilidade Microbiana , Fenóis/análise
17.
Int J Biol Macromol ; 131: 1021-1031, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30910671

RESUMO

This study explored Pholiota nameko (P. nameko) polysaccharide fractions, PNP-40, PNP-60, and PNP-80, purified by gradient concentrations of ethanol (40%, 60%, and 80% (v/v)). The physicochemical properties, functional group composition, moisture-preserving, and antioxidant ability were determined. The results indicate that the polysaccharide contents of PNP-40, PNP-60, and PNP-80 are 45.12%, 78.04%, and 72.22%, respectively, while the ß-glucan, protein, and uronic acid contents are 20.20%, 12.20%, and 10.15%, respectively; 11.24%, 14.53%, and 26.94%; and 5.99%, 7.73%, and 3.78%. Furthermore, PNP-60 has better moisture absorption, while PNP-80 has better antioxidant ability and H2O2-injury resistance activity. Monosaccharide composition analysis shows that P. nameko belongs to heteropolysaccharides, which consists of galactose, glucose, and mannose with different types and ratios, and the molecular weight are distributed at 4.40-333.49kDa. It was found that different polysaccharide fractions have the potential to be a moisturizer and an antioxidant, and their active ingredients could be used in the development of cosmetic ingredients.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Polissacarídeos Fúngicos/química , Polissacarídeos Fúngicos/farmacologia , Pholiota/química , Absorção Fisico-Química , Antioxidantes/isolamento & purificação , Fenômenos Químicos , Precipitação Fracionada , Polissacarídeos Fúngicos/isolamento & purificação , Quelantes de Ferro/química , Quelantes de Ferro/isolamento & purificação , Quelantes de Ferro/farmacologia , Peso Molecular , Monossacarídeos , Espectroscopia de Infravermelho com Transformada de Fourier , beta-Glucanas
18.
Mini Rev Med Chem ; 19(19): 1564-1576, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30827237

RESUMO

Iron overload disorder and diseases where iron mismanagement plays a crucial role require orally available iron chelators with favourable pharmacokinetic and toxicity profile. Desferrithiocin (DFT), a tridentate and orally available iron chelator has a favourable pharmacokinetic profile but its use has been clinically restricted due to its nephrotoxic potential. The chemical architecture of the DFT has been naturally well optimized for better iron chelation and iron clearance from human biological system. Equally they are also responsible for its toxicity. Hence, subsequent research has been devoted to develop a non-nephrotoxic analogue of DFT without losing its iron clearance ability. The review has been designed to classify the compounds reported till date and to discuss the structure activity relationship with reference to modifications attempted at different positions over pyridine and thiazoline ring of DFT. Compounds are clustered under two major classes: (i) Pyridine analogues and (ii) phenyl analogue and further each class has been further subdivided based on the presence or absence and the number of hydroxy functional groups present over pyridine or phenyl ring of the DFT analogues. Finally a summary and few insights into the development of newer analogues are provided.


Assuntos
Di-Hidropiridinas/química , Quelantes de Ferro/química , Tiazóis/química , Derivados de Benzeno/química , Di-Hidropiridinas/uso terapêutico , Humanos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/patologia , Piridinas/química , Relação Estrutura-Atividade , Tiazóis/uso terapêutico
19.
Food Chem ; 286: 154-159, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30827589

RESUMO

Many packaged goods undergo transition metal-catalyzed oxidative spoilage. Recently, a nonmigratory photocurable metal-chelating coating was developed as an innovative active packaging approach to control oxidation of foods. In the present study, we investigate the influence of competing ions and increasing viscosity on the iron-chelating capacity and antioxidant efficacy of this coating in a model complex food system. The addition of calcium and magnesium causes a decrease in iron chelating capacity; however, 61% chelating capacity of materials was retained when 0.8 M sodium was present. Materials retained iron-chelating capacity even in solutions of 2700 cP, similar to the viscosity of salad dressing. Additionally, metal-chelating films significantly delayed transition metal-catalyzed ascorbic acid degradation, even in the presence of competing ions and at increased viscosity. These results suggest that metal-chelating active packaging coatings may present a new technological approach to addressing consumer demands for reduced additive use while controlling food spoilage and waste.


Assuntos
Embalagem de Alimentos/métodos , Quelantes de Ferro/química , Metais/química , Polímeros/química , Antioxidantes/química , Ácido Ascórbico/química , Ácido Ascórbico/metabolismo , Cálcio/química , Alimentos , Iminoácidos/química , Magnésio/química , Metilcelulose/química , Oxirredução , Propriedades de Superfície , Viscosidade
20.
Biometals ; 32(3): 395-408, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30701380

RESUMO

Desferrioxamine B (DFOB) is a siderophore native to Streptomyces pilosus biosynthesised by the DesABCD enzyme cluster as a high affinity Fe(III) chelator. Although DFOB has a long clinical history for the treatment of chronic iron overload, limitations encourage the development of new analogues. This review describes a recent body of work that has used precursor-directed biosynthesis (PDB) to access new DFOB analogues. PDB exploits the native biosynthetic machinery of a producing organism in culture medium augmented with non-native substrates that compete against native substrates during metabolite assembly. The method allows access to analogues of natural products using benign methods, compared to multistep organic synthesis. The disadvantages of PDB are the production of metabolites in low yield and the need to purify complex mixtures. Streptomyces pilosus medium was supplemented with different types of non-native diamine substrates to compete against native 1,5-diaminopentane to generate DFOB analogues containing alkene bonds, fluorine atoms, ether or thioether functional groups, or a disulfide bond. All analogues retained function as Fe(III) chelators and have properties that could broaden the utility of DFOB. These PDB studies have also added knowledge to the understanding of DFOB biosynthesis.


Assuntos
Desferroxamina/metabolismo , Quelantes de Ferro/metabolismo , Streptomyces/química , Desferroxamina/análogos & derivados , Desferroxamina/química , Quelantes de Ferro/química , Estrutura Molecular , Streptomyces/metabolismo
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