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1.
Br J Radiol ; 93(1111): 20200034, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32374626

RESUMO

Necrosis plays vital roles in living organisms which is related closely with various diseases. Non-invasively necrotic imaging can be of great values in clinical decision-making, evaluation of individualized treatment responses, and prediction of patient prognosis. This narrative review will demonstrate how the evolution of quinones for necrotic imaging has been promoted by searching for their active centers. In this review, we summarized the recent developments of various quinones with the continuous simplified π-conjugated cores in necrotic imaging and speculated their possible molecular mechanisms might be attributed to their intercalations with exposed DNA in necrotic tissues. We discussed their clinical challenges of necrotic imaging with quinones and their future translation studies deserved to be explored in personalized patient treatment.


Assuntos
Sondas Moleculares , Infarto do Miocárdio/patologia , Necrose/diagnóstico por imagem , Quinonas , Animais , Antraquinonas/química , Células/patologia , DNA/análise , Humanos , Sondas Moleculares/química , Infarto do Miocárdio/diagnóstico por imagem , Naftoquinonas/química , Quinonas/química , Quinonas/classificação , Ratos
2.
Food Chem ; 322: 126754, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32283367

RESUMO

During storage of coffee, the key aroma 2-furfurylthiol becomes less active, the mechanisms of this loss and ways to mitigate it were investigated. Aroma profiles were analyzed using GC-MS and sensory properties were evaluated by Quantitative Descriptive Analysis. Quinones, as the oxidation products of hydroxydroquinone, was found to actively bind 2-furfurylthiol, which accounted for the loss of 2-furfurylthiol. To mitigate this loss, ingredients were screened for their ability to prevent 2-furfurylthiol from loss. Cysteine had the highest 2-furfurylthiol releasing efficiency and ascorbic acid was also selected due to its 2-furfurylthiol releasing ability in Fenton reaction system. Concentrations were optimized and the addition of 0.045 g/L cysteine and 0.05 g/L ascorbic acid directly protected aroma during storage, these included 2-furfurylthiol, dimethyltrisulfide, methyl furfuryl disulfide, 4-ethylguaiacol and 4-vinylguaiacol. Ultimately, sensory testing showed a direct enhancement in nutty, sulfurous and roasted aroma attributes, an increase in flavour intensity and preference over shelf life.


Assuntos
Café/química , Furanos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Compostos de Sulfidrila/metabolismo , Compostos Orgânicos Voláteis/análise , Ácido Ascórbico/química , Café/metabolismo , Culinária/métodos , Cisteína/química , Armazenamento de Alimentos , Furanos/química , Análise dos Mínimos Quadrados , Quinonas/química , Quinonas/metabolismo , Compostos de Sulfidrila/química , Paladar , Compostos Orgânicos Voláteis/química
3.
Biochim Biophys Acta Proteins Proteom ; 1868(6): 140412, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32179183

RESUMO

Matrix metalloproteinases (MMPs) are zinc-dependent extracellular matrix remodeling endopeptidases. MMPs cleave various matrix proteins such as collagen, elastin, gelatin and casein. MMPs are often implicated in pathological processes, such as cancer progression including metastasis. Meanwhile, microorganisms produce various secondary metabolites having unique structures. We designed and synthesized dehydroxymethylepoxyquinomicin (DHMEQ) based on the structure of epoxyquinomicin C derived from Amycolatopsis as an inhibitor of NF-κB. This compound inhibited cancer cell migration and invasion. Since DHMEQ is comparatively unstable in the body, we designed and synthesized a stable DHMEQ analog, SEMBL. SEMBL also inhibited cancer cell migration and invasion. We also looked for inhibitors of cancer cell migration and invasion from microbial culture filtrates. As a result, we isolated a known compound, ketomycin, from Actinomycetes. DHMEQ, SEMBL, and ketomycin are all NF-κB inhibitors, and inhibited the expression of MMPs in the inhibition of cellular migration and invasion. These are all compounds with comparatively low toxicity, and may be useful for the development of anti-metastasis agents.


Assuntos
Antineoplásicos/farmacologia , Benzamidas/antagonistas & inibidores , Cicloexanonas/antagonistas & inibidores , Metaloproteinases da Matriz/efeitos dos fármacos , Metaloproteinases da Matriz/metabolismo , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Actinobacteria/metabolismo , Animais , Antineoplásicos/química , Benzamidas/síntese química , Benzamidas/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Cicloexanonas/síntese química , Glioxilatos/antagonistas & inibidores , Glioxilatos/metabolismo , Humanos , Metaloproteinase 11 da Matriz/efeitos dos fármacos , Metaloproteinase 11 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/efeitos dos fármacos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/efeitos dos fármacos , Metaloproteinase 9 da Matriz/metabolismo , Modelos Moleculares , Subunidade p50 de NF-kappa B/metabolismo , Invasividade Neoplásica , Neoplasias , Quinonas/química
4.
Food Chem ; 317: 126454, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32113140

RESUMO

The reaction efficiency of o-benzoquinones with amines (L-lysine, Nα-acetyl-L-lysine, glycine, L-methionine and L-arginine), thiols (L-cysteine and Nα-acetyl-L-cysteine) and protein (bovine serum albumin) were determined at pH 5.0, 7.0 and 8.0 and scan rate of 10, 50 and 100 mV/s by cyclic voltammetry. Nucleophiles containing multiple nucleophilic groups and nucleophilic group possessing low pKa value would enhance the reactivity of nucleophiles towards o-benzoquinones. The reactivity of different o-benzoquinones with L-lysine/L-cysteine followed the order: protocatechuic acid quinone ≈ catechol quinone > 4-methylbenzoquinone ≈ caffeic acid quinone > rosmarinic acid quinone > chlorogenic acid quinone. The reactivity of quinones would be decreased by the steric hindrance of substituents on quinone ring, and it would also be weakened by enhancing electron cloud density of quinone ring. Adducts generated by the interaction of 4-methylbenzoquinone with amines and thiols were tentatively identified as amine-quinone adduct and thiol-phenol adduct respectively by UPLC-QTOF-MS/MS and cyclic voltammetry.


Assuntos
Aminoácidos/química , Benzoquinonas/química , Técnicas Eletroquímicas/métodos , Aminas/química , Catecóis/química , Cromatografia Líquida , Cisteína/química , Hidroxibenzoatos/química , Fenóis , Quinonas/química , Compostos de Sulfidrila/química , Espectrometria de Massas em Tandem
5.
Biochim Biophys Acta Bioenerg ; 1861(5-6): 148173, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32059842

RESUMO

Infrared absorption bands associated with the neutral state of quinones in the A1 binding site in photosystem I (PSI) have been difficult to identify in the past. This problem is addressed here, where time-resolved step-scan FTIR difference spectroscopy at 77 K has been used to study PSI with six different quinones incorporated into the A1 binding site. (P700+A1- - P700A1) and (A1- - A1) FTIR difference spectra (DS) were obtained for PSI with the different quinones incorporated, and several double-difference spectra (DDS) were constructed from the DS. From analysis of the DS and DDS, in combination with density functional theory based vibrational frequency calculations of the quinones, the neutral state bands of the incorporated quinones are identified and assigned. For neutral PhQ in the A1 binding site, infrared absorption bands were identified near 1665 and 1635 cm-1, that are due to the C1O and C4O stretching vibrations of the incorporated PhQ, respectively. These assignments indicate a 30 cm-1 separation between the C1O and C4O modes, considerably less than the ~80 cm-1 found for similar modes of PhQ-. The C4O mode downshifts due to hydrogen bonding, so the suggestion is that hydrogen bonding is weaker for the neutral state compared to the anion state, indicating radical-induced proton dynamics associated with the quinone in the A1 binding site in PSI.


Assuntos
Complexo de Proteína do Fotossistema I/química , Quinonas/química , Amidas/química , Ânions , Sítios de Ligação , Isótopos de Carbono , Transporte de Elétrons , Ésteres/química , Modelos Moleculares , Fotossíntese , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Vibração
6.
J Agric Food Chem ; 68(8): 2506-2515, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32013414

RESUMO

Thiol groups of cysteine (Cys) residues in proteins react with quinones, oxidation products of polyphenols, to form protein-polyphenol adducts. The aim of the present work was to quantify the amount of adduct formed between Cys residues and 4-methylcatechol (4MC) in minced beef. A Cys-4MC adduct standard was electrochemically synthesized and characterized by liquid chromatography-mass spectrometry (LC-MS) as well as NMR spectroscopy. Cys-4MC adducts were quantified after acidic hydrolysis of myofibrillar protein isolates (MPIs) and LC-MS/MS analysis of meat containing either 500 or 1500 ppm 4MC and stored at 4 °C for 7 days under a nitrogen or oxygen atmosphere. The concentrations of Cys-4MC were found to be 2.2 ± 0.3 nmol/mg MPI and 8.1 ± 0.9 nmol/mg MPI in meat containing 500 and 1500 ppm 4MC, respectively, and stored for 7 days under oxygen. The formation of the Cys-4MC adduct resulted in protein thiol loss, and ca. 62% of the thiol loss was estimated to account for the formation of the Cys-4MC adduct for meat containing 1500 ppm 4MC. Furthermore, protein polymerization increased in samples containing 4MC as evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the polymerization was found to originate from protein-polyphenol interactions as evaluated by a blotting assay with staining by nitroblue tetrazolium.


Assuntos
Cisteína/química , Guaiacol/química , Carne/análise , Fenol/química , Animais , Bovinos , Proteínas Musculares/química , Oxirredução , Quinonas/química , Espectrometria de Massas em Tandem
7.
Int J Syst Evol Microbiol ; 70(1): 346-351, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31592761

RESUMO

A new aerobic betaproteobacterium, strain SA-152T, was isolated from the water of a crater lake. 16S rRNA gene sequence analysis revealed that strain SA-152T belonged to the family Oxalobacteraceae (order Burkholderiales) and was phylogenetically related to Solimicrobium silvestre S20-91T with 97.09 % and to Herminiimonas arsenicoxydans ULPAs1T with 96.00 % 16S rRNA gene pairwise sequence similarity. Cells of strain SA-152T were rod-shaped, non-motile, oxidase-negative and catalase-positive. Its fatty acid profile was dominated by two fatty acids, C16 : 1 ω7c and C16 : 0, the major respiratory quinones were Q-8 and Q-7, and the main polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The G+C content of the genomic DNA of strain SA-152T was 48.3 mol%. The new bacterium can be distinguished from closely related genera Solimicrobium, Herminiimonas, Rugamonas and Undibacterium based on its non-motile and oxidase-negative cells. On the basis of the phenotypic, chemotaxonomic and genomic data, strain SA-152T is considered to represent a novel species of a new genus, for which the name Sapientia aquatica gen. nov., sp. nov. is proposed. The type strain of Sapientia aquatica is SA-152T (=DSM 29805T=NCAIM B.02613T).


Assuntos
Lagos/microbiologia , Oxalobacteraceae/classificação , Filogenia , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oxalobacteraceae/isolamento & purificação , Fosfolipídeos/química , Quinonas/química , RNA Ribossômico 16S/genética , Romênia , Análise de Sequência de DNA
8.
Chem Commun (Camb) ; 56(3): 415-418, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31821393

RESUMO

We report a novel 1,2-catechol based radioiodinated precursor for radioiodination of bicyclo[6.1.0]nonyne (BCN) installed biologically active molecules using a strain-promoted oxidation-controlled cyclooctyne-1,2-quinone cycloaddition reaction (SPOCQ) under ambient conditions. Compared to the reported methodologies, the new strategy demonstrates some clear advantages, including high in vitro and in vivo stability, high radiochemical yield, and exceptionally fast reaction kinetics at micro-molar concentration.


Assuntos
Reação de Cicloadição , Quinonas/química , Compostos Radiofarmacêuticos/química , Animais , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/química , Catecóis/química , Coração/diagnóstico por imagem , Radioisótopos do Iodo/química , Marcação por Isótopo , Cinética , Camundongos , Camundongos Endogâmicos ICR , Oxirredução , Compostos Radiofarmacêuticos/síntese química , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único
9.
Int J Syst Evol Microbiol ; 70(2): 1288-1293, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31778351

RESUMO

A Gram-stain-negative, motile, facultative anaerobic rod-shaped marine bacterium, designated strain D4-2T, was isolated from a sample of seawater collected at Dong-do marina, Dokdo Island, in the East Sea of the Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain D4-2T was affiliated with members of genus Shewanella and closely related to Shewanella intestini XMDDZSB0408T (97.4%), followed by Shewanella gelidii RZB5-4T (96.7 %) and Shewanella inventionis KX27T (96.1 %). D4-2T has a single circular chromosome of 4.72 Mbp with a DNA G+C content of 44.5 mol%. Average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) values between strain D4-2T and the previously mentioned type strains of species of the genus Shewanella were in range of 69-83.8 % and 20.5-21.7 %, respectively. Growth was observed at 10-36 °C (optimum 29-32 °C), at pH 6-9 (optimum pH 7), and with 1-6% NaCl (optimum 2%). The predominant fatty acids (>10 %) of D4-2T were iso-C15:0 and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The respiratory quinones were Q-7, Q-8, MK-7 and MMK-7. Phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, an unidentified aminolipid and four unidentified lipids were detected in D4-2T. On the basis of phenotypic, chemotaxonomic and molecular properties, D4-2T represents a novel species of the genus Shewanella, for which the name Shewanella maritima sp. nov. is proposed with D4-2T as the type strain (=KCTC 72040T=JCM 33294T).


Assuntos
Filogenia , Água do Mar/microbiologia , Shewanella/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Quinonas/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Shewanella/isolamento & purificação
10.
Int J Syst Evol Microbiol ; 70(2): 935-943, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31730030

RESUMO

A polyphasic approach was used to investigate the taxonomic status of two bacterial strains, WS 5072T and WS 5092, isolated from skimmed milk concentrate and raw cow's milk. The 16S rRNA and rpoD gene sequences affiliated the strains to the same, hitherto unknown, Pseudomonas species. Further examinations of the draft genomes based on multilocus sequence analysis and average nucleotide identity confirmed the presence of a novel Pseudomonas species. It was most closely related to Pseudomonas fragi DSM 3456T with 86.3 % ANIm. The DNA G+C content of strain WS 5072T was 56.3 mol%. Cells were aerobic, Gram-negative, catalase and oxidase positive, rod-shaped and motile. Growth occurred at 4-34 °C, pH 5.5-8.0 and with salt concentrations of up to 7 %. The major cellular polar lipids were phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The dominating quinone was Q-9 with 94 %, with noticeable amounts of Q-8 (5 %) and traces of Q-7 and Q-10. Fatty acid profiles showed a composition common for Pseudomonas with the major component C16 : 0. Based on these results, the novel species Pseudomonas saxonica sp. nov. is proposed, with the type strain WS 5072T (=DSM 108989T=LMG 31234T) and the additional strain WS 5092 (=DSM 108990=LMG 31235).


Assuntos
Microbiologia de Alimentos , Leite/microbiologia , Filogenia , Pseudomonas/classificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Bovinos , DNA Bacteriano/genética , Ácidos Graxos/química , Feminino , Genes Bacterianos , Alemanha , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pseudomonas/isolamento & purificação , Quinonas/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Bioelectrochemistry ; 131: 107372, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31759220

RESUMO

Pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase is one of the extensively studied sugar-oxidizing enzymes used as a biocatalyst for biosensors and biofuel cells. A novel pyranose dehydrogenase (CcPDH) derived from the basidiomycete Coprinopsis cinerea is the first discovered eukaryotic PQQ-dependent enzyme. This enzyme carries a b-type cytochrome domain that is homologous to the cytochrome domain of cellobiose dehydrogenase (CDH); thus, CcPDH is a quinohemoprotein. CcPDH catalyzes the oxidation of various aldose sugars and shows significant activity toward the reverse-chair conformation of pyranoses. Interdomain electron transfer occurs in CcPDH similar to CDH, from the PQQ cofactor in the catalytic domain to the heme b in the cytochrome domain. This enzyme is able to direct electrical communication with electrodes, without artificial electron mediators, thus allowing direct electron transfer (DET)-type bioelectrocatalysis. In this review, we briefly describe recent progress in research on the biochemical discovery of CcPDH and the development of (bio)electrochemical applications (an amperometric biosensor) based on DET reactions.


Assuntos
Técnicas Eletroquímicas/instrumentação , Hemeproteínas/química , Quinonas/química , Biomarcadores Tumorais/metabolismo , Técnicas Biossensoriais , Eucariotos
12.
Mater Sci Eng C Mater Biol Appl ; 106: 110230, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753349

RESUMO

There is an urgent need for new antibacterial strategies to overcome the emergence of antibiotic resistance. Antibacterial photodynamic therapy (APDT) may be an effective method to deliver photosensitizers for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we report that the photosensitizer hypocrellin A (HA) loaded into lipase-sensitive methoxy poly (ethylene glycol)-block-poly(ε-caprolactone) (mPEG-PCL) micelles showed high anti-MRSA activity in vitro and in vivo by PDT. Once the micelles come into contact with bacteria that secrete lipase, the PCL is degraded to release HA. Our results showed that the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of mPEG-PCL/HA micelles after light irradiation were 0.69 and 1.38 mg/L (HA concentration), respectively. In the dark, the MIC and MBC of the micelles were 250 and 500 mg/L (HA concentration), respectively. The fluorescent stain results further demonstrated the photodynamic antibacterial activity of mPEG-PCL/HA micelles. The survival rate of mice subjected to experimental acute peritonitis increased to 86% after treated with the micelles. The polymeric micelles showed low hemolytic activity and biocompatibility, simultaneously preventing aggregation in vivo and enhancing the water solubility of HA. Thus, the photosensitizer HA loaded micelles could be used as APDT for infections caused by bacteria without antibiotic resistance.


Assuntos
Lipase/química , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Perileno/análogos & derivados , Polímeros/química , Quinonas/química , Quinonas/uso terapêutico , Animais , Antibacterianos/química , Antibacterianos/uso terapêutico , Portadores de Fármacos/química , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Micelas , Testes de Sensibilidade Microbiana , Perileno/química , Perileno/uso terapêutico , Fotoquimioterapia
13.
Molecules ; 24(22)2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31731682

RESUMO

Twenty-seven L-shaped ortho-quinone analogs were designed and synthesized using a one pot double-radical synthetic strategy followed by removing methyl at C-3 of the furan ring and introducing a diverse side chain at C-2 of the furan ring. The synthetic derivatives were investigated for their cytotoxicity activities against human leukemia cells K562, prostate cancer cells PC3, and melanoma cells WM9. Compounds TB1, TB3, TB4, TB6, TC1, TC3, TC5, TC9, TC11, TC12, TC14, TC15, TC16, and TC17 exhibited a better broad-spectrum cytotoxicity on three cancer cells. TB7 and TC7 selectively displayed potent inhibitory activities on leukemia cells K562 and prostate cancer cells PC3, respectively. Further studies indicated that TB3, TC1, TC3, TC7, and TC17 could significantly induce the apoptosis of PC3 cells. TC1 and TC17 significantly induced apoptosis of K562 cells. TC1, TC11, and TC14 induced significant apoptosis of WM9 cells. The structure-activity relationships evaluation showed that removing methyl at C-3 of the furan ring and introducing diverse side chains at C-2 of the furan ring is an effective strategy for improving the anticancer activity of L-shaped ortho-quinone analogs.


Assuntos
Antineoplásicos , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citotoxinas , Neoplasias , Quinonas , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células K562 , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Células PC-3 , Quinonas/síntese química , Quinonas/química , Quinonas/farmacologia , Relação Estrutura-Atividade
14.
Biochim Biophys Acta Bioenerg ; 1860(12): 148082, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669461

RESUMO

Redox titration using fluorescence measurements of photosystem II (PSII) has long shown that impairment of the water-oxidizing Mn4CaO5 cluster upshifts the redox potential (Em) of the primary quinone electron acceptor QA by more than 100 mV, which has been proposed as a photoprotection mechanism of PSII. However, the molecular mechanism of this long-distance interaction between the Mn4CaO5 cluster and QA in PSII remains unresolved. In this study, we reinvestigated the effect of depletion of the Mn4CaO5 cluster on Em(QA-/QA) using Fourier transform infrared (FTIR) spectroelectrochemistry, which can directly monitor the redox state of QA at an intended potential. Light-induced FTIR difference measurements at a series of electrode potentials for intact and Mn-depleted PSII preparations from spinach and Thermosynechococcus elongatus showed that depletion of the Mn4CaO5 cluster hardly affected the Em(QA-/QA) values. In contrast, fluorescence spectroelectrochemical measurement using the same PSII sample, electrochemical cell, and redox mediators reproduced a large upshift of apparent Em upon Mn depletion, whereas a smaller shift was observed when weaker visible light was used for fluorescence excitation. Thus, the possibility was suggested that the measuring light for fluorescence disturbed the titration curve in Mn-depleted PSII, in contrast to no interference of infrared light with the PSII reactions in FTIR measurements. From these results, it was concluded that the Mn4CaO5 cluster does not directly regulate Em(QA-/QA) to control the redox reactions on the electron acceptor side of PSII.


Assuntos
Manganês/química , Complexo de Proteína do Fotossistema II/química , Quinonas/química , Cianobactérias , Elétrons , Manganês/metabolismo , Oxirredução , Complexo de Proteína do Fotossistema II/metabolismo , Quinonas/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Spinacia oleracea , Água/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-31678841

RESUMO

Leishmania is the aethiological agent responsible for the visceral leishmaniasis, a serious parasite-borne disease widely spread all over the World. The emergence of resistant strains makes classical treatments less effective; therefore, new and better drugs are necessary. Naphthoquinones are interesting compounds for which many pharmacological properties have been described, including leishmanicidal activity. This work shows the antileishmanial effect of two series of terpenyl-1,4-naphthoquinones (NQ) and 1,4-anthraquinones (AQ) obtained from natural terpenoids, such as myrcene and myrceocommunic acid. They were evaluated both in vitro and ex vivo against the transgenic iRFP-Leishmania infantum strain and also tested on liver HepG2 cells to determine their selectivity indexes. The results indicated that NQ derivatives showed better antileishmanial activity than AQ analogues, and among them, compounds with a diacetylated hydroquinone moiety provided better results than their corresponding quinones. Regarding the terpenic precursor, compounds obtained from the monoterpenoid myrcene displayed good antiparasitic efficiency and low cytotoxicity for mammalian cells, whereas those derived from the diterpenoid showed better antileishmanial activity without selectivity. In order to explore their mechanism of action, all the compounds have been tested as potential inhibitors of Leishmania type IB DNA topoisomerases, but only some compounds that displayed the quinone ring were able to inhibit the recombinant enzyme in vitro. This fact together with the docking studies performed on LTopIB suggested the existence of another mechanism of action, alternative or complementary to LTopIB inhibition. In silico druglikeness and ADME evaluation of the best leishmanicidal compounds has shown good predictable druggability.


Assuntos
Antiprotozoários/farmacologia , DNA Topoisomerases/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/enzimologia , Quinonas/farmacologia , Animais , Antraquinonas/farmacologia , Camptotecina/química , Camptotecina/farmacologia , DNA Topoisomerases/química , DNA Topoisomerases/genética , Resistência a Medicamentos , Feminino , Células Hep G2/parasitologia , Humanos , Leishmaniose Visceral/tratamento farmacológico , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Naftoquinonas/farmacologia , Quinonas/química , Baço/citologia , Inibidores da Topoisomerase/química , Inibidores da Topoisomerase/farmacologia
16.
ACS Appl Mater Interfaces ; 11(48): 44989-44998, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31755268

RESUMO

Tumor hypoxia severely limits the therapeutic efficacy of solid tumors in photodynamic therapy. One strategy is to develop photosensitizers with simultaneously high efficiency in photodynamic (PDT) and photothermal therapies (PTT) in a single natural-origin phototheranostic agent to overcome this problem. However, less attention has been paid to the natural-origin phototheranostic agent with high PDT and PTT efficiencies even though they have negligible side effects and are environmentally sustainable in comparison with many reported phototheranostic agents. In addition, almost all clinical applied photosensitizers are of natural origin so far. Herein, we synthesized a natural product-based hypocrellin derivative (AETHB), with a high singlet oxygen quantum yield of 0.64 as an efficient photosensitizer different from commercially available porphyrin-based photosensitizers. AETHB is further assembled with human serum albumin to construct nanoparticles (HSA-AETHB NPs) with a high photothermal conversion efficiency (more than 50%). As-prepared HSA-AETHB NPs have shown good water solubility and biocompatibility, pH and light stability, wide absorption (400-750 nm), and NIR emission centered at 710 nm. More importantly, HSA-AETHB NPs can be applied for fluorescent/photoacoustic dual-mode imaging and simultaneously highly efficient PDT/PTT in hypoxic solid tumors. Therefore, this natural-origin multifunctional phototheranostic agent is showing very promising for effective, precise, and safe cancer therapy in clinical applications.


Assuntos
Hipertermia Induzida , Neoplasias/terapia , Perileno/análogos & derivados , Fotoquimioterapia , Quinonas/química , Albumina Sérica/química , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Raios Infravermelhos , Camundongos , Camundongos Nus , Nanopartículas/química , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Perileno/administração & dosagem , Perileno/química , Quinonas/administração & dosagem , Nanomedicina Teranóstica
17.
Molecules ; 24(20)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623105

RESUMO

Human parasitic protozoa cause a large number of diseases worldwide and, for some of these diseases, there are no effective treatments to date, and drug resistance has been observed. For these reasons, the discovery of new etiological treatments is necessary. In this sense, parasitic metabolic pathways that are absent in vertebrate hosts would be interesting research candidates for the identification of new drug targets. Most likely due to the protozoa variability, uncertain phylogenetic origin, endosymbiotic events, and evolutionary pressure for adaptation to adverse environments, a surprising variety of prenylquinones can be found within these organisms. These compounds are involved in essential metabolic reactions in organisms, for example, prevention of lipoperoxidation, participation in the mitochondrial respiratory chain or as enzymatic cofactors. This review will describe several prenylquinones that have been previously characterized in human pathogenic protozoa. Among all existing prenylquinones, this review is focused on ubiquinone, menaquinone, tocopherols, chlorobiumquinone, and thermoplasmaquinone. This review will also discuss the biosynthesis of prenylquinones, starting from the isoprenic side chains to the aromatic head group precursors. The isoprenic side chain biosynthesis maybe come from mevalonate or non-mevalonate pathways as well as leucine dependent pathways for isoprenoid biosynthesis. Finally, the isoprenic chains elongation and prenylquinone aromatic precursors origins from amino acid degradation or the shikimate pathway is reviewed. The phylogenetic distribution and what is known about the biological functions of these compounds among species will be described, as will the therapeutic strategies associated with prenylquinone metabolism in protozoan parasites.


Assuntos
Antineoplásicos/farmacologia , Antiprotozoários/farmacologia , Parasitos/efeitos dos fármacos , Quinonas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antiprotozoários/química , Antiprotozoários/metabolismo , Vias Biossintéticas , Humanos , Estrutura Molecular , Parasitos/metabolismo , Quinonas/química , Quinonas/metabolismo , Simbiose/efeitos dos fármacos
18.
Chem Biodivers ; 16(12): e1900442, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31633271

RESUMO

Due to the potentially harmful effects of some synthetic dyes, there is an increasing demand for natural colorants. Recent literature has emphasized the necessity of investigating new sources of dyes. This review discusses the biological sources of dyes derived from the rich plant diversity of Madagascar. As one of the first contributions on the use of these dyestuffs for dyeing textiles, it provides an overview of 128 dye plant species with other potential applications for coloring materials in industry. A detailed description of the botanical and chemical properties of these dyestuffs is given. We believe that the Madagascar plant diversity may be a promising source of novel colorants not yet investigated. We considered it worthwhile to carry out a thorough scientific study of a set of Malagasy plants carefully selected for their coloring properties together with their potential use and valorization in specialized industries where use of natural colorants would be a particular interest.


Assuntos
Corantes/química , Plantas/química , Carotenoides/química , Flavonoides/química , Madagáscar , Malpighiaceae/química , Malpighiaceae/metabolismo , Casca de Planta/química , Casca de Planta/metabolismo , Plantas/metabolismo , Quinonas/química , Taninos/química
19.
Phytochemistry ; 166: 112077, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31374519

RESUMO

Radical scavenging activity and subsequent oxidation resulting in quinone products represent one of the important features of phenols occurring in plants and other biological systems. However, corresponding thermochemistry data can be still considered scarce. For phenol and 25 para-substituted phenols, we investigate the thermodynamics of the individual reaction steps, including three subsequent hydrogen atom transfers, as well as hydroxyl HO radical addition, leading to final ortho-quinone formation. The substituent and solvent effect of water on corresponding reactions enthalpies is elucidated. Solvent enhances substituent induced changes in the investigated reaction enthalpies. The reliability of employed computational methods for the thermodynamics of hydrogen atom donating ability of studied phenols and catechols is assessed, too. Obtained linear equations enable estimation of studied reaction enthalpies from Hammett constants of substituents.


Assuntos
Depuradores de Radicais Livres/química , Fenóis/química , Quinonas/química , Radical Hidroxila/química , Isomerismo , Relação Estrutura-Atividade , Termodinâmica
20.
Phytochemistry ; 167: 112096, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31470169

RESUMO

Although Morinda umbellata L. has been used in numerous folk medicines, there is a lack of phytochemical studies on this plant. Sixteen undescribed quinones, namely, ten anthraquinones (umbellatas A-J), one naphthohydroquinone (umbellata K), one naphthohydroquinone dimer (umbellata L), and four dinaphthofuran quinones (umbellatas M-P), were isolated from the aerial parts of Morinda umbellata L. (Rubiaceae). The structures of all the isolated quinones were elucidated based on spectroscopic methods. Four of the unknown quinones (umbellatas A, H, K and M) showed potent cytotoxic effects against A431, A2780, NCI-H460, HCT116, HepG2, and MCF-7 human cancer cell lines with IC50 values of 1.3-7.1 µM. These results reveal potential lead compounds for the development of new anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Morinda/química , Componentes Aéreos da Planta/química , Quinonas/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Quinonas/química
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