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1.
Food Chem ; 329: 127132, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32504917

RESUMO

It has been proven that at increased temperature, sterols can undergo various chemical reactions e.g., oxidation, dehydrogenation, dehydration and polymerisation. The objectives of this study are to prove the existence of dimers and to quantitatively analyse the dimers (3ß,3'ß-disteryl ethers). Sterol-rich samples were heated at 180 °C, 200 °C and 220 °C for 1 to 5 h. Quantitative analyses of the 3ß,3'ß-disteryl ethers were conducted using liquid extraction, solid-phase extraction and gas chromatography coupled with mass spectrometry. Additionally, for the analyses, suitable standards were synthetized from native sterols. To identify the mechanism of 3ß,3'ß-disteryl ether formation at high temperatures, an attempt was made to use the proposed synthesis method. Additionally, due to the association of sterols and sterol derivatives with atherosclerosis, preliminary studies with synthetized 3ß,3'ß-disteryl ethers on endothelial cells were conducted.


Assuntos
Éteres/química , Esteróis/química , Linhagem Celular , Células Endoteliais , Éteres/síntese química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Espectrometria de Massas , Oxirredução , Extração em Fase Sólida , Temperatura
2.
Proc Natl Acad Sci U S A ; 117(26): 14948-14957, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32541034

RESUMO

Diverting aminoacyl-transfer RNAs (tRNAs) from protein synthesis is a well-known process used by a wide range of bacteria to aminoacylate membrane constituents. By tRNA-dependently adding amino acids to glycerolipids, bacteria change their cell surface properties, which intensifies antimicrobial drug resistance, pathogenicity, and virulence. No equivalent aminoacylated lipids have been uncovered in any eukaryotic species thus far, suggesting that tRNA-dependent lipid remodeling is a process restricted to prokaryotes. We report here the discovery of ergosteryl-3ß-O-l-aspartate (Erg-Asp), a conjugated sterol that is produced by the tRNA-dependent addition of aspartate to the 3ß-OH group of ergosterol, the major sterol found in fungal membranes. In fact, Erg-Asp exists in the majority of "higher" fungi, including species of biotechnological interest, and, more importantly, in human pathogens like Aspergillus fumigatus We show that a bifunctional enzyme, ergosteryl-3ß-O-l-aspartate synthase (ErdS), is responsible for Erg-Asp synthesis. ErdS corresponds to a unique fusion of an aspartyl-tRNA synthetase-that produces aspartyl-tRNAAsp (Asp-tRNAAsp)-and of a Domain of Unknown Function 2156, which actually transfers aspartate from Asp-tRNAAsp onto ergosterol. We also uncovered that removal of the Asp modifier from Erg-Asp is catalyzed by a second enzyme, ErdH, that is a genuine Erg-Asp hydrolase participating in the turnover of the conjugated sterol in vivo. Phylogenomics highlights that the entire Erg-Asp synthesis/degradation pathway is conserved across "higher" fungi. Given the central roles of sterols and conjugated sterols in fungi, we propose that this tRNA-dependent ergosterol modification and homeostasis system might have broader implications in membrane remodeling, trafficking, antimicrobial resistance, or pathogenicity.


Assuntos
Ácido Aspártico/metabolismo , Aspergillus fumigatus/metabolismo , RNA Fúngico/metabolismo , Aminoacil-RNA de Transferência/metabolismo , Esteróis/metabolismo , Aminoacilação , Ácido Aspártico/química , Aspergillus fumigatus/química , Aspergillus fumigatus/genética , RNA Fúngico/química , RNA Fúngico/genética , Aminoacil-RNA de Transferência/química , Aminoacil-RNA de Transferência/genética , Esteróis/química
3.
Chemistry ; 26(19): 4256-4260, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32031278

RESUMO

We report the first chemical synthesis of eurysterol A, a cytotoxic and antifungal marine steroidal sulfate with a unique C8-C19 oxy-bridged cholestane skeleton. After C19 hydroxylation of cholesteryl acetate, used as an inexpensive commercial starting material, the challenging oxidative functionalization of ring B was achieved by two different routes to set up a 5α-hydroxy-7-en-6-one moiety. As a key step, an intramolecular oxa-Michael addition was exploited to close the oxy-bridge (8ß,19-epoxy unit). DFT calculations show this reversible transformation being exergonic by about -30 kJ mol-1 . Along the optimized (scalable) synthetic sequence, the target natural product was obtained in only 11 steps in 5 % overall yield. In addition, an access to (isomeric) 7ß,19-epoxy steroids with a previously unknown pentacyclic ring system was discovered.


Assuntos
Antifúngicos/síntese química , Esteroides/química , Esteróis/síntese química , Antifúngicos/química , Hidroxilação , Isomerismo , Estrutura Molecular , Oxirredução , Esteróis/química
4.
RNA ; 26(5): 541-549, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32014999

RESUMO

The PI3K/Akt/mTOR kinase pathway is extensively deregulated in human cancers. One critical node under regulation of this signaling axis is eukaryotic initiation factor (eIF) 4F, a complex involved in the control of translation initiation rates. eIF4F-dependent addictions arise during tumor initiation and maintenance due to increased eIF4F activity-generally in response to elevated PI3K/Akt/mTOR signaling flux. There is thus much interest in exploring eIF4F as a small molecule target for the development of new anticancer drugs. The DEAD-box RNA helicase, eIF4A, is an essential subunit of eIF4F, and several potent small molecules (rocaglates, hippuristanol, pateamine A) affecting its activity have been identified and shown to demonstrate anticancer activity in vitro and in vivo in preclinical models. Recently, a number of new small molecules have been reported as having the capacity to target and inhibit eIF4A. Here, we undertook a comparative analysis of their biological activity and specificity relative to the eIF4A inhibitor, hippuristanol.


Assuntos
Antineoplásicos/química , Fator de Iniciação 4A em Eucariotos/química , Neoplasias/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/química , Esteróis/química , Antineoplásicos/farmacologia , Benzofuranos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Compostos de Epóxi/química , Fator de Iniciação 4A em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4F em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4F em Eucariotos/química , Humanos , Macrolídeos/química , Neoplasias/genética , Fosfatidilinositol 3-Quinases/genética , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Esteróis/farmacologia , Serina-Treonina Quinases TOR/genética , Tiazóis/química
5.
J Exp Clin Cancer Res ; 39(1): 37, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32075676

RESUMO

BACKGROUND: Arnidiol is a pentacyclic triterpene diol that has multiple pharmacological activities. However, the apoptotic activities of arnidiol in human cancer cells have not yet been explored, nor has the mechanism by which arnidiol induces apoptosis been examined in depth. METHODS: MDA-MB-231 cells and xenografted mice were treated with arnidiol. Mitochondrial fission and apoptosis were determined by immunofluorescence, flow cytometry and related molecular biological techniques. The interaction and colocalization of cofilin and Drp1 was determined by immunoprecipitation and immunofluorescence assays. RESULTS: Arnidiol induces mitochondrial fission and apoptosis through mitochondrial translocation of Drp1 and cofilin. Importantly, the interaction of Drp1 and cofilin in mitochondria is involved in arnidiol-induced mitochondrial fission and apoptosis. Knockdown of either Drp1 or cofilin abrogated arnidiol-induced mitochondrial translocation, interaction of Drp1 and cofilin, mitochondrial fission and apoptosis. Only dephosphorylated Drp1 (Ser637) and cofilin (Ser3) were translocated to the mitochondria. Mutants of Drp1 S637A and cofilin S3A, which mimic the dephosphorylated forms, enhanced mitochondrial fission and apoptosis induced by arnidiol, whereas mutants of Drp1 S637D and cofilin S3E, which mimic the phosphorylated forms, suppressed mitochondrial fission and apoptosis induced by arnidiol. A mechanistic study revealed that ROCK1 activation plays an important role in the arnidiol-mediated Drp1 and cofilin dephosphorylation and mitochondrial translocation, mitochondrial fission, and apoptosis. CONCLUSIONS: Our data reveal a novel role of both Drp1 and cofilin in the regulation of mitochondrial fission and apoptosis and suggest that arnidiol could be developed as a potential agent for the treatment of human cancer.


Assuntos
Fatores de Despolimerização de Actina/metabolismo , Apoptose/efeitos dos fármacos , Dinaminas/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Esteróis/farmacologia , Triterpenos/farmacologia , Quinases Associadas a rho/metabolismo , Animais , Apoptose/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Mitocôndrias/genética , Dinâmica Mitocondrial/genética , Estrutura Molecular , Mutação , Fosforilação , Transporte Proteico , Esteróis/química , Triterpenos/química , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases Associadas a rho/genética
6.
Anal Chim Acta ; 1097: 110-119, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-31910950

RESUMO

Enlightened by the high specificity and reactivity of thiol radical toward allyl, here, we first established a rapid thiol radical-based chemical isotope-labelling (CIL) strategy coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis for the quantitative profiling of sterols. In this strategy, N-(4-(carbazole-9-yl)-phenyl)-N-maleimide labelled derivative of ethylenedithiol (NCPM-d0-SH) and its deuterated analogue NCPM-d2-SH were employed as a novel pair of CIL reagents to efficiently label sterols. Under lighting condition, the thiol radical obtained from NCPM-d0/d2-SH attacks one allyl hydrogen in the B-ring of sterols to produce a reactive radical intermediate which can quickly react with another thiol radical to form the last labelled derivatives. This labelling reaction can rapidly complete only within 1.5 min. Absorbingly, the NCPM-d0-SH and NCPM-d2-SH labelled derivatives of sterols can produce two specific product ions (PIs) containing different isotope tags at m/z of 431.6 and 433.6 via collision induced dissociation, which were employed to develop the multiple reaction monitoring (MRM) mode-based analysis. According to the specific mass differences with a fixed value, the peak pairs with similar retention times can be easily extracted from the two PIs spectrums and designated as the candidates for the identification of sterols. NCPM-d0-SH and NCPM-d2-SH labelled derivatives of sterols can be readily distinguished from their several ion chromatograms. Thus, sterols from two samples labelled by different isotope tags were ionized at the same conditions and measured respectively, providing excellent identification and precise quantitation by compensating the matrix effect and instrument fluctuation during MS-based analysis. The detection sensitivities of thiol-containing drugs improved by 53.5-560.3-fold due to NCPM-labelling. The limits of detection (LODs) and the limits of quantitation (LOQs) were in the range of 0.15-0.40 µg kg-1 and 0.50-1.30 µg kg-1, respectively. Using the developed method, we quantitatively profiled five sterols in vegetable oils with good applicability. As promising, the proposed thiol radical-based CIL strategy is a potential platform for the quantitation of sterols.


Assuntos
Marcação por Isótopo , Esteróis/análise , Compostos de Sulfidrila/química , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão , Radicais Livres/química , Estrutura Molecular , Esteróis/química
7.
Biochim Biophys Acta Biomembr ; 1862(2): 183105, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31682816

RESUMO

The aim of this study was to investigate the factors that govern the activity and selectivity of two potent antimicrobial peptides (AMPs) using lipid membrane models of bacterial, erythrocyte and fungal cells. These models were used in calcein liposome leakage experiments to explore peptide efficiency. The AMPs (Pin2 and its variant Pin2[GVG]) showed highest affinity towards the bacterial models in the nanomolar range, followed by the erythrocyte and fungal systems. The presence of sterols modulated the variant's selectivity, while the wild type was unaffected. Liposome leakage experiments with Fluorescein Isothiocyanate-dextran (FITC)-dextran conjugates indicated that pore size depended on peptide concentration. Dynamic Light Scattering revealed peptide aggregation in aqueous solution, and that aggregate size was related to activity. The interacting peptides did not alter liposome size, suggesting pore forming activity rather than detergent activity. Atomic Force Microscopy showed differential membrane absorption, being greater in the bacterial model compared to the mammalian model, and pore-like defects were observed. Electrophysiological assays with the Tip-Dip Patch Clamp method provided evidence of changes in the electrical resistance of the membrane. Membrane potential experiments showed that liposomes were also depolarized in the presence of the peptides. Both peptides increased the Laurdan Generalized Polarization of the bacterial model indicating increased viscosity, on the contrary, no effect was observed with the erythrocyte and the fungal models. Peptide membrane insertion and pore formation was corroborated with Langmuir Pressure-Area isotherms and Brewster Angle Microscopy. Finally, molecular dynamics simulations were used to get an insight into the molecular mechanism of action.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Membrana Celular/efeitos dos fármacos , Lipossomas Unilamelares/química , Animais , Peptídeos Catiônicos Antimicrobianos/química , Bactérias , Membrana Celular/química , Membrana Eritrocítica/efeitos dos fármacos , Fungos , Fluidez de Membrana , Potenciais da Membrana , Esteróis/química , Viscosidade
8.
J Sci Food Agric ; 100(2): 500-508, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31435948

RESUMO

BACKGROUND: In the present study a metabolomics-based approach was used to discriminate among different hazelnut cultivars and to trace their geographical origins. Ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-ESI/QTOF-MS) was used to profile phenolic and sterolic compounds. RESULTS: Compounds were identified against an in-house database using accurate monoisotopic mass and isotopic patterns. The screening approach was designed to discern 15 hazelnut cultivars and to discriminate among the geographical origins of six cultivars from the four main growing regions (Chile, Georgia, Italy, and Turkey). This approach allowed more than 1000 polyphenols and sterols to be annotated. The metabolomics data were elaborated with both unsupervised (hierarchical clustering) and supervised (orthogonal projections to latent structures discriminant analysis, OPLS-DA) statistics. These multivariate statistical tools allowed hazelnut samples to be discriminated, considering both 'cultivar type' and 'geographical origin'. Flavonoids (anthocyanins, flavanols and flavonols - VIP scores 1.34-1.49), phenolic acids (mainly hydroxycinnamics - VIP scores 1.35-1.55) together with cholesterol, ergosterol, and stigmasterol derivatives (VIP scores 1.34-1.49) were the best markers to discriminate samples according to geographical origin. CONCLUSIONS: This work illustrates the potential of untargeted profiling of phenolics and sterols based on UHPLC-ESI/QTOF mass spectrometry to discriminate hazelnut and support authenticity and origin. © 2019 Society of Chemical Industry.


Assuntos
Corylus/química , Nozes/química , Extratos Vegetais/química , Chile , Cromatografia Líquida de Alta Pressão , Corylus/classificação , Corylus/metabolismo , Análise Discriminante , República da Geórgia , Itália , Espectrometria de Massas , Metabolômica , Análise Multivariada , Nozes/classificação , Nozes/metabolismo , Fenóis/química , Fenóis/metabolismo , Extratos Vegetais/metabolismo , Esteróis/química , Esteróis/metabolismo , Turquia
9.
Methods Mol Biol ; 1980: 223-232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-29159730

RESUMO

Constituents of microalgae and sample preparation for UPLC-ELSD and GC-MS analyses are described. Bound fatty acids from acylglycerols, alkylacylglycerols, galactosyldiacylglycerols, glycerophospholipids, and sterol esters are derivatized by using transesterification with sodium methoxide to form fatty acid methyl esters. Compounds containing free hydroxyl groups, either present originally or formed during previous step, like free fatty acids, sterols, α-tocopherol, phytol, and nonesterified alkoxyglycerols, are trimethylsilylated. The compounds in algal lipid extract are subsequently derivatized by these two steps.


Assuntos
Cromatografia Líquida de Alta Pressão , Ácidos Graxos não Esterificados/química , Cromatografia Gasosa-Espectrometria de Massas , Lipídeos/química , Esteróis/química , Esterificação , Ésteres , Ácidos Graxos não Esterificados/análise , Lipídeos/análise , Esteróis/análise
10.
Chin J Nat Med ; 17(8): 624-630, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31472900

RESUMO

Five new polyhydroxylated furostanol saponins were isolated from the roots and rhizomes of Tupistra chinensis, and their structures were determined as tupistrosides J-N (1-5), together with four known furostanol saponins (6-9), on the basis of physico-chemical properties and spectral analysis. Among them, compounds 3 and 5 showed cytotoxicity against human cancer cell lines SW620 with IC50 values of 72.5 ± 2.4 and 77.3 ± 2.5 µmol·L-1, respectively. Compound 4 showed cytotoxicity against human cancer cell line HepG2 with IC50 value of 88.6 ± 2.1 µmol·L-1.


Assuntos
Antineoplásicos/química , Liliaceae/química , Saponinas/química , Esteróis/química , Células A549 , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Extratos Vegetais/química , Rizoma/química , Saponinas/farmacologia , Esteróis/farmacologia
11.
Biochim Biophys Acta Biomembr ; 1861(12): 183060, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499020

RESUMO

In recent years, hopanoids, a group of pentacyclic compounds found in bacterial membranes, are in the spotlight since it was proposed that they induce order in lipid membranes in a similar way cholesterol do in eukaryotes, despite their structural differences. We studied here whether diplopterol (an abundant hopanoid) promoted similar effects on model membranes as sterols do. We analyzed the compaction, dynamics, phase segregation, permeability and compressibility of model membranes containing diplopterol, and compared with those containing sterols from animals, plants and fungi. We also tested the effect that the incubation with diplopterol had on hopanoid-lacking bacteria. Our results show that diplopterol induces phase segregation, increases lipid compaction, and decreases permeability on phospholipid membranes, while retaining membrane fluidity and compressibility. Furthermore, the exposition to this hopanoid decreases the permeability of the opportunistic pathogen Pseudomonas aeruginosa and increases the resistance to antibiotics. All effects promoted by diplopterol were similar to those generated by the sterols. Our observations add information on the functional significance of hopanoids as molecules that play an important role in membrane organization and dynamics in model membranes and in a bacterial system.


Assuntos
Permeabilidade da Membrana Celular/fisiologia , Membrana Celular/química , Triterpenos/metabolismo , Membrana Celular/fisiologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Bicamadas Lipídicas/química , Lipídeos de Membrana/química , Lipídeos de Membrana/fisiologia , Membranas/química , Membranas/fisiologia , Modelos Biológicos , Permeabilidade , Fosfolipídeos/química , Fosfolipídeos/fisiologia , Pseudomonadaceae/metabolismo , Esteróis/química , Triterpenos/farmacologia
12.
Eur J Med Chem ; 182: 111647, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31499362

RESUMO

Liver X Receptor (LXR) is a potential drug target for atherosclerosis. One of the major challenges in taking LXR modulators to the clinic is steatosis. It was reported that sterol LXR agonists selectively activate LXR in the intestine and macrophage cells rather than in the liver. We hypothesize that sterol LXR agonists may selectively inhibit atherosclerosis without causing hepatic lipogenesis. Thus, based on LXR structure, 12 sterol compounds were designed and tested in a dual-luciferase reporter gene experiment. It was confirmed that compounds 4 and 6 were LXR agonists. Further experiments demonstrated that compounds 4 and 6 inhibit the formation of macrophage foam cells without inducing triglyceride accumulation in either hepatocytes or adipocytes. In vivo studies demonstrated that compound 4 promotes reverse cholesterol transport without inducing hepatic lipogenesis. Thus, we report that these compounds with sterol scaffolds can be promising leads for the treatment of atherosclerosis without inducing steatosis.


Assuntos
Aterosclerose/tratamento farmacológico , Descoberta de Drogas , Receptores X do Fígado/agonistas , Esteróis/farmacologia , Células 3T3-L1 , Animais , Aterosclerose/metabolismo , Diferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Lipogênese/efeitos dos fármacos , Receptores X do Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Estrutura Molecular , Células RAW 264.7 , Esteróis/síntese química , Esteróis/química , Relação Estrutura-Atividade
13.
Sci Adv ; 5(9): eaaw6490, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31555730

RESUMO

Hedgehog signaling is central in embryonic development and tissue regeneration. Disruption of the pathway is linked to genetic diseases and cancer. Binding of the secreted ligand, Sonic hedgehog (ShhN) to its receptor Patched (PTCH1) activates the signaling pathway. Here, we describe a 3.4-Å cryo-EM structure of the human PTCH1 bound to ShhNC24II, a modified hedgehog ligand mimicking its palmitoylated form. The membrane-embedded part of PTCH1 is surrounded by 10 sterol molecules at the inner and outer lipid bilayer portion of the protein. The annular sterols interact at multiple sites with both the sterol-sensing domain (SSD) and the SSD-like domain (SSDL), which are located on opposite sides of PTCH1. The structure reveals a possible route for sterol translocation across the lipid bilayer by PTCH1 and homologous transporters.


Assuntos
Proteínas Hedgehog/química , Bicamadas Lipídicas/química , Receptor Patched-1/química , Esteróis/química , Transporte Biológico , Microscopia Crioeletrônica , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/ultraestrutura , Humanos , Bicamadas Lipídicas/metabolismo , Receptor Patched-1/metabolismo , Receptor Patched-1/ultraestrutura , Domínios Proteicos , Esteróis/metabolismo
14.
Molecules ; 24(16)2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31434231

RESUMO

Sparassis crispa is a kind of edible fungus widely grows in the north temperate zone, which shows various medicinal properties. Due to the complexity of chemical constitutes of this species, few investigations have acquired a comprehensive configuration for the chemical profile of it. In this study, a strategy based on ultra-high performance liquid chromatography (UPLC) combined with Orbitrap mass spectrometer (MS) was established for rapidly characterizing various chemical components in S. crispa. Through the summarized MS/MS fragmentation patterns of reference compounds and systematic identification strategy, a total of 110 components attributed to six categories were identified for the first time. Moreover, allergic rhinitis (AR) is a worldwide inflammatory disease seriously affecting human health, and the development of drugs to treat AR has been a topic of interest. It has been reported that the extracts of S. crispa showed obvious inhibitory effects on degranulation of mast cell- and allergen-induced IgE and proinflammatory mediators, but the active components and specific mechanism were still not clear. Src family kinases (SFKs) participate in the initial stage of allergy occurrence, which are considered the targets of AR treatment. Herein, on the basis of that self-built chemical database, virtual screening was applied to predict the potential SFKs inhibitors in S. crispa, using known crystal structures of Hck, Lyn, Fyn, and Syk as receptors, followed by the anti-inflammatory activity evaluation for screened hits by intracellular calcium mobilization assay. As results, sparoside A was directly confirmed to have strong anti-inflammatory activity with an IC50 value of 5.06 ± 0.60 µM. This study provides a useful elucidation for the chemical composition of S. crispa, and demonstrated its potential inhibitory effects on AR, which could promote the research and development of effective agents from natural resources.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Espectrometria de Massas/métodos , Polyporales/química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Quinases da Família src/antagonistas & inibidores , Alcaloides/análise , Alcaloides/química , Animais , Anti-Inflamatórios não Esteroides/química , Benzofuranos/análise , Benzofuranos/química , Linhagem Celular , Cromatografia Líquida/métodos , Simulação por Computador , Avaliação Pré-Clínica de Medicamentos , Humanos , Ratos , Rinite Alérgica/tratamento farmacológico , Sesquiterpenos/análise , Sesquiterpenos/química , Esteróis/análise , Esteróis/química , Espectrometria de Massas em Tandem
15.
Environ Sci Pollut Res Int ; 26(31): 31555-31580, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31440968

RESUMO

Southeast Asia has undergone rapid developments in terms of urbanization, economic and population growth. The progress in sewerage treatment infrastructure has not kept pace with such developments. The inadequacy and inefficiency of sewerage systems has prompted the release of untreated sewage into the aquatic environment of Southeast Asia causing many waterborne illnesses since surface water is utilized for recreational, agricultural and aquaculture purposes and, above all, as a source of water intake in Southeast Asia. This paper will review the current data on molecular markers of sewage pollution including sterols and linear alkylbenzenes (LABs) in Southeast Asian aquatic environment to clarify the state of sewage pollution and the competence of sewage treatment plants (STPs) in this area. Despite the importance of sewage pollution research in the region, the number of studies using molecular markers to trace the sources of sewage pollution is limited. So far, indicators of sewage pollution have been investigated in aquatic environments of Indonesia, Vietnam, Malaysia, the Philippines, Thailand, Cambodia and Brunei among Southeast Asian countries. The concentrations and diagnostic ratios of faecal sterols and LABs show the release of untreated and primary treated urban waste into water bodies of these countries. Further studies are required to fill the data gaps in Southeast Asia and come to a better understanding of the trends of sewage pollution in this part of the world. Graphical abstract.


Assuntos
Biomarcadores/química , Esgotos/química , Esteróis/química , Ásia Sudeste , Brunei , Camboja , Monitoramento Ambiental , Poluição Ambiental , Indonésia , Malásia , Filipinas , Crescimento Demográfico , Esteróis/análise , Tailândia , Vietnã
16.
Phytochemistry ; 167: 112097, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31445450

RESUMO

This work used Δ5-sterols and their degradation products to compare the efficiency of biotic and abiotic degradation processes in senescent Mediterranean marine (Posidonia oceanica) and terrestrial (Quercus ilex and Smilax aspera) angiosperms. Type II photosensitized oxidation processes appeared to be more efficient in P. oceanica than in Q. ilex and S. aspera. The low efficiency of these processes in senescent terrestrial angiosperms was attributed to: (i) the fast degradation of the sensitizer (chlorophyll) in these organisms and (ii) the relatively high on-ground temperatures observed in Mediterranean regions favoring the diffusion of singlet oxygen outside the membranes. Senescent leaves of P. oceanica contained the highest proportions of photochemically-produced 6-hydroperoxysterols, likely due to the presence of trace amounts of metal ions in seawater catalyzing selective homolytic cleavage of 5- and 7-hydroperoxysterols. Bacterial metabolites of sitosterol and its photooxidation products could be detected in senescent leaves of P. oceanica but not Q. ilex or S. aspera. These results confirmed that biotic and abiotic degradation processes may be intimately linked in the environment.


Assuntos
Magnoliopsida/metabolismo , Esteróis/metabolismo , Biomarcadores/química , Biomarcadores/metabolismo , Magnoliopsida/crescimento & desenvolvimento , Região do Mediterrâneo , Folhas de Planta/metabolismo , Esteróis/química
17.
Chem Biodivers ; 16(8): e1900318, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31364803

RESUMO

Sponges from freshwater environments, unlike marine's, are poorly known producers of natural compounds with medicinal purposes. Amazonian sponges produce massive large specimens and are widely spread, taxonomically diverse and their metabolites could represent a new frontier on unusual natural products to treat diseases such as Alzheimer's and Malaria. Species of Metania and Drulia (Metaniidae) genera are major contributors to the fauna of Amazonian freshwater sponges. Methanolic extracts from several species from these genera had their inhibitory activities evaluated in vitro, for parasite Plasmodium falciparum and acetyl and butyrylcholinesterase enzymes (AChE and BChE). All extracts were able to inhibit AChE, although no activity was observed towards BChE. Drulia uruguayensis extract was the most potent, inhibiting AChE with IC50 =1.04 mg/mL. For antiplasmodial activity, all species showed inhibition to P. falciparum, but Metania reticulata being the most efficient with IC50 =2.7 µg/mL. Mass spectrometry analyses evidenced the presence of fatty acids and sterols in active extracts.


Assuntos
Antiprotozoários/química , Inibidores da Colinesterase/química , Poríferos/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/química , Plasmodium falciparum/efeitos dos fármacos , Poríferos/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Esteróis/química
18.
Can J Microbiol ; 65(12): 870-879, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31398296

RESUMO

In this study, we examined the lipid composition of two strains of the tropical basidiomycete Favolaschia manipularis (Berk.) Teng, which differ in their adaptive potential to high (35 °C) and low (5 °C) temperatures. The results suggest that adaptation to extreme temperatures involves a change in the molecular composition of sterols, in addition to other well-known mechanisms of regulating membrane thickness and fluidity, such as changes in the lipid unsaturation and in the proportion of bilayer- and non-bilayer-forming lipids. It was demonstrated for the first time that adaptation to high temperature stress in fungi is accompanied by the accumulation of 9(11)-dehydroergosterol and ergosterol peroxide. Furthermore, increased thermal plasticity correlates with high storage lipid (triglycerides) content, accumulation of phosphatidic acid in the membrane, and an equal proportion of bilayer and non-bilayer lipids in the membrane.


Assuntos
Agaricales/química , Agaricales/fisiologia , Lipídeos/fisiologia , Temperatura , Adaptação Fisiológica , Ergosterol/análogos & derivados , Ergosterol/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Esteróis/química
19.
ACS Appl Mater Interfaces ; 11(33): 29498-29511, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31339692

RESUMO

Supramolecular photosensitizers based on nanosized drug delivery or combination therapy have been proposed as a promising strategy for cancer treatment. Herein, we screen and develop a series of multifunctional single-component, carrier-based, natural small-molecule sterols (ergosterol, ß-sitosterol, and stigmasterol) that simultaneously possess self-assembly ability, anticancer activity, and better biocompatibility and biodegradability to deliver photosensitizer chlorin e6 (Ce6) for significantly combined and safe antitumor photodynamic therapy. The resultant ergosterol-Ce6 nanodrugs (Ergo-Ce6 NPs) have enhanced reactive oxygen species (ROS) generation by promoting type I photoreactions, while Ce6 mainly exists in the monomer state in assembled Ergo-Ce6 NPs via intermolecular π-π stacking and hydrophobic interactions. In addition, with the improved water solubility and stability and higher intercellular ROS generation, Ergo-Ce6 NPs show remarkably in vitro phototoxicity with approximately 73% and 92% cell inhibition ratios to 4T1 and MCF-7 cancer cells at a rather low dosage of Ce6 (1 µg/mL), respectively. Moreover, the excellent tumor targeting ability of Ergo NPs and prolonged blood circulation ensure a quick tumor accumulation of Ergo-Ce6 NPs, resulting in a significantly enhanced in vivo anticancer efficiency of 86.4%, higher than that of the anticancer ability of Ergo NPs (51.0%) or Ce6 PDT alone (59.5%). Furthermore, the resulting nanodrugs have better biocompatibility and biodegradability and low in vivo toxicity, and all of which ensure a safe tumor therapy. This study provides a promising perspective to develop more natural self-assembled biological small-molecule nanomaterials for the fabrication of novel medicinal photosensitizers for clinical application in the future.


Assuntos
Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Esteróis/química , Sistemas de Liberação de Medicamentos , Humanos , Células MCF-7 , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Superóxidos/química
20.
Nat Protoc ; 14(8): 2546-2570, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31341291

RESUMO

Distal cholesterol biosynthesis (CB) has recently taken center stage as a promising drug target in several diseases previously not linked to this biochemical pathway, including cardiovascular disease, cancer, multiple sclerosis and Alzheimer's disease. Most enzymes involved in this pathway are hard to isolate, warranting dedicated analytical tools for biochemical screening. We describe the use of gas chromatography-electron ionization mass spectrometry (GC-MS) in a whole-cell screening assay aimed at monitoring interactions with all enzymes of distal CB in a single experiment. Following cell culture and lipid extraction, the trimethylsilyl ethers of sterols are analyzed by GC-MS. Analytical data for 23 relevant sterols (intermediates) are provided, allowing their unambiguous identification. Sterol pattern analysis reveals the target enzyme on the basis of characteristic marker sterols, whereas quantification of 2-13C-acetate incorporation correlates with the inhibitory activity of drug candidates. The protocol can be used by both experienced scientists and newcomers to the field, allowing detection and quantification of small molecule-enzyme interactions in distal CB. The entire protocol can be carried out within two working days.


Assuntos
Colesterol/metabolismo , Técnicas Citológicas/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Bioensaio/métodos , Colesterol/análise , Colesterol/química , Sistemas de Liberação de Medicamentos , Células HL-60 , Humanos , Esteróis/análise , Esteróis/química , Esteróis/metabolismo
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