Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Gastroenterology ; 167(5): 1008-1018.e5, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38964420

RESUMO

BACKGROUND & AIMS: Homozygous ZZ alpha-1 antitrypsin (AAT) deficiency produces mutant AAT (Z-AAT) proteins in hepatocytes, leading to progressive liver fibrosis. We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT messenger RNA, reducing deleterious protein synthesis. METHODS: This ongoing, phase 2 study randomized 40 patients to subcutaneous placebo or fazirsiran 25, 100, or 200 mg. The primary endpoint was percent change in serum Z-AAT concentration from baseline to week 16. Patients with fibrosis on baseline liver biopsy received treatment on day 1, at week 4, and then every 12 weeks and had a second liver biopsy at or after weeks 48, 72, or 96. Patients without fibrosis received 2 doses on day 1 and at week 4. RESULTS: At week 16, least-squares mean percent declines in serum Z-AAT concentration were -61%, -83%, and -94% with fazirsiran 25, 100, and 200 mg, respectively, vs placebo (all P < .0001). Efficacy was sustained through week 52. At postdose liver biopsy, fazirsiran reduced median liver Z-AAT concentration by 93% compared with an increase of 26% with placebo. All fazirsiran-treated patients had histologic reduction from baseline in hepatic globule burden. Portal inflammation improved in 5 of 12 and 0 of 8 patients with a baseline score of >0 in the fazirsiran and placebo groups, respectively. Histologic meta-analysis of histologic data in viral hepatitis score improved by >1 point in 7 of 14 and 3 of 8 patients with fibrosis of >F0 at baseline in the fazirsiran and placebo groups, respectively. No adverse events led to discontinuation, and pulmonary function tests remained stable. CONCLUSIONS: Fazirsiran reduced serum and liver concentrations of Z-AAT in a dose-dependent manner and reduced hepatic globule burden. (ClinicalTrials.gov, Number NCT03945292).


Assuntos
Cirrose Hepática , Deficiência de alfa 1-Antitripsina , alfa 1-Antitripsina , Humanos , Deficiência de alfa 1-Antitripsina/tratamento farmacológico , Deficiência de alfa 1-Antitripsina/diagnóstico , Deficiência de alfa 1-Antitripsina/complicações , Deficiência de alfa 1-Antitripsina/genética , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , alfa 1-Antitripsina/genética , alfa 1-Antitripsina/administração & dosagem , Resultado do Tratamento , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/diagnóstico , Fígado/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Método Duplo-Cego , Biópsia , Terapêutica com RNAi , Relação Dose-Resposta a Droga , Adulto Jovem , RNA Interferente Pequeno
2.
Bioorg Chem ; 153: 107769, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39236582

RESUMO

Promoting endogenous neurogenesis for brain repair is emerging as a promising strategy to mitigate the functional impairments associated with various neurological disorders characterized by neuronal death. Diterpenes featuring tigliane, ingenane, jatrophane and lathyrane skeletons, frequently found in Euphorbia plant species, are known protein kinase C (PKC) activators and exhibit a wide variety of pharmacological properties, including the stimulation of neurogenesis. Microbial transformation of these diterpenes represents a green and sustainable methodology that offers a hitherto little explored approach to obtaining novel derivatives and exploring structure-activity relationships. In the present study, we report the biotransformation of euphoboetirane A (4) and epoxyboetirane A (5), two lathyrane diterpenoids isolated from Euphorbia boetica, by Mucor circinelloides MC NRRL3631. Our findings revealed the production of nine biotransformation products (6-14), including jatrophane derivatives originated through an unprecedented rearrangement from the parent lathyranes. The chemical structures and absolute configurations of the new compounds were elucidated through comprehensive analysis using NMR and ECD spectroscopy, as well as MS. The study evaluated how principal metabolites and their derivatives affect TGFα and NRG1 release, as well as their potential to promote proliferation or differentiation in cultures of NSC isolated from the SVZ of adult mice. In order to shed some light on the mechanisms underlying the ability of 12 as a neurogenic compound, the interactions of selected compounds with PKC δ-C1B were analyzed through molecular docking and molecular dynamics. Based on these, it clearly appears that the ability of compound 12 to form both acceptor and donor hydrogen bonds with certain amino acid residues in the enzyme pocket leads to a higher affinity compound-PKC complex, which correlates with the observed biological activity.

3.
Int J Mol Sci ; 25(4)2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38396965

RESUMO

Lathyrane-type diterpenes have a wide range of biological activities. Among them, euphoboetirane A (1) exerts neurogenesis-promoting activity. In order to increase the structural diversity of this type of lathyrane and explore its potential use in neurodegenerative disorders, the biotransformation of 1 by Streptomyces puniceus BC-5GB.11 has been investigated. The strain BC-5GB.11, isolated from surface sediments collected from the intertidal zone of the inner Bay of Cadiz, was identified as Streptomyces puniceus, as determined by phylogenetic analysis using 16S rRNA gene sequence. Biotransformation of 1 by BC-5GB.11 afforded five products (3-7), all of which were reported here for the first time. The main biotransformation pathways involved regioselective oxidation at non-activated carbons (3-5) and isomerization of the ∆12,13 double bond (6). In addition, a cyclopropane-rearranged compound was found (7). The structures of all compounds were elucidated on the basis of extensive NMR and HRESIMS spectroscopic studies.


Assuntos
Diterpenos , Streptomyces , RNA Ribossômico 16S/genética , Filogenia , Diterpenos/química , Biotransformação
4.
Bioorg Chem ; 127: 105979, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35753117

RESUMO

Chemical epigenetic manipulation of Botrytis cinerea strain B05.10 with the histone deacetylase inhibitor SAHA led to the isolation of a new cryptic metabolite, botrycinereic acid (22a). This compound was also overproduced by inactivating the stc2 gene, which encodes an unknown sesquiterpene cyclase. Its structure and absolute configuration were determined by extensive spectroscopic NMR and HRESIMS studies, and electronic circular dichroism calculations. Its biosynthesis was studied by feeding 2H and 13C isotopically labeled precursors to B. cinerea Δstc2 mutant. A detailed analysis of the labeling and coupling patterns into botrycinereic acid (22a) revealed that this compound derives from l-phenylalanine and l-leucine.


Assuntos
Botrytis
5.
Org Biomol Chem ; 17(12): 3218-3224, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30840013

RESUMO

The capacity of hydrazone bonds to readily undergo component exchange processes sees their extensive utilization in dynamic combinatorial chemistry. The kinetics of hydrazone exchange are optimal at pH ∼4.5, which limits the use of hydrazone-based dynamic combinatorial libraries, particularly for biological targets which are only stable at near-neutral pH values. It would thus be advantageous if hydrazone exchange proceeded with faster rates at pH values closer to neutral. We experimentally and computationally evaluated the hypothesis that hydrazones possessing neighbouring acidic or basic functional groups within the carbonyl-derived moitety of the hydrazone would enhance exchange rates. Our work suggests that judiciously placed N- or O-hydrogen bond acceptors within the carbonyl-derived moiety of the hydrazone stabilize transition states via hydrogen bonding interactions, providing a valuable boost to exchange kinetics at near-neutral pH values. We anticipate these findings will be of interest in dynamic combinatorial chemistry, dynamic covalent polymers/materials, functionalized nanoparticles and interlocked molecules, all of which may benefit from hydrazone exchange processes able to operate at near-neutral pH values.

6.
J Nat Prod ; 82(9): 2517-2528, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31507181

RESUMO

Lathyrane-type diterpenes previously have been proven to promote proliferation of neural precursor cells (NPCs) by targeting and activating one or more protein kinase C (PKC) isozymes. Aiming to find new drug candidates with a lathyrane skeleton to modulate adult neurogenesis through PKC activation, a phytochemical study of a methanol extract of the aerial parts of Euphorbia boetica was carried out. Seven new diterpenes, representing the premyrsinane (1-3), myrsinane (4, 5), and cyclomyrsinane types (6, 7), along with three known diterpenes, belonging to the cyclomyrsinane (8) and lathyrane types (9, 10), were isolated. The chemical structures and relative configurations of the new compounds were determined by extensive NMR spectroscopic studies and comparison with known compounds. The absolute configurations for compounds 2, 3, 6, and 7 were proposed, based on a comparison of the experimental ECD spectra of compounds 2 and 7 with those of known related compounds. The activity of lathyrane compounds 9 and 10 as promoters of NPC proliferation was evaluated using a neurosphere assay. Both compounds increased the size of neurospheres in a dose-dependent manner when proliferation was stimulated by the epidermal growth factor and the basic fibroblast growth factor.


Assuntos
Proliferação de Células/efeitos dos fármacos , Diterpenos/isolamento & purificação , Euphorbia/química , Células-Tronco Neurais/efeitos dos fármacos , Diterpenos/farmacologia , Humanos , Estrutura Molecular , Células-Tronco Neurais/citologia , Análise Espectral/métodos
7.
Curr Microbiol ; 75(4): 431-440, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29147762

RESUMO

Botrytis cinerea is considered a model organism for the study of plant-pathogen interaction showing great genetic diversity and a high degree of morphological variability depending on environmental conditions. The use of new compounds and plant-based elicitors may trigger the expression of different B. cinerea genes, providing new sources of virulence factors. This work is focused on elucidating the phenotypic effect in B. cinerea of different carbon sources such as glucose, cellulose and tomato cell walls (TCW). Production of botrydial and dihydrobotrydial toxins was evaluated using thin-layer chromatography (TLC), proton nuclear magnetic resonance spectroscopy (1H-NMR) and mass spectrometry (UPLC-HRESIMS). Expression of the toxin biosynthesis gene BcBOT2 was followed using RT-qPCR. Results show an inhibition of the toxin biosynthesis pathway when TCW are present as a sole carbon source, suggesting that the toxin is only produced when rich molecules, like glucose, are available for fungal metabolism. That suggests a connection between gene expression of virulence factors and environmental conditions, where the silent genes can be induced by different culture conditions.


Assuntos
Aldeídos/metabolismo , Botrytis/metabolismo , Compostos Bicíclicos com Pontes/metabolismo , Micotoxinas/metabolismo , Doenças das Plantas/microbiologia , Solanum lycopersicum/microbiologia , Botrytis/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Interações Hospedeiro-Patógeno
8.
Int J Colorectal Dis ; 32(10): 1503-1507, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28717840

RESUMO

AIM: The aim of this study was to analyze the results of nonoperative management of patients with perforated acute diverticulitis with extraluminal air and to identify risk factors that may lead to failure and necessity of surgery. METHODS: Methods included observational retrospective cohort study of patients between 2010 and 2015 with diagnosis of diverticulitis with extraluminal air and with nonoperative management initial. Patient demographics, clinical, and analytical data were collected, as were data related with computed tomography. Univariate and multivariate analyses with Wald forward stepwise logistic regression were performed to analyze results and to identify risk factors potentially responsible of failure of nonoperative management. RESULTS: Nonoperative management was established in 83.12% of patients diagnosed with perforated diverticulitis (64 of 77) with an overall success rate of 84.37%, a mean hospital stay of 11.98 ± 7.44 days and only one mortality (1.6%). Patients with pericolic air presented a greater chance of success (90.2%) than patients with distant air (61.5%). American Society of Anesthesiologists (ASA) grade III-IV (OR, 5.49; 95% CI, 1.04-29.07) and the distant location of air (OR, 4.81; 95% CI, 1.03-22.38) were the only two factors identified in the multivariate analysis as risk factors for a poor nonoperative treatment outcome. Overall recurrence after conservative approach was 20.4%; however, recurrence rate of patients with distant air was twice than that of patients with pericolic air (37.5 vs 17.39%). Only 14.8% of successfully treated patients required surgery after the first episode. CONCLUSION: Nonoperative management of perforated diverticulitis is safe and efficient. Special follow-up must be assumed in patients ASA III-IV and with distant air in CT.


Assuntos
Doença Diverticular do Colo/terapia , Nível de Saúde , Perfuração Intestinal/terapia , Adulto , Ar , Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Tratamento Conservador , Doença Diverticular do Colo/complicações , Doença Diverticular do Colo/cirurgia , Feminino , Hidratação , Humanos , Perfuração Intestinal/etiologia , Perfuração Intestinal/cirurgia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Fatores de Risco , Falha de Tratamento
9.
J Nat Prod ; 80(7): 2161-2165, 2017 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-28678491

RESUMO

A novel diterpenoid, gaditanone (2), which possesses an unprecedented 5/6/4/6-fused gaditanane tetracyclic ring skeleton, and a new jatrophane (1) were isolated from the aerial parts of Euphorbia gaditana. The chemical structures and absolute configurations were determined by extensive spectroscopic NMR studies and ECD data analysis. A proposed biosynthetic pathway is presented for compound 2.


Assuntos
Diterpenos/isolamento & purificação , Euphorbia/química , Vias Biossintéticas , Diterpenos/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Espanha
10.
Biofouling ; 33(10): 892-903, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29083230

RESUMO

Zwitterionic materials display antifouling promise, but their potential in marine anti-biofouling is still largely unexplored. This study evaluates the effectiveness of incorporating small quantities (0-20% on a molar basis) of zwitterions as sulfobetaine methacrylate (SBMA) or carboxybetaine methacrylate (CBMA) into lauryl methacrylate-based coatings whose relatively hydrophobic nature encourages adhesion of the diatom Navicula incerta, a common microfouling organism responsible for the formation of 'slime'. This approach allows potential enhancements in antifouling afforded by zwitterion incorporation to be easily quantified. The results suggest that the incorporation of CBMA does provide a relatively minor enhancement in fouling-release performance, in contrast to SBMA which does not display any enhancement. Studies with coatings incorporating mixtures of varying ratios of the cationic monomer [2-(methacryloyloxy)ethyl]trimethylammonium chloride and the anionic monomer (3-sulfopropyl)methacrylate, which offer a potentially lower cost approach to the incorporation of anionic and cationic charge, suggest these monomers impart little significant effect on biofouling.


Assuntos
Betaína/análogos & derivados , Incrustação Biológica/prevenção & controle , Diatomáceas/efeitos dos fármacos , Metacrilatos/farmacologia , Polímeros/farmacologia , Betaína/química , Betaína/farmacologia , Diatomáceas/fisiologia , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Polímeros/química , Propriedades de Superfície
11.
Sensors (Basel) ; 16(10)2016 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-27775556

RESUMO

A technique that combines the spatial resolution of a 3D structured-light (SL) imaging system with the spectral analysis of a hyperspectral short-wave near infrared system was developed for freshness predictions of gilthead sea bream on the first storage days (Days 0-6). This novel approach allows the hyperspectral analysis of very specific fish areas, which provides more information for freshness estimations. The SL system obtains a 3D reconstruction of fish, and an automatic method locates gilthead's pupils and irises. Once these regions are positioned, the hyperspectral camera acquires spectral information and a multivariate statistical study is done. The best region is the pupil with an R² of 0.92 and an RMSE of 0.651 for predictions. We conclude that the combination of 3D technology with the hyperspectral analysis offers plenty of potential and is a very promising technique to non destructively predict gilthead freshness.


Assuntos
Técnicas Biossensoriais/métodos , Conservação de Alimentos/métodos , Imageamento Tridimensional/métodos , Dourada , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Análise Multivariada
12.
Int J Neuropsychopharmacol ; 19(1)2015 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-26224011

RESUMO

BACKGROUND: Neuropsychiatric and neurological disorders frequently occur after brain insults associated with neuronal loss. Strategies aimed to facilitate neuronal renewal by promoting neurogenesis constitute a promising therapeutic option to treat neuronal death-associated disorders. In the adult brain, generation of new neurons occurs physiologically throughout the entire life controlled by extracellular molecules coupled to intracellular signaling cascades. Proteins participating in these cascades within neurogenic regions constitute potential pharmacological targets to promote neuronal regeneration of injured areas of the central nervous system. METHODOLOGY: We have performed in vitro and in vivo approaches to determine neural progenitor cell proliferation to understand whether activation of kinases of the protein kinase C family facilitates neurogenesis in the adult brain. RESULTS: We have demonstrated that protein kinase C activation by phorbol-12-myristate-13-acetate induces neural progenitor cell proliferation in vitro. We also show that the nontumorogenic protein kinase C activator prostratin exerts a proliferative effect on neural progenitor cells in vitro. This effect can be reverted by addition of the protein kinase C inhibitor G06850, demonstrating that the effect of prostratin is mediated by protein kinase C activation. Additionally, we show that prostratin treatment in vivo induces proliferation of neural progenitor cells within the dentate gyrus of the hippocampus and the subventricular zone. Finally, we describe a library of diterpenes with a 12-deoxyphorbol structure similar to that of prostratin that induces a stronger effect than prostratin on neural progenitor cell proliferation both in vitro and in vivo. CONCLUSIONS: This work suggests that protein kinase C activation is a promising strategy to expand the endogenous neural progenitor cell population to promote neurogenesis and highlights the potential of 12-deoxyphorbols as pharmaceutical agents to facilitate neuronal renewal.


Assuntos
Proliferação de Células/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Ésteres de Forbol/farmacologia , Proteína Quinase C/metabolismo , Animais , Animais Recém-Nascidos , Bromodesoxiuridina/metabolismo , Morte Celular/efeitos dos fármacos , Diferenciação Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ventrículos Cerebrais/citologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Regulação para Cima/efeitos dos fármacos
13.
Bioorg Med Chem ; 23(13): 3379-87, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25971873

RESUMO

Solvent-free desymmetrisation of meso-dialdehyde 1 with chiral 1-phenylethan-1-ol, led to preparation of 4-silyloxy-6-alkyloxytetrahydro-2H-pyran-2-one (+)-3a with a 96:4 dr Deprotected lactone (+)-19a and the related racemic lactones 16a-18a present a lactone moiety resembling the natural substrate of HMG-CoA reductase and their antifungal properties have been evaluated against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. These compounds were selectively active against B. cinerea, while inactive against C. gloeosporioides.


Assuntos
Botrytis/efeitos dos fármacos , Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/síntese química , Glutaral/análogos & derivados , Piranos/síntese química , Aldeídos/química , Botrytis/crescimento & desenvolvimento , Botrytis/isolamento & purificação , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/isolamento & purificação , Contagem de Colônia Microbiana , Fungicidas Industriais/farmacologia , Glutaral/química , Hidroximetilglutaril-CoA-Redutases NADP-Dependentes/química , Lactonas/química , Mimetismo Molecular , Álcool Feniletílico/química , Doenças das Plantas/microbiologia , Piranos/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade , Vitis/microbiologia
14.
Nanomedicine ; 11(3): 579-88, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25661921

RESUMO

In vitro drug allergy tests have limited sensitivity, partly due to a poor understanding of the immunological recognition of in vitro drug-protein conjugates. We have designed and synthesized multivalent mono- and bi-epitope dendrimeric antigen (DeAn) conjugates and studied their chemical and tridimensional structures. We describe differences in the spatial distribution and conformation of these conjugated epitopes for the first time: a partially hidden benzylpenicilloyl and a more exposed amoxicilloyl. Our data suggest that DeAn conjugates provide a useful model for studying IgE recognition in patients who suffer from an allergic reaction to benzylpenicillin and/or amoxicillin. 1D and 2D NMR, MDS and immunochemical studies provide evidence that both antigen composition and tridimensional distribution play key roles in IgE-antigen recognition. Bi-epitope DeAn conjugates could potentially allow the diagnosis of patients allergic to any of these two drugs with a single test and represent the basis for a broadly-applicable in vitro assay. From the clinical editor: The prevalence of allergic drug reactions is rising and there is an imperative need to identify patients at risk. In this interesting and important article, the authors developed a novel method for detecting drug specific IgE antibodies, responsible for allergic reactions, by using multivalent mono- and bi-epitope Dendrimeric Antigen (DeAn) conjugates. The continued success of this research may pave way of eventual development of a simple diagnostic test.


Assuntos
Amoxicilina/química , Dendrímeros/química , Hipersensibilidade a Drogas/imunologia , Epitopos/química , Imunoglobulina E/química , Penicilina G/química , Amoxicilina/imunologia , Epitopos/imunologia , Feminino , Humanos , Imunoglobulina E/imunologia , Masculino , Penicilina G/imunologia
15.
J Org Chem ; 79(23): 11349-58, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25372296

RESUMO

The structure 3,4-dihydroxy-2,4,6,8-tetramethyldec-8-enolide (1) was assigned to a metabolite of Botrytis cinerea, but the spectra of several synthetic analogues had significant differences from that of 1. Examination of the constituents of a B. cinerea mutant that overproduces polyketides gave sufficient quantities of 1, now named cinbotolide, for chemical transformations. These led to a revised γ-butyrolactone structure for the metabolite. This structure has been confirmed by an asymmetric total synthesis, which also established its absolute configuration.


Assuntos
4-Butirolactona/química , Macrolídeos/química , Policetídeos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Policetídeos/síntese química , Estereoisomerismo
16.
Plants (Basel) ; 13(6)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38592850

RESUMO

Premyrsinane-type diterpenoids have been considered to originate from the cyclization of a suitable 5,6- or 6,17-epoxylathyrane precursor. Their biological activities have not been sufficiently explored to date, so the development of synthetic or microbial approaches for the preparation of new derivatives would be desirable. Epoxyboetirane A (4) is an 6,17-epoxylathyrane isolated from Euphorbia boetica in a large enough amount to be used in semi-synthesis. Transannular cyclization of 4 mediated by Cp2TiIIICl afforded premyrsinane 5 in good yield as an only diasteroisomer. To enhance the structural diversity of premyrsinanes so their potential use in neurodegenerative disorders could be explored, compound 5 was biotransformed by Mucor circinelloides NRRL3631 to give rise to hydroxylated derivatives at non-activated carbons (6-7), all of which were reported here for the first time. The structures and absolute configurations of all compounds were determined through extensive NMR and HRESIMS spectroscopic studies.

17.
J Nat Prod ; 76(6): 1016-24, 2013 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-23730968

RESUMO

Research has been conducted on the biotransformation of (8S,9R)-isocaryolan-9-ol (4a) and (1S,2S,5R,8S)-8-methylene-1,4,4-trimethyltricyclo[6.2.1.0(2,5)]undecan-12-ol (5a) by the fungal phytopathogen Botrytis cinerea. The biotransformation of compound 4a yielded compounds 6-9, while the biotransformation of compound 5a yielded compounds 10-13. The activity of compounds 4a and 5a against B. cinerea has been evaluated. (8R,9R)-Isocaryolane-8,9-diol (6), a major metabolite of compound 4a, shows activity compared to its parent compound 4a, which is inactive. The effect of isocaryolanes 3, 4a, and 5a, together with their biotransformation products 6-8, 10, and 14-17, on the germination and radicle and shoot growth of Lactuca sativa (lettuce) has also been determined. Compounds 7-13 are described for the first time.


Assuntos
Botrytis/metabolismo , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Aldeídos/química , Aldeídos/metabolismo , Biotransformação , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/metabolismo , Lactuca/crescimento & desenvolvimento , Lactuca/fisiologia , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade
18.
Clin Res Hepatol Gastroenterol ; 47(2): 102066, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36509354

RESUMO

AIMS: Heterozygous alpha-1-antitrypsin (A1AT) Pi*MZ variant has been shown to increase the risk of developing liver cirrhosis in patients with non-alcoholic fatty liver disease (NAFLD). We aimed to determine the association between heterozygous Pi*MZ and Pi*MS variants and development of hepatic decompensation events in NAFLD patients. METHODS: We included patients with NAFLD who also had A1AT genotyping performed from 2005 to 2020. We recorded demographic and clinical variables, and data on hepatic events (ascites, hepatic encephalopathy, esophageal variceal bleed, or hepatocellular carcinoma), if any. We performed binary logistic regression analysis to assess the association between A1AT variants and hepatic events, and calculated Odds ratio (OR) with their 95% confidence intervals (Cl). RESULTS: We included 1532 patients with NAFLD, of which 1249 patients had Pi*MM, 121 had Pi*MS, and 162 had Pi*MZ. Of the 1532 patients, hepatic events developed in 521 (34%) patients. The percentage of patients with Pi*MZ variant was significantly higher in patients with hepatic events as compared to patients without hepatic events (18.7 % vs 8.1%, p<0.0001). Pi*MZ variant was noted to significantly increase the odds of developing hepatic events in NAFLD patients, unadjusted OR: 1.82 (1.3-2.5, p<0.001), adjusted OR (for age, sex, body mass index, and diabetes mellitus) 1.76 (1.2-2.5, p = 0.002). Pi*MS variant did not increase the odds of hepatic events in NAFLD patients, OR: 0.92 (0.6-1.4, p = 0.70). CONCLUSION: Patients with NAFLD and A1AT Pi*MZ variant are at increased risk for developing hepatic decompensation. NAFLD patients should be offered A1AT genotyping for risk stratification, counseling, and multidisciplinary intervention for NAFLD.


Assuntos
Cirrose Hepática , Hepatopatia Gordurosa não Alcoólica , alfa 1-Antitripsina , Humanos , Carcinoma Hepatocelular , Cirrose Hepática/genética , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia
19.
Ecol Evol ; 13(3): e9889, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36950370

RESUMO

Environmental heterogeneity is an important driver of ecological communities. Here, we assessed the effects of local and landscape spatial environmental heterogeneity on ant community structure in temperate seminatural upland grasslands of Central Germany. We surveyed 33 grassland sites representing a gradient in elevation and landscape composition. Local environmental heterogeneity was measured in terms of variability of temperature and moisture within and between grasslands sites. Grassland management type (pasture vs. meadows) was additionally included as a local environmental heterogeneity measure. The complexity of habitat types in the surroundings of grassland sites was used as a measure of landscape environmental heterogeneity. As descriptors of ant community structure, we considered species composition in terms of nest density, community evenness, and functional response traits. We found that extensively grazed pastures and within-site heterogeneity in soil moisture at local scale, and a high diversity of land cover types at the landscape scale affected ant species composition by promoting higher nest densities of some species. Ant community evenness was high in wetter grasslands with low within-site variability in soil moisture and surrounded by a less diverse landscape. Fourth-corner models revealed that ant community structure response to environmental heterogeneity was mediated mainly by worker size, colony size, and life history traits related with colony reproduction and foundation. We discuss how within-site local variability in soil moisture and low-intensity grazing promote ant species densities and highlight the role of habitat temperature and humidity affecting community evenness. We hypothesize that a higher diversity of land cover types in a forest-dominated landscape buffers less favorable environmental conditions for ant species establishment and dispersal between grasslands. We conclude that spatial environmental heterogeneity at local and landscape scale plays an important role as deterministic force in filtering ant species and, along with neutral processes (e.g., stochastic colonization), in shaping ant community structure in temperate seminatural upland grasslands.

20.
Plants (Basel) ; 12(22)2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38005743

RESUMO

Diterpenes from the Euphorbia genus are known for their ability to regulate the protein kinase C (PKC) family, which mediates their ability to promote the proliferation of neural precursor cells (NPCs) or neuroblast differentiation into neurons. In this work, we describe the isolation from E. resinifera Berg latex of fifteen 12-deoxyphorbol esters (1-15). A triester of 12-deoxy-16-hydroxyphorbol (4) and a 12-deoxyphorbol 13,20-diester (13) are described here for the first time. Additionally, detailed structural elucidation is provided for compounds 3, 5, 6, 14 and 15. The absolute configuration for compounds 3, 4, 6, 13, 14 and 15 was established by the comparison of their theoretical and experimental electronic circular dichroism (ECD) spectra. Access to the above-described collection of 12-deoxyphorbol derivatives, with several substitution patterns and attached acyl moieties, allowed for the study of their fragmentation patterns in the collision-induced dissociation of multiple ions, without precursor ion isolation mass spectra experiments (HRMSE), which, in turn, revealed a correlation between specific substitution patterns and the fragmentation pathways in their HRMSE spectra. In turn, this allowed for a targeted UHPLC-HRMSE analysis and a biased non-targeted UHPLC-HRMSE analysis of 12-deoxyphorbols in E. resinifera latex which yielded the detection and identification of four additional 12-deoxyphorbols not previously isolated in the initial column fractionation work. One of them, identified as 12-deoxy-16-hydroxyphorbol 20-acetate 13-phenylacetate 16-propionate (20), has not been described before.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA