Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Can J Microbiol ; 70(6): 238-251, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38452350

RESUMO

The phyllosphere, a reservoir of diverse microbial life associated with plant health, harbors microbial communities that are subject to various complex ecological processes acting at multiple scales. In this study, we investigated the determinants of the spatiotemporal variation in bacterial and fungal communities within the apple tree phyllosphere, employing 16S and ITS amplicon sequencing. Our research assessed the impact of key factors-plant compartment, site, time, and cultivar-on the composition and diversity of leaf and flower microbial communities. Our analyses, based on samples collected from three cultivars in three orchards in 2022, revealed that site and time are the strongest drivers of apple tree phyllosphere microbial communities. Conversely, plant compartment and cultivar exhibited minor roles in explaining community composition and diversity. Predominantly, bacterial communities comprised Hymenobacter (25%) and Sphingomonas (10%), while the most relatively abundant fungal genera included Aureobasidium (27%) and Sporobolomyces (10%). Additionally, our results show a gradual decrease in alpha-diversity throughout the growth season. These findings emphasize the necessity to consider local microbial ecology dynamics in orchards, especially as many groups worldwide aim for the development of biocontrol strategies (e.g., by manipulating plant-microbe interactions). More research is needed to improve our understanding of the determinants of time and site-specific disparities within apple tree phyllosphere microbial communities across multiple years, locations, and cultivars.


Assuntos
Bactérias , Fungos , Malus , Microbiota , Folhas de Planta , Malus/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Folhas de Planta/microbiologia , Análise Espaço-Temporal , Biodiversidade , Micobioma , Flores/microbiologia , RNA Ribossômico 16S/genética
2.
Bioorg Med Chem Lett ; 30(2): 126783, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31753699

RESUMO

5α-Dihydrotestosterone (5α-DHT) possesses a great affinity for the androgen receptor (AR), and its binding to AR promotes the proliferation of prostate cancer (PC) cells in androgen-dependent PC. Primarily synthesized from testosterone (T) in testis, 5α-DHT could also be produced from 5α-androstane-3α,17ß-diol (3α-diol), an almost inactive androgen, following non-classical pathways. We reported the chemical synthesis of non-commercially available [4-14C]-3α-diol from [4-14C]-T, and the development of a biological assay to identify inhibitors of the 5α-DHT formation from radiolabeled 3α-diol in LAPC-4 cell PC model. We measured the inhibitory potency of 5α-androstane derivatives against the formation of 5α-DHT, and inhibition curves were obtained for the most potent compounds (IC50 = 1.2-14.1 µM). The most potent inhibitor 25 (IC50 = 1.2 µM) possesses a 4-(4-CF3-3-CH3O-benzyl)piperazinyl methyl side chain at C3ß and 17ß-OH/17α-CCH functionalities at C17 of a 5α-androstane core.


Assuntos
Androgênios/metabolismo , Androstano-3,17-diol/metabolismo , Di-Hidrotestosterona/metabolismo , Androstano-3,17-diol/química , Linhagem Celular Tumoral , Di-Hidrotestosterona/química , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/química , Receptores Androgênicos/metabolismo , Relação Estrutura-Atividade
3.
Bioorg Med Chem Lett ; 28(22): 3554-3559, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30297283

RESUMO

17ß-Hydroxysteroid dehydrogenase type 10 (17ß-HSD10) is a mitochondrial enzyme known for its potential role in Alzheimer's Disease (AD). 17ß-HSD10, by its oxidative activity, could decrease the concentration of two important neurosteroids, allopregnanolone (ALLOP) and 17ß-estradiol (E2), respectively preventing their neurogenesis and neuroprotective effects. Since the inhibition of 17ß-HSD10 could lead to a new treatment for AD, we developed two biological assays using labeled ALLOP or E2 as substrates to measure the inhibitory activity of compounds against pure 17ß-HSD10 protein. After the optimization of different parameters (time, concentration of enzyme, substrate and cofactor), analogs of the first reported steroidal inhibitor of 17ß-HSD10 in intact cells were screened to determine their inhibitory potency for the ALLOP or the E2 oxidation. One compound, androstane derivative 5, possesses the best dual inhibition against both transformations (ALLOP, IC50 = 235 µM and E2, IC50 = 610 µM). Some compounds are dual inhibitors to a lesser extent, and others seem selective for one of the transformations in particular. By developing two reliable assays and by identifying a first generation of steroidal inhibitors of pure 17ß-HSD10, this preliminary study opens the door to new and more potent inhibitors.


Assuntos
17-Hidroxiesteroide Desidrogenases/metabolismo , Inibidores Enzimáticos/química , Estradiol/metabolismo , Pregnanolona/metabolismo , Esteroides/química , 17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , 5-alfa-Di-Hidroprogesterona/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Estrona/metabolismo , Células HEK293 , Humanos , Esteroides/metabolismo , Esteroides/uso terapêutico , Relação Estrutura-Atividade
4.
Bioorg Med Chem Lett ; 27(2): 299-302, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27903409

RESUMO

The synthesis of two series of novel substituted pyrimidine derivatives bearing a sulfamide group have been described and their in vitro cancer growth inhibition activities have been evaluated against three human tumour cell lines (HT-29, M21, and MCF7). In general, growth inhibition activity has been enhanced by the introduction of a bulky substituent on the aromatic ring with the best compound having GI50<6µM for all the human tumour cell lines. The MCF7 selective compounds were evaluated on four additional human invasive breast ductal carcinoma cell lines (MDA-MB-231, MDA-MB-468, SKBR3, and T47D) and were selective against T47D cell line in all cases except one, suggesting a potential antiestrogen activity.


Assuntos
Antineoplásicos/farmacologia , Pirimidinas/farmacologia , Sulfonamidas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-Atividade , Sulfonamidas/química
5.
Nat Commun ; 14(1): 713, 2023 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-36759607

RESUMO

Many plant pathogens induce water-soaked lesions in infected tissues. In the case of Pseudomonas syringae (Pst), water-soaking effectors stimulate abscisic acid (ABA) production and signaling, resulting in stomatal closure. This reduces transpiration, increases water accumulation, and induces an apoplastic microenvironment favorable for bacterial growth. Stomata are sensitive to environmental conditions, including light. Here, we show that a period of darkness is required for water-soaking, and that a constant light regime abrogates stomatal closure by Pst. We find that constant light induces resistance to Pst, and that this effect requires salicylic acid (SA). Constant light did not alter effector-induced accumulation of ABA, but induced greater SA production, promoting stomatal opening despite the presence of ABA. Furthermore, application of a SA analog was sufficient to prevent pathogen-induced stomatal closure and water-soaking. Our results suggest potential approaches for interfering with a common virulence strategy, as well as providing a physiological mechanism by which SA functions in defense against pathogens.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/fisiologia , Ácido Salicílico , Estômatos de Plantas/fisiologia , Ácido Abscísico/farmacologia , Água
6.
Eur J Med Chem ; 209: 112909, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33081987

RESUMO

17beta-Hydroxysteroid dehydrogenase type 10 (17ß-HSD10) is the only mitochondrial member of 17ß-HSD family. This enzyme can oxidize estradiol (E2) into estrone (E1), thus reducing concentration of this neuroprotective steroid. Since 17ß-HSD10 possesses properties that suggest a possible role in Alzheimer's disease, its inhibition appears to be a therapeutic strategy. After we identified the androsterone (ADT) derivative 1 as a first steroidal inhibitor of 17ß-HSD10, new analogs were synthesized to increase the metabolic stability, to improve the selectivity of inhibition over 17ß-HSD3 and to optimize the inhibitory potency. From six D-ring derivatives of 1 (17-CO), two compounds (17ß-H/17α-OH and 17ß-OH/17α-CCH) were more metabolically stable and did not inhibit the 17ß-HSD3. Moreover, solid phase synthesis was used to extend the molecular diversity on the 3ß-piperazinylmethyl group of the steroid base core. Eight over 120 new derivatives were more potent inhibitors than 1 for the transformation of E2 to E1, with the 4-(4-trifluoromethyl-3-methoxybenzyl)piperazin-1-ylmethyl-ADT (D-3,7) being 16 times more potent (IC50 = 0.14 µM). Finally, D-ring modification of D-3,7 provided 17ß-OH/17α-CCH derivative 25 and 17ß-H/17α-OH derivative 26, which were more potent inhibitor than 1 (1.8 and 2.4 times, respectively).


Assuntos
17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Doença de Alzheimer/tratamento farmacológico , Inibidores Enzimáticos/síntese química , Bibliotecas de Moléculas Pequenas/química , Esteroides/síntese química , Biocatálise , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Estradiol/química , Estrona/química , Células HEK293 , Humanos , Piperazina/química , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Técnicas de Síntese em Fase Sólida , Esteroides/metabolismo , Esteroides/farmacologia , Relação Estrutura-Atividade
7.
Eur J Med Chem ; 147: 130-149, 2018 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-29427906

RESUMO

The ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) was recently shown to promote mineralization of the aortic valve, hence, its inhibition represents a significant target. A quinazoline-4-piperidine sulfamide compound (QPS1) has been described as a specific and non-competitive inhibitor of NPP1. We report herein the synthesis and in vitro inhibition studies of novel quinazoline-4-piperidine sulfamide analogues using QPS1 as the lead compound. Of the 26 derivatives prepared, four compounds were found to have Ki < 105 nM against human NPP1.


Assuntos
Amidas/farmacologia , Inibidores Enzimáticos/farmacologia , Piperidinas/farmacologia , Pirofosfatases/antagonistas & inibidores , Quinazolinas/farmacologia , Amidas/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Estrutura Molecular , Diester Fosfórico Hidrolases/metabolismo , Piperidinas/química , Pirofosfatases/metabolismo , Quinazolinas/química , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA