Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 479
Filtrar
1.
Front Plant Sci ; 15: 1418762, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39280946

RESUMO

Phytochelatin synthase (PCS) is a critical enzyme involved in heavy metal detoxification in organisms. In this study, we aim to comprehensively investigate the molecular and functional characteristics of the PCS1 gene from Nicotiana tabacum by examining its enzymatic activity, tissue-specific expression pattern, Cd-induced expression, as well as the impact on Cd tolerance and accumulation. The results demonstrated that the amino acid sequence of NtPCS1 shared a high similarity in its N-terminal region with PCS from other species. The enzymatic activity of NtPCS1 was found to be enhanced in the order Ag2+ > Cd2+ > Cu2+ > Pb2+ > Hg2+ > Fe2+ > Zn2+. In addition, RT-PCR data indicated that NtPCS1 gene is constitutively expressed, with the highest expression observed in flowers, and that its transcript levels are up-regulated by CdCl2. When tobacco overexpressing NtPCS1 (PCS1 lines) were grown under CdCl2 stress, they produced more phytochelatins (PCs) than WT plants, but this did not result in increased Cd accumulation. However, in a root growth assay, the PCS1 lines exhibited hypersensitivity to Cd. The overexpression of NtPCS1 itself does not appear to be the primary cause of this heightened sensitivity to Cd, as the Arabidopsis thaliana Atpcs1 mutant overexpressing NtPCS1 actually exhibited enhanced tolerance to Cd. Furthermore, the addition of exogenous glutathione (GSH) progressively reduced the Cd hypersensitivity of the PCS1 lines, with the hypersensitivity even being completely eliminated. Surprisingly, the application of exogenous GSH led to a remarkably enhanced Cd accumulation in the PCS1 lines. This study enriches our understanding of the molecular function of the NtPCS1 gene and suggests a promising avenue for Cd tolerance through the heterologous expression of PCS genes in different species.

2.
Medicine (Baltimore) ; 103(36): e39337, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39252297

RESUMO

BACKGROUND: Emergence delirium (ED) is a common occurrence in pediatric postanesthesia events, leading to negative outcomes. Dexmedetomidine (DEX), as an anesthesia adjuvant, has shown promise in preventing ED in adult surgeries, and it has been increasingly used in pediatric surgical settings. However, its effectiveness in other postanesthesia events, such as MRI examinations and ambulatory surgery centers, remains unclear. This meta-analysis aims to assess the safety and efficacy of DEX in preventing ED in various pediatric postanesthesia events beyond surgery. METHODS: Prospective randomized controlled trials were searched in Pubmed, Web of Science, and EBSCO until October 13, 2023. Comparisons were made between DEX and other sedatives or analgesics in different postanesthesia events (including surgery operations, the examination of MRI, day surgery, and invasive action). Subgroup analyses were conducted based on drug delivery methods, medication timing, DEX dosages, use of analgesics, event types, and recovery time. RESULTS: A total of 33 trials involving 3395 patients were included. DEX significantly reduced the incidence of ED (odds ratios [OR] = 0.23, 95% confidence interval [CI]: 0.19-0.27, I2 = 37%, P < .00001). Intranasal delivery of DEX was the most effective (OR 0.18, 95% CI: 0.10-0.32, P < .00001, I2 = 0%). DEX also showed benefits in day surgery and mask insertion events (OR 0.30, 95% CI: 0.14-0.26, P = .001, I2 = 0%). CONCLUSION: DEX demonstrates superior efficacy in preventing ED in pediatric postanesthesia events compared to other sedatives and analgesics. Its use is recommended in various settings for its safety and effectiveness in managing ED.


Assuntos
Dexmedetomidina , Delírio do Despertar , Hipnóticos e Sedativos , Ensaios Clínicos Controlados Aleatórios como Assunto , Dexmedetomidina/uso terapêutico , Dexmedetomidina/administração & dosagem , Humanos , Delírio do Despertar/prevenção & controle , Hipnóticos e Sedativos/uso terapêutico , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/efeitos adversos , Criança
4.
Org Lett ; 26(36): 7632-7637, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39235108

RESUMO

Penicillium daleae L3SO is a fungus isolated from the rhizospheric soil of the chloroplast-deficient plant Monotropa uniflora. A chemical study on the rice fermentation of this fungus led to the isolation and identification of two cage-like polyketides, penidaleodiolide A (1) and its biosynthetic-related congener penidaleodiolide B (2). The structures of 1 and 2 were determined by a combination of extensive spectroscopic analysis, biosynthetic consideration, chemical derivatization, and computational methods. Compound 1 harbors an unusual tricyclo[4.3.04,9]nonane scaffold, unprecedented in polyketide natural products. The hypothetical biosynthetic pathways for 1 and 2 were postulated and were supported by CRISPR/Cas9 genome editing results. Penidaleodiolide A (1) showed a significant inhibitory effect on the action potentials of murine hippocampal basket neurons and decreased the frequency of spontaneous excitatory postsynaptic currents in a concentration-dependent manner (the inhibition ratios were 0.30 ± 0.02 for 1 µM, 0.37 ± 0.03 for 10 µM, and 0.50 ± 0.07 for 20 µM) while being devoid of cytotoxicity against the nerve cells.


Assuntos
Penicillium , Policetídeos , Policetídeos/química , Policetídeos/farmacologia , Policetídeos/isolamento & purificação , Penicillium/química , Penicillium/metabolismo , Animais , Camundongos , Estrutura Molecular , Transmissão Sináptica/efeitos dos fármacos , Microbiologia do Solo , Neurônios/efeitos dos fármacos , Hipocampo/metabolismo
6.
Bioorg Chem ; 151: 107684, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39094507

RESUMO

Twenty-nine sesquiterpenoids, including pseudoguaiane-type (1-11), eudesmane-type (12-23), and carabrane-type (24-29), have been identified from the plant Carpesium abrotanoides. Of them, compounds 1-4, 12-15, and 24-27, namely carpabrotins A-L, are twelve previously undescribed ones. Compound 3 possessed a pseudoguaiane backbone with a rearrangement modification at C-11, C-12 and C-13, while compound 4 suffered a carbon bond break between the C-4 and C-5 to form a rare 4,5-seco-pseudoguaiane lactone. Compounds 1-3, 5, 13-16 and 25-27 exhibited anti-inflammatory activity by inhibiting NO production in LPS-induced RAW264.7 macrophages with IC50 values less than 40 µM, while compounds 1, 2, 5, 13, 14, 16, and 25-27 showed significant inhibitory activity comparable to that of dexamethasone. The anti-atopic dermatitis (AD) effects of compounds 5 and 16 were tested according to 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in KM mice, and the results revealed that the major products 5 and 16 improved the histological features of AD-like skin lesions and mast cell infiltration in mice. This study suggested that sesquiterpenoids in C. abrotanoides should play a key role in its anti-inflammatory use.


Assuntos
Asteraceae , Óxido Nítrico , Sesquiterpenos , Animais , Camundongos , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Asteraceae/química , Células RAW 264.7 , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Óxido Nítrico/metabolismo , Estrutura Molecular , Relação Estrutura-Atividade , Relação Dose-Resposta a Droga , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Macrófagos/efeitos dos fármacos , Masculino
7.
Phytochemistry ; 228: 114253, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39168425

RESUMO

Cultivation and extraction of the fungus Stereum hirsutum (Willd.) Pers. yielded 12 isopentenyl benzene derivatives, including six previously undescribed derivatives, named stereuins A-F. Their structures were established based on NMR and mass spectroscopy analyses, supplemented by comparison with previously reported data. Stereuins A-C are unique benzoate derivatives containing fatty acid subunits. Stereuins D and E feature a valylene group and a 6/6/6 ring system. In vitro, stereuin A significantly promoted neurite outgrowth. Several compounds exhibited antibacterial activity against Staphylococcus aureus. Stereuin F has an IC50 value of 5.2 µg/mL against S. aureus, comparable to the positive control, penicillin G sodium (1.4 µg/mL).


Assuntos
Antibacterianos , Testes de Sensibilidade Microbiana , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Estrutura Molecular , Basidiomycota/química , Relação Estrutura-Atividade , Animais , Derivados de Benzeno/farmacologia , Derivados de Benzeno/química , Derivados de Benzeno/isolamento & purificação , Crescimento Neuronal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ratos
8.
Nat Prod Res ; : 1-10, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39084318

RESUMO

The Paeonia ostii, also known as "Feng Dan" have a crucial role in folk medicine to treat lumbar muscles strain, knee osteoarthritis and cervical spondylosis. In this study, four new phenolic compounds, specifically Paeoniaostiph A-E (1-4) phenolic compounds were characterised through spectroscopic techniques, including 1D and 2D NMR, HRESIMS, UV, IR, and electronic circular dichroism computations to explore their structures. Cytotoxicity and NO production inhibition of the new phenolic compounds were also studied. The results of the cytotoxicity experiment showed that compound 1 is cytotoxic to two human cancer cell lines with IC50 values ranging from 13.3 to 13.5 µM. Compounds 1 and 2 showed certain inhibitory activity on NO production. This is the first report on isolating the components from natural sources.

9.
Nat Prod Bioprospect ; 14(1): 41, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38955923

RESUMO

In this study, the effects of sea buckthorn oil (SBO), fish oil (FO) and an enzymatically synthesized structured lipid (SL) on serum, short-chain fatty acids (SCFAs) and intestinal microbiota in Sprague-Dawley (SD) rats were investigated. The results demonstrated that FO, SBO, and SL effectively reduced the levels of high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in the serum of SD rats. SBO increased serum triglyceride levels, while FO elevated total cholesterol levels. Furthermore, all three dietary lipids decreased short-chain fatty acid production and enhanced intestinal microbiota diversity. FO increased the abundance of intestinal microbiota including Romboutsia, Lactobacillus, Escherichia-Shigella, and Lachnospiraceae_NK4A136_group. Conversely, all three dietary lipids reduced the abundance of Klebsiella and Blautia. These findings provide a foundation for understanding the functionality of SBO and FO as well as their potential application in synthesizing novel SLs to regulate intestinal microbiota.

10.
Heliyon ; 10(11): e32360, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38961913

RESUMO

Background: The presence of peripheral inflammatory cells has been linked to the prognosis of cancer. This study aims to investigate the distinct roles of absolute neutrophil count (ANC) and absolute monocyte count (AMC) in differentiating renal cell carcinoma (RCC) from renal angiomyolipoma (RAML), as well as their prognostic significance in RCC. Methods: We conducted a comprehensive analysis of peripheral immune cell data, clinicopathological data, and tumor characteristics in patients diagnosed with RCC or RAML from January 2015 to December 2021. Receiver operating characteristic (ROC) curves, as well as univariate and multivariate analyses, were employed to assess the diagnostic utility of AMC and ANC in differentiating between RCC and RAML. Kaplan-Meier curve analysis was used to study the survival of RCC patients with different AMC and ANC. The prognostic value of AMC and ANC in RCC was investigated using COX univariate and multivariate analysis. The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were used for bioinformatic correlation analysis. Results: A total of 1120 eligible patients were included in the study. The mean preoperative AMC and ANC in patients with RCC were found to be significantly higher compared to those in patients with RAML (P = 0.001 and P < 0.001, respectively). High preoperative AMC and ANC significantly correlated with smoking history, tumor length, gross hematuria, and high T Stage, N stage, and pathological grade. In multivariate analyses, an ANC> 3.205 *10^9/L was identified to be independently associated with the presence of RCC (HR = 1.618, P = 0.008). High AMC and ANC were significantly associated with reduced OS and PFS (P < 0.05), and ANC may be an independent prognostic factor. Public database analysis showed that signature genes of tumor-associated macrophages (TAMs) and tumor-associated neutrophils (TANs) were highly expressed in ccRCC. Conclusions: Elevated preoperative ANC and AMC can distinguish RCC from RAML and predict poor prognosis in patients with RCC. Furthermore, the signature genes of TAMs and TANs exhibit high expression levels in clear cell RCC.

11.
Medicine (Baltimore) ; 103(28): e38710, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38996153

RESUMO

PURPOSE: Postoperative shivering (POS) is a common and vital complication after anesthesia, which may result in serious consequences and uncomfortable experiences. Acetaminophen has been used to treat fever and mild to moderate pain. However, there is not enough evidence to prove its advantage for POS. This meta-analysis aimed to explore the prophylactic use of acetaminophen as a valid agent for POS. METHODS: Two researchers independently searched PubMed, the Cochrane Library, and Embase for controlled clinical trials. The meta-analysis of randomized controlled trials (RCTs) was performed by Review Manager. RESULTS: Nine trials with 856 patients were included in our meta-analysis. Acetaminophen significantly reduced POS compared with placebo (pooled risk ratio [RR]: 0.43, 95% confidence interval [CI]: 0.35-0.52). What is more, not only 15 mg/kg but also 1000 mg intravenous acetaminophen could reduce the incidence of shivering compared with placebo. CONCLUSION: Our present meta-analysis demonstrates that the intravenous prophylactic infusion of acetaminophen may prevent POS, and the results may provide new evidence to expand the clinical value of acetaminophen in addition to its routine usage.


Assuntos
Acetaminofen , Complicações Pós-Operatórias , Ensaios Clínicos Controlados Aleatórios como Assunto , Estremecimento , Estremecimento/efeitos dos fármacos , Humanos , Acetaminofen/administração & dosagem , Acetaminofen/uso terapêutico , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/tratamento farmacológico , Analgésicos não Narcóticos/administração & dosagem , Analgésicos não Narcóticos/uso terapêutico , Infusões Intravenosas , Administração Intravenosa
12.
China CDC Wkly ; 6(24): 574-579, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38934021

RESUMO

What is already known about this topic?: Foodborne diseases, representing significant food safety and public health challenges globally, are not well-documented in terms of incidence, particularly for cases characterized by acute gastroenteritis (AGI) in China. What is added by this report?: This study developed a pyramid model to estimate the incidence of five pathogens, stratified by gender and age. The estimated incidences per 100,000 people with 95% uncertainty intervals (UI) are as follows: Norovirus, 3,188.28 (95% UI: 2,518.03, 7,296.96); Salmonella spp., 1,295.59 (95% UI: 1,002.62, 1,573.11); diarrheagenic E. coli (DEC), 782.62 (95% UI: 651.19, 932.05); Vibrio parahaemolyticus, 404.06 (95% UI: 342.19, 468.93); and Shigella spp., 26.73 (95% UI: 21.05, 33.46). What are the implications for public health practice?: This study elucidates the incidence rates across various gender and age groups, thereby identifying priority populations for targeted preventive interventions aimed at reducing disease burden. These insights are crucial for the development of public health policies and management of food safety risks.

13.
J Org Chem ; 89(12): 9031-9042, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38829824

RESUMO

A cooperative Rh/achiral phosphoric acid-enabled [3+3] cycloaddition of in situ-generated carbonyl ylides with quinone monoimines has been developed. With the ability to build up the molecular complexity rapidly and efficiently, this method furnishes highly functionalized oxa-bridged benzofused dioxabicyclo[3.2.1]octane scaffolds bearing two quaternary centers in good to excellent yields under mild conditions. Moreover, the utility of the current method was demonstrated by gram-scale synthesis and elaboration of the products into various functionalized oxa-bridged heterocycles.

14.
Phytochemistry ; 224: 114169, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38825030

RESUMO

Continued interest in the bioactive alkaloids led to the isolation of five undescribed alkaloids (1-5), ophiorglucidines A-E, and seven known analogues (6-12) from the water-soluble fraction of Ophiorrhiza japonica. The structures were elucidated based on spectroscopic data and quantum calculations as well as X-ray crystallographic analysis. The structure of 1 was characterized as a hexacyclic skeleton including a double bridge linking the indole and the monoterpene moieties, which is the first report of a single crystal with this type of structure. Moreover, the inhibitory effect of zwitterionic indole alkaloid glycosides on xanthine oxidase was found for the first time. The alkaloids 2 and 3, both of which have a pentacyclic zwitterionic system, were more active than the reference inhibitor, allopurinol (IC50 = 11.1 µM) with IC50 values of 1.0 µM, and 2.5 µM, respectively. Structure-activity relationships analyses confirmed that the carbonyl group at C-14 was a key functional group responsible for the inhibitory effects of these alkaloids.


Assuntos
Inibidores Enzimáticos , Alcaloides Indólicos , Monoterpenos , Rubiaceae , Xantina Oxidase , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/metabolismo , Rubiaceae/química , Relação Estrutura-Atividade , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Monoterpenos/química , Monoterpenos/farmacologia , Monoterpenos/isolamento & purificação , Estrutura Molecular , Relação Dose-Resposta a Droga , Modelos Moleculares , Cristalografia por Raios X
15.
Front Plant Sci ; 15: 1396183, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38726299

RESUMO

Aboveground biomass (AGB) is regarded as a critical variable in monitoring crop growth and yield. The use of hyperspectral remote sensing has emerged as a viable method for the rapid and precise monitoring of AGB. Due to the extensive dimensionality and volume of hyperspectral data, it is crucial to effectively reduce data dimensionality and select sensitive spectral features to enhance the accuracy of rice AGB estimation models. At present, derivative transform and feature selection algorithms have become important means to solve this problem. However, few studies have systematically evaluated the impact of derivative spectrum combined with feature selection algorithm on rice AGB estimation. To this end, at the Xiaogang Village (Chuzhou City, China) Experimental Base in 2020, this study used an ASD FieldSpec handheld 2 ground spectrometer (Analytical Spectroscopy Devices, Boulder, Colorado, USA) to obtain canopy spectral data at the critical growth stage (tillering, jointing, booting, heading, and maturity stages) of rice, and evaluated the performance of the recursive feature elimination (RFE) and Boruta feature selection algorithm through partial least squares regression (PLSR), principal component regression (PCR), support vector machine (SVM) and ridge regression (RR). Moreover, we analyzed the importance of the optimal derivative spectrum. The findings indicate that (1) as the growth stage progresses, the correlation between rice canopy spectrum and AGB shows a trend from high to low, among which the first derivative spectrum (FD) has the strongest correlation with AGB. (2) The number of feature bands selected by the Boruta algorithm is 19~35, which has a good dimensionality reduction effect. (3) The combination of FD-Boruta-PCR (FB-PCR) demonstrated the best performance in estimating rice AGB, with an increase in R² of approximately 10% ~ 20% and a decrease in RMSE of approximately 0.08% ~ 14%. (4) The best estimation stage is the booting stage, with R2 values between 0.60 and 0.74 and RMSE values between 1288.23 and 1554.82 kg/hm2. This study confirms the accuracy of hyperspectral remote sensing in estimating vegetation biomass and further explores the theoretical foundation and future direction for monitoring rice growth dynamics.

16.
Front Plant Sci ; 15: 1404238, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38799101

RESUMO

The Soil Plant Analysis Development (SPAD) is a vital index for evaluating crop nutritional status and serves as an essential parameter characterizing the reproductive growth status of winter wheat. Non-destructive and accurate monitorin3g of winter wheat SPAD plays a crucial role in guiding precise management of crop nutrition. In recent years, the spectral saturation problem occurring in the later stage of crop growth has become a major factor restricting the accuracy of SPAD estimation. Therefore, the purpose of this study is to use features selection strategy to optimize sensitive remote sensing information, combined with features fusion strategy to integrate multiple characteristic features, in order to improve the accuracy of estimating wheat SPAD. This study conducted field experiments of winter wheat with different varieties and nitrogen treatments, utilized UAV multispectral sensors to obtain canopy images of winter wheat during the heading, flowering, and late filling stages, extracted spectral features and texture features from multispectral images, and employed features selection strategy (Boruta and Recursive Feature Elimination) to prioritize sensitive remote sensing features. The features fusion strategy and the Support Vector Machine Regression algorithm are applied to construct the SPAD estimation model for winter wheat. The results showed that the spectral features of NIR band combined with other bands can fully capture the spectral differences of winter wheat SPAD during the reproductive growth stage, and texture features of the red and NIR band are more sensitive to SPAD. During the heading, flowering, and late filling stages, the stability and estimation accuracy of the SPAD model constructed using both features selection strategy and features fusion strategy are superior to models using only a single feature strategy or no strategy. The enhancement of model accuracy by this method becomes more significant, with the greatest improvement observed during the late filling stage, with R2 increasing by 0.092-0.202, root mean squared error (RMSE) decreasing by 0.076-4.916, and ratio of performance to deviation (RPD) increasing by 0.237-0.960. In conclusion, this method has excellent application potential in estimating SPAD during the later stages of crop growth, providing theoretical basis and technical support for precision nutrient management of field crops.

17.
Nat Prod Res ; : 1-9, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38770927

RESUMO

The Marsdenia tenacissima, has been used as traditional Chinese medicine for six hundred years. Our chemical investigation on the stem of Marsdenia tenacissima led to the isolation of one new pregnane glycoside, namely, marsdeoside J (compound 1) and twelve known compounds. The structure of the new compound was elucidated by spectroscopic analysis including 1D and 2D NMR, HRESIMS, IR, and UV. The absolute configurations of the sugar moiety were identified by comparing the specific optical rotations and Rf values with those of the commercially available standards and the data reported in the literature. Compound 1 showed cytotoxicities against five human cancer cell lines, with IC50 values ranging from 6.5 to 18.1 µM and certain inhibitory activities on NO production.

18.
Materials (Basel) ; 17(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38730811

RESUMO

This paper investigates the impact of varying the part geometric complexity and 3D printing process setup on the resulting structural load bearing capacity of fiber composites. Three levels of geometric complexity are developed through 2.5D topology optimization, 3D topology optimization, and 3D topology optimization with directional material removal. The 3D topology optimization is performed with the SIMP method and accelerated by high-performance computing. The directional material removal is realized by incorporating the advection-diffusion partial differential equation-based filter to prevent interior void or undercut in certain directions. A set of 3D printing and mechanical performance tests are performed. It is interestingly found that, the printing direction affects significantly on the result performance and if subject to the uni direction, the load-bearing capacity increases from the 2.5D samples to the 3D samples with the increased complexity, but the load-bearing capacity further increases for the 3D simplified samples due to directional material removal. Hence, it is concluded that a restricted structural complexity is suitable for topology optimization of 3D-printed fiber composites, since large area cross-sections give more degrees of design freedom to the fiber path layout and also makes the inter-layer bond of the filaments firmer.

19.
J Agric Food Chem ; 72(23): 13154-13163, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38780776

RESUMO

Finding safe and environmentally friendly fungicides is one of the important strategies in modern pesticide research and development. In this work, the antipathogenic effects of the fungus Trichaptum laricinum against the anthracnose pathogen Colletotrichum anthrisci were studied. The EtOAc extract of T. laricinum showed remarkable antifungal activity against C. anthrisci with an inhibition rate of 50% at 256 µg/mL. Bioguided isolation of the cultural broth of T. laricinum produced four new drimane sesquiterpenes, trichalarins A-D (1-4), and six other metabolites (5-10). Their structures were established by extensive spectroscopic methods, quantum chemical calculations, and single-crystal X-ray diffraction. All compounds exhibited antifungal activity against C. anthrisci with minimum inhibitory concentrations (MICs) of 8-64 µg/mL in vitro. Further in vivo assay suggested that compounds 2, 6, and 9 could significantly inhibit C. anthrisci growth in avocado fruit with inhibition rates close to 80% at the concentration of 256 µg/mL, while compounds 2 and 6 had an inhibition rate over 90% at the concentration of 512 µg/mL. The EtOAc extract of T. laricinum had no inhibitory effect on Pinus massoniana seed germination and growth at the concentration of 2 mg/mL, showing good environmental friendliness. Thus, the fungus T. laricinum could be considered as an ideal biocontrol strain, and its metabolites provided a diverse material basis for the antibiotic agents.


Assuntos
Colletotrichum , Fungicidas Industriais , Testes de Sensibilidade Microbiana , Doenças das Plantas , Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Fungicidas Industriais/química , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Estrutura Molecular , Sesquiterpenos/farmacologia , Sesquiterpenos/química
20.
RSC Adv ; 14(16): 11002-11006, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38586440

RESUMO

Carpesabrolide A (1), featuring an unprecedented fumaric acid-guaiane sesquiterpenoid hybrid, has been isolated from the folk medicinal plant Carpesium abrotanoides. The structure with absolute configuration has been established by spectroscopic methods and single crystal X-ray diffraction analysis. The plausible biosynthetic pathway for 1 is proposed. Compound 1 shows significant anti-inflammatory activity by inhibiting NO production with an IC50 value of 2.7 µM.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA