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1.
J Asian Nat Prod Res ; 25(6): 528-539, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35920176

RESUMO

Twenty-two metabolites were isolated from Penicillium sp. CPCC 401423 cultured on rice. The structures of all compounds were elucidated mainly by MS and NMR analysis as well as the necessary CD experimental evidence, of which penicillidione A (1), penicillidione B (2), (E)-4-[(4-acetoxy-3-methyl-2-butenyl)oxy]phenylacetic acid (3), (S)-2-hydroxy-2-{4-[(3-methyl-2-butenyl)oxy]phenyl} (4), (S)-4-(2,3-dihydroxy-3-methyl-butoxy)phenylacetic acid (5), (E)-4-[(3-carboxy-2-butenyl)oxy]benzoic acid (6), (Z)-4-[(4-hydroxy-3-methyl-2-butenyl)oxy]benzoic acid (7), open-cycled N-demethylmelearoride A (12), and penostatin M (16) were identified as new compounds. The cytotoxic activity against human pancreatic carcinoma cell line MIA PaCa-2a was detected. Among them, compounds 13-15 and 22 displayed significant cytotoxicity against MIA-PaCa-2 cells with IC50 values of 8.9, 36.5, 31.8, and 22.3 µM, respectively (positive control gemcitabine IC50 65.0 µM).


Assuntos
Antineoplásicos , Penicillium , Humanos , Penicillium/química , Antineoplásicos/química , Fenilacetatos , Linhagem Celular Tumoral , Ácido Benzoico , Estrutura Molecular
2.
Zhongguo Zhong Yao Za Zhi ; 48(6): 1491-1497, 2023 Mar.
Artigo em Zh | MEDLINE | ID: mdl-37005836

RESUMO

By investigating the contamination status and predicting the exposure risk of mycotoxin in Coicis Semen, we aim to provide guidance for the safety supervision of Chinese medicinal materials and the formulation(revision) of mycotoxin limit standards. The content of 14 mycotoxins in the 100 Coicis Semen samples collected from five major markets of Chinese medicinal materials in China was determined by UPLC-MS/MS. The probability evaluation model based on Monte Carlo simulation method was established after Chi-square test and One-way ANOVA of the sample contamination data. Health risk assessment was performed on the basis of margin of exposure(MOE) and margin of safety(MOS). The results showed that zearalenone(ZEN), aflatoxin B_1(AFB_1), deoxynivalenol(DON), sterigmatocystin(ST), and aflatoxin B_2(AFB_2) in the Coicis Semen samples had the detection rates of 84%, 75%, 36%, 19%, and 18%, and the mean contamination levels of 117.42, 4.78, 61.16, 6.61, and 2.13 µg·kg~(-1), respectively. According to the limit standards in the Chinese Pharmacopoeia(2020 edition), AFB_1, AFs and ZEN exceeded the standards to certain extents, with the over-standard rates of 12.0%, 9.0%, and 6.0%, respectively. The exposure risks of Coicis Semen to AFB_1, AFB2, ST, DON, and ZEN were low, while 86% of the samples were contaminated with two or more toxins, which needs more attention. It is suggested that the research on the combined toxicity of different mycotoxins should be strengthened to accelerate the cumulative exposure assessment of mixed contaminations and the formulation(revision) of toxin limit standards.


Assuntos
Coix , Micotoxinas , Humanos , Micotoxinas/análise , Aflatoxina B1/análise , Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Espectrometria de Massas em Tandem/métodos
3.
Zhongguo Zhong Yao Za Zhi ; 47(3): 628-634, 2022 Feb.
Artigo em Zh | MEDLINE | ID: mdl-35178944

RESUMO

This study aimed to establish a method for synchronous detection of 14 mycotoxins in Pseudostellariae Radix and investigate its contamination with mycotoxins, so as to provide technical guidance for monitoring the quality of Chinese medicinal materials and medication safety. The sample was extracted with 80% acetonitrile in an oscillator for 1 h, purified using the modified QuEChERS purifying agent(0.1 g PSA + 0.3 g C_(18) + 0.3 g MgSO_4), and separated on a Waters HSS T3 chromatographic column(2.1 mm×100 mm, 1.8 µm). The gradient elution was carried out with 0.1% formic acid in water and acetonitrile, followed by the scanning in the multi-reaction monitoring(MRM) mode and the analysis of mycotoxin contamination in 26 Pseudostellariae Radix samples. The recovery rates of the established method were within the range of 82.17%-113.6%, with the RSD values less than 7% and the limits of quantification(LOQ) being 0.019-0.976 µg·kg~(-1). The detection rate of 14 mycotoxins in 26 batches of medicinal materials was 53.85%. The detection rate of sterigmatocystin(ST) was the highest, followed by those of zearalenone(ZEN), aflatoxin G_2(AFG_2), fumonisin B_1(FB_1), HT-2 toxin, and nivalenol(NIV). Their respective detection rates were 38.46%, 26.92%, 23.08%, 11.54%, 11.54%, and 7.69%, with the pollution ranges being 1.48-69.65, 0.11-31.05, 0.11-0.66, 0.28-0.83, 20.86-42.56, and 0.46-1.84 µg·kg~(-1), respectively. The established method for the detection of 14 mycotoxins is accurate, fast and reliable. The research results have very important practical significance for guiding the monitoring and prevention and control of exogenous fungal contamination of Chinese medicinal materials.


Assuntos
Aflatoxinas , Micotoxinas , Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Medicamentos , Contaminação de Alimentos/análise , Micotoxinas/análise , Raízes de Plantas/química , Espectrometria de Massas em Tandem/métodos
4.
Int J Syst Evol Microbiol ; 70(3): 1691-1697, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31935182

RESUMO

Strain CPCC 203383T, isolated from the surface-sterilized fruit of Cerasus pseudocerasus (Lindl.) G. Don, was taxonomically characterized based on a polyphasic investigation. It had the highest 16S rRNA gene sequence similarities with Ornithinimicrobium pekingense DSM 21552 (97.2 %) and O. kibberense DSM 17687T (97.2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain formed a distinct phyletic branch within the genus Ornithinimicrobium and the whole genome sequence data analyses supported that strain CPCC 203383T was phylogenetically related to the Ornithinimicrobium species. The isolate shared a range of phenotypic patterns reported for members of the genus Ornithinimicrobium, but also had a range of cultural, physiological and biochemical characteristics that separated it from related Ornithinimicrobium species. The menaquinone was MK-8(H4). The polar lipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylinositol (PI) and unidentified lipids (ULs). The major fatty acids (>5 %) were iso-C15 : 0, anteiso-C15 : 0, iso-C16:0, 9-methyl C16 : 0, iso-C17 : 0 and anteiso-C17 : 0. The cell wall peptidoglycan contains l-ornithine as diagnostic diamino acid and an interpeptide bridge consisting of L-Orn←L-Ala←Gly←D-Asp. The combined genotypic and phenotypic data indicated that the isolate represents a novel species of the genus Ornithinimicrobium, for which the name Ornithinimicrobium cerasi sp. nov. is proposed, with CPCC 203383T(=NBRC 113522T=KCTC 49200T) as the type strain. The DNA G+C composition is 72.3 mol%. The availability of new data allows for an emended description of the genus Ornithinimicrobium.


Assuntos
Actinobacteria/classificação , Filogenia , Prunus/microbiologia , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácidos Graxos/química , Frutas/microbiologia , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
5.
Molecules ; 24(12)2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31242703

RESUMO

The v-raf murine sarcoma viral homolog B1 (BRAF) inhibitor drug vemurafenib (PLX4032) is used to treat melanoma; however, epidemiological evidence reveals that it could cause cutaneous keratoacanthomas and squamous cell carcinoma in cancer patients with the most prevalent HRASQ61L mutation. In a two-stage skin carcinogenesis mouse model, the skin papillomas induced by 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) (DT) resemble the lesions in BRAF inhibitor-treated patients. In this study, we investigated the bioactivity of Mentha aquatica var. Kenting Water Mint essential oil (KWM-EO) against PDV cells, mouse keratinocytes bearing HRASQ61L mutation, and its effect on inhibiting papilloma formation in a two-stage skin carcinogenesis mouse model with or without PLX4032 co-treatment. Our results revealed that KWM-EO effectively attenuated cell viability, colony formation, and the invasive and migratory abilities of PDV cells. Induction of G2/M cell-cycle arrest and apoptosis in PDV cells was also observed. KWM-EO treatment significantly decreased the formation of cutaneous papilloma further induced by PLX4032 in DT mice (DTP). Immunohistochemistry analyses showed overexpression of keratin14 and COX-2 in DT and DTP skin were profoundly suppressed by KWM-EO treatment. This study demonstrates that KWM-EO has chemopreventive effects against PLX4032-induced cutaneous side-effects in a DMBA/TPA-induced two-stage carcinogenesis model and will be worth further exploration for possible application in melanoma patients.


Assuntos
Anticarcinógenos/química , Anticarcinógenos/farmacologia , Mentha/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Inibidores de Proteínas Quinases/efeitos adversos , Vemurafenib/efeitos adversos , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Antagonismo de Drogas , Camundongos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/patologia
6.
Age Ageing ; 47(4): 551-557, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29528375

RESUMO

BACKGROUND: many people living with dementia remain underdiagnosed and unrecognised. Screening strategies are important for early detection. OBJECTIVE: to examine whether the Lawton's Instrumental Activities of Daily Living (IADL) scale, compared with other cognitive screening tools-the Mini-Mental State Examination (MMSE), and the Ascertain Dementia 8-item Informant Questionnaire (AD8)-can identify older (≥ 65 years) adults with dementia. DESIGN: population-based cross-sectional observational study. SETTING: all 19 counties in Taiwan. PARTICIPANTS: community-dwelling older adults (n = 10,340; mean age 74.87 ± 6.03). METHODS: all participants underwent a structured in-person interview. Dementia was identified using National Institute on Aging-Alzheimer's Association core clinical criteria for all-cause dementia. Receiver operator characteristic curves were used to determine the discriminant abilities of the IADL scale, MMSE and AD8 to differentiate participants with and without dementia. RESULTS: we identified 917 (8.9%) participants with dementia, and 9,423 (91.1%) participants without. The discriminant abilities of the MMSE, AD8 and IADL scale (cutoff score: 6/7; area under curve = 0.925; sensitivity = 89%; specificity = 81%; positive likelihood ratio = 4.75; accuracy = 0.82) were comparable. Combining IADL with AD8 scores significantly improved overall accuracy: specificity = 93%; positive likelihood ratio = 11.74; accuracy = 0.92. CONCLUSIONS: our findings support using IADL scale to screen older community-dwelling residents for dementia: it has discriminant power comparable to that of the AD8 and MMSE. Combining the IADL and the AD8 improves specificity.


Assuntos
Atividades Cotidianas , Envelhecimento/psicologia , Cognição , Demência/diagnóstico , Avaliação da Deficiência , Avaliação Geriátrica/métodos , Vida Independente , Inquéritos e Questionários , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Demência/fisiopatologia , Demência/psicologia , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Taiwan
7.
Biochim Biophys Acta ; 1840(7): 2340-50, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24747731

RESUMO

BACKGROUND: Folate is an essential nutrient for cell survival and embryogenesis. 10-Formyltetrahydrofolate dehydrogenase (FDH) is the most abundant folate enzyme in folate-mediated one-carbon metabolism. 10-Formyltetrahydrofolate dehydrogenase converts 10-formyltetrahydrofolate to tetrahydrofolate and CO2, the only pathway responsible for formate oxidation in methanol intoxication. 10-Formyltetrahydrofolate dehydrogenase has been considered a potential chemotherapeutic target because it was down-regulated in cancer cells. However, the normal physiological significance of 10-Formyltetrahydrofolate dehydrogenase is not completely understood, hampering the development of therapeutic drug/regimen targeting 10-Formyltetrahydrofolate dehydrogenase. METHODS: 10-Formyltetrahydrofolate dehydrogenase expression in zebrafish embryos was knocked-down using morpholino oligonucleotides. The morphological and biochemical characteristics of fdh morphants were examined using specific dye staining and whole-mount in-situ hybridization. Embryonic folate contents were determined by HPLC. RESULTS: The expression of 10-formyltetrahydrofolate dehydrogenase was consistent in whole embryos during early embryogenesis and became tissue-specific in later stages. Knocking-down fdh impeded morphogenetic movement and caused incorrect cardiac positioning, defective hematopoiesis, notochordmalformation and ultimate death of morphants. Obstructed F-actin polymerization and delayed epiboly were observed in fdh morphants. These abnormalities were reversed either by adding tetrahydrofolate or antioxidant or by co-injecting the mRNA encoding 10-formyltetrahydrofolate dehydrogenase N-terminal domain, supporting the anti-oxidative activity of 10-formyltetrahydrofolate dehydrogenase and the in vivo function of tetrahydrofolate conservation for 10-formyltetrahydrofolate dehydrogenase N-terminal domain. CONCLUSIONS: 10-Formyltetrahydrofolate dehydrogenase functioned in conserving the unstable tetrahydrofolate and contributing to the intracellular anti-oxidative capacity of embryos, which was crucial in promoting proper cell migration during embryogenesis. GENERAL SIGNIFICANCE: These newly reported tetrahydrofolate conserving and anti-oxidative activities of 10-formyltetrahydrofolate dehydrogenase shall be important for unraveling 10-formyltetrahydrofolate dehydrogenase biological significance and the drug development targeting 10-formyltetrahydrofolate dehydrogenase.


Assuntos
Desenvolvimento Embrionário/genética , Ácido Fólico/metabolismo , Morfogênese/genética , Estresse Oxidativo/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Sequência de Aminoácidos , Animais , Ácido Fólico/genética , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Humanos , Morfolinos , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento
8.
Acta Crystallogr D Biol Crystallogr ; 71(Pt 4): 1006-21, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25849409

RESUMO

10-Formyltetrahydrofolate dehydrogenase (FDH), which is composed of a small N-terminal domain (Nt-FDH) and a large C-terminal domain, is an abundant folate enzyme in the liver and converts 10-formyltetrahydrofolate (10-FTHF) to tetrahydrofolate (THF) and CO2. Nt-FDH alone possesses a hydrolase activity, which converts 10-FTHF to THF and formate in the presence of ß-mercaptoethanol. To elucidate the catalytic mechanism of Nt-FDH, crystal structures of apo-form zNt-FDH from zebrafish and its complexes with the substrate analogue 10-formyl-5,8-dideazafolate (10-FDDF) and with the products THF and formate have been determined. The structures reveal that the conformations of three loops (residues 86-90, 135-143 and 200-203) are altered upon ligand (10-FDDF or THF) binding in the active site. The orientations and geometries of key residues, including Phe89, His106, Arg114, Asp142 and Tyr200, are adjusted for substrate binding and product release during catalysis. Among them, Tyr200 is especially crucial for product release. An additional potential THF binding site is identified in the cavity between two zNt-FDH molecules, which might contribute to the properties of product inhibition and THF storage reported for FDH. Together with mutagenesis studies and activity assays, the structures of zNt-FDH and its complexes provide a coherent picture of the active site and a potential THF binding site of zNt-FDH along with the substrate and product specificity, lending new insights into the molecular mechanism underlying the enzymatic properties of Nt-FDH.


Assuntos
Oxirredutases atuantes sobre Doadores de Grupo CH-NH/química , Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Ácido Fólico/análogos & derivados , Formiatos/metabolismo , Hidrólise , Modelos Moleculares , Dados de Sequência Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Conformação Proteica , Estrutura Terciária de Proteína , Alinhamento de Sequência , Tetra-Hidrofolatos/metabolismo
9.
PLoS One ; 19(3): e0290648, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38446803

RESUMO

Under the repeated action of aircraft taxiing load, the subgrade plastic deformation becomes the key factor affecting the service performance of the airfields when salinized silt is used to fill the subgrade. In this study, the dynamic triaxial tests were carried out on a region in the northern part of China to study the effects of different salt contents on the dynamic characteristics of silt under cyclic loading. A prediction model for the salinized silt dynamic strength with a plastic strain of 4% as the failure criterion for the subgrade was thus proposed. It is found that with the increase of dynamic stress amplitude, the salinized silt plastic deformation transforms gradually from plastic deformation to incremental failure. The salt contents significantly influence the plastic strain and critical dynamic stress of silt. The strength of the salinized silt specimen is related to the ion concentration in the soil pores and the arrangement pattern of soil particles, as indicated by the progressive strength increase of the salinized silt at the low salt content of 1% and a further gradual decrease at high salt content.


Assuntos
Cloreto de Sódio na Dieta , Cloreto de Sódio , Aeronaves , Automóveis , Solo
10.
J Formos Med Assoc ; 112(8): 473-81, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23871551

RESUMO

BACKGROUND/PURPOSE: The aims of our study were to: (1) develop the Disability Grading Decision Support System (DGDSS) and to (2) compare the new International Classification of Functioning, Disability, and Health (ICF)-based disability determination tool (ICF-DDT) with the diagnosis-based disability determination tool (D-DDT). METHODS: A total of 9357 patients recruited from 236 accredited institutions were evaluated using the ICF-DDT and the D-DDT, and the presence, severity, and category of the disability identified using the two determination tools were compared. In the DGDSS, the ICF-DDT consisted of four models comprising nine modules to determine the presence and the severity of the disability. The differences between models (modules) are the different combinations of World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) and Scale of Body Functions and Structures. RESULTS: Compared with the D-DDT, more patients were determined to be disability-free when using the ICF-DDT. Module 1-1 had the highest profoundly severe rate, and module 2-2 had the highest mild and moderate disability rates. Module 2-1 had the highest severe disability rate. Module 1-1 resulted in the smallest difference, and module 3-1 resulted in the largest difference, compared with the D-DDT. Feedback from users suggested that the DGDSS is a robust system if the original data are accurate. CONCLUSION: The presence, severity, and category of the disability determined using the ICF-DDT and the D-DDT were significantly different. The results of the DGDSS provide information for policymakers to determine the optimal allocation of social welfare and medical resources for people with disabilities.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Avaliação da Deficiência , Humanos , Projetos Piloto , Índice de Gravidade de Doença , Taiwan
11.
Front Immunol ; 14: 1181987, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37449201

RESUMO

Pulmonary hypertension (PH) is a progressive, pulmonary vascular disease with high morbidity and mortality. Unfortunately, the pathogenesis of PH is complex and remains unclear. Existing studies have suggested that inflammatory factors are key factors in PH. Interleukin-6 (IL-6) is a multifunctional cytokine that plays a crucial role in the regulation of the immune system. Current studies reveal that IL-6 is elevated in the serum of patients with PH and it is negatively correlated with lung function in those patients. Since IL-6 is one of the most important mediators in the pathogenesis of inflammation in PH, signaling mechanisms targeting IL-6 may become therapeutic targets for this disease. In this review, we detailed the potential role of IL-6 in accelerating PH process and the specific mechanisms and signaling pathways. We also summarized the current drugs targeting these inflammatory pathways to treat PH. We hope that this study will provide a more theoretical basis for targeted treatment in patients with PH in the future.


Assuntos
Hipertensão Pulmonar , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/terapia , Interleucina-6/metabolismo , Pulmão/patologia , Inflamação/patologia , Transdução de Sinais
12.
Hum Mov Sci ; 87: 103049, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36525823

RESUMO

Continuous steering movement (CSM) is an essential component of the upper extremity (UE) task during vehicle driving, and could be a suitable candidate for multi-joint rehabilitation programs for patients with UE disabilities. This study aims to evaluate the UE muscle activation during CSM and how the rotating speed and direction affect CSM's kinematic and kinetic performance. Surface electromyography (EMG), hand contact information, and steering torque were measured under fast (180°/s) and slow (60°/s) constant-velocity CSM to reveal the activation of shoulder and elbow muscles, temporal characteristics, and force exertion during the stance and swing phases of a CSM cycle. Data from 24 normal young adults showed that shorter contact duration but higher force exertion occurred in the hand moving in an outward steering direction during only fast CSM in either the clockwise (CW) or counterclockwise (CCW) direction. During a steering cycle (either fast or slow speed), the triceps brachii, sternal part of the pectoralis major (PS), and posterior deltoid play major roles in generating steering torque in the CW direction of the CSM. In contrast, the PS, clavicular part of the pectoralis major (PC), and anterior deltoid (AD) largely contribute to torque generation during the CCW CSM. During the swing phase of CSM, AD, PC, and PS are the major muscles that move the hand for the next grasping of the steering wheel in all four conditions. Using the mean activation profiles of the major contributing muscles, the functional roles of these elbow and shoulder muscles were analyzed and are discussed herein. These findings help us to further understand the activation patterns of UE muscles and the kinematic and kinetic changes during two rotating directions and two speeds of CSM, and suggest important implications for future practice in clinical training.


Assuntos
Músculo Esquelético , Extremidade Superior , Adulto Jovem , Humanos , Extremidade Superior/fisiologia , Músculo Esquelético/fisiologia , Eletromiografia , Cotovelo , Braço , Movimento/fisiologia
13.
J Asian Nat Prod Res ; 14(11): 1039-45, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23106376

RESUMO

Asiatic acid (AA) is a natural triterpenoid possessing anti-inflammatory, anticancer, neuroprotective, and hepatoprotective activities. Structural modification of AA may provide valuable information for further structure-activity relationship analysis. Biotransformation is an efficient, specific, and environment friendly technology for structural modification of complicated natural products. In this study, the capabilities of twenty-five strains of filamentous fungi to transform AA were screened. Two new and one known oxidation products metabolized by Fusarium avenaceum AS 3.4594 were isolated. Their chemical structures were characterized as 2-oxo-3ß,15α,23-trihydroxyurs-12-en-28-oic acid (1), 3-oxo-2,15α,23-trihydroxyurs-1,12-dien-28-oic acid (2), and 2-oxo-3ß,23-dihydroxyurs-12-en-28-oic-acid (3) by extensive analysis of spectroscopic data.


Assuntos
Fusarium/metabolismo , Triterpenos Pentacíclicos/isolamento & purificação , Biotransformação , Fusarium/química , Hepatócitos/efeitos dos fármacos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Oxirredução , Triterpenos Pentacíclicos/química , Triterpenos Pentacíclicos/metabolismo , Estereoisomerismo , Triterpenos
14.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o614, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22412525

RESUMO

In the title compound, C(27)H(20)O(2), the phenyl ring is oriented with respect to the naphthalene ring systems at 57.87 (6) and 85.12 (6)°. The two naphthalene ring systems make a dihedral angle of 70.10 (4)°. In the mol-ecule, the hy-droxy groups are involved in a strong intra-molecular O-H⋯O hydrogen bond. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds occur. A weak C-H⋯π inter-action is also observed in the crystal.

15.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 6): o1611, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22719416

RESUMO

In the crystal structure of the title salt, C(6)H(5)N(2) (+)·Cl(-), the pyridinium cation links to the Cl(-) anion via an N-H⋯Cl hydrogen bond. Weak C-H⋯Cl inter-actions also occur.

16.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 6): o1625, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22719428

RESUMO

In the title compound, 2C(6)H(4)N(2)·C(2)H(2)O(4), the oxalic acid mol-ecule lies about an inversion center. The pyridine ring of the pyridine-4-carbonitrile mol-ecule is almost planar, the largest deviation from the least-squares plane being 0.006 (1) Å; the nitrile N atom deviates from this plane by 0.114 (1) Å. In the crystal, the oxalic acid mol-ecules and the pyridine-4-carbonitrile mol-ecules form stacks. Neighboring mol-ecules within the stacks are related by translation in the a direction, with inter-planar distances of 3.183 (1) and 3.331 (2) Å, respectively. Each oxalic acid mol-ecule forms strong O-H⋯N hydrogen bonds with two mol-ecules of pyridine-4-carbonitrile. Besides this, there are also weak C-H⋯O inter-actions.

17.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 6): o1695, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22719488

RESUMO

The title compound, C(6)H(5)N(2) (+)·NO(3) (-), is a proton-transfer compound between 4-cyano-pyridine and nitric acid. In the asymmetric unit, the components are linked by a strong N-H⋯O hydrogen bond. In the crystal, mol-ecules are linked into a C(6) chain along [010] by C-H⋯O inter-actions.

18.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 6): o1825, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22719597

RESUMO

In the title compound, C(6)H(5)N(2) (+)·Br(-), the pyridine N atom is protonated and involved in an inter-molecular N-H⋯Br hydrogen bond which, together with weak C-H⋯N hydrogen bonds, results in the formation of a chain along the c axis. Weak inter-molecular C-H⋯Br inter-actions between pyridine H atoms and Br(-) anions connect these chains into a network parallel to the bc plane.

19.
Nanoscale ; 14(29): 10428-10438, 2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35815897

RESUMO

Binary transition metal oxides (BTMOs) are regarded as potential anode materials for lithium-ion batteries (LIBs) owing to their low cost, high specific capacities, and environmental friendliness. In this work, MnV2O6 nanoflakes are successfully synthesized by a facile hydrothermal method. When evaluated as an anode material for LIBs, benefiting from the activation process, the as-prepared MnV2O6 nanoflake electrode delivers a high reversible specific capacity of 1439 mA h g-1 after 300 cycles at a current density of 200 mA g-1, and especially presents a specific capacity of 1010 mA h g-1 after 700 cycles at a higher current density of 1 A g-1. Furthermore, MnV2O6 shows a pleasurable rate capability; a reversible specific capacity of 867 mA h g-1 can be obtained at a current density of 2000 mA g-1, and when the current density is returned to 200 mA g-1 and continues for another 80 cycles, the specific capacity can still reach 1499 mA h g-1. Meanwhile, the morphology variation and electrochemical kinetic behavior of the MnV2O6 electrode during cycling are scrutinized in detail. After that, the electrochemical reaction mechanism of MnV2O6 during the discharge/charge process is corroborated by in situ X-ray diffraction (XRD), which involves the coexistence of a conversion reaction and solid solution behavior. The practical application of MnV2O6 nanoflakes as an anode material is examined as well. Sure enough, the NCM811//MnV2O6 full-cell exhibits excellent lithium-storage performance.

20.
Dalton Trans ; 51(12): 4644-4652, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35212335

RESUMO

Metal vanadates have been popularly advocated as promising anode materials for lithium-ion batteries (LIBs) benefiting from their high theoretical specific capacity and abundant resources. Given that manganese and vanadium are reasonably economical elements and enjoy assorted redox reactions, they have extensive application prospects in energy storage systems. Here, we synthesized cubic MnV2O4 as an anode for LIBs by an efficient sol-gel process. As a result, the MnV2O4 electrode delivers distinguished electrochemical performance, including an appealing reversible specific capacity of nearly 1325 mA h g-1 for 500 cycles at 200 mA g-1, excellent cycling stability with a capacity of 399 mA h g-1 up to 500 cycles at 2000 mA g-1 and a favorable rate capability of 516/410 mA h g-1 at 1000/2000 mA g-1 (when the current density recuperates to 200 mA g-1, the specific capacity still boosts as the number of cycles increases). What's more, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) under various scan rates and scanning electron microscopy (SEM) are executed to ascertain with a greater depth the electrochemical kinetic characteristics and morphology of the MnV2O4 electrode in different states. These results make known that MnV2O4 is a credible anode material for LIBs, and such a facile and economical synthetic route can be extended to the preparation of other metal vanadate materials.

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