检索结果-南通市图书馆

Taxifolin stability: In silico prediction and in vitro degradation with HPLC-UV/UPLCe ESI-MS monitoring

Journal of Pharmaceutical Analysis 2021年第2期11卷 232-240页

作者： Fernanda Cristina Stenger Moura Carmem Lúciados Santos Machado Favero Reisdorfer Paula Angelica Garcia Couto Maurizio Ricci valdir cechinel-filho Tiago J.Bonomini Louis P.Sandjo Tania Mari Belle Bresolin Pharmaceutical Sciences Graduate Program School of Health SciencesCourse of PharmacyUniversidade do Vale do ItajaíItajaíSC88302-202Brazil Laboratory of Research and Development of Drugs Pharmaceutical Sciences Graduate ProgramSchool of Health SciencesCourse of PharmacyUniversidade Federal do PampaUruguaianaRS97500-970Brazil Department of Pharmaceutical Science Universita degli Studi di PerugiaPerugiaPG06123Italy Chemistry Department Universidade Federal de Santa CatarinaTrindadeFlorian opolisSC88040-900Brazil

Taxifolin has a plethora of therapeutic activities and is currently isolated from the stem bark of the tree Larix gmelinni(Dahurian larch). It is a flavonoid of high commercial interest for its use in supplements or in antioxidant-rich functional foods. However, its poor stability and low bioavailability hinder the use of flavonoid in nutritional or pharmaceutical formulations. In this work, taxifolin isolated from the seeds of Mimusops balata, was evaluated by in silico stability prediction studies and in vitro forced degradation studies(acid and alkaline hydrolysis, oxidation, visible/UV radiation, dry/humid heating) monitored by high performance liquid chromatography with ultraviolet detection(HPLC-UV) and ultrahigh performance liquid chromatography-electrospray ionization-mass spectrometry(UPLC-ESI-MS). The in silico stability prediction studies indicated the most susceptible regions in the molecule to nucleophilic and electrophilic attacks, as well as the sites susceptible to oxidation. The in vitro forced degradation tests were in agreement with the in silico stability prediction, indicating that taxifolin is extremely unstable(class 1) under alkaline hydrolysis. In addition, taxifolin thermal degradation was increased by *** the other hand, with respect to photosensitivity, taxifolin can be classified as class 4(stable).Moreover, the alkaline degradation products were characterized by UPLC-ESI-MS/MS as dimers of taxifolin. These results enabled an understanding of the intrinsic lability of taxifolin, contributing to the development of stability-indicating methods, and of appropriate drug release systems, with the aims of preserving its stability and improving its bioavailability.

关键词： Dihydroquercetin In silico stability prediction Forced degradation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Psychopharmacological Profile of Hydroalcoholic Extract and P-Hydroxybenzoic Acid Obtained from <i>Bourreria huanita</i>(Boraginaceae) in Mice

引用

Pharmacology & Pharmacy 2014年第11期5卷 983-995页

作者： Iandra Holzmann Daiane Cattani Micheli Corso Daiane Perondi Sabrina Zanella Cristiani Burger Luiz Carlos Klein Júnior valdir cechinel filho Sully M. Cruz Miguel F. Torres Armando Cáceres Márcia Maria de Souza Programa de Pós-Graduação em Ciências Farmacêuticas Universidade do Vale do Itajaí Itajaí Brazil Núcleo de Investigações Químico Farmacêuticas Universidade do Vale do Itajaí Itajaí Brazil Facultad de CCQQ y Farmacia Universidad de San Carlos Guatemala City Guatemala

Bourreria huanita (Lex.) Hemsl. (Boraginaceae) is a very rare and highly appreciated tree in Mesoamerica for its medicinal properties and beauty. It grows in a region extending from central Mexico to Costa Rica. Ethnobotanical surveys have shown that the infusion of dried flowers is popularly used as a tranquilizer to cure several diseases. In the present study we report the isolation of p-hydroxybenzoic acid (pHBZ) obtained from the hydroalcoholic extract (HE) of B. huanita, and the effect of both, the extract and the compound on the central nervous system in mice. HE of B. huanita (100, 150, 300 mg/kg) and pHBZ (10 mg/kg) were orally administered to mice and 1 h later, behavioral tests were performed. The effects of HE and pHBZ were tested by pentylenetetrazole (PTZ) and strychnine (STR) induced seizures, pentobarbital-induced hypnosis, the forced swimming test and the tail suspension test, the elevated plus maze, apomorphine-induced stereotypy and the climbing test, the inhibitory avoidance test and the open-field test. B. huanita extract produced hypnotic, anxiolytic and antidepressant effects in animals, with no change in motor performance. On the other hand, the extract did not reduce PTZ and STR-induced convulsions, apomorphine-induced stereotypy or climbing. Moreover, no changes were observed in the animals’ memory. The compound pHBZ was effective only in the depression tests. The results obtained in the present study suggest that B. huanita exhibited sedative, antidepressant and hypnotic activities in mice, and that the antidepressant activity may be mediated by an isolated compound identified as pHBZ.

关键词： Bourreria huanita Antidepressant Sedative and Hypnotic Activities P-Hydroxybenzoic Acid

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Elastic scattering of ^(13)C and ^(14)C isotopes on a ^(208)Pb target at energies of approximately five times the Coulomb barriers

引用

Chinese Physics C 2024年第3期48卷 65-71页

作者：杨过段芳芳王康杨彦云孙志宇 valdir Guimarães 庞丹阳陈文棣金磊许世伟马军兵马朋白真汪凌昊刘泉王惠仁吕冰锋郭松 Mukhi Kumar Raju 王秀华李荣华张玉虎周小红胡正国徐瑚珊 CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100080China Instituto de Física Universidade de São PauloRua do Matão1371São Paulo 05508-090SPBrazil School of Physics and Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang UniversityBeijing 100191China School of Physics Science and Engineering Tongji UniversityShanghai 200092China School of physics and Optoelectronic Engineering Anhui UniversityHefei 230601China Department of Physics GITAM School of ScienceGITAM UniversityVisakhapatnam 530045India

The elastic scattering angular distributions of ^(13)C at 340 MeV and ^(14)C at 294 MeV and 342 MeV on a ^(208)Pb target,which correspond to approximately five times the Coulomb barriers,were measured at the Radioactive Ion Beam Line in *** data were analyzed within the optical model and continuum-discretized coupled-channels(CDCC)framework,and the results of both calculations could effectively account for the experimental *** differential cross sections of elastic scattering revealed no particular suppression at the Coulomb nuclear interference peak angles,suggesting that the breakup coupling effects on the elastic scattering angular distributions were negligibly small in this incident energy *** contributions from the couplings with inelastic states to the elastic cross sections were of minor importance within the angular range covered by these experiments.

关键词： elastic scattering radioactive ion beam angular distribution optical model coupling effects

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nutrition and exercise can attenuate inflammatory and psychobiological changes in hypoxia?

引用

Asian Pacific Journal of Tropical Biomedicine 2017年第1期7卷 86-90页

作者： Aline Venticinque Caris Wanessa Ysis valdir de Aquino Lemos Ricardo Bottura Ronaldo Vagner Thomatieli dos Santos Department of Psychobiology Federal University of Sao Paulo(UNIFESP)SantosBrazil Department of Bioscience Federal University of Sao Paulo(UNIFESP)SantosBrazil

Exposure to hypoxia causes damage in several physiological systems, whose tissues are dependent on the O2 supply. Recently, there has been growing attention on the immunosuppressive and inflammatory potential of the hypoxia, including stimulation, nuclear factor kappa B pathway in macrophages and Th2 response from lymphocytes. These changes may result in transient immunosuppression and happen at the same time to worsening of cognition and other psychobiological aspects. Furthermore, exercise and nutrition, especially glutamine supplementation may provide important role, not pharmacological partially reversing the effects of hypoxia. In fact, recent studies show that moderate exercise can improve cognition in people exposed to hypoxia while the exercise associated with glutamine supplementation can reverse the increase in inflammatory markers and the Th1/Th2 balance. This review aims to bring the light of the discussion about nonpharmacological ways to prevent the effects of hypoxia on the connection between the immune system and the central nervous system.

关键词： Physical exercise High altitude Inflammation Cognition Glutamine

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

血管紧张素Ⅱ诱导产生的活性氧簇参与延髓的心血管反射(英文)

引用

Neuroscience Bulletin 2011年第4期27卷 269-274页

作者： valdir A.Braga Eduardo Colombari Mariana G.Jovita 坎皮纳联邦大学制药技术实验室圣保罗州立大学生理学与病理学系

脑干是中枢神经系统中的一个重要部位,参与心血管反射,例如压力感受性反射和外周化学感受性反射。孤束核和延髓头端腹外侧是脑干中重要的两个部位,在心血管自主调节中扮演重要角色。神经递质血管紧张素II能通过活化一些通路,诱导产生活... 详细信息

脑干是中枢神经系统中的一个重要部位,参与心血管反射,例如压力感受性反射和外周化学感受性反射。孤束核和延髓头端腹外侧是脑干中重要的两个部位,在心血管自主调节中扮演重要角色。神经递质血管紧张素II能通过活化一些通路,诱导产生活性氧簇,进而参与脑干心血管反射。研究表明,在中枢神经系统中,活性氧簇与一些病理疾病相关,例如高血压、心衰竭和睡眠性呼吸暂停。然而,活性氧簇在脑干心血管反射中的作用目前尚不明确。本文主要就最近关于活性氧簇在脑干中压力感受性反射和外周化学感受性反射中作用的一些发现进行综述及讨论。

关键词：血管紧张素Ⅱ 过氧化物延髓头端腹外侧孤束核压力反射外周化学反射

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Toward Establishing the Productive Chain for Triterpene-Based Amazonian Oleoresins as Valuable Non-Timber Forest Products

引用

Open Journal of Forestry 2017年第2期7卷 188-208页

作者： Antonio C. Siani Roseane Moraes valdir F. Veiga Junior Institute of Drug Technology Oswaldo Cruz Foundation Rio de Janeiro Brazil Chemistry Department Amazonas Federal University Manaus Brazil

In the Amazonian rainforest, many species of Burseraceae known locally as “breu” are explored for the medicinal and aromatic uses of their trunk exudates. This material also has a long-standing use by the forest communities in building and caulking boats as well as in the making of wooden utensils and general crafts. Breu are strongly aromatic due volatile terpenes in their composition that are separated from the crude resin by steam distillation. The remaining residue amorphous “hard resin” is primary used for application in woodworking. Despite the potential for application in paints, varnishes and odor fixatives, the commercialization of the hard resin has not surpassed the local market level. In order to achieve and establish a more valorized market for this Amazonian non-timber forest product, the existing and potential demands need to be estimated, a draft of the production chain needs to be drawn up and care needs to be taken to provide products of the highest possible quality. This study aimed to identify and organize the main issues necessary for the attainment of these goals and its value chain, and identify the technologies that would improve the quality of the Amazonian breu as a raw material. A review of the data available in the literature and the analytical techniques that could be applied to generate standards for the extraction, purification, and analysis of the hard resin fraction was made. Quality issues based on physicochemical standards might affect the productive chain by: i) helping to consolidate the appropriate methodologies for collecting and storing the raw material;ii) adding value and qualifying the primary improvement processes and iii) supporting the certification of the raw materials for commercialization. Potentiate this material to reach high-level markets might boost the production demand and improve the rain forest communities’ income.

关键词： Burseraceae Breu Terpenoid Resins Productive Chain Technological Value Aggregation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Proposed Relief Map of the Suitability of the Maranhão River Basin, Brazil, for Anthropogenic Use

引用

Journal of Geographic Information System 2016年第3期8卷 351-360页

作者： valdir A. Steinke Ercilia Torres Steinke Mario Diniz Araujo Neto Maria Ligia Cassol Pinto University of Brasilia Brasília Brazil

In this paper, we proposed a method for mapping the suitability of land for intensive anthropogenic use in the Maranhao River Basin, in the state of Goiás, Brazil. We analyzed existing 1:250,000 maps of the local geology, drainage system topography and geomorphological features. We generated new information based on our analysis, including a compilation of basic morphometric data and a map of the slopes in the basin, which we used to construct the geomorphological suitability map of the watershed. Our results indicate that 40% of the study area can support intensive anthropogenic use;the remaining 60% of the basin area is categorized as “fragile” regarding the expansion of intensive land use.

关键词： Morphometry GIS Environmental Management Suitability of the Watershed Land Use Policy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Risk Factors Associated with Acinetobacter baumannii Infections in Patients in an Intensive Care Unit of a Public Hospital in Paraná

引用

Advances in Infectious Diseases 2022年第1期12卷 90-105页

作者： Mirian Carla Bortolamedi da Silva Maria Helena Brandeleiro Werlang valdir Spada Júnior Guilherme Welter Wendt Ana Paula Vieira Franciele Ani Caovilla Follador Léia Carolina Lucio Cleide Viviane Busanello Martins Kérley Braga Pereira Bento Casaril Paulo Cezar Nunes Fortes Lirane Elize Defante Ferreto Post-Graduante Program Health Sciences University of Wester Paraná (UNIOESTE) Francisco Beltr&#227 o Brazil State of the Health of Paraná (SESA-PR) Francisco Beltr&#227 o Brazil

To identify risk factors for A. baumannii infection in patients hospitalized in an Intensive Care Unit (ICU) of a tertiary public hospital in Paraná, Brazil, a retrospective paired case-control study (ratio 1:2) was conducted from January 2018 to December 2020. Patients in the case group were hospitalized in the ICU with A. baumanni (n = 68 cases) and were compared with patients in the control group, without infection by A. baumannii (n = 136). Both were matched by age (±10 years), sex, and ICU stay (±5 days). Conditional multiple logistic regression was used to determine statistically significant risk factors based on the results of bivariate analyses. Mortality was higher in infected (cases) than in non-infected patients (51.5% vs. 39.7%). The incidence and bacterial resistance increased annually. At bivariate analysis, cases had longer hospital stays (median 35 vs. 22 days, p A. baumannii and antimicrobial resistance. There is need for surveillance, and constant evaluation of control actions. Risk factors were colonization, previous hospitalization, and hospitalization time. This is essential for the decision-making of professionals and optimization of prevention, control, and therapeutic management actions.

关键词： Acinetobacter baumannii Risk-Factors Infection Intensive Care

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analytical Determination of Benzophenone-3 in Sunscreen Preparations Using Boron-Doped Diamond Electrodes

引用

American Journal of Analytical Chemistry 2011年第3期2卷 383-391页

作者： Michelli Thomaz Laranjeira Fabio de Lima Silvio Cesar de Oliveira valdir Souza Ferreira Robson Tadeu Soares de Oliveira 不详

A new electroanalytical procedure was developed for the determination of Benzophenone-3 (BENZO) in commercial sunscreen as the active ingredient. The procedure is based on the use of electrochemical methods as cyclic and square-wave voltammetry, with boron-doped diamond (BDD) electrodes. The reduction of BENZO in Britton-Robinson buffer (0.1 mol●L–1) using this type of electrode gives rise to one irreversible peak in –1.30 V (versus Ag/AgCl) in presence of cationic surfactant cetyltrimethylammonium bromide (CTABr). The proposed electrochemical method was successfully applied to the analysis of commercially available pharmaceutical preparations.

关键词： Boron-Doped Diamond Benzophenone-3 BENZO and Square-Wave Voltammetry

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Miscibility Behavior of Polyacrylamides Poly(Ethylene Glycol)Blends:Flory Huggins Interaction Parameter Determined by Thermal Analysis

引用

Journal of Modern Physics 2013年第7期4卷 45-51页

作者： Maria Elisa S.R.Silva valdir Mano Raquel R.J.Pacheco Roberto F.S.Freitas Department of Chemical Engineering Federal University of Minas GeraisBelo HorizonteBrazil Department de Natural Sciences Federal University of Sao Joao del ReiSao Joao del ReiMinas GeraisBrazil

Blends of polyacrylamide—PAM, poly(N-isopropylacrylamide)—PNIPAAm, poly(N-tert-butylacrylamide)—PTBAA, poly(N,N-dimethylacrylamide)—PDMAA and poly(N,N-diethylacrylamide)—PDEAA with poly(ethylene glycol)— PEG were prepared by casting in methanol and water at concentrations of 20 wt%, 40 wt%, 60 wt%, and 80 wt% in PEG. The miscibility of the components was studied by Differential Scanning Calorimetry—DSC. All blend systems are characterized by a single glass transition temperature (Tg), close to the Tg of the amorphous component. The Hoffman Weeks method was used to determine equilibrium melting temperature (Tm) data. The determination of the melt point depression of the blends allowed the calculation of Flory-Huggins interaction parameter (χ12) of the two polymers in the melt, by using the Nishi Wang equation. The interaction parameters, calculated for all the blends, are slightly negative and close to zero, suggesting a partial miscibility between the components.

关键词： Polyacrylamides Poly(Ethylene Glycol) Polymer Blends Flory-Huggins Interaction Parameter Differential Scanning Calorimetry

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：