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1.
Artigo em Inglês | MEDLINE | ID: mdl-38652277

RESUMO

Arnicolide D, a potent sesquiterpene lactone from Centipeda minima, has emerged as a promising anticancer candidate, demonstrating significant efficacy in inhibiting cancer cell proliferation, inducing apoptosis, and suppressing metastasis across various cancer models. This comprehensive study delves into the molecular underpinnings of Arnicolide D's anticancer actions, emphasizing its impact on key signaling pathways such as PI3K/AKT/mTOR and STAT3, and its role in modulating cell cycle and survival mechanisms. Quantitative data from preclinical studies reveal Arnicolide D's dose-dependent cytotoxicity against cancer cell lines, including nasopharyngeal carcinoma, triple-negative breast cancer, and human colon carcinoma, showcasing its broad-spectrum anticancer potential. Given its multifaceted mechanisms and preclinical efficacy, Arnicolide D warrants further investigation in clinical settings to validate its therapeutic utility against cancer. The evidence presented underscores the need for rigorous pharmacokinetic and toxicological studies to establish safe dosing parameters for future clinical trials.

2.
Carbohydr Polym ; 336: 122121, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38670753

RESUMO

This study aimed to modify chitosan (CS) by gamma irradiation and use it as a surface coating of nanoparticles (NPs) fabricated of poly lactic-co-glycolic acid (PLGA) to create mostly biocompatible nanosystems that can transport drugs to neurons. Gamma irradiation produced irradiated CS (CSγ) with a very low molecular weight (15.2-19.2 kDa). Coating NPs-PLGA with CSγ caused significant changes in their Z potential, making it slightly positive (from -21.7 ± 2.8 mV to +7.1 ± 2.3 mV) and in their particle size (184.4 0.4 ± 7.9 nm to 211.9 ± 14.04 nm). However, these changes were more pronounced in NPs coated with non-irradiated CS (Z potential = +54.0 ± 1.43 mV, size = 348.1 ± 16.44 nm). NPs coated with CSγ presented lower cytotoxicity and similar internalization levels in SH-SY5Y neuronal cells than NPs coated with non-irradiated CS, suggesting higher biocompatibility. Highly biocompatible NPs are desirable as nanocarriers to deliver drugs to the brain, as they help maintain the structure and function of the blood-brain barrier. Therefore, the NPs developed in this study could be evaluated as drug-delivery systems for treating brain diseases.


Assuntos
Quitosana , Nanopartículas , Neurônios , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Quitosana/química , Humanos , Nanopartículas/química , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Portadores de Fármacos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Tamanho da Partícula , Raios gama
3.
Cells ; 12(23)2023 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-38067163

RESUMO

Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant inherited disease characterized by progressive ataxia and retinal degeneration. SCA7 belongs to a group of neurodegenerative diseases caused by an expanded CAG repeat in the disease-causing gene, resulting in aberrant polyglutamine (polyQ) protein synthesis. PolyQ ataxin-7 is prone to aggregate in intracellular inclusions, perturbing cellular processes leading to neuronal death in specific regions of the central nervous system (CNS). Currently, there is no treatment for SCA7; however, a promising approach successfully applied to other polyQ diseases involves the clearance of polyQ protein aggregates through pharmacological activation of autophagy. Nonetheless, the blood-brain barrier (BBB) poses a challenge for delivering drugs to the CNS, limiting treatment effectiveness. This study aimed to develop a polymeric nanocarrier system to deliver therapeutic agents across the BBB into the CNS. We prepared poly(lactic-co-glycolic acid) nanoparticles (NPs) modified with Poloxamer188 and loaded with rapamycin to enable NPs to activate autophagy. We demonstrated that these rapamycin-loaded NPs were successfully taken up by neuronal and glial cells, demonstrating high biocompatibility without adverse effects. Remarkably, rapamycin-loaded NPs effectively cleared mutant ataxin-7 aggregates in a SCA7 glial cell model, highlighting their potential as a therapeutic approach to fight SCA7 and other polyQ diseases.


Assuntos
Ataxias Espinocerebelares , Humanos , Ataxina-7/genética , Ataxina-7/metabolismo , Ataxias Espinocerebelares/tratamento farmacológico , Ataxias Espinocerebelares/genética , Neurônios/metabolismo , Neuroglia/metabolismo , Sirolimo
4.
Int J Mol Sci ; 24(22)2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38003659

RESUMO

Polyamines (Pas) are short molecules that exhibit two or three amine groups that are positively charged at a physiological pH. These small molecules are present in high concentrations in a wide variety of organisms and tissues, suggesting that they play an important role in cellular physiology. Polyamines include spermine, spermidine, and putrescine, which play important roles in age-related diseases that have not been completely elucidated. Aging is a natural process, defined as the time-related deterioration of the physiological functions; it is considered a risk factor for degenerative diseases such as cardiovascular, neurodegenerative, and musculoskeletal diseases; arthritis; and even cancer. In this review, we provide a new perspective on the participation of Pas in the cellular and molecular processes related to age-related diseases, focusing our attention on important degenerative diseases such as Alzheimerߣs disease, Parkinsonߣs disease, osteoarthritis, sarcopenia, and osteoporosis. This new perspective leads us to propose that Pas function as novel biomarkers for age-related diseases, with the main purpose of achieving new molecular alternatives for healthier aging.


Assuntos
Poliaminas , Espermidina , Espermina/fisiologia , Putrescina
5.
Pharmaceutics ; 15(7)2023 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-37514100

RESUMO

Wound healing is a complex process that involves restoring the structure of damaged tissues through four phases: hemostasis, inflammation, proliferation, and remodeling. Wound dressings are the most common treatment used to cover wounds, reduce infection risk and the loss of physiological fluids, and enhance wound healing. Despite there being several types of wound dressings based on different materials and fabricated through various techniques, polymeric films have been widely employed due to their biocompatibility and low immunogenicity. Furthermore, they are non-invasive, easy to apply, allow gas exchange, and can be transparent. Among different methods for designing polymeric films, solvent casting represents a reliable, preferable, and highly used technique due to its easygoing and relatively low-cost procedure compared to sophisticated methods such as spin coating, microfluidic spinning, or 3D printing. Therefore, this review focuses on the polymeric dressings obtained using this technique, emphasizing the critical manufacturing factors related to pharmaceuticals, specifically discussing the formulation variables necessary to create wound dressings that demonstrate effective performance.

6.
Pharmaceutics ; 15(6)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37376043

RESUMO

This work proposes a combination of polyethylene glycol 400 (PEG) and trehalose as a surface modification approach to enhance PLGA-based nanoparticles as a drug carrier for neurons. PEG improves nanoparticles' hydrophilicity, and trehalose enhances the nanoparticle's cellular internalization by inducing a more auspicious microenvironment based on inhibiting cell surface receptor denaturation. To optimize the nanoprecipitation process, a central composite design was performed; nanoparticles were adsorbed with PEG and trehalose. PLGA nanoparticles with diameters smaller than 200 nm were produced, and the coating process did not considerably increase their size. Nanoparticles entrapped curcumin, and their release profile was determined. The nanoparticles presented a curcumin entrapment efficiency of over 40%, and coated nanoparticles reached 60% of curcumin release in two weeks. MTT tests and curcumin fluorescence, with confocal imaging, were used to assess nanoparticle cytotoxicity and cell internalization in SH-SY5Y cells. Free curcumin 80 µM depleted the cell survival to 13% at 72 h. Contrariwise, PEG:Trehalose-coated curcumin-loaded and non-loaded nanoparticles preserved cell survival at 76% and 79% under the same conditions, respectively. Cells incubated with 100 µM curcumin or curcumin nanoparticles for 1 h exhibited 13.4% and 14.84% of curcumin's fluorescence, respectively. Moreover, cells exposed to 100 µM curcumin in PEG:Trehalose-coated nanoparticles for 1 h presented 28% fluorescence. In conclusion, PEG:Trehalose-adsorbed nanoparticles smaller than 200 nm exhibited suitable neural cytotoxicity and increased cell internalization proficiency.

7.
Osteoporos Int ; 33(7): 1429-1444, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35247062

RESUMO

This systematic review aimed to identify short- and long-term associated factors to functional recovery of elderly hip fracture patients after discharge. We identified 43 studies reporting 74 associated factors to functional recovery; most of them were biological, sociodemographic, or inherent factors to patients' baseline characteristics, including their pre-facture functional capacity. PURPOSE: This systematic review aimed to identify short- and long-term associated factors to functional recovery of elderly hip fracture patients after hospital discharge. We assessed the use of the hip fracture core-set and key-performance indicators for secondary fracture reduction. METHODS: A search was performed in seven electronic databases. Observational studies reporting predictors after usual care of elderly patients with hip fracture diagnoses receiving surgical or conservative treatment were included. Primary outcomes considered were part of the domains corresponding to functional capacity. RESULTS: Of 3873 references identified, and after the screening and selection process, 43 studies were included. Sixty-one functional measures were identified for ten functional outcomes, including BADLs, IADLs, ambulation, and mobility. Biological characteristics such as age, sex, comorbidities, cognitive status, nutritional state, and biochemical parameters are significantly associated. Determinants such as contact and size of social network and those related to institutional care quality are relevant for functional recovery at six and 12 months. Age, pre-fracture function, cognitive status, and complications continue to be associated five years after discharge. We found 74 associated factors to functional recovery of elderly hip fracture patients. Ten of the studies reported rehabilitation programs as suggested in KPI 9; none used the complete hip fracture core-set. CONCLUSION: Most of the associated factors for functional recovery of elderly hip fracture were biological, sociodemographic, or inherent factors to patients' baseline characteristics, including their pre-facture functional capacity. For the core-set and KPI's, we found an insufficient use and report. This study reports 61 different instruments to measure functional capacity. REGISTRATION NUMBER: PROSPERO (CRD42020149563).


Assuntos
Fraturas do Quadril , Idoso , Fixação de Fratura , Fraturas do Quadril/cirurgia , Humanos , Prognóstico , Estudos Prospectivos , Recuperação de Função Fisiológica
8.
Pharmaceutics ; 13(7)2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34371710

RESUMO

Seven of the most frequent spinocerebellar ataxias (SCAs) are caused by a pathological expansion of a cytosine, adenine and guanine (CAG) trinucleotide repeat located in exonic regions of unrelated genes, which in turn leads to the synthesis of polyglutamine (polyQ) proteins. PolyQ proteins are prone to aggregate and form intracellular inclusions, which alter diverse cellular pathways, including transcriptional regulation, protein clearance, calcium homeostasis and apoptosis, ultimately leading to neurodegeneration. At present, treatment for SCAs is limited to symptomatic intervention, and there is no therapeutic approach to prevent or reverse disease progression. This review provides a compilation of the experimental advances obtained in cell-based and animal models toward the development of gene therapy strategies against polyQ SCAs, providing a discussion of their potential application in clinical trials. In the second part, we describe the promising potential of nanotechnology developments to treat polyQ SCA diseases. We describe, in detail, how the design of nanoparticle (NP) systems with different physicochemical and functionalization characteristics has been approached, in order to determine their ability to evade the immune system response and to enhance brain delivery of molecular tools. In the final part of this review, the imminent application of NP-based strategies in clinical trials for the treatment of polyQ SCA diseases is discussed.

9.
Materials (Basel) ; 14(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200640

RESUMO

Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

10.
Environ Sci Pollut Res Int ; 28(14): 17275-17289, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33394413

RESUMO

Biomass burning from grassland, forests, and agricultural waste results in large amounts of gases and particles emitted to the atmosphere, which affect air quality, population health, crop development, and natural vegetation. Regional atmospheric circulations can transport those plumes of pollutants over hundreds of kilometers, affecting vulnerable environments such as those considered protected natural areas (PNAs). This study evaluates the spatiotemporal distribution of active fires detected, and associated emissions, in central and southern Mexico from satellite data between March and June 2017, to assess the impact of the smoke plumes on protected ecosystems. The arrival of smoke plumes to selected PNAs (both near large urban centers and in remote areas) is assessed using airmass forward trajectories from selected emission sources. The spatial distribution of the remotely derived aerosol optical depth confirms the regional impact of particle emissions from the observed fires on PNAs, particularly in central Mexico. The identified areas of high fire density are also associated with large coarse particle concentrations at the surface. Moreover, there is a significant contribution of organic carbon to the total coarse particle mass, 60% on average. Finally, while most of the impact in ambient pollution is observed in PNAs located close to the regions with active fires in southern Mexico and Central America, the long-range transport of smoke plumes reaching the USA was also confirmed.


Assuntos
Poluentes Atmosféricos , Incêndios , Poluentes Atmosféricos/análise , Biomassa , Ecossistema , Monitoramento Ambiental , México
11.
Am J Gastroenterol ; 116(Suppl 1): S4, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37461935

RESUMO

BACKGROUND: Persons with inflammatory bowel diseases (IBD) endure the uncomfortable symptomatology of the disease, while trying to carry out daily activities. Given that IBD is not physically distinctive, it may be overlooked and lead to discrimination in the workplace and school. We aim to describe work and study experiences from patients with IBD. METHODS: A questionnaire containing sociodemographic, psychological, and medical inquiries was administered to patients with IBD in a tertiary care clinic. The survey captured past and present employment and scholarly status. Productivity was established by the number of early leaves or absences patients experienced due to disease symptomatology. Qualitative and quantitative data were analyzed using descriptive statistics. The study is approved by the UPR-MSC IRB. RESULTS: A total of 120 patients, 59 males and 61 females, with a mean age of 27.00 ± 9.71 were recruited. 91 participants had CD, while 29 had UC. 94% of subjects had some form of income. At the time of interview, 83 patients were working. 19% did not tell the employer of their IBD, while 19% felt discriminated at work due to their condition. 38% said the disease has limited their work goals. Of those working, 74 had to leave early or absent themselves due to disease manifestation. In the last year, 39% of patients had absented themselves for 1-2 days, 27% for 3-4 days, 9% for 5-6 days, 4% for 7-8 days, 3% for 9-10 days and 18% for more than 10 days. The mean of absences from work was 4.4 days. Patients with UC were significantly more prone to work absences than patients with CD (P = 0.0243). 69 patients were studying while having the condition. 67% achieved a college or higher degree, while 33% had high school or less. 34% had to drop a course during their school years. Of the 23 patients who experienced withdrawals, 74% had a total withdrawal from school, while 26% had a partial withdrawal at some point. 14% did not inform of their IBD at school, 12% felt discriminated because of their condition and 32% said the disease has limited their educational goals. 87% of those studying had to miss or leave school early due to disease manifestation. In the last year, 24% of patients had absented themselves for 1-2 days, 29% for 3-4 days, 7% for 5-6 days, 7% for 7-8 days, 3% for 9-10 days and 30% for more than 10 days. The mean of absences was 5.6 days. School absences were not significantly different between subjects with CD and UC (P = 0.384). 22% of participants deemed themselves as a person with a disability given their condition, while 8% did not know whether they should consider themselves as such. Perception of disability was not significantly different between patients with CD and UC (P = 0.870). CONCLUSION: Absenteeism is a significant factor affecting productivity in patients with IBD. Perception of disability may also impact work and study experiences. Raising awareness is essential for patient support in these settings.

12.
Health Equity ; 4(1): 84-90, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32258959

RESUMO

Purpose: Low-income children are disproportionately affected by high rates of food insecurity and obesity, placing them at risk for poor health outcomes. Diets that are rich in fruits and vegetables (FV) are associated with health benefits such as reducing the risk of obesity. Despite these benefits, American children do not consume nationally recommended amounts of fruits (63%) and vegetables (90%) per day. Data reveal that young children exhibit increased food neophobia toward vegetables. One way to decrease food neophobia is to introduce FV to young children via recipe tasting. The purpose of the study was to increase willingness to try FV among low-income children using live characters at Summer Food Service Program Sites. Methods: The study design was a small-scale pilot study to conduct taste tests of recipes with 125 low-income children. Researchers created recipe-tasting stations at two different sites. At Site 1, characters promoting FV characters were present at the recipe-tasting station. At Site 2, researchers presented recipes without characters being present. Taste tests were conducted once per week for a period of 4 weeks using two previously validated instruments, Taste Test Tool and the Taste and Rate Questionnaire. Results: Results demonstrated that introducing FV recipes with characters showed a trend toward increasing willingness to try FV among low-income children. Data also suggested that low-income children had limited exposure to specific FV before recipe tastings. Conclusion: The use of characters is a promising approach to increase willingness to try FV among low-income children.

13.
J Org Chem ; 84(22): 14795-14804, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31638391

RESUMO

The design of novel nucleoside analogues bearing a C2' all-carbon quaternary center is described. The construction of this all-carbon stereogenic center involves the use of photoredox catalysis to initiate an intramolecular attack of a silyl-tethered vinyl functionality on a tertiary radical. Density functional theory calculations were performed to explore the origin of the high syn diastereoselectivity obtained through the preferred 5-exo-trig cyclization mode. The intramolecular vinyl addition also enables the preparation of the complementary configuration of the C2' all-carbon stereocenter when performed after lactonization.

14.
J Mol Model ; 22(5): 116, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27132239

RESUMO

A theoretical study was undertaken regarding the regioselective Lewis acid-promoted intramolecular cyclization of novel enaminones 1-3 leading to the corresponding benzofurans 4-5 and indoles 6. The density functional theory (DFT) and hard and soft acids and bases (HSAB) principle provided data to describe the electronic effects of the substituents in the reactivity of the benzene ring and the enaminone moiety. The condensed and local Fukui functions for nucleophilic and electrophilic attacks of the reactants accounted for the experimentally observed preference, in regard to precursors 1-3, of the cyclization between the C6' carbon (rather than the C2' carbon) of the benzene ring and the C3 center of the enaminone moiety.


Assuntos
Benzofuranos/química , Indóis/química , Modelos Moleculares , Naftoquinonas/química , Ciclização , Conformação Molecular , Teoria Quântica , Análise de Regressão , Estereoisomerismo , Termodinâmica
15.
Bioorg Med Chem ; 22(21): 5871-82, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25311563

RESUMO

In the search for new potential hypolipidemic agents, the present study focused on the synthesis of 2-acyl phenols (6a-c and 7a-c) and their saturated side-chain alkyl phenols (4a-c and 5a-c), and on the evaluation of their hypolipidemic activity using a murine Tyloxapol-induced hyperlipidemic protocol. The whole series of compounds 4-7 greatly and significantly reduced elevated serum levels of total cholesterol, LDL-cholesterol, and triglycerides, with series 6 and 7 showing the greatest potency ever found in our laboratory. At the minimum dose (25mg/kg/day), the latter compounds lowered cholesterol by 68-81%, LDL by 72-86%, and triglycerides by 59-80%. This represents a comparable performance than that shown by simvastatin. Experimental evidence and docking studies suggest that the activity of these derivatives is associated with the inhibition of HMG-CoA reductase.


Assuntos
Anisóis/química , Anisóis/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/síntese química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Fenóis/química , Fenóis/farmacologia , Derivados de Alilbenzenos , Animais , Sítios de Ligação , Domínio Catalítico , Colesterol/sangue , LDL-Colesterol/sangue , Cristalografia por Raios X , Ativação Enzimática/efeitos dos fármacos , Humanos , Hidroximetilglutaril-CoA Redutases/química , Hidroximetilglutaril-CoA Redutases/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Conformação Molecular , Simulação de Acoplamento Molecular , Ligação Proteica , Triglicerídeos/sangue , Aumento de Peso/efeitos dos fármacos
16.
Org Lett ; 16(21): 5698-701, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25320862

RESUMO

The design of a novel nucleoside scaffold that exhibits an all-carbon quaternary center is reported. This allows for both α- and ß-anomers of a given 2'-deoxy-2',2'-difluoro nucleoside analog (NA) to have potential biological activity. Using an intramolecular atom-transfer reaction, an all-carbon quaternary center was obtained without the use of heavy metals and/or harsh conditions. The chemistry developed is efficient, easily scalable and leads to novel libraries of molecules.


Assuntos
Nucleosídeos/química , Silício/química , Catálise , Estrutura Molecular , Estereoisomerismo
17.
Org Lett ; 14(6): 1648-51, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22369698

RESUMO

Enantioselective synthesis of the enantiomer of caloundrin B was achieved by strategic aldol coupling of an enantiopure trioxaadamantane-containing ketone with a racemic pyrone-containing aldehyde via kinetic resolution. In the presence of imidazole, ent-caloundrin B is cleanly isomerized to ent-siphonarin B confirming the proposed structure and absolute configuration for caloundrin B and establishing that it is a plausible biosynthetic product from which siphonarin B and baconipyrones A and C can originate.


Assuntos
Adamantano/análogos & derivados , Cetonas/síntese química , Compostos de Espiro/síntese química , Adamantano/síntese química , Adamantano/química , Aldeídos/química , Animais , Produtos Biológicos , Cetonas/química , Estrutura Molecular , Moluscos/química , Pironas/síntese química , Pironas/química , Compostos de Espiro/química , Estereoisomerismo
18.
Nat Prod Commun ; 6(7): 1005-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21834246

RESUMO

Morinda citrifolia, has been reported to posses different biological activities and almost all parts of this have been studied phytochemically. However there are few studies on the seeds of fruit. The objective of present study was investigated the effect to Noni Seed Oil (NSO) on serum lipid levels in normolipidemic and hyperlipidemic induced mice. We find that administration of noni oil causes a reduction in total cholesterol and triglycerides levels in both models. However hypolipidemic effect is higher when hyperlipidemia is presented.


Assuntos
Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/farmacologia , Morinda/química , Extratos Vegetais/farmacologia , Animais , Colesterol/sangue , Hiperlipidemias/sangue , Hipolipemiantes/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos ICR , Extratos Vegetais/isolamento & purificação , Distribuição Aleatória , Sementes/química , Triglicerídeos/sangue
19.
Bioorg Med Chem ; 18(12): 4238-48, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20576575

RESUMO

A series of alpha-asarone-based analogues was designed by conducting docking experiments with published crystal structures of human HMG-CoA reductase. Indeed, synthesis and evaluation of this series showed a highly hypocholesterolemic in vivo activity in a murine model, as predicted by previous docking studies. In agreement with this model, the polar groups attached to the benzene ring could play a key role in the enzyme binding and probably also in its biological activity, mimicking the HMG-moiety of the natural substrate. The hypolipidemic action mechanism of these compounds was investigated by developing a simple, efficient, and novel model for determining HMG-CoA reductase inhibition. The partial purification of the enzyme from Schizosaccharomyces pombe allowed for testing of alpha-asarone- and fibrate-based analogues, resulting in positive and significant inhibitory activity.


Assuntos
Anisóis/química , Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/síntese química , Schizosaccharomyces/efeitos dos fármacos , Derivados de Alilbenzenos , Animais , Anisóis/síntese química , Anisóis/uso terapêutico , Sítios de Ligação , Simulação por Computador , Diabetes Mellitus Experimental/tratamento farmacológico , Modelos Animais de Doenças , Desenho de Fármacos , Humanos , Hidroximetilglutaril-CoA Redutases/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos ICR
20.
J Org Chem ; 74(12): 4447-54, 2009 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-19449845

RESUMO

The stereoselectivity of aldol reactions of chiral reactants can be factorized into to three stereocontrol elements: the diastereoface selectivities of the ketone enol(ate) and aldehyde and the relative topicity of the coupling. Application of the multiplicativity rule to these elements leads to the prediction that kinetic resolution (KR) should be possible if all three stereocontrol elements are strongly biased. As a corollary, the enantioselectivity of the kinetic resolution should be switchable by a change in the sense of selectivity of any of the stereocontrol elements. This hypothesis was tested using aldehyde and ketone reactants with high diastereoface selectivities and developing reaction conditions that strongly favor either syn or anti relative topicity. The aldehyde 2 undergoes aldol reactions with near-exclusive Felkin diastereoface selectivity, and hydroxy-protected derivatives of ketone 1 (R = MOM, Et(3)Si, or Ac) undergo aldol reactions with high diastereoface selectivity to give 3,5-trans adducts. High levels of anti and syn relative topicity were obtained with dicyclohexylboron enolates and Ti(O(i)Pr)(4)Li "ate" enolates, respectively. Using these enolates, aldol reactions of (+/-)-2 with (+/-)-1 gave two of the eight possible diastereomeric adducts (3 from a diastereoselective like combination of reactant enantiomers and 4 from a diastereoselective unlike combination) predominantly (>95% of the adducts) in ratios of 0.05-20:1; boron enolates favored the like reaction (3:4, 15-20:1) and Ti "ate" enolates favored the unlike reaction (3:4, 1:10-20). Under these conditions, the ratio of like and unlike products is a measure of the mutual kinetic enantioselection (MKE) and reflects the ratio of the rate constants for the competing like and unlike reactions. For each of the four diastereomers of 1, the reactions with the highest MKEs in favor of the like (3) or unlike products (4) were repeated using highly enantioenriched ketone. These reactions occurred with the expected KR (s = 10-20) allowing selective access to enantioenriched diastereomers of 3 or 4 from (+/-)-2. These adducts are useful for polypropionate synthesis, and this design strategy for KR should be applicable to related processes.

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