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1.
Catheter Cardiovasc Interv ; 99(3): 889-895, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34390296

RESUMO

OBJECTIVES: We aimed to describe hemodynamic performance and clinical outcomes at 30-day follow-up of the balloon-expandable (BE) Myval transcatheter heart valve (THV) in low-risk patients. BACKGROUND: The results of the next-generation BE Myval THV in low-risk aortic stenosis (AS) patients are still unknown. METHODS: Retrospective registry performed in nine European centers including patients with low predicted operative mortality risk according to Society of thoracic surgeons (STS) and European system for cardiac operative risk evaluation (EuroSCORE-II) scores. RESULTS: Between September 2019 and February 2021, a total of 100 patients (51% males, mean age 80 ± 6.5 years) were included. Mean STS score and EuroSCORE-II were 2.4 ± 0.8% and 2.2 ± 0.7%, respectively. Intermediate sizes were used in 39% (21.5 mm: 8%, 24.5 mm: 15%, 27.5 mm: 15%). There were no cases of valve embolization, coronary artery occlusion, annulus rupture, or procedural death. A definitive pacemaker implantation was needed in eight patients (8%). At 30-day follow-up aortic valve area (0.7 ± 0.2 vs. 2.1 ± 0.6 cm2 ) and mean aortic valve gradient (43.4 ± 11.1 vs. 9.0 ± 3.7 mmHg) improved significantly (p < 0.001). Moderate aortic regurgitation occurred in 4%. Endpoints of early safety and clinical efficacy were 3 and 1%, respectively. CONCLUSIONS: Hemodynamic performance and 30-day clinical outcomes of the BE Myval THV in low-risk AS patients were favorable. Longer-term follow-up is warranted.


Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/etiologia , Estenose da Valva Aórtica/cirurgia , Feminino , Humanos , Masculino , Desenho de Prótese , Estudos Retrospectivos , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodos , Resultado do Tratamento
2.
J Org Chem ; 86(4): 3344-3355, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33533618

RESUMO

We have proven that the biomimetic-like synthesis of cannabinoids from citral and the corresponding phenolic counterpart may well be carried out using water as a solvent. The influence of different additives such as surfactants was also analyzed. Rationalization of the reaction mode and regiochemistry of the processes were provided in terms of "on water" and "in water" reactions. The same reactions were conducted in organic media using Ga(III) salts as catalysts. Worthy of being underlined, an unprecedented formal [2+2+2] process was found to occur between two citral molecules and the corresponding phenolic species in both aqueous and organic environments. Computational studies were performed in order to gain a comprehensive mechanistic and energetic understanding of the different steps of this singular process. Finally, the influence of SDS micelles in the chemical behavior of olivetol and citral was also pursued using PGSE diffusion and NOESY NMR studies. These data permitted to tentatively propose the existence of a mixed micelle between olivetol and SDS assemblies.


Assuntos
Canabinoides , Micelas , Solventes , Tensoativos , Água
3.
J Org Chem ; 84(11): 6886-6894, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31083906

RESUMO

The system I2/dimethyl sulfoxide mediates the one-step transformation of α-isopropylidene ketones into furan rings following a biomimetic approach. This methodology has been used for the synthesis of terpene furans such as mintfurane, curzerene, atractylon, and isoatractylon, all of them possessing interesting biological activities. The synthesis of linderazulene directly from 4,5-epoxygermacrone via a cascade reaction shows the potential of this protocol. Additionally, this compound proved to show significant ixodicidal activity.


Assuntos
Alcenos/química , Dimetil Sulfóxido/química , Furanos/síntese química , Iodo/química , Cetonas/química , Terpenos/química , Furanos/química , Estrutura Molecular , Terpenos/síntese química
4.
J Org Chem ; 84(21): 13764-13779, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31559826

RESUMO

We have developed and rationalized a biomimetic transformation mimicking halimane synthases based on a Lewis acid-catalyzed cascade of cyclizations and rearrangements of epoxypolyprenes. Two rings, three stereogenic centers, and a new double bond were generated in a single chemical operation. Based on this cascade transformation, we achieved a unified strategy toward the stereoselective total syntheses of halimene-type terpenoids and analogues as a proof-of-concept study. This method has been applied to the rapid synthesis of diterpene isotuberculosinol, a virulence factor of Mycobacterium tuberculosis as a representative example.


Assuntos
Diterpenos/metabolismo , Compostos de Epóxi/química , Ligases/metabolismo , Catálise , Ciclização , Compostos de Epóxi/síntese química
5.
J Nat Prod ; 82(1): 9-15, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30601659

RESUMO

The first total synthesis of a natural diterpene valparane, (-)-valpara-2,15-diene (1), has been achieved from all -trans-geranylgeraniol (9), a natural renewable compound. The key steps involve a Ti(III)-mediated radical cyclization of the chiral monoepoxypolyene (14 R,15 R)-14,15-epoxy,16- tert-butyldimethylsilyloxygeranyllinalyl acetate (8) to give the 6,6,7-tricyclic intermediate 7 with stereocontrolled formation of six stereocenters; a stereo- and regio-directed contraction of the A ring in 7 to produce a cyclopentane ring; and the ready generation of the target isopropenyl group. This research provides access to structurally related natural products such as the sesquiterpene (+)-isodaucene (3), the synthesis of which is also reported herein.


Assuntos
Diterpenos/síntese química , Sesquiterpenos/síntese química , Ciclização , Diterpenos/química , Estereoisomerismo
6.
Molecules ; 24(16)2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31404973

RESUMO

Currently, the use of synthetic pesticides is the main method of plant protection applied in agri- and horticulture. However, its excessive use leads to the development of pesticide resistance, a contamination of the environment, toxicity to non-target organisms, and risks for human health. With the ultimate aim of contributing to the develop of a more sustainable pest management, we used the natural product germacrone (compound 1), reported to possess significant insecticidal activity, as starting material for the generation of molecular diversity (2-24). Some of the generated derivatives are natural compounds, such as 1,10-epoxygermacrone (2), 4,5-epoxygermacrone (3), gajutsulactone A (7), germacrol (11), isogermacrone (14), 9-hydroxyeudesma-3,7(11)dien-6-one (19), eudesma-4,7(11),dien-8-one (20), eudesma-3,7(11)-dien-8-one (21) and eudesma-4(15),7(11)-dien-8-one (22). Compounds, 7,11-9,10-diepoxigermacr-4,5-en-8-ol (17), 7,11-epoxieudesma-4,7(11)-dien-8-one (23) and 7,11-epoxieudesma-3,7(11)-dien-8-one (24) are described for the first time. The biocidal activity of most of these compounds was assayed against the tick Hyalomma lusitanicum. The acaricidal effects of compound 24 were four times higher than that of germacrone (1). Compound 2 is an insect antifeedant a thousand times more potent than germacrone against Rhopalosiphum padi, which makes this substance a promising selective antifeedant against this cereal pest.


Assuntos
Afídeos/crescimento & desenvolvimento , Inseticidas , Ixodidae/crescimento & desenvolvimento , Sesquiterpenos de Germacrano , Animais , Inseticidas/síntese química , Inseticidas/química , Inseticidas/farmacologia , Sesquiterpenos de Germacrano/síntese química , Sesquiterpenos de Germacrano/química , Sesquiterpenos de Germacrano/farmacologia , Relação Estrutura-Atividade
7.
J Nat Prod ; 79(4): 831-7, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26913544

RESUMO

Efficient procedures based on the use of iodine for the aromatization of a series of terpenoids possessing diene and homoallylic or allylic alcohol functionalities are described. Different examples are reported as a proof-of-concept study. Furthermore, iodine also proved to mediate the dehydrogenation of testosterone.


Assuntos
Iodo/química , Terpenos/química , Humanos , Estrutura Molecular , Propanóis/química , Testosterona/química
8.
J Nat Prod ; 79(2): 261-6, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26797293

RESUMO

Several preparations were obtained from the aerial parts of predomesticated Lavandula luisieri, including the essential oil and ethanolic, hexane, and ethyl acetate extractives. Additionally, pilot plant vapor pressure extraction was carried out at a pressure range of 0.5-1.0 bar to give a vapor pressure oil and an aqueous residue. A chemical study of the hexane extract led to the isolation of six necrodane derivatives (1, 2, and 4-7), with four of these (1, 2, 5, and 7) being new, as well as camphor, a cadinane sesquiterpene (9), tormentic acid, and ursolic acid. The EtOAc and EtOH extracts contained a mixture of phenolic compounds with rosmarinic acid being the major component. Workup of the aqueous residue resulted in the isolation of the necrodane 3 and (1R*,2S*,4R*)-p-menth-5-ene-1,2,8-triol (8), both new natural compounds. The structures of the new compounds were established based on their spectroscopic data. The phytotoxic and nematicidal activities of these compounds were evaluated.


Assuntos
Antinematódeos/isolamento & purificação , Antinematódeos/farmacologia , Terpenos/isolamento & purificação , Terpenos/farmacologia , Animais , Anti-Infecciosos/farmacologia , Antinematódeos/química , Afídeos/efeitos dos fármacos , Lavandula/química , Estrutura Molecular , Monoterpenos , Ressonância Magnética Nuclear Biomolecular , Óleos Voláteis/análise , Componentes Aéreos da Planta/química , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Espanha , Spodoptera/efeitos dos fármacos , Terpenos/química , Triterpenos/isolamento & purificação , Ácido Ursólico
9.
Org Biomol Chem ; 13(11): 3462-9, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25665946

RESUMO

A detailed experimental and theoretical study corroborates that the reductive deoxygenation of activated (allylic or benzylic) alcohols with excess Ti(III) proceeds via an allyl(benzyl)-radical and allyl(benzyl)-Ti, which is protonated, regioselectively in the case of allylic derivatives. The H atom of the newly formed C-H bond in the product originates from the -OH group of the starting material. The deoxygenation of lithium alkoxides or alcohols by using 1.0 mol of Ti(III) leads to the corresponding dimerization products in good yields. An excellent agreement with the experimental data was obtained by using a reaction kinetics simulator to discriminate between competing reactions.


Assuntos
Álcoois/química , Compostos Organometálicos/química , Oxigênio/química , Teoria Quântica , Titânio/química , Dimerização , Radicais Livres/química , Estrutura Molecular , Oxirredução
10.
Molecules ; 19(2): 1748-62, 2014 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-24496268

RESUMO

The synthesis of a cyclohexane skeleton possessing different oxygenated functional groups at C-3, C-8 and C-9, and a D1,6-double bond has been accomplished in 10 steps with an overall 17% yield. This compound is a key intermediate for access to a wide range of compounds of the bioactive trisporoid family. The synthetic sequence consists of the preparation of a properly functionalized epoxygeraniol derivative, and its subsequent stereoselective cyclization mediated by Ti(III). This last step implies a domino process that starts with a homolytic epoxide opening followed by a radical cyclization and regioselective elimination. This concerted process gives access to the cyclohexane moiety with stereochemical control of five of its six carbon atoms.


Assuntos
Carbono/química , Compostos de Epóxi/química , Ácidos Graxos Insaturados/química , Catálise , Ciclização , Cicloexanos/química , Ácidos Graxos Insaturados/síntese química , Estrutura Molecular , Estereoisomerismo
11.
Biomolecules ; 14(8)2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39199343

RESUMO

Cyclic acid anhydride is a not very widespread structure in nature, but with a determining role in natural products possessing this functionality in their skeleton. To the best of our knowledge, no revision of terpenes containing cyclic anhydrides has been previously reported. The result was that more than 100 terpenic cyclic anhydrides and related compounds were found to be in need of being reported. This review has been systematically organized by terpene skeletons, from the smallest to largest, describing their sources and bioactivities. In addition, different biosynthetic pathways for their final oxidations, namely, routes A, B and C, leading to the formation of these heterocyclic natural products, have been proposed. We have also included the most plausible precursors of these natural products, which mostly happened to be present in the same natural source. Some molecules derived from terpene cyclic anhydrides, such as their natural imide derivatives, have also been described due to their significant biological activity. In this sense, special attention has been paid to cantharidin because of its historical relevance and its broad bioactivity. A plausible biosynthesis of cantharidin has been proposed for the first time. Finally, cyclic anhydride structures that were firstly assigned as anhydrides and later corrected have been also described.


Assuntos
Anidridos , Produtos Biológicos , Terpenos , Terpenos/química , Terpenos/metabolismo , Anidridos/química , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Vias Biossintéticas , Humanos , Animais
12.
Biomolecules ; 14(7)2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39062494

RESUMO

The search for new compounds with biocidal potential was carried out, focusing on the longipinenes 1-7 from the plant species Santolina viscosa Lag. Compounds 1, 2, and 5 showed remarkable molecular diversity when treated in acidic reaction conditions. Protonic, Lewis, and heterogeneous compounds were used in the treatment. Three main models of reaction have been observed: isomerization of the double bond (8-10); rearrangements to longibornane-based skeleton (11-15) and ring-opening to himachalane-based skeleton (16-18). Secolongibornane aldehydes 23 and 24 were obtained after epoxide opening under the same reaction conditions. The elucidation of the structures of the new compounds was carried out using spectroscopic data and was supported by computational theoretical calculations of 13C NMR spectra. Additionally, high-resolution mass spectrometry and single-crystal X-ray diffraction analysis were employed for certain compounds. Natural longipinenes 4-7, methyl esters 1-3 of corresponding natural carboxylic acids and the isomerized and derivatives compounds 8-19 exhibit moderate to high insecticidal activity against R. padi and M. persicae insects. Longipinene 5 shows potent inhibition against the root growth of the plants L. perenne and L. sativa, as well as compound 2 on the leaves of L. perenne. Furthermore, significant ixocidal and nematicidal activity was found for this latter compound.


Assuntos
Inseticidas , Animais , Inseticidas/química , Inseticidas/farmacologia , Catálise , Estrutura Molecular , Norbornanos/química , Norbornanos/farmacologia
13.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-39251129

RESUMO

INTRODUCTION AND OBJECTIVES: Thrombocytopenia frequently occurs after transcatheter aortic valve implantation (TAVI) but its impact is poorly understood. We aimed to analyze the incidence, clinical impact, and predictors of acquired thrombocytopenia after TAVI. METHODS: This retrospective multicenter registry included 3913 patients undergoing TAVI with a baseline platelet count of ≥ 100 *109/L. Acquired thrombocytopenia was defined as a decrease in baseline platelet count of ≥ 50% (early nadir ≤ 3 days and late nadir ≥ 4 days) post-TAVI. The primary endpoint was 30-day all-cause mortality and secondary endpoints were procedural safety and 2-year all-cause mortality. RESULTS: The incidence of acquired thrombocytopenia was 14.8% (early nadir: 61.5%, late nadir: 38.5%). Thirty-day mortality occurred in 112 (3.0%) patients and was significantly higher in those with thrombocytopenia (8.5% vs 2.0%, adjusted OR, 2.3; 95%CI, 1.3-4.2). Procedural safety was lower and 2-year mortality was higher in patients with thrombocytopenia vs those without (52.1 vs 77.0%; P <.001, and 30.2% vs 16.8%; HR, 2.2, 95%IC, 1.3-2.7) and especially in those with late nadir thrombocytopenia (45.8% vs 54.5%; P=.056, and 38.6% vs 23.8%, HR, 2.1; 95%CI, 1.5-2.9). Independent predictors of thrombocytopenia comprised baseline and procedural factors such as body surface area, absence of diabetes, poorer renal function, peripheral vascular disease, nontransfemoral access, vascular complications, type of transcatheter heart valve, and earlier TAVI procedures. CONCLUSIONS: Acquired thrombocytopenia was common (15%) after TAVI and was associated with increased short- and mid-term mortality and decreased procedural safety. Moreover, late thrombocytopenia compared with early thrombocytopenia was associated with significantly worse clinical outcomes. Further investigations are needed to elucidate the etiologic mechanisms behind these findings.

14.
Chemistry ; 19(21): 6598-612, 2013 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-23592563

RESUMO

Treatment of germacrone (1) with different electrophiles, and of its epoxy derivatives germacrone-4,5-epoxide (2), germacrone-1,10-epoxide (3) and isogermacrone-4,5-epoxide (4) with Brönsted/Lewis acids and Ti(III), gives rise to a great structural diversity. Thus, by using a maximum of two steps, the production of more than 40 compounds corresponding to 14 skeletons is described. Computational calculations rationalizing the structural divergence produced are also described. Finally, since some of the compounds generated are bioactive natural sesquiterpenes, the mechanisms of formation of these substances will provide new insights in their biosynthesis.


Assuntos
Compostos de Epóxi/química , Modelos Teóricos , Sesquiterpenos de Germacrano/química , Ciclização , Ácidos de Lewis/química , Estrutura Molecular , Sesquiterpenos de Germacrano/síntese química
15.
Org Biomol Chem ; 11(4): 559-62, 2013 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-23147747

RESUMO

The first synthesis of (+)-myrrhanol C (1), an antitumor polypodane-type bicyclic triterpene with inhibitory activity against androgen insensitive prostate cancers, is reported herein (IC(50) 10 µmolar). A key step in our convergent synthesis of (+)-myrrhanol C and related analogues is the employment of a microbial stereo- and regioselective late stage C-H oxidation. A low-waste and sustainable process has been developed to prepare (+)-myrrhanol C for further biological studies.


Assuntos
Antineoplásicos/química , Antineoplásicos/síntese química , Desenho de Fármacos , Neoplasias da Próstata/tratamento farmacológico , Triterpenos/química , Triterpenos/síntese química , Antineoplásicos/uso terapêutico , Técnicas de Química Sintética , Humanos , Cinética , Masculino , Estereoisomerismo , Especificidade por Substrato , Triterpenos/uso terapêutico
16.
Org Biomol Chem ; 11(33): 5404-8, 2013 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-23863958

RESUMO

The first total synthesis of the natural apocarotenoids (+)-apotrisporin E (1) and (+)-apotrientriols A and B (2-3) has been accomplished. The structure, relative stereochemistry and the assignation of the absolute configuration have been confirmed. This is a fast and easy access to this family of natural products whose key steps are a diastereoselective cyclization and a HWE olefination to attach the dienic side chain. This work also opens the door to the synthesis of other apocarotenoids such as trisporols and trisporic acids.


Assuntos
Carotenoides/química , Cicloexanonas/síntese química , Glicóis/síntese química , Ciclização , Cicloexanonas/química , Glicóis/química , Estrutura Molecular , Estereoisomerismo
17.
Org Lett ; 25(29): 5401-5405, 2023 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-37338151

RESUMO

The biomimetic formal synthesis of the antibiotic platensimycin for the treatment of infection by multidrug-resistant bacteria was accomplished starting from either ent-kaurenoic acid or grandiflorenic acid, each of which is a natural compound available in multigram scale from its natural source. Apart from the natural origin of the selected precursors, the keys of the described approach are the long-distance functionalization of ent-kaurenoic acid at C11 and the efficient protocol for the A-ring degradation of the diterpene framework.


Assuntos
Adamantano , Diterpenos , Diterpenos/metabolismo , Aminobenzoatos
18.
Rev Esp Cardiol (Engl Ed) ; 76(1): 19-24, 2023 Jan.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35570121

RESUMO

INTRODUCTION AND OBJECTIVES: We aimed to describe the feasibility and preliminary outcomes of commissural alignment (CA) for the balloon-expandable transcatheter heart valve. METHODS: The relationship among native commissures and transcatheter aortic valve implantation neocommissures was analyzed in 10 consecutive patients with tricuspid severe aortic stenosis undergoing transcatheter aortic valve implantation after guided implantation based on computed tomography analysis with a self-developed software. CA was predicted by in silico bio-modelling in the 10 patients and the calculated rotation was applied during crimping. Degrees of CA and coronary overlap (CO) were measured through 1-month follow up computed tomography. Transvalvular residual gradients and the rate of paravalvular leak were also analyzed. RESULTS: Mean commissural misalignment was 16.7±8°. Four patients showed mild misalignment but none of them showed a moderate or severe degree of misalignment. The in silico model accurately predicted the final in vivo position with a correlation coefficient of 0.983 (95%CI, 0.966-0.992), P <.001. Severe CO with right coronary ostium occurred in 3 patients likely due to ostial eccentricity, and CO was not present with the left coronary artery in any of the patients. Mean transaortic gradient was 6.1±3.3mmHg and there were no moderate-severe paravalvular leaks. CONCLUSIONS: Patient-specific rotation during valve crimping based on preprocedural computed tomography is feasible with balloon-expandable devices and is associated with the absence of moderate or severe commissural misalignment and left main CO.


Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Humanos , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Estudos de Viabilidade , Resultado do Tratamento , Substituição da Valva Aórtica Transcateter/métodos , Desenho de Prótese
19.
Rev Esp Cardiol (Engl Ed) ; 76(7): 503-510, 2023 Jul.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35934294

RESUMO

INTRODUCTION AND OBJECTIVES: Transthyretin cardiac amyloidosis (ATTR-CA) patients often have atrial fibrillation and increased bleeding/thrombogenic risks. We aimed to evaluate outcomes of left atrial appendage closure (LAAC) compared with patients without a known diagnosis of CA. METHODS: Comparison at long-term of patients diagnosed with ATTR-CA who underwent LAAC between 2009 and 2020 and those without a known diagnosis of CA. RESULTS: We studied a total of 1159 patients. Forty patients (3.5%) were diagnosed with ATTR-CA; these patients were older and had more comorbidities, higher HAS-BLED and CHA2DS2-VASc scores, and lower left ventricular function. Successful LAAC was achieved in 1137 patients (98.1%) with no differences between groups. Regarding in-hospital and follow-up complications, there were no differences between the groups in ischemic stroke (5% vs 2.5% in those without a known diagnosis of CA; P=.283), hemorrhagic stroke (2.5% and 0.8% in the control group; P=.284), major or minor bleeding. At the 2-year follow-up, there were no significant differences in mortality (ATTR-CA: 20% vs those without known CA: 13.6%, 0.248); however, the at 5-year follow-up, ATTR-CA patients had higher mortality (40% vs 19.2%; P <.001) but this difference was unrelated to hemorrhagic complications or ischemic stroke. CONCLUSIONS: LAAC could reduce the risk of bleeding complications and ischemic cerebrovascular events without increasing the rate of early or mid-term complications. Although long-term survival was impaired in ATTR-CA patients, it was comparable to that of patients without a known diagnosis of CA at the 2-year follow-up, suggesting that LAAC for patients with ATTR-CA might not be futile.


Assuntos
Amiloidose , Apêndice Atrial , Fibrilação Atrial , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Hemorragia/complicações , Fibrilação Atrial/complicações , Fibrilação Atrial/cirurgia , Fibrilação Atrial/diagnóstico , Amiloidose/complicações , Amiloidose/diagnóstico , Resultado do Tratamento
20.
J Org Chem ; 77(1): 341-50, 2012 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-22141741

RESUMO

An asymmetric concise total synthesis of the (+)-seco-C-oleanane 1 was accomplished. The successful route to this natural product involves as the key step a stepwise regio- and stereocontrolled catalytic radical polyene cascade cyclization from preoleanatetraene oxide (16), a process mediated by Cp(2)TiCl. The use of this single-electron-transfer complex permits mild cyclization conditions without using unnecessary prefunctionalizations and stops the process at the bicyclic level. Theoretical data revealed high activation energy for the third ring closure, which would account for the control of the cyclization. This process also led to natural (-)-achilleol B, camelliol A, and (+)-seco-ß-amyrin as minor compounds.


Assuntos
Produtos Biológicos/síntese química , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Triterpenos/síntese química , Produtos Biológicos/química , Catálise , Ciclização , Estrutura Molecular , Ácido Oleanólico/síntese química , Teoria Quântica , Estereoisomerismo , Triterpenos/química
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