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1.
J Healthc Eng ; 2021: 6761364, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34336164

RESUMO

The objective of this study was to explore the diagnosis of severe sepsis complicated with acute kidney injury (AKI) by ultrasonic image information based on the artificial intelligence pulse coupled neural network (PCNN) algorithm. In this study, an algorithm of ultrasonic image information enhancement based on the artificial intelligence PCNN was constructed and compared with the histogram equalization algorithm and linear transformation algorithm. After that, it was applied to the ultrasonic image diagnosis of 20 cases of severe sepsis combined with AKI in hospital. The condition of each patient was diagnosed by ultrasound image performance, change of renal resistance index (RRI), ultrasound score, and receiver operator characteristic curve (ROC) analysis. It was found that the histogram distribution of this algorithm was relatively uniform, and the information of each gray level was obviously retained and enhanced, which had the best effect in this algorithm; there was a marked individual difference in the values of RRI. Overall, the values of RRI showed a slight upward trend after admission to the intensive care unit (ICU). The RRI was taken as the dependent variable, time as the fixed-effect model, and patients as the random effect; the parameter value of time was between 0.012 and 0.015, p=0.000 < 0.05. Besides, there was no huge difference in the ultrasonic score among different time measurements (t = 1.348 and p=0.128 > 0.05). The area under the ROC curve of the RRI for the diagnosis of AKI at the 2nd day, 4th day, and 6th day was 0.758, 0.841, and 0.856, respectively, which was all greater than 0.5 (p < 0.05). In conclusion, the proposed algorithm in this study could significantly enhance the amount of information in ultrasound images. In addition, the change of RRI values measured by ultrasound images based on the artificial intelligence PCNN was associated with AKI.

2.
Front Microbiol ; 12: 710364, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34305878

RESUMO

Four new indole-terpenoids (1-4) named encindolene A, 18-O-methyl-encindolene A, encindolene B, and encindolene C, as well as three known analogs (5-7), were isolated from the fungus Penicillium sp. HFF16 from the rhizosphere soil of Cynanchum bungei Decne. The structures of compounds including absolute configurations were elucidated by spectroscopic data and electronic circular dichroism (ECD) analysis. Anti-inflammatory activity evaluation revealed that compounds 1-7 inhibit the production of nitric oxide with IC50 values of 79.4, 49.7, 81.3, 40.2, 86.7, 90.1, and 54.4 µM, respectively, and decrease the levels of tumor necrosis factor-α, interleukin-6 contents in lipopolysaccharide-induced RAW264.7 macrophages.

3.
Am J Transl Res ; 13(6): 6846-6854, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34306435

RESUMO

OBJECTIVE: This study was designed to demonstrate the predictive value of Pulse indicate Contour Cardiac Output (PiCCO) monitoring technique combined with troponin I (cTnI) detection in septic myocardial dysfunction (SMD) of the elderly. METHODS: One hundred and nineteen elderly patients with SMD treated in our hospital from March 2016 to September 2019 were enrolled and allocated into the joint group (JG; 64 cases) for capacity management of fluid resuscitation under the guidance of PiCCO monitoring technique and cTnI detection, and the control group (CG; 55 cases) for conventional capacity management. Clinical indicators, hemodynamics, improvement of myocardial injury markers and inflammatory factors 6 h and 36 h post intervention, fluid balance 6 h, 12 h and 36 h post intervention, drug consumption (norepinephrine), treatment effect and 28-day hospitalization mortality were compared between the two groups. RESULTS: After resuscitation, the urine volume per hour and the fluid resuscitation volume were higher while the blood lactic acid (BLA) expression was lower in JG as compared to CG. JG presented a remarkably lower central venous pressure (CVP) than CG after resuscitation, with notably higher mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2). In comparison with CG, JG displayed dramatically lower cTnI and N-terminal pro-brain natriuretic peptide (NT-ProBNP) 6 h and 36 h post intervention, as well as evidently reduced interleukin-6 (IL-6), procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP). After 36 h of intervention, the fluid balance was evidently lower in JG than in CG. JG showed statistically less use of norepinephrine, less time of mechanical ventilation and ICU stay, and noticeably lower incidence of multiple organ dysfunction syndrome (MODS), as well as dramatically lower 28-day hospitalization mortality than CG post intervention. CONCLUSIONS: PiCCO monitoring technique combined with cTnI detection is high-performing in fluid resuscitation of elderly patients with SMD, which can meliorate the myocardial function of patients, reduce medication and facilitate disease recovery.

4.
Genomics ; 113(5): 3083-3091, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34237377

RESUMO

Revealing genomic variation of representative and diverse germplasm is the cornerstone of deploying genomics information into genetic improvement programs of species of agricultural importance. Here we report the re-sequencing of 239 japonica rice elites representing the genetic diversity of japonica germplasm in China, Japan and Korea. A total of 4.8 million SNPs and PAV of 35,634 genes were identified. The elites from Japan and Korea are closely related and relatively less diverse than those from China. A japonica rice pan-genome was constructed, and 35 Mb non-redundant novel sequences were identified, from which 1131 novel genes were predicted. Strong selection signals of genomic regions were detected on most of the chromosomes. The heading date genes Hd1 and Hd3a have been artificially selected during the breeding process. The results from this study lay the foundation for future whole genome sequences-enabled breeding in rice and provide a paradigm for other species.

5.
Front Microbiol ; 12: 668938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841388

RESUMO

Two new thio-compounds named aspergerthinol A and B (1 and 2) and two new monoterpenes named aspergerthinacids A and B (3 and 4) were isolated from the fungus Aspergillus sp. CYH26 from the rhizosphere soil of Cynanchum bungei Decne. The structures of compounds were elucidated by spectroscopic data and quantum NMR and ECD calculations. Compounds 1 and 2 represented a new family of sulfur containing natural products with a 3-methyl-4H-cyclopenta[b]thiophen-4-one skeleton. Compounds 1-4 showed inhibitory activities against nitric oxide (NO) with IC50 values of 38.0, 19.8, 46.3, and 56.6 µM, respectively.

6.
New Phytol ; 231(3): 1056-1072, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33892513

RESUMO

The improvement of cold adaptation has contributed to the increased growing area of rice. Standing variation and de novo mutation are distinct natural sources of beneficial alleles in plant adaptation. However, the genetic mechanisms and evolutionary patterns underlying these sources in a single population during crop domestication remain elusive. Here we cloned the CTB2 gene, encoding a UDP-glucose sterol glucosyltransferase, for cold tolerance in rice at the booting stage. A single standing variation (I408V) in the conserved UDPGT domain of CTB2 originated from Chinese Oryza rufipogon and contributed to the cold adaptation of Oryza sativa ssp. japonica. CTB2 is located in a 56.8 kb region, including the previously reported gene CTB4a in which de novo mutation arose c. 3200 yr BP in Yunnan province, China, conferring cold tolerance. Standing variation of CTB2 and de novo mutation of CTB4a underwent stepwise selection to facilitate cold adaptation to expand rice cultivation from high-altitude to high-latitude regions. These results provide an example of stepwise selection on two kinds of variation and describe a new molecular mechanism of cold adaptation in japonica rice.


Assuntos
Oryza , Alelos , China , Domesticação , Genes de Plantas , Oryza/genética , Seleção Genética
7.
R Soc Open Sci ; 7(6): 192243, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32742685

RESUMO

As one of the abiotic stresses, low temperature severely threatens rice production during its entire growth period, especially during the booting stage. In the present study, transcriptome analysis was performed comparing Longjing (LJ) 25 (chilling-tolerant) and LJ 11 (chilling-sensitive) rice varieties to identify genes associated with chilling tolerance in rice spikelets. A total of 23 845 expressed genes and 13 205 differentially expressed genes (DEGs) were identified, respectively. Gene ontology (GO) enrichment analyses revealed 'response to cold' (containing 180 DEGs) as the only category enriched in both varieties during the entire cold treatment period. Through MapMan analysis, we identified nine and six DEGs related to the Calvin cycle and antioxidant enzymes, respectively, including OsRBCS3, OsRBCS2, OsRBCS4, OsAPX2 and OsCATC, that under chilling stress were markedly downregulated in LJ11 compared with LJ25. Furthermore, we predicted their protein-protein interaction (PPI) network and identified nine hub genes (the threshold of co-expressed gene number ≥ 11) in Cytoscape, including three RuBisCO-related genes with 14 co-expressed genes. Under chilling stress, antioxidant enzyme activities (peroxidase (POD) and catalase (CAT)) were downregulated in LJ11 compared with LJ25. However, the content of malondialdehyde (MDA) was higher in LJ11 compared with LJ25. Collectively, our findings identify low temperature responsive genes that can be effectively used as candidate genes for molecular breeding programmes to increase the chilling tolerance of rice.

8.
R Soc Open Sci ; 7(11): 201081, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33391797

RESUMO

Rice is sensitive to low temperatures, specifically at the booting stage. Chilling tolerance of rice is a quantitative trait loci that is governed by multiple genes, and thus, its precise identification through the conventional methods is an arduous task. In this study, we investigated the candidate genes related to chilling tolerance at the booting stage of rice. The F2 population was derived from Longjing25 (chilling-tolerant) and Longjing11 (chilling-sensitive) cross. Two bulked segregant analysis pools were constructed. A 0.82 Mb region containing 98 annotated genes on chromosomes 6 and 9 was recognized as the candidate region associated with chilling tolerance of rice at the booting stage. Transcriptomic analysis of Longjing25 and Longjing11 revealed 50 differentially expressed genes (DEGs) on the candidate intervals. KEGG pathway enrichment analysis of DEGs was performed. Nine pathways were found to be enriched, which contained 10 DEGs. A total of four genes had different expression patterns or levels between Longjing25 and Longjing11. Four out of the 10 DEGs were considered as potential candidate genes for chilling tolerance. This study will assist in the cloning of the candidate genes responsible for chilling tolerance and molecular breeding of rice for the development of chilling-tolerant rice varieties.

9.
Drug Deliv ; 26(1): 328-342, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30905189

RESUMO

Efficient cellular delivery of biologically active molecules is one of the key factors that affect the discovery and development of novel drugs. The plasma membrane is the first barrier that prevents direct translocation of chemic entities, and thus obstructs their efficient intracellular delivery. Generally, hydrophilic small molecule drugs are poor permeability that reduce bioavailability and thus limit the clinic application. The cellular uptake of macromolecules and drug carriers is very inefficient without external assistance. Therefore, it is desirable to develop potent delivery systems for achieving effective intracellular delivery of chemic entities. Apart from of the types of delivery strategies, the composition of the cell membrane is critical for delivery efficiency due to the fact that cellular uptake is affected by the interaction between the chemical entity and the plasma membrane. In this review, we aimed to develop a profound understanding of the interactions between delivery systems and components of the plasma membrane. For the purpose, we attempt to present a broad overview of what delivery systems can be used to enhance the intracellular delivery of poorly permeable chemic entities, and how various delivery strategies are applied according to the components of plasma membrane.


Assuntos
Membrana Celular/metabolismo , Sistemas de Liberação de Medicamentos , Preparações Farmacêuticas/administração & dosagem , Animais , Disponibilidade Biológica , Transporte Biológico , Portadores de Fármacos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo
10.
Future Med Chem ; 10(9): 1055-1066, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29676183

RESUMO

AIM: The research of novel and potent antidiabetic agents is urgently needed for the control of the exploding diabetic population. We previously reported the synthesis and antidiabetic activity of natural 8-(6"-umbelliferyl)-apigenin (1), but its antidiabetic targets are not known. Therefore, four series of derivatives were synthesized and evaluated for their antidiabetic activities. Results & methodology: Compounds (5a) and (14a) were identified as new α-glucosidase and α-amylase dual inhibitors. The kinetic analysis of the most potent α-glucosidase inhibitor of each series of compounds revealed that they inhibited α-glucosidase in irreversible modes. In addition, compounds (5a) and (14a) showed potent glucose consumption-promoting activity. CONCLUSION: Compounds (5a) and (14a) could be regarded as promising starting points for the development of antidiabetic candidates.


Assuntos
Cumarínicos/síntese química , Cumarínicos/farmacologia , Flavonoides/síntese química , Flavonoides/farmacologia , Glucose/metabolismo , Inibidores de Glicosídeo Hidrolases/síntese química , Inibidores de Glicosídeo Hidrolases/farmacologia , Cumarínicos/química , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/metabolismo , Flavonoides/química , Inibidores de Glicosídeo Hidrolases/química , Células Hep G2 , Humanos , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Cinética , Relação Estrutura-Atividade , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo
11.
Eur J Med Chem ; 145: 370-378, 2018 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-29335203

RESUMO

Telomerase is aberrantly expressed in many cancers and plays an important role in the development of cellular immortality and oncogenesis, which makes it a potential cancer therapeutic target for drug discovery. Here, we constructed a firefly luciferase reporter driven by the human telomerase reverse trancriptase (hTERT) gene promoter to screen for inhibitory compounds. Compound 5c was discovered and shown to significantly inhibit the promoter activity of hTERT gene. Furthermore, five analogs of compound 5c were synthesized, and compound 8b was shown to be a more potent inhibitor of hTERT gene promoter activity and subsequent expression of hTERT mRNA and protein. The viability of HeLa cells was inhibited by a knockdown of hTERT gene expression, and the same effect was also observed by treating with compound 8b. Moreover, our results indicated that compound 8b induced apoptosis of HeLa cells, and activated caspase-9 and caspase-3 enzymes. Taken together, these results suggested that compound 8b down-regulates the expression of hTERT and induces mitochondrial-dependent apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Regiões Promotoras Genéticas/efeitos dos fármacos , Inibidores da Transcriptase Reversa/farmacologia , Telomerase/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Mitocôndrias/metabolismo , Estrutura Molecular , Regiões Promotoras Genéticas/genética , Inibidores da Transcriptase Reversa/síntese química , Inibidores da Transcriptase Reversa/química , Relação Estrutura-Atividade , Telomerase/genética , Telomerase/metabolismo
12.
Eur J Med Chem ; 138: 577-589, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-28704760

RESUMO

Two novel flavonoids (±)-Anastatins A and B as well as 14 analogs, which containing a benzofuran moiety, were synthesized by using halogenation, Suzuki coupling reaction and an oxidation/Oxa-Michael reaction cascade as the key steps. The structures of the new flavonoids were confirmed by 1H NMR, 13C NMR and HRMS. The antioxidant activities of them as well as the key intermediates were evaluated by ferric reducing antioxidant power (FRAP) assay and the active compounds were evaluated in the PC12 cell model of hydrogen peroxide (H2O2)-induced oxidative damage. SAR studies suggested that, for in vitro antioxidant activity, aurone derivatives showed better bioactivity than flavone counterparts. However, cyclization to benzofuran and connecting the two conjugated parts as a whole conjugated system by a double bond diminished the in vitro antioxidant activity. Among them, the most potent compound 24c was significantly decreased H2O2-caused cell injury. The apoptotic rate (Annexin V+) of H2O2-damaged PC12 cells was 60.7% while that of the compound 24c-treated cells decreased to 5.9% and 4.1% at 10 µM and 100 µM respectively.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Flavonoides/farmacologia , Peróxido de Hidrogênio/antagonistas & inibidores , Animais , Antioxidantes/síntese química , Antioxidantes/química , Relação Dose-Resposta a Droga , Flavonoides/síntese química , Flavonoides/química , Peróxido de Hidrogênio/farmacologia , Estrutura Molecular , Células PC12 , Ratos , Relação Estrutura-Atividade
13.
Eur J Med Chem ; 125: 760-769, 2017 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-27721159

RESUMO

Paris Saponin I (PSI), a steroidal sponins isolated from plant, has been exhibited antitumor and many other biological activities. In this study, we investigated the role and underlying mechanisms of PSI in the synergistic regulation of antitumor activity of Camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) in four types of lung cancer cells. The inhibitory evaluation showed that PSI could significantly reduce the CPT/HCPT-mediated cell proliferation and enhance the sensitivities of H1299, H460 and H446 lung cancer cells to CPT/HCPT. Mechanism study indicated that PSI improved the CPT/HCPT induced apoptosis in lung cancer cells through mitochondria pathway including cytochrome C release and activation of caspase-9 and -3 cascades. Furthermore, PSI plus CPT/HCPT also increased the up-regulation of Bax and down-regulation of Bcl-2 and Bcl-XL in H460 and H446 cells. Moreover, PSI enhanced CPT/HCPT-mediated inhibition of p38 MAPK and activation of phosphorylation of p38 MAPK in H1299 cells, and suppression of Akt and ERK pathways activation in H460 cells as well as in H446 cells. Collectively, our results demonstrated that PSI functions as a chemosensitizer by enhancing apoptosis through influencing p38 MAPK, ERK, and Akt pathways in lung cancer cells, and the combination with CPT/HCPT might be a promising strategy for the development of new therapeutic agents.


Assuntos
Camptotecina/farmacologia , Diosgenina/análogos & derivados , Sinergismo Farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Saponinas/farmacologia , Western Blotting , Camptotecina/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Diosgenina/síntese química , Diosgenina/química , Diosgenina/farmacologia , Humanos , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Saponinas/síntese química , Saponinas/química , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Eur J Med Chem ; 122: 674-683, 2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-27448923

RESUMO

The naturally occurring flavone 8-(6″-umbelliferyl)apigenin, a hybrid structure of apigenin and coumarin, as well as seven of its analogues were synthesized for the first time by using iodination and Suzuki coupling reactions as key steps. The synthesis of 8-(6″-umbelliferyl)-apigenin was achieved in seven linear steps from the commercially available 1-(2,4,6-trihydroxyphenyl)ethan-1-one and 7-hydroxyl coumarine with 31% overall yield. Effects of these compounds on glucose disposal were investigated in adipocytes. All of the flavonoid and coumarin hydrids were found to have better bioactivities than their corresponding flavonoid cores. The most potent compound 15 (10 µΜ) could promote glucose consumption by 57% which exhibited similar effect as the positive control metformin at 1 mM. Moreover, fluorescence microscopy showed that four 8-(6″-umbelliferyl)apigenin analogues 2, 15, 30 and 31 could promote the 2-NBDG uptake into 3T3-L1 cells, which consist with those observed in the regulation of glucose.


Assuntos
Apigenina/síntese química , Apigenina/farmacologia , Desenho de Fármacos , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacologia , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Alquilação , Animais , Apigenina/química , Técnicas de Química Sintética , Glucose/metabolismo , Hipoglicemiantes/química , Camundongos
15.
Planta Med ; 80(12): 993-1000, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25057854

RESUMO

Quercetin, luteolin, and epigallocatechin gallate are flavonoids abundant in edible and medicinal plants with beneficial effects on glucose homeostasis. This study explored the action of these flavonoids on glucose disposal in adipocytes. Quercetin, luteolin, and epigallocatechin gallate enhanced glucose consumption with the positive regulation of AMP-activated kinase phosphorylation, and the AMP-activated kinase inhibitor compound C abolished their effects on glucose consumption. Luteolin and epigallocatechin gallate, but not quercetin, increased sirtuin 1 abundance, and their regulation of glucose consumption was also attenuated by co-treatment with sirtuin 1 inhibitor nicotinamide. Quercetin, luteolin, and epigallocatechin gallate suppressed nuclear factor-κB activation by inhibition of p65 phosphorylation with beneficial regulation of adipokine expression, whereas these actions were diminished by coincubation with compound C. The sirtuin 1 inhibitor nicotinamide attenuated the effects of luteolin and EGCG on p65 phosphorylation and adipokine expression without any influence on the activity of quercetin. Results of Western blot and fluorescence microscopy also showed that quercetin, luteolin, and epigallocatechin gallate increased Akt substrate of 160 kDa phosphorylation and promoted 2-deoxy-D-glucose uptake by adipocytes under basal and inflammatory conditions. These findings suggested that quercetin, luteolin, and epigallocatechin gallate inhibited inflammation and promoted glucose disposal in adipocytes with the regulation of AMP-activated kinase and/or sirtuin 1.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/efeitos dos fármacos , Catequina/análogos & derivados , Glucose/metabolismo , Luteolina/farmacologia , Quercetina/farmacologia , Sirtuína 1/metabolismo , Células 3T3-L1 , Adipócitos/metabolismo , Adipocinas/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Catequina/farmacologia , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Camundongos , NF-kappa B/metabolismo , Niacinamida/farmacologia , Fosforilação , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
16.
Tetrahedron ; 70(2): 276-279, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24729640

RESUMO

This paper describes the selective syntheses of two cis-isomer enriched cyclopentanone fragrances: (Z)-3-(2-oxopropyl)-2-(pent-2-en-1-yl)cyclopentanone (4 steps, 62% overall yield, 67% cis) and Magnolione® (5 steps, 60% overall yield, 55% cis). In addition, the asymmetric synthesis of (3aR,7aS)-5-methyl-2,3,3a,4,7,7a-hexahydro-1H-inden-1-one as well as (3a'R,7a'S)-5'-methyl-2',3',3a',4',7',7a'-hexahydrospiro[[1,3]dioxolane-2,1'-indene]) has been realized by an efficient kinetic resolution, which enables the selective synthesis of the 2S,3R-isomer-enriched 3 and 4.

17.
J Org Chem ; 77(10): 4801-11, 2012 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-22519642

RESUMO

The total syntheses of the lycopodium alkaloids fawcettimine, fawcettidine, lycoflexine, and lycoposerramine B have been accomplished through an efficient, unified, and stereocontrolled strategy that relies on a Diels-Alder reaction to construct the cis-fused 6,5-carbocycles with one all-carbon quaternary center. Access to the enantioselective syntheses of both antipodes of those alkaloids can be achieved by kinetic resolution of the earliest intermediate via a Sharpless asymmetric dihydroxylation (Sharpless AD). Compared to existing approaches to these alkaloids, our synthetic route possesses superior stereocontrol over the C-4 and C-15 stereogenic centers as well as allowing for more functional variation on the 6-membered ring.


Assuntos
Alcaloides/química , Alcaloides/síntese química , Compostos Heterocíclicos com 3 Anéis/química , Compostos Heterocíclicos com 3 Anéis/síntese química , Oximas/química , Oximas/síntese química , Estrutura Molecular , Estereoisomerismo
18.
Acta Crystallogr C ; 59(Pt 11): o611-2, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14605406

RESUMO

An N,N'-disubstituted dithiooxamide derivative reacts with 1,2-dibromoethane to produce the title compound, C(18)H(18)N(2)S(2), a heterocycle with a double Schiff base. In the crystal structure, the molecule of the title compound lies on a twofold axis. Weak C-H...pi interactions are the principal intermolecular forces, mediating the formation of layers parallel to the ab plane. Each molecule participates as donor and acceptor in two such contacts.

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