RESUMO
To investigate the antitumor mechanism of artemisninin, a flexible docking analysis was used to score all kinds of functions of 11 Qinghaosu derivatives and transferrin with different resolutions. The distances of Asp-63, Tyr-188, His-249, Arg-124 and Lys-296 with Qinghaosu were less than 0.5 nm, separately. Meanwhile, the higher is the activity of Qinghaosu derivatives the higher is the score. Our model explains that Fe2+ is more feasible to react with Qinghaosu, and not involved in other metabolism in presence of transferrin. Docking results unveil that Iron(II)-transferrin increased the cytotoxicity of Qinghaosu derivatives and provide a rational basis for further design and synthesis of novel Qinghaosu derivatives.
Assuntos
Antineoplásicos Fitogênicos , Química , Farmacologia , Artemisininas , Química , Farmacologia , Domínio Catalítico , Descoberta de Drogas , Modelos Químicos , Estrutura Molecular , Ligação Proteica , Transferrina , QuímicaRESUMO
A series of genistein's phosphates were synthesized through a simplified Atherton-Todd reaction and the structures of the phosphates were determined by electrospray ionization mass spectrometry (ESI-MS) and NMR. In case of monophosporyl derivatives, NMR spectra show that substitutions occur at the 7-position of genistein but not at its 4' and 5-position. Moreover, the non-covalent complexes of lysozyme with the four new genistein phosphates were detected by ESI-MS.
Assuntos
Interações Medicamentosas , Genisteína , Metabolismo , Espectroscopia de Ressonância Magnética , Muramidase , Química , Fosforilação , Mapeamento de Interação de Proteínas , Métodos , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
<p><b>AIM</b>To study the interaction mechanism of bovine serum albumin (BSA) with luteolin and apigenin.</p><p><b>METHODS</b>Fluorescence quenching method and non-radioactive energy transfer theory were used.</p><p><b>RESULTS</b>The binding constants at different temperature were determined and the quenching mechanism of them were suggested as static quenching. The transfer efficiency of energy and distance between BSA and luteolin or apigenin were investigated according to the mechanism of the Förster energy transference.</p><p><b>CONCLUSION</b>The interaction between them seems to be strong and the binding force were mainly hydrophobic force. B(3')-OH,B(4')-OH strengthened the interaction of flavonoids and BSA.</p>
Assuntos
Apigenina , Química , Transferência de Energia , Luteolina , Química , Ligação Proteica , Soroalbumina Bovina , Química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , TermodinâmicaRESUMO
<p><b>AIM</b>To investigate antimalarial mechanism of Qinghaosu ( QHS) and its derivatives.</p><p><b>METHODS</b>The electronic structure of QHS and its derivatives were completely optimized and calculated at B3LYP/6-31G * level, while the route was at HF/STO-3G level.</p><p><b>RESULTS</b>The peroxide bridge is the active center of QHS and induced by ferrous iron to produce cyclic product.</p><p><b>CONCLUSION</b>Heme can link with QHS derivatives.</p>
Assuntos
Antimaláricos , Química , Artemisia , Química , Artemisininas , Química , Transporte de Elétrons , Radicais Livres , Química , Heme , Química , Modelos Químicos , Peróxidos , Química , Plantas Medicinais , Química , Teoria QuânticaRESUMO
<p><b>OBJECTIVE</b>To establish a simple rapid and sensitive nested RT-PCR method for detection of SARS coronavirus RNA by designing the specific primers for SARS and optimizing the parameters for PCR.</p><p><b>METHODS</b>Primers and fluorescent probes were designed according to the sequences of SARS coronavirus genes available from GenBank. The optimization of the parameters for PCR was performed in PE 7700 thermal cycle. The 36 serum samples and 40 mouthwash of SARS patients and 80 samples of healthy people were tested.</p><p><b>RESULTS</b>The positive rate of patient serum and mouthwash was 33.6%, (12/36) and 67.5%, (27/40), respectively, while the positive rate of healthy people was zero (0/160).</p><p><b>CONCLUSION</b>The simple nested RT-PCR method was a rapid, efficient and sensitive one for SARS early diagnosis.</p>
Assuntos
Humanos , Secreções Corporais , Virologia , Primers do DNA , RNA Viral , Sangue , Genética , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Métodos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Genética , Sensibilidade e Especificidade , Síndrome Respiratória Aguda Grave , Sangue , Diagnóstico , VirologiaRESUMO
In this paper, we synthesized a novel nucleoside analog by coupling thymine with dimethyl dicarboxylate biphenyl (DDB). The structure of the target compound was determined using 1H nuclear magnetic resonance (NMR) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The fragmentation pathways were studied in details through ESI-MS/MS. By comparing with unsubstituted nucleosides, such as AZT, MCI, d4T and DDI, it was found that the nucleoside analog coupled with DDB would not yield the daughter ions corresponding to the fragments of the nucleoside base and arabinofuranose analogs, but would lose a neutral molecule HF and DDB easily. However, the unsubstituted nucleosides could lightly yield the fragment ions of the nucleoside base and sugar ring. Hence, electrospray ionization mass spectrometry combined with tandem mass spectrometry (MS/MS) provides a convenient method to recognize the substituted and unsubstituted nucleosides.
Assuntos
Nucleosídeos de Pirimidina/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Dioxóis/química , Nucleosídeos de Pirimidina/síntese químicaRESUMO
<p><b>OBJECTIVE</b>To develop a method for detection of coxsackie B virus type 1-6 by RT-PCR.</p><p><b>METHODS</b>A pair of primers were designed to amplify all types of coxsackie B virus 1-6 efficiently. The PCR product was hybridized in micro-wells in which 6 type specific oligonucleotide probes had been coated respectively, colorimetric detection was performed to discriminate the types of coxsackie B virus.</p><p><b>RESULTS</b>This method was shown to be concordant with the IgM ELISA, 71.7% of anti-coxsackie B positive cases could be detected by RT-PCR.</p><p><b>CONCLUSION</b>The RT-PCR method can type coxsackie B virus efficiently and provides a tool for clinical diagnosis and epidemiological investigation.</p>
Assuntos
Humanos , Primers do DNA , Enterovirus Humano B , Classificação , Genética , Infecções por Enterovirus , Diagnóstico , Virologia , Ensaio de Imunoadsorção Enzimática , Imunoglobulina M , Sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa , MétodosRESUMO
<p><b>AIM</b>To synthesize new fluoroquinolone analogues as antibacterial compounds.</p><p><b>METHODS AND RESULTS</b>By reaction of acryl chloride(chloro-carbonic ester) with sodium sulfocyanate, acyl isosulfocyanic ester were easily obtained. Twelve 7-(4-acylamino-thiocarbamoyl-1-piperazinyl) fluoroquinolone analogues (1-12) were synthesized through modifying the 7-piperazine of norflorxacin and ciprofloxacin with isosulfocyanic ester synthesized above. The structures of synthesized compounds were characterized by 1HNMR, IR and elemental analysis.</p><p><b>CONCLUSION</b>Antibacterial activities of the new compounds were evaluated in vitro compared with norflorxacin. Compounds 5, 7, 10 and 12 showed antibacterial activities.</p>
