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1.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33602814

RESUMO

The ubiquitin E3 ligase Bre1-mediated H2B monoubiquitination (H2Bub) is essential for proper DNA replication and repair in eukaryotes. Deficiency in H2Bub causes genome instability and cancer. How the Bre1-H2Bub pathway is evoked in response to DNA replication or repair remains unknown. Here, we identify that the single-stranded DNA (ssDNA) binding factor RPA acts as a key mediator that couples Bre1-mediated H2Bub to DNA replication and repair in yeast. We found that RPA interacts with Bre1 in vitro and in vivo, and this interaction is stimulated by ssDNA. This association ensures the recruitment of Bre1 to replication forks or DNA breaks but does not affect its E3 ligase activity. Disruption of the interaction abolishes the local enrichment of H2Bub, resulting in impaired DNA replication, response to replication stress, and repair by homologous recombination, accompanied by increased genome instability and DNA damage sensitivity. Notably, we found that RNF20, the human homolog of Bre1, interacts with RPA70 in a conserved mode. Thus, RPA functions as a master regulator for the spatial-temporal control of H2Bub chromatin landscape during DNA replication and recombination, extending the versatile roles of RPA in guarding genome stability.


Assuntos
Reparo do DNA , Replicação do DNA , Histonas/metabolismo , Proteína de Replicação A/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , DNA de Cadeia Simples , Histonas/genética , Recombinação Homóloga , Metanossulfonato de Metila/toxicidade , Domínios e Motivos de Interação entre Proteínas/genética , Proteína de Replicação A/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
2.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34140406

RESUMO

Single-stranded DNA (ssDNA) covered with the heterotrimeric Replication Protein A (RPA) complex is a central intermediate of DNA replication and repair. How RPA is regulated to ensure the fidelity of DNA replication and repair remains poorly understood. Yeast Rtt105 is an RPA-interacting protein required for RPA nuclear import and efficient ssDNA binding. Here, we describe an important role of Rtt105 in high-fidelity DNA replication and recombination and demonstrate that these functions of Rtt105 primarily depend on its regulation of RPA. The deletion of RTT105 causes elevated spontaneous DNA mutations with large duplications or deletions mediated by microhomologies. Rtt105 is recruited to DNA double-stranded break (DSB) ends where it promotes RPA assembly and homologous recombination repair by gene conversion or break-induced replication. In contrast, Rtt105 attenuates DSB repair by the mutagenic single-strand annealing or alternative end joining pathway. Thus, Rtt105-mediated regulation of RPA promotes high-fidelity replication and recombination while suppressing repair by deleterious pathways. Finally, we show that the human RPA-interacting protein hRIP-α, a putative functional homolog of Rtt105, also stimulates RPA assembly on ssDNA, suggesting the conservation of an Rtt105-mediated mechanism.


Assuntos
Reparo do DNA , Replicação do DNA , Proteínas de Ligação a RNA/metabolismo , Proteína de Replicação A/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Transporte Ativo do Núcleo Celular , Proteínas de Transporte/metabolismo , Núcleo Celular/metabolismo , Quebras de DNA de Cadeia Dupla , DNA de Cadeia Simples/metabolismo , Conversão Gênica , Deleção de Genes , Duplicação Gênica , Humanos , Modelos Biológicos , Ligação Proteica , Rad51 Recombinase/metabolismo
3.
Phytochem Anal ; 35(5): 1186-1196, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38639052

RESUMO

INTRODUCTION: Smilacis Glabrae Rhizoma (SGR) is rich in chemical constituents with a variety of pharmacological activities. However, in-depth research has yet to be conducted on the chemical and pharmacodynamic constituents of SGR. MATERIALS AND METHODS: In this study, the chemical constituents of SGR were analyzed using liquid chromatography-mass spectrometry, and the pharmacodynamic compounds responsible for the medicinal effects of SGR were elucidated through a literature review. RESULTS: In total, 20 potentially new compounds, including 16 flavonoids (C19, C20, and C27-C40) and four phenylpropanoids (C107, C112, C113, and C118), together with 161 known ones were identified in the ethanol extract of SGR using liquid chromatography-mass spectrometry, and 25 of them were unequivocally identified by comparison with reference compounds. Moreover, 17 known constituents of them were identified in the plants of genus Smilax for the first time, and 16 were identified in the plant Smilax glabra Roxb. for the first time. Of 161 known compounds, 84 constituents (including isomers) have been reported to have 17 types of pharmacological activities, covering all known pharmacological activities of SGR; among these 84 bioactive constituents, six were found in the plants of genus Smilax for the first time and five were found in S. glabra for the first time, which are new bioactive constituents found in the plants of genus Smilax and the plant S. glabra, respectively. CONCLUSION: The results provide further information on the chemical composition of SGR, laying the foundation for the elucidation of the pharmacodynamic substances of SGR.


Assuntos
Rizoma , Smilax , Espectrometria de Massas por Ionização por Electrospray , Cromatografia Líquida de Alta Pressão/métodos , Rizoma/química , Smilax/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Flavonoides/análise , Flavonoides/química , Flavonoides/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Estrutura Molecular
4.
Zhongguo Zhong Yao Za Zhi ; 49(6): 1641-1660, 2024 Mar.
Artigo em Zh | MEDLINE | ID: mdl-38621949

RESUMO

This study explored the existence forms(original constituents and metabolites) of Tiantian Capsules, Aloe, and Tiantian Capsules without Aloe in rats for the first time, aiming to clarify the contribution of Aloe to the existence form of Tiantian Capsules. Rats were administrated with corresponding drugs by gavage once a day for seven consecutive days. All urine and feces samples were collected during the seven days of administration, and blood samples were collected 0.5, 1, and 1.5 h after the last administration. UHPLC-Q-TOF-MS was employed to detect and identify the original constituents and metabolites in the samples. A total of 34, 28, and 2 original constituents and 64, 94, and 0 metabolites were identified in the samples of rats administrated with Aloe, Tiantian Capsules, and Tiantian Capsules without Aloe, respectively. The main metabolic reactions were methylation, hydrogenation, hydroxylation, dehydroxylation, glucuronidation, and sulfation. This study clarified for the first time the existence forms and partial metabolic pathways of Aloe, Tiantian Capsules, and Tiantian Capsules without Aloe in rats, laying a foundation for revealing their effective forms. The findings are of great significance to the research on the functioning mechanism and quality control of Aloe and Tiantian Capsules.


Assuntos
Aloe , Medicamentos de Ervas Chinesas , Ratos , Animais , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/metabolismo , Administração Oral , Fezes , Cápsulas
5.
BMC Infect Dis ; 23(1): 521, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37553613

RESUMO

BACKGROUND: Although most patients can recover from SARS-CoV-2 infection during the short-term, the long-term effects of COVID-19 on the brain remain explored. Functional MRI (fMRI) could potentially elucidate or otherwise contribute to the investigation of the long COVID syndrome. A lower fMRI response would be translated into decreased brain activity or delayed signal transferring reflecting decreased connectivity. This research aimed to investigate the long-term alterations in the local (regional) brain activity and remote (interregional) functional connection in recovered COVID-19. METHODS: Thirty-five previously hospitalized COVID-19 patients underwent 3D T1weighed imaging and resting-state fMRI at 6-month follow-up, and 36 demographic-matched healthy controls (HCs) were recruited accordingly. The amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity (FC) was used to assess the regional intrinsic brain activity and the influence of regional disturbances on FC with other brain regions. Spearman correlation analyses were performed to evaluate the association between brain function changes and clinical variables. RESULTS: The incidence of neurosymptoms (6/35, 17.14%) decreased significantly at 6-month follow-up, compared with COVID-19 hospitalization stage (21/35, 60%). Compared with HCs, recovered COVID-19 exhibited higher ALFF in right precuneus, middle temporal gyrus, middle and inferior occipital gyrus, lower ALFF in right middle frontal gyrus and bilateral inferior temporal gyrus. Furthermore, setting seven abnormal activity regions as seeds, we found increased FC between right middle occipital gyrus and left inferior occipital gyrus, and reduced FC between right inferior occipital gyrus and right inferior temporal gyrus/bilateral fusiform gyrus, and between right middle frontal gyrus and right middle frontal gyrus/ supplementary motor cortex/ precuneus. Additionally, abnormal ALFF and FC were associated with clinical variables. CONCLUSIONS: COVID-19 related neurological symptoms can self heal over time. Recovered COVID-19 presented functional alterations in right frontal, temporal and occipital lobe at 6-month follow-up. Most regional disturbances in ALFF were related to the weakening of short-range regional interactions in the same brain function.


Assuntos
Mapeamento Encefálico , COVID-19 , Humanos , Mapeamento Encefálico/métodos , Síndrome de COVID-19 Pós-Aguda , Seguimentos , COVID-19/diagnóstico por imagem , SARS-CoV-2 , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
6.
Molecules ; 27(21)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36364095

RESUMO

Nardosinone, a sesquiterpene peroxide, is one of the main active constituents of the ethnomedicine Nardostachyos Radix et Rhizoma, and it has many bioactivities, such as antiarrhythmia and cardioprotection. To elucidate its in vivo existence forms, its metabolism is first studied using mice. All urine and feces are collected during the six days of oral dosing of nardosinone, and blood is collected at one hour after the last dose. Besides, to validate some metabolites, a fast experiment is performed, in which nardosinone was orally administered and the subsequent one-hour urine is collected and immediately analyzed by UHPLC-Q-TOF-MS. In total, 76 new metabolites are identified in this study, including 39, 51, and 12 metabolites in urine, plasma, and feces, respectively. Nardosinone can be converted into nardosinone acid or its isomers. The metabolic reactions of nardosinone included hydroxylation, hydrogenation, dehydration, glucuronidation, sulfation, demethylation, and carboxylation. There are 56 and 20 metabolites with the structural skeleton of nardosinone and nardosinone acid, respectively. In total, 77 in vivo existence forms of nardosinone are found in mice. Nardosinone is mainly excreted in urine and is not detected in the feces. These findings will lay the foundation for further research of the in vivo effective forms of nardosinone and Nardostachyos Radix et Rhizoma.


Assuntos
Medicamentos de Ervas Chinesas , Ratos , Camundongos , Animais , Cromatografia Líquida de Alta Pressão/métodos , Ratos Sprague-Dawley , Sesquiterpenos Policíclicos , Medicamentos de Ervas Chinesas/química , Fezes/química , Administração Oral
7.
Zhongguo Zhong Yao Za Zhi ; 46(3): 645-660, 2021 Feb.
Artigo em Zh | MEDLINE | ID: mdl-33645032

RESUMO

A high performance liquid chromatography with a diode array detector combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry(HPLC-DAD-ESI-IT-TOF-MS~n, HPLC-MS~n) method was established for qualitative analysis of the chemical components of ethyl acetate extract from Sinopodophylli Fructus. The analysis was performed on a Kromasil 100-5 C_(18)(4.6 mm×250 mm, 5 µm) column, with a mobile phase consisted of 0.1% formic acid(A) and acetonitrile(B) for gradient at a flow rate of 1.0 mL·min~(-1). Electrospray ionization ion trap time-of-flight multistage mass spectrometry was applied for qualitative analysis under positive and negative ion modes. With use of reference substance, characteristic fragmentation and their HR-MS data, 102 components were identified, including 67 flavonoids and 35 lignans. Among them, 45 compounds were reported in Sinopodophylli Fructus for the first time and 19 compounds were identified as new compounds. PharmMapper was used to predict the bioactivity of compounds that were first reported in Sinopodophylli Fructus, and 20 compounds of them were identified to have potential anticancer activity. The results showed that there were many isomers in the ethyl acetate extract of Folium Nelumbinis, and a total of 19 groups of isomers were found. Among them, C_(21)H_(20)O_8 had the highest number of isomers(18 compounds), all of which were α-peltatin or its isomers; C_(21)H_(20)O_7 ranked second, with 10 compounds, all of which were 8-prenylquercetin-3-methyl ether or its isomers. In conclusion, an HPLC-MS~n method was established for qualitative analysis of the ethyl acetate extract(with anti-breast cancer activity) from Sinopodophylli Fructus in this study, which will provide the evidence for clarifying pharmacological active ingredients of the ethyl acetate extract from Sinopodophylli Fructus against breast cancer.


Assuntos
Acetatos , Espectrometria de Massas por Ionização por Electrospray , Cromatografia Líquida de Alta Pressão , Frutas
8.
BMC Infect Dis ; 20(1): 567, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32746805

RESUMO

BACKGROUND: To assess the dynamic changes in clinical and CT characteristics of COVID-19 patients with different epidemiology histories. METHODS: Fifty-three discharged COVID-19 patients were enrolled at Beijing YouAn Hospital, Capital Medical University, between January 21 and March 10, 2020. Spearman correlation analysis was performed between CT scores and laboratory indicators. Patients were divided into the Wuhan group (lived in or with travel to Wuhan, numbering 30 cases) and non-Wuhan group (close contacts or unknown exposure, totaling 23 cases). The CT and laboratory findings were compared between and within groups during the clinical process. RESULTS: Fever (88.7%), cough (64.2%), fatigue (34%), and abnormal laboratory indicators, including lymphopenia, reduced albumin, albumin/globulin (A/G), and elevated C-reactive protein (CRP), were mainly observed. Subpleural ground-glass opacities (86.8%) were usually detected at admission. The CT scores were highly correlated with lymphocytes, CRP, albumin, and A/G at initial and follow-ups (all p < 0.05). Four days after admission, most patients (66.7% Wuhan, 47.8% non-Wuhan) showed progression, and the CT scores of Wuhan significantly increased (p = 0.015). Eight days after admission, the vast majority of patients (69.2% Wuhan, 100% non-Wuhan, p = 0.006) presented improvement, and the CT scores of non-Wuhan were significantly lower than Wuhan (p = 0.006). Pneumonia was completely absorbed in most patients 2-4 weeks after discharge. CONCLUSIONS: CT plays a crucial role in the early diagnosis and monitoring of changes in COVID-19. Lymphocytes, CRP, albumin, and A/G are expected to predict disease severity and prognosis. Viral pathogenicity in non-endemic areas may be weaker than core-infected areas. In most patients, lung lesions can disappear around 4 weeks after discharge.


Assuntos
Betacoronavirus , Proteína C-Reativa/análise , Infecções por Coronavirus/diagnóstico por imagem , Tosse/epidemiologia , Febre/epidemiologia , Linfopenia/diagnóstico , Pneumonia Viral/diagnóstico por imagem , Albumina Sérica Humana/análise , Soroglobulinas/análise , Adulto , Idoso , COVID-19 , Infecções por Coronavirus/virologia , Tosse/virologia , Progressão da Doença , Feminino , Febre/virologia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Alta do Paciente , Pneumonia Viral/virologia , Prognóstico , Estudos Retrospectivos , SARS-CoV-2 , Tomografia Computadorizada por Raios X , Viagem
9.
Nucleic Acids Res ; 46(21): 11326-11339, 2018 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-30304473

RESUMO

Repair of DNA double-strand breaks (DSBs) requires eviction of the histones around DNA breaks to allow the loading of numerous repair and checkpoint proteins. However, the mechanism and regulation of this process remain poorly understood. Here, we show that histone H2B ubiquitination (uH2B) promotes histone eviction at DSBs independent of resection or ATP-dependent chromatin remodelers. Cells lacking uH2B or its E3 ubiquitin ligase Bre1 exhibit hyper-resection due to the loss of H3K79 methylation that recruits Rad9, a known negative regulator of resection. Unexpectedly, despite excessive single-strand DNA being produced, bre1Δ cells show defective RPA and Rad51 recruitment and impaired repair by homologous recombination and response to DNA damage. The HR defect in bre1Δ cells correlates with impaired histone loss at DSBs and can be largely rescued by depletion of CAF-1, a histone chaperone depositing histones H3-H4. Overexpression of Rad51 stimulates histone eviction and partially suppresses the recombination defects of bre1Δ mutant. Thus, we propose that Bre1 mediated-uH2B promotes DSB repair through facilitating histone eviction and subsequent loading of repair proteins.


Assuntos
Dano ao DNA , Histonas/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/química , Ubiquitinação , Trifosfato de Adenosina/química , Cromatina/química , Quebras de DNA de Cadeia Dupla , Reparo do DNA , DNA de Cadeia Simples/química , Recombinação Homóloga , Microscopia de Fluorescência , Mutação , Recombinação Genética , Schizosaccharomyces/metabolismo , Análise de Sequência de RNA
10.
Molecules ; 25(19)2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32992581

RESUMO

Asari Radix et Rhizoma (ARR) is an important traditional Chinese medicine. Volatile organic compounds (VOCs) are the main active constituents of ARR. Research on the metabolite profile of VOCs and the difference of absorbed constituents in vivo after an administration of ARR decoction and powder will be helpful to understand the pharmacological activity and safety of ARR. In this study, headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) was applied to profile the VOCs from ARR in rats in vivo. A total of 153 VOCs were tentatively identified; 101 were original constituents of ARR (98 in the powder-treated group and 43 in the decoction-treated group) and 15 were metabolites, and their metabolic reactions were mainly oxidation and reduction, with only two cases of methylation and esterification, and 37 unclassified compounds were identified only in the ARR-treated group. Of the 153 VOCs identified, 131 were reported in rats after oral administration of ARR for the first time, containing 79 original constituents, 15 metabolites, and 37 unclassified compounds. In the powder-treated group, methyleugenol, safrole, 3,5-dimethoxytoluene (3,5-DMT), 2,3,5-trimethoxytoluene (2,3,5-TMT), and 3,4,5-trimethoxytoluene (3,4,5-TMT) were the main absorbed constituents, the relative contents of which were significantly higher compared to the decoction-treated group, especially methyleugenol, safrole, and 3,5-DMT. In the decoction-treated group, 3,4,5-TMT, 2,3,5-TMT, kakuol, and eugenol were the main constituents with a higher content and wider distribution. The results of this study provide a reference for evaluating the efficacy and safety of ARR.


Assuntos
Asarum/química , Medicamentos de Ervas Chinesas/farmacologia , Extratos Vegetais/farmacologia , Rizoma/química , Compostos Orgânicos Voláteis , Animais , Medicamentos de Ervas Chinesas/química , Masculino , Medicina Tradicional Chinesa , Extratos Vegetais/química , Pós , Ratos , Ratos Sprague-Dawley , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/farmacologia
11.
Molecules ; 25(23)2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33256251

RESUMO

Astragali Radix total flavonoids (ARTF) is one of the main bioactive components of Astragali Radix (AR), and has many pharmacological effects. However, its metabolism and effective forms remains unclear. The HPLC-DAD-ESI-IT-TOF-MSn technique was used to screen and tentatively identify the in vivo original constituents and metabolites of ARTF and to clarify their distribution in rats after oral administration. In addition, modern chromatographic methods were used to isolate the main metabolites from rat urine and NMR spectroscopy was used to elucidate their structures. As a result, 170 compounds (23 original constituents and 147 metabolites) were tentatively identified as forms existing in vivo, 13 of which have the same pharmacological effect with ARTF. Among 170 compounds, three were newly detected original constituents in vivo and 89 were new metabolites of ARTF, from which 12 metabolites were regarded as new compounds. Nineteen original constituents and 65 metabolites were detected in 10 organs. Four metabolites were isolated and identified from rat urine, including a new compound (calycoisn-3'-O-glucuronide methyl ester), a firstly-isolated metabolite (astraisoflavan-7-O-glucoside-2'-O-glucuronide), and two known metabolites (daidzein-7-O-sulfate and calycosin-3'-O-glucuronide). The original constituents and metabolites existing in vivo may be material basis for ARTF efficacy, and these findings are helpful for further clarifying the effective forms of ARTF.


Assuntos
Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacocinética , Flavonoides/química , Flavonoides/farmacocinética , Metaboloma , Metabolômica , Administração Oral , Animais , Astragalus propinquus , Cromatografia Líquida de Alta Pressão , Monitoramento de Medicamentos , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/metabolismo , Flavonoides/administração & dosagem , Metabolômica/métodos , Estrutura Molecular , Ratos , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Relação Estrutura-Atividade , Distribuição Tecidual
12.
Zhongguo Zhong Yao Za Zhi ; 45(6): 1374-1383, 2020 Mar.
Artigo em Zh | MEDLINE | ID: mdl-32281351

RESUMO

The present work is to establish an HPLC characteristic chromatograms of Asarum heterotropoides var. mandshuricum(AH) and A. sieboldii(AS), combined with cluster analysis for the identification of the two species, and predict their potential anti-inflammatory related targets by network pharmacological method. Eighty-nine samples(12 batches of AS and 77 batches of AH) were analyzed, and 11 characteristic peaks were identified by reference substances, UV spectrum and LC-MS. Cluster analysis showed that AS and AH were divided into two groups, and the ratio of characteristic peak areas can be used to distinguish them. When the ratio of characteristic peak sarisan to kakuol was greater than 5, it was AS, and when the ratio was less than 2, it was AH. The network pharmacological analysis of 119 constituents of Asari Radix et Rhizoma suggested that the anti-inflammatory effect of Asari Radix et Rhizoma might be related to COX-2, COX-1, iNOS, MAPK14, NR3 C1, PPARG and TNF. Among them, COX-2 is a relatively key target, which interacted with the characteristic constituents, asarinin, sesamin, safrole, methyleugenol and sarisan. The characteristic constituents asarinin and sesamin also interacted with the iNOS and MAPK14. Safrole and sarisan can also interact with iNOS, COX-1 and LAT4 H. Methyleugenol also showed interaction with COX-1 and LAT4 H. Since asarinin and sesamin interacted with three targets, COX-2, iNOS and MAPK14, it implied that they were the main active constituents for the anti-inflammatory activity of Asari Radix et Rhizoma. The COX-2 inhibitory activities of asarinin and sesamin were further studied by molecular docking and bioassay. The HPLC method established was simple, feasible and reliable, with predicted anti-inflammatory targets and anti-inflammatory constituents, which could provide a reference for improving the quality evaluation system of Asari Radix et Rhizoma.


Assuntos
Anti-Inflamatórios/isolamento & purificação , Asarum/química , Cromatografia Líquida de Alta Pressão , Simulação de Acoplamento Molecular , Compostos Fitoquímicos/isolamento & purificação , Rizoma/química
13.
Biochemistry ; 58(15): 2009-2016, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30900876

RESUMO

S-DNA (stretched DNA) is an elongated base-paired DNA conformation under high tension. Because the RecA/Rad51 family DNA recombinases form helical filaments on DNA and mediate the formation of the DNA triplex (D-loop), in which the DNA is stretched, and because the extension of these nucleoprotein filaments is similar to the extension of S-DNA, S-DNA has long been hypothesized as a possible state of DNA that participants in RecA/Rad51-mediated DNA strand exchange in homologous recombination. Such a hypothesis, however, is still lacking direct experimental studies. In this work, we have studied the polymerization and strand exchange on S-DNA mediated by Escherichia coli RecA, human Rad51, and Saccharomyces cerevisiae Rad51 by single-molecule magnetic tweezers. We report that RecA/Rad51 polymerizes faster on S-DNA than on B-DNA with the same buffer conditions. Furthermore, the RecA/Rad51-mediated DNA triplex forms faster from S-DNA than from B-DNA together with the homologous single-stranded DNA. These results provide evidence that S-DNA can interact with RecA and Rad51 and shed light on the possible functions of S-DNA.


Assuntos
Pareamento de Bases , Proteínas de Ligação a DNA/química , DNA/química , Proteínas de Escherichia coli/química , Rad51 Recombinase/química , Recombinases Rec A/química , Proteínas de Saccharomyces cerevisiae/química , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Humanos , Conformação de Ácido Nucleico , Polimerização , Ligação Proteica , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Recombinases Rec A/genética , Recombinases Rec A/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Estresse Mecânico
14.
Molecules ; 24(10)2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31121832

RESUMO

Medicarpin is a bioactive pterocarpan that has been attracting increasing attention in recent years. However, its metabolic fate in vivo is still unknown. To clarify its metabolism and the distribution of its metabolites in rats after oral administration, the HPLC-ESI-IT-TOF-MSn technique was used. A total of 165 new metabolites (13 phase I and 152 phase II metabolites) were tentatively identified, and 104, 29, 38, 41, 74, 28, 24, 15, 42, 8, 10, 3, and 17 metabolites were identified in urine, feces, plasma, the colon, intestine, stomach, liver, spleen, kidney, lung, heart, brain, and thymus, respectively. Metabolic reactions included demethylation, hydrogenation, hydroxylation, glucuronidation, sulfation, methylation, glycosylation, and vitamin C conjugation. M1 (medicarpin glucuronide), M5 (vestitol-1'-O-glucuronide) were distributed to 10 organs, and M1 was the most abundant metabolite in seven organs. Moreover, we found that isomerization of medicarpin must occur in vivo. At least 93 metabolites were regarded as potential new compounds by retrieving information from the Scifinder database. This is the first detailed report on the metabolism of ptercarpans in animals, which will help to deepen the understanding of the metabolism characteristics of medicarpin in vivo and provide a solid basis for further studies on the metabolism of other pterocarpans in animals.


Assuntos
Pterocarpanos/administração & dosagem , Pterocarpanos/farmacocinética , Administração Oral , Animais , Química Encefálica , Cromatografia Líquida de Alta Pressão , Colo/química , Fezes/química , Fígado/química , Masculino , Metaboloma , Estrutura Molecular , Plasma/química , Pterocarpanos/química , Ratos , Ratos Sprague-Dawley , Baço/química , Distribuição Tecidual , Urina/química
15.
Zhongguo Zhong Yao Za Zhi ; 44(22): 4924-4931, 2019 Nov.
Artigo em Zh | MEDLINE | ID: mdl-31872602

RESUMO

This experiment aims to explore the metabolites of n-butanol and water soluble fraction of an ethanol extracts from Angelicae Sinensis Radix in rats. The chemical constituents of n-butanol and water extracts from Angelicae Sinensis Radix were identified by HPLC-DAD-ESI-IT-TOF-MS~n,and the in vivo metabolites of n-butanol and water extracts were analyzed. By analyzing n-butanol and water extracts from Angelicae Sinensis Radix,25 compounds were detected and identified,in which 11 phthalide glycosides were firstly reported. And 19 compounds were detected and identified in rat urine,including 2 prototype constituents and 17 metabolites,and the17 metabolites were new compounds. The method can identify the main constituents and metabolites of extracts from traditional Chinese medicine accurately and rapidly,and provide evidence for interpreting effective forms and pharmacodynamics substance( prototype,metabolites,or both) of Angelicae Sinensis Radix.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Animais , Cromatografia Líquida de Alta Pressão , Glicosídeos , Ratos , Espectrometria de Massas por Ionização por Electrospray
16.
Biomed Chromatogr ; 32(7): e4218, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29470860

RESUMO

Harpagoside, an iridoid glycoside, is the major bioactive constituent of the traditional Chinese medicine Scrophulariae Radix. High-performance liquid chromatography with a diode array detector combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry (HPLC-ESI-IT-TOF-MSn ) was used to profile and identify the metabolites of harpagoside in rats in vivo and to study the distribution of these metabolites in rats for the first time. A total of 45 metabolites were identified, 37 of which were postulated to be new compounds. The number of detected metabolites in the heart, liver, spleen, lung, kidney, stomach and small intestine was 2, 9, 6, 16, 4, 16 and 6, respectively, which indicated that the target organs of harpagoside should be spleen, lung and stomach. The main types of metabolic reactions of harpagoside in rats are hydrolysis, reduction, sulfuric acid addition, hydroxylation, methoxylation, sulfate substitution, methylation, glucose conjugation and amino acid conjugation. Furthermore, 23 metabolites were determined to have bioactivities based on the literature and 'PharmMapper' analysis. These findings are useful for better comprehension of the effective forms, target organs and pharmacological effects of harpagoside. Moreover, these findings provide a reference for studying the metabolism and distribution of iridoid compounds.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Glicosídeos/análise , Glicosídeos/farmacocinética , Piranos/análise , Piranos/farmacocinética , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Glicosídeos/química , Glicosídeos/metabolismo , Masculino , Piranos/química , Piranos/metabolismo , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
17.
Molecules ; 23(10)2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30347747

RESUMO

Sibirioside A and angoroside C are two important phenylpropanoid glycosides of the traditional Chinese medicine Scrophulariae Radix. High performance liquid chromatography, coupled with an ion trap time-of-flight multistage mass spectrometry equipped with electrospray ionization source (HPLC-ESI-IT-TOF-MSn), was applied to the profile and we identified the metabolites of sibirioside A and angoroside C in vivo in rats. A total of four metabolites of sibirioside A were identified: SM1, SM2 and SM3 which were known as new compounds. A total of 25 metabolites were detected for angoroside C: AM4, AM5, AM6, AM7, AM16, AM17, AM20, AM21, AM22, AM23 and AM25 which were identified to be new compounds. The main metabolic reactions were hydrolysis, reduction, hydroxylation, methylation, sulfation, and gluconylation. The prototype of sibirioside A was widely distributed in tissues found in the heart, liver, spleen, lung, kidney, stomach and small intestine of rats, and mainly distributed in the stomach, small intestine, kidney and liver. But for angoroside C, nothing was found in the viscera except the stomach and small intestine. The metabolites of sibirioside A were mainly eliminated from feces, while it was urine for the metabolites of angoroside C. Furthermore, 19 metabolites were likely to have bioactivities based on the 'PharmMapper' analysis, which roughly matched the known pharmacological activities of Scrophulariae Radix (SR) and the prototypes. One of the main pharmacological activities of SR in traditional Chinese medicine is anti-diabetes, and the predicted results showed that SM1, SM2, SM3, AM2, AM4, AM5, AM6, AM9, AM10, AM11, AM12, AM13, AM15, AM18, AM19, AM24, and AM25 might be used to cure diabetes. These findings provide a reference for studying the metabolism, distribution and pharmacological actions of phenylpropanoid glycosides in vivo.


Assuntos
Ácidos Cumáricos/metabolismo , Medicamentos de Ervas Chinesas/administração & dosagem , Glicosídeos/metabolismo , Medicina Tradicional Chinesa , Fenilpropionatos/metabolismo , Trissacarídeos/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/administração & dosagem , Ácidos Cumáricos/química , Medicamentos de Ervas Chinesas/química , Glicosídeos/administração & dosagem , Glicosídeos/química , Humanos , Fenilpropionatos/administração & dosagem , Fenilpropionatos/química , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Ratos , Ratos Sprague-Dawley , Scrophularia/química , Espectrometria de Massas por Ionização por Electrospray , Distribuição Tecidual/efeitos dos fármacos , Trissacarídeos/administração & dosagem , Trissacarídeos/química
18.
Zhongguo Zhong Yao Za Zhi ; 43(1): 123-133, 2018 Jan.
Artigo em Zh | MEDLINE | ID: mdl-29552822

RESUMO

This experiment was performed to analyze and identify the chemical constituents of Sinopodophylli Fructus by HPLC-DAD-ESI-IT-TOF-MSn. The analysis was performed on an Agilent Zorbax SB-C18 (4.6 mm×250 mm, 5 µm) column.The mobile phase consisted of 0.1% formic acid was used for gradient at a flow rate of 1.0 mL·min⁻¹. Electrospray ionization ion trap time-of-flight multistage mass spectrometry was applied for qualitative analysis under positive and negative ion modes. The results indicated that 54 compounds consisted of 18 lignans and 36 flavonoids from Xiaoyelian had been detected by their HRMS data, the information of literature and reference substance. Among them, 27 compounds were reported in Sinopodophylli Fructus for the first time. In conclusion, an HPLC-DAD-ESI-IT-TOF-MSn method was established to qualitative analysis of Xiaoyelian in this study, which will provide the evidence for evaluating the quality of Xiaoyelian herbs, clarifying the mechanism, and guiding the development of pharmacological active ingredients.


Assuntos
Berberidaceae/química , Medicamentos de Ervas Chinesas/química , Flavonoides/análise , Frutas/química , Lignanas/análise , Cromatografia Líquida de Alta Pressão , Compostos Fitoquímicos/análise , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
19.
Molecules ; 22(1)2017 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-28098805

RESUMO

Anti-inflammatory compounds were investigated from the ethanol extract of the roots and rhizomes of Asarum heterotropoides var. mandshuricum, a traditional Chinese medicine called Xixin and used for pain and inflammatory. Nine new compounds were isolated, including six new lignans, neoasarinin A-C (1-3), neoasarininoside A and B (4 and 5), and asarinin B (7), and one new monoterpene, asarincin A (8), two new amides, asaramid II and III (10 and 11), and one new natural monoterpene, asaricin B (9), along with 37 known compounds (6, 12-47). Their structures and absolute configurations were elucidated on the basis of spectroscopic methods and chemical analyses. This is the first report of the absolute configuration of asarinin A (6). The 8-O-4' neolignans (1-5) were reported in the genus Asarum for the first time. The 15 compounds 17, 19, 22-25, 28, 31, 36, 40, 42, 43, 45-47 were isolated from the genus Asarum, and compounds 16, 32, 33, 37 and 39 were isolated from A. heterotropoides var. mandshuricum for the first time. Thirty-seven of the isolates were evaluated for anti-inflammatory activity against the release of ß-glucuronidase in polymorphonuclear leukocytes (PMNs) induced by the platelet-activating factor (PAF), and compounds 1, 4, 7, 8, 14, 17-19, 22, 24, 25, 29, 30, 32, 33, 40-43, 45, and 46 showed potent anti-inflammatory activities in vitro, with 27.9%-72.6% inhibitions at 10-5 mol/L. The results of anti-inflammatory assay suggested that lignans obtained from the CHCl3 extract might be the main active components of Xixin.


Assuntos
Amidas/química , Anti-Inflamatórios/química , Asarum/química , Medicamentos de Ervas Chinesas/química , Lignanas/química , Monoterpenos/química , 1-Alquil-2-acetilglicerofosfocolina Esterase/antagonistas & inibidores , 1-Alquil-2-acetilglicerofosfocolina Esterase/farmacologia , Amidas/isolamento & purificação , Amidas/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Clorofórmio , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Etanol , Glucuronidase/antagonistas & inibidores , Glucuronidase/metabolismo , Humanos , Lignanas/isolamento & purificação , Lignanas/farmacologia , Estrutura Molecular , Monoterpenos/isolamento & purificação , Monoterpenos/farmacologia , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Extratos Vegetais/química , Raízes de Plantas/química , Cultura Primária de Células , Ratos , Rizoma/química , Solventes/química , Relação Estrutura-Atividade
20.
Planta Med ; 82(4): 362-70, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26829520

RESUMO

Angelicae Sinensis Radix is commonly used in traditional Chinese medicine. Pharmacological studies show that Angelicae Sinensis Radix has clear anticoagulant activity. Therefore, in this study, the anticoagulant activity of crude Angelicae Sinensis Radix extracts was investigated by measuring the thrombin times of the extracts. The results revealed that the petroleum ether-soluble fraction of Angelicae Sinensis Radix exhibited significant anticoagulant activity in vitro, and 26 compounds were characterized by high-performance liquid chromatography with diode array detection combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry. In addition, 5 prototype constituents, 24 in vivo metabolites in rat urine and 7 prototype constituents, and 9 in vitro metabolites in the rat hepatic S9 incubation system of the petroleum ether-soluble fraction were tentatively identified. All metabolites were found from Angelicae Sinensis Radix for the first time. Among them, 13 (three ferulic acid-related constituents, six senkyunolide D-related constituents, and four senkyunolide F-related constituents) were identified as new metabolites (new compounds). This study is the first to qualitatively characterize the chemical constituents of the potent anticoagulative extract of Angelicae Sinensis Radix and to explore its metabolism. The result is a notable improvement in the discovery of Angelicae Sinensis Radix metabolites, and it provides the chemical basis for the effective forms and pharmacodynamic substances (prototypes, metabolites, or both) of the anticoagulant activity of Angelicae Sinensis Radix.


Assuntos
Angelica sinensis/química , Anticoagulantes/química , Medicamentos de Ervas Chinesas/química , Animais , Anticoagulantes/metabolismo , Anticoagulantes/farmacologia , China , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Raízes de Plantas/química , Coelhos , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas por Ionização por Electrospray/métodos
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