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1.
Bioorg Med Chem Lett ; 30(21): 127504, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827631

RESUMO

25-OH ginsenosides are potent and rare prodrugs in natural sources. However current strategies for such modification always end up in undesirable side products and unsatisfied yield that hinders them from further applications. Herein, ginsenoside Rg1 was thoroughly converted into 20(S/R)-Rh1 and 25-OH-20(S/R)-Rh1 by Cordyceps Sinensis in an optimum medium. The chemical correctness of either 25-OH-20(S/R)-Rh1 epimers was validated by LC-IT-TOF-MSn and 13C NMR spectrometry. The biocatalytic pathway was established as Rg1 â†’ 20(S/R)-Rh1 â†’ 25-OH-20(S/R)-Rh1. The molar bioconversion rate for total 25-OH-20(S/R)-Rh1 was calculated to be 82.5%, of which S-configuration accounted for 43.2% while R-configuration 39.3%. These two 25-OH derivatives are direct hydration products from 20(S/R)-Rh1 without other side metabolites, suggesting this is a highly regioselective process. In conclusion, this biocatalytic system could be harnessed to facilitate the preparation of diversified 25-OH ginsenosides with high yields of the target compound and simple chemical background in the reaction mixture.

2.
J Sep Sci ; 43(12): 2436-2446, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32227667

RESUMO

Four types of middle-pressure chromatogram isolated gels are evaluated for adsorption or desorption characteristics of ginsenosides from Panax ginseng. Among them, SP207SS and SP2MGS were selected for dynamic investigations based on their static adsorption or desorption capacity of total ginsenoside. Their adsorption kinetics was better explained by pseudosecond-order model and isotherms were preferably fitted to Langmuir model. Dynamic breakthrough experiments indicated an optimum sample loading speed of 4 bed volume/h for either SP207SS or SP2MGS. Desorption speed was determined to be 2 bed volume/h according to desorption amount of total ginsenoside in their effluents. Eight ginsenosides were identified and quantified by high performance liquid chromatography-triple quadropole-mass spectrometry in total ginsenoside extract and different fractions during stepwise dynamic elution. For SP207SS, 27.62% of loaded ginsenosides was detected in 40% ethanol fraction, while 59.12% of them were found in 60% ethanol fraction. As on SP2MGS, the number went to 53.71 and 44.43%, respectively. Recovery rate of ginsenosides were calculated to 78.65% for SP207SS and 89.53% for SP2MGS, respectively. Intriguingly, content of Rg1 and Re in 40% ethanol fraction from SP207SS became 20.1 and 18.6 times higher than that in total ginsenoside extract by one-step elution, which could be leveraged for the facile enrichment of these two ginsenosides from natural sources.

3.
RNA Biol ; 8(5): 861-72, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21788734

RESUMO

Although there are plenty of evidence that single-nucleotide polymorphisms (SNPs) that fall within coding sequences of genes are involved in recurrent pregnancy loss (RPL), it is still unknown whether the polymorphisms in microRNAs (miRNAs) are related with RPL. In this study, we established this kind of association by confirming significant differences in genotype distribution of rs41275794 (P= 0.0005) and rs12976445 (P= 0.001) within the pri-miR-125a in 217 Han Chinese patients of RPL compared with 431 controls. Based on this observation, two-locus haplotypes were constructed and the A-T haplotype was found to be associated with an increased risk of RPL (OR=2.84, 95%C.I. 1.98-4.07, P=0.0000000057). Further analysis showed that the levels of pre- and mature- miR-125a were down-regulated in the cells transfected with the A-T haplotype, which was consistent with in vivo detection that the level of mature miR-125a was lower in 30 pregnant women with A-T haplotype than that with G-C haplotype. During in vitro RNA processing assays, we found a similar decrease in the amount of pre-miR-125a and decline in binding capacity of nuclear factors to pri-miR-125a with A-T haplotype. More importantly, the reduction in miR-125a, as a consequence of A-T haplotype, further led to less efficient inhibition of target genes, LIFR and ERBB2, which play important roles in the embryo implantation and decidualization. Thus, our data collectively suggest that two common polymorphisms in pre-miR-125a might contribute to the genetic predisposition to RPL by disrupting the production of miR-125a, which consequently interfered in the expression and function of target genes of miR-125a.


Assuntos
Aborto Habitual/genética , MicroRNAs/genética , Polimorfismo de Nucleotídeo Único , Aborto Habitual/etnologia , Grupo com Ancestrais do Continente Asiático , Estudos de Casos e Controles , China , Implantação do Embrião/genética , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , MicroRNAs/biossíntese , Gravidez , Receptor ErbB-2/genética
4.
Cell Physiol Biochem ; 23(4-6): 347-58, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19471102

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are small noncoding RNAs whose function as modulators of gene expression is crucial for the proper control of cell growth. Although many microRNAs were found to express in central nervous system (CNS), the role of the regulatory networks in which they are involved and their function in the pathological process of nerve cells are only just emerging. In the present study, the possible mechanisms by which one neuronal miRNAs, miR-125b, affected the growth of nervous cells were investigated using in vitro cell line model. METHODS: The expression pattern of miR-125b in ATRA-treated human glioma cell lines was detected by Northern blotting and in situ localization. The effect of miR-125b on the proliferation and apoptosis of human glioma cells was analyzed by MTS assay, TUNEL and Flow cytometry analysis. In addition, the identification of target gene of miR-125b was studied by dual-luciferase activity assay and Immunoblot Analysis. RESULTS: We found differential expression of miR-125b in 1.0 microM all-trans-retinoic acid (ATRA)-treated human glioma cell lines. Up-regulation of miR-125b partially restored cell viability and inhibited cell apoptosis in U343 cells treated by ATRA. Down-regulation of miR-125b decreased human glioma cells proliferation and enhanced the sensitivity of human glioma cells to ATRA-induced apoptosis. In addition, we found an inverse relationship between the expression of miR-125b and the cell apoptosis-related protein Bcl-2 modifying factor (Bmf), and miR-125b can interact with 3'-untranslated region (UTR) of Bmf. CONCLUSION: These findings indicate that overexpression of miR-125b promotes human glioma cell proliferation and inhibits ATRA-induced cell apoptosis and low expression of miR-125b sensitizes cells to ATRA-induced apoptosis. BMF may play an important role in the process of miR-125b influencing cell apoptosis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose , Proliferação de Células , Glioma/metabolismo , MicroRNAs/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Sequência de Bases , Regulação para Baixo , Glioma/genética , Humanos , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Tretinoína/farmacologia , Células Tumorais Cultivadas , Proteína X Associada a bcl-2/metabolismo
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