Latest ArticlesBromodomain-containing proteins (BCPs) can specifically recognize acetylated lysine (KAc) in histones and other substrate proteins. Recently, several kinase inhibitors were found to inhibit bromodomains, such as the PLK1 inhibitor BI-2536 and the JAK2 inhibitor TG101209, which bind to BRD4 with IC50 values of 25 nmol·L-1 and 130 nmol·L-1, respectively. To obtain potent BRD4 inhibitors from inhibitor BI-2536, we used dihydroquinoxalin-2(1H)-one to replace the 7, 8-dihydropteridin-6(5H)-one in BI2536. By exploring the structure-activity relationships of the new dihydroquinoxalin-2(1H)-one structures, we obtained a novel phenyl side chain series of BRD4 inhibitors. We identified several potent BRD4 inhibitors, especially compounds 16, 22, 28 and 29, which had IC50 values below 100 nmol·L-1 in fluorescence anisotropy (FA) assays, indicating this series of compounds are worth to fruther investigation.
The protein-protein interactions play an important role in life science. At present, many methods are developed with preferences of the amino acid residues, which do not offer the relative spatial information for the residue groups. However, the spatial information for the residue groups is important in the design of the protein-protein interactions. We proposed a new model, which is named 'tri-prism' model, by deep mining the existing protein-protein interaction patterns and refining the preference and the relative spatial information for the combination pairs of the residue groups. The model not only provided the preferences, but also offered the relative spatial information for the triplets combination pairs of the residue groups. The model was able to analyze the triplets combination pairs of the residue groups based on the preference factor, amino acid composition, and protein secondary structure. The model was applied to the interface of the PD-1/PD-L2 protein. According to the diversity characters of the composition and the spatial information between the combination pairs of the residue groups at the interface of the PD-1/PD-L2 protein and the predicted ones, we put forward the suggestions for the mutations of the residues, which offered a new view in the study of protein-protein interactions.
The study aims to establish an LC-MS/MS method for the determination of S-(+)-ibuprofen (S-IBP) and R-(-)-ibuprofen (R-IBP), which may be used subsequently to investigate the pharmacokinetics of ibuprofen enantiomers in healthy Chinese volunteers. Naproxen was used as an internal standard. The separation was achieved on a Chiralpak AD-3R column (4.6 mm×150 mm, 3.0 μm) with a mobile phase consisting of acetonitrile/0.01% formic acid aqueous solution (40:60) at a flow rate of 750 μL·min-1 within 23.0 min. Naproxen and the internal standard were measured by a triple-quadrupole mass spectrometer in negative electron electronic spray ion (ESI) mode using multiple reaction monitoring (MRM). The extracted ions monitored following MRM transitions were m/z 205.1→161.0 for ibuprofen enantiomers and m/z 229.1→185.0 for the internal standard naproxen. Plasma samples were pretreated through methanol precipitation. The calibration curve of S-IBP and R-IBP in human plasma was linear over the concentration rang of (0.05-30.00) μg·mL-1. The lower limit of quantitation was 0.05 μg·mL-1. The intra-and inter-run precisions of S-IBP at three quality control levels were within 2.2%-4.2%, the relative deviation of the assay was within -12.0%-13.0%. The intra-and inter-run precisions of R-IBP at three quality control levels were within 2.0%-8.2%, the relative deviation of the assay was within -11.5%-10.6%. The plasma samples were stable at room temperature (25℃) for 6 h, at -30℃ for 47 days and during three freeze-thaw cycles. The method was proved to be convenient, accurate and sensitive, and suitable for the pharmacokinetics study of ibuprofen enantiomers in healthy Chinese volunteers after a single oral dose of 300 mg ibuprofen extended-release capsule.
Using a UHPLC-TOF/MS method combined with software of Masslynx V4.1 and database in the literatures, a total of 20 polygala oligosaccharide esters (POEs) were identified in 60% ethanol extract of Kai Xin San (KXS-60%E). Furthermore, 14 POEs as well as 4 POE-metabolites were identified in rat plasma. The results revealed that POEs and POE-metabolites which were identified in rat plasma, were key components in KXS-60%E and the potential bioactive compounds for KXS action in the treatment of AD.
Due to the characteristics of propofol of high time-varying, and complex compartment model, the traditional method of nonlinear mixed effects modeling (NONMEM) has miscellaneous of variables and plenty of artificial factors in the estimation of propofol. This study was aimed to build a propofol prediction model based on the differential evolution (DE) algorithm and grey model. DE was used to optimize the pa-rameter of multi-variable grey model (MGM) and to build a model of prediction of the plasma concentration of propofol based on the grey model. It was compared with the results of NONMEM algorithm. In conclusion, the median performance error (MDPE) of DE-MGM was -4.6%, while the result of NONMEM is -12.13%. The median absolute performance error (MDAPE) of GA-BP neural network is 13.19%, while that of NONMEM is 23.12%. The experimental results suggest that the new method is suitable to determine the short half-life of anesthesia drug propofol with higher accuracy.
Charge-reversal nanocarrier was constructed to enhance lysosomal escape and improve an-titumor effect. We synthesized the cholesterol-polyethyleneimine-hexahydrophthalic anhydride (Chol-PEI-HHPA) polymer and characterized by 1H NMR. The charge-reversal liposomes (Lipo-HHPA) were synthesized and the hematoporphyrin monomethyl ether (HMME) was loaded. pH-triggered charge conversion was determined at different pH values. The lysosomal escape and cytotoxicity of the Lipo-HHPA were evaluated in MCF-7 cells. The Lipo-HHPA was uniform with an average particle size of 102 nm. Upon the irradiation of ultrasound, burst release of HMME could be observed. The zeta potential of Lipo-HHPA changed sharply from negative (-23.5 mV) to positive (+21.2 mV) over the pH range of 7.4-4.5. In the cellular uptake experiment, the lysosomal escape of Lipo-HHPA was observed. HMME loaded Lipo-HHPA displayed obviously enhanced cytotoxicity towards MCF-7 cells. These results indicate that the charge-reversal liposomes hold a great potential in improving the cytotoxicity and antitumor effect.
Based on the principle of particle design, the powder of Xiaojin Pills was prepared, and the quality uniformity was investigated by means of powder characterizations and content uniformity. By studying the mixed crushing rules of the classified materials and the design principle of the powder particles of Chinese medicine, the powder of the Xiaojin Pills was prepared. At the same time, the manmade mixed powder and the control powder prepared by pharmacopoeia were prepared. The mixed homogeneity of the three powders was evaluated by particle size distribution and color difference. The GC-MS and LC-MS/MS were used to study the homogeneity of their contents. The best preparation process of particle design powder is:materials easily crushed are smashed for 50 min in the vibrating ultrafine mill with -15℃, then add the materials difficultly crushed into the mill and let them crushed together for 3 min. The particle size range of manmade mixed powder was the largest with the particle size difference being more than 100 microns, the RSD value being 26.07%. The particle size range was more than 50 microns in the powder prepared by pharmacopoeia, and the RSD was nearly 15%. The difference in particle size was only around 4 μm and the RSD value was 3.18%. The color difference test showed that the composite chromatism (dE*) value of the powder prepared by pharmacopoeia was the largest for the RSD was 84.56%. The RSD of manmade mixed powder and the powder prepared by Pharmacopeia were 53.83% and 32.83%, respectively. The RSD value of the particle designed powder's muscone content is about 50% of the other two kinds of powders. The contents of 10 components in powders were determined by LC-MS/MS. The RSD values of the particle designed powder were much smaller than other two kinds of powders. Results indicate that the uniformity of the particle designed powder is better than other two kinds of powders. Chinese medicine particle design technology can effectively improve the uniformity of traditional Chinese medicine powder.
Rubia cordifolia L. has been used as a traditional Chinese medicine for several centuries. In recent years, the resources of wild Rubia cordifolia have been declined sharply due to increased utilization and rising price. Therefore, it is of great urgency to evaluate and protect resources of wild plant of Rubia cordifolia. In our study, sixty-four individuals that represent eight wild populations of Rubia cordifolia L. were analyzed by Start Codon Targeted Polymorphism (SCoT) molecular markers. Genetic distance was calculated by POPGENE 3.2 software, cluster analysis was generated by NTSYS 2.10 software based on UPGMA method and Mantel Test was used to analysis the relationship between the genetic distances and geographical distance among the wild populations. The results showed a high genetic diversity of wild populations of Rubia cordifolia L. in Shaanxi province. A total of 182 bands were produced by 14 primers, among which 163 bands were polymorphic bands, and the percentage of polymorphic bands was 89.56%. The average value of Nei's genetic diversity index (H) was 0.293 6, Shannon's information index (I) was 0.444 6, genetic differentiation coefficient (Gst) was 0.555 3, and the gene flow (Nm) was 0.440 8, the wild populations were ranked by genetic diversity:AK > YL > SL > BJ > TC > YA > WN > XY. Mantel Test analysis demonstrated that the significant correlation was found between the genetic distances and geographical distances (r=0.776 4, P < 0.05). There is a significant correlation between geographical and genetic distances. This study provides a theoretical basis for the protection and development of the resources of wild Rubia cordifolia L. germplasms.
Fragments of the human indoleamine 2, 3-dioxygenase 1 (IDO1) gene 5'-UTR (untranslated 1 245 bp region) promoters were amplified by PCR and cloned into pGL4.20 vector in the construction of reporter vector pGL4-IDO1-luc. A549 cells were transfected with the constructed plasmid and IDO1 inhibitor screening model was established with dual-luciferase reporter assay. Based on the model, we screened natural small molecules which could down-regulate the expression of IDO1 on tumor cells. The anti-tumor activities were examined by MTT, Western blotting and lactic dehydrogenase (LDH) release assays. Toosendanin (NS-180) down regulated the IDO1 expression and inhibited IFN-γ-induced STAT1 and STAT3 phosphorylation in A549 cells. Moreover, NS-180 significantly increased the cytotoxicity of co-cultured NK cells on A549 cells in LDH release assays. In summary, NS-180 is a novel and potent IDO1 inhibitor, which has an antitumor activity for cancer immunotherapies.
Recent studies indicate that insulin-sensitizing activity of TZDs occurs through the inhibition of PPARγ Ser273 phosphorylation mediated by cyclin-dependent kinase 5(Cdk5), which is resulted from the binding activity for PPARγ. While, the side effects of TZDs may be related to the agonistic potency for PPARγ. In this article, 15 target compounds were designed and synthesized based on the structure of PPAR γ partial agonist INT131, with the aim of maintaining the insulin-sensitizing activity and reducing the side effects of INT131. The structures of these compounds were confirmed by 1H NMR and ESI-MS, and their binding activities and agonistic potencies for PPARγ were measured. The binding activity of compound 15 is 88.47% of rosiglitazone, which is similar to INT131 (98.55%), but the agonistic potency of compound 15 is 1.41% of rosiglitazone, obviously lower than INT131 (15.18%).
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