Latest ArticlesStrategies and techniques are extremely important to improve the evaluation efficiency and fully guarantee the consistency of dosage forms. For preparations with a structural feature as solid dosage forms and particulate dispersion systems, the structures of dosage forms are the outcome of the specific formulation and production process, which determine the drug delivery behaviors as well as the pharmacokinetics of the dosage forms. Conventional techniques failed to quantitatively determine the structures of dosage forms. Synchrotron radiation micro-computed tomography is a new generation of structural quantitative characterization technology in revealing the internal structure of dosage forms with unprecedented capability for quantitative characterization of the static and dynamic structures of dosage forms, enabling to reversely analyze the production process and identify the structure differences between the generics and brand products. Based on synchrotron radiation micro-computed tomography methodology researches and applications in static structures (powders, particulate systems, tablets, films, membranes, etc.), dynamic structures (hydration) and de-formulation of production process, we have classified the structures of dosage forms into four levels from macro-scope to molecular level as dosage forms, granular intermediates for formulation, dynamic structure and molecular structures, and proposed dosage form structure based new strategy for consistency evaluation. Along with conventional dissolution/ release behavior similarity, the internal structure consistency ensures high consistency between the brand product and the generics.
The paper was aimed to investigate the association of VDR polymorphisms with tacrolimus (FK506) concentration in Chinese renal transplant recipients. A total of 114 renal transplant recipients receiving tacrolimus were genotyped for VDR rs1540339 and rs2853559 by Agena Bioscience MassARRAY® system and CYP3A5*3 by PCR-RFLP method. Trough concentrations of tacrolimus on day 7 after renal transplantation were collected from clinical data. Statistical analysis was performed with Spearman's correlation, Mann-Whitney U test and Kruskal-Wallis H test. The dose-adjusted concentration of tacrolimus in VDR rs2853559 GA and GG carriers were considerably higher than that of AA carriers. After stratification by CYP3A5*3 genotypes, VDR rs2853559 GA and GG carriers had a higher dose-adjusted tacrolimus concentration than that in AA carriers in CYP3A5 nonexpresser. CYP3A5*3 and VDR rs2853559 explained 45.6% variability of tacrolimus C0/D. In CYP3A5 non-expressers, VDR rs2853559 explained 14.4% variability of tacrolimus C0/D. The results illustrated that VDR rs2853559 polymorphisms was associated with tacrolimus concentrations, and the determination of this SNP may be useful for individualized medicine of tacrolimus.
A series of novel benzimidazole and benzothiazole derivatives were designed and synthesized as inhibitors of SIRT1-SIRT3. The target compounds were synthesized from potassium O-ethyldithiocarbonate through a three-step route. The structures of the obtained compounds were elucidated by 1H NMR and HR-MS. Of all compounds, six showed potent SIRT2-inhibitory activities with IC50 values ranging from 2.8 to 21.2 μmol·L-1. Among them, compound 10c displayed the most potent SIRT2-inhibitory activities (IC50 = 2.8 μmol·L-1), with more than 35-fold selectivity over SIRT1 and SIRT3 (IC50 > 100 μmol·L-1).
Acting as the key step of various cell signaling pathways, protein-protein interaction (PPIs) plays a significant role in the regulation of biological functions. Many of the proteins involved are potential drug targets, therefore manipulation of PPI would greatly a great interest in physiology and pharmacology. Most PPIs could not be directly targeted by small molecule drugs due to their flat and shallow interaction surfaces. Selective regulator may be obtained by extraction and chemical synthesis helical peptide that forms folding substructure scaffold in PPI. However, most peptides when separated from its protein progenitor are not able to maintain its biological active helical structure, but tend to form random coil conformation, which is vulnerable to enzyme and suffer low potency and drugability. By modification through all-hydrocarbon bridged cyclic peptide designating 'stapled peptide', it turned out to be the most effective and directive methodology to solve the drawbacks. Stapled peptide not only can boost its potency, but also its biostability and cell permeability. These significant advantages make peptide stapling an important way of modification, which may definitely generate more and more peptide drug candidates targeting PPIs in the foreseen future. In this paper, chemistry and bioactivity of the stapled peptides reported up-to-date are systematically reviewed and discussed.
Rhizoma Dioscoreae Bulbiferae is a traditional Chinese medicine with hepatotoxicity, but the metabolic profile of fatty acids has not been identified in the rats with liver injury. In this project, a gas chromatography-mass spectrometry method was applied to simultaneous quantification of 16 non-esterified fatty acids (NEFA) and esterified fatty acids (EFA) in the serum of control, ethanol extraction of Rhizoma Dioscoreae Bulbiferae (ethanol extraction, ET) and diosbulbin B (DB)-treated rats. Meanwhile, the change of fatty acid metabolic profile of liver injured rats was analyzed by principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The results of NEFA concentration indicated that the serum concen-trations of palmitic acid (C16:0), stearic acid (C18:0), palmitoleic acid (C16:1n7), oleic acid (C18:1n9), vaccenic acid (C18:1n7), linoleic acid (C18:2n6), linolenic acid (C18:3n3), eicosatrienoic acid (C20:3n6), arachidonic acid (C20:4n6) and docosahexaenoic acid (C22:6n3) in DB-treated rats decreased significantly, while that of C18:2n6 and C20:3n6 obviously increased and that of C20:4n6 and C22:6n3 noticeably dropped in ET-treated rats when compared with control. Furthermore, the results of EFA concentration illus-trated that the serum concentrations of C16:0, C18:0, C20:4n6, C22:6n3 and eicosapentaenoic acid (C20:5n3) in two toxic groups were remarkably decreased when compared with control. The fatty acid meta-bolic profiles of the two toxic groups exhibited significant difference from the normal levels, and the degree of deviation of ET group was higher than that of DB group. More importantly, the results of PLS-DA showed that C20:4n6 and C22:6n3 were important indicators of the hepatotoxicity induced by ET and DB, and the serum concentrations of the two fatty acids had good correlation with the levels of alanine aminotransferase, aspartate aminotransferase and total bilirubin using Pearson's correlation analysis and canonical correlation analysis (CCA). Therefore, C20:4n6 and C22:6n3 were identified as potential biomarkers of ET and DB-induced liver injury. The project can provide a foundation for furture investigation of molecular mechanism of hepato-toxicity caused by Rhizoma Dioscoreae Bulbiferae.
In our study of the chemical constituents of the dried mature fruits of Arctium lappa L., ten compounds were isolated by various chromatography methods and preparative HPLC. Their structures were elucidated as (7R, 8R)-4, 7, 9, 9'-tetrahydroxy-3, 3'-dimethoxy-8-4'-oxyneolign-7'-ene-9'-O-β-D-glucopyranoside (1), (7R, 8R)-4, 7, 9, 9'-tetrahydroxy-3, 3'-dimethoxy-8-O-4'-neolignan-9'-O-β-D-glucopyranoside (2), (7R, 8R)-4, 7, 9, 9'-tertahydroxy-3, 3'-dimethoxy-8-4'-oxyneolignan (3), (7S, 8R)-dihydrodehydrodiconiferylalcohol-4-O-β-D-glucopyranoside (4), (7S, 8R, 7'R, 8'R)-pinoresinol-4, 4'-di-O-β-D-glucopyranoside (5), (8S, 7'S, 8'R)-4, 4', 9'-trihydroxy-3, 3'-dimethoxy-7', 9-epoxylignan-7-oxo-4'-O-β-D-glucopyranoside (6), 2-methoxy-4-hydroxyphenol-1-O-β-D-xylopyranosyl-(1→6)-O-β-D-glucopyranoside (7), 3-methoxy-4-hydroxyphenol-1-O-β-D-xylopyranosyl-(1→6)-O-β-D-glucopyranoside (8), 4-hydroxy-3-methoxybenzylalcohol-4-O-β-D-xylopyranosyl-(1→6)-O-β-D-glucopyranoside (9) and 2-phenethyl β-primeveroside (10) by their spectroscopic data (IR, UV, CD, MS, HR-ESI-MS, and 1D and 2D NMR) and comparison to literature data. Compound 1 is a new 8-O-4'-neolignan. Compounds 2-10 were isolated from the dried mature fruits of Arctium lappa L. for the first time.
Parkinson's disease (PD) is the most prevalent neurodegenerative disorder, with several risk factors contributing to the onset, such as aging, genetics, oxidative stress and neuroinflammation. There are several PD animals that mimics different risk factor. α-Synuclein mutation mice and systemic lipopolysaccharide (LPS) injection mice are two kinds of most common animal models that replicate genetic mutation and neuroinflammation, respectively. However, in these two animal models, the pathogenesis occurred after a long period of stimulation. In the present study, four-month-old α-synucleintransgenic mice (A53T) were intraperitoneally injected with LPS once a week for continuous 8 weeks to simulate the inflammatory response. The behavioral results showed that the time of mice staying on the rod and the performance score were markedly decreased, indicating motor dysfunction. Dopaminergic neuronal function also decreased. It was noted that the movement dysfunction and pathological changes were aggravated in LPS plus α-synuclein challenged mice compared with LPS or α-synuclein stimulated alone, suggesting that the double attack had synergistic effects. Mechanistic study demonstrated that LPS and α-synuclein combined challenge led to obvious neuroinflammatory response and apoptosis, which might contribute to motor and dopaminergic neuronal dysfunction. In addition, differential proteomic study showed that the expression of CD99L2 and COX7RP significantly increased in the midbrain of LPS plus α-synuclein challenged mice, which were closely related to inflammation and apoptosis, and might be involved in the pathogenesis of PD. In conclusion, the present study demonstrated that LPS could potentiate dopaminergic neuronal function in α-synuclein transgenic mice, which might be an ideal method to develop PD animal model.
Complement activation-related pseudo-allergic reactions (CARPA) may represent 77% of all immune-mediated immediate hypersensitivity reactions. Because of the universality of the CARPA response and correlation between it and drug properties, complement activity tests are recommended as one of the tests for immunotoxicity and bioequivalence of drugs. However, in-vivo tests of complement activation are complicated, and the immunological differences between different individuals and between human and animal, making it very necessary to establish a standard and sample evaluation model for testing the effects of drugs on complement activity. In this study, the standard reaction serum was prepared by pooling sera collected from 40 healthy blood donors; a standard positive control was prepared by incubation with a heat-agglutinated IgG and zymosan A; SC5b-9, C5a, C4d and Bb were chosen as the test targets and evaluation criteria of the results was defined, all of these constituted the in-vitro model. By using this in-vitro model, the immunological toxicity of the different prescription of antifungal drug amphotericin B, and voriconazole for injection, and the bioequivalence of amphotericin B liposome formulations were studied.
Lymphoid-specific tyrosine phosphatase (LYP) is a phosphatase that is encoded by protein tyrosine phosphatase non-receptor type 22 and is mainly distributed in lymphoid. In psychological condition, LYP inhibits T-cell receptor (TCR) signaling in association with C-terminal kinase (CSK). While in pathological condition, mutant LYP dissociates with CSK, which augments the inhibition of TCR signaling and leads to autoimmune diseases. Consequently, LYP is now considered as a new target of type Ⅰ diabetes, rheumatic arthritis and Graves disease and some other autoimmune disorders. This review mainly focuses on the development of LYP inhibitors in their structures and activities.
The appropriate regulation of intracellular bioenergy and nutrient metabolism is a basic requirement for proper function and survival of pancreatic beta cells, where mitochondria-endoplasmic reticulum (ER)-associations play crucial roles. Mitochondria are changed dynamically according to intracellular energy and nutrients, which provides material foundation for energy homeostasis; while ER regulates metabolic enzymes and protein synthesis in different pathways. This review sheds light upon the development of mitochondria-ER associations and its role in the regulation of insulin secretion in pancreatic beta cell. The impact on beta cell viability is discussed. Interruption of calcium and redox oxidative species results in reduction of glucose-stimulated insulin secretion, while intracellular calcium levels could be partial altered by depleting calcium from the ER. Given the tight link between ER and mitochondria, the association are crucial to the homeostasis and are an indicator of overall beta cell status, with a potential as a novel drug target for treatment of type 2 diabetes mellitus.