A rapid and sensitive bioanalytical LC–MS/MS method for the quantitation of a novel CDK5 inhibitor 20–223 (CP668863) in plasma: Application to in vitro metabolism and plasma protein-binding studies

A rapid, selective, and sensitive liquid chromatography coupled with tandem mass spectrometry (MS/MS) method was developed and validated for the quantitation of the novel CDK5 inhibitor ‘20–223' in mouse plasma. Separation of analytes was achieved by a reverse-phase ACE Excel C₁₈ column (1.7 μm, 100 × 2.1 mm) with gradient elution using 0.1% formic acid (FA) in methanol and 0.1% FA as the mobile phase. Analytes were monitored by MS/MS with an electrospray ionization source in the positive multiple reaction monitoring mode. The MS/MS response was linear over the concentration range 0.2–500 ng/mL for 20–223. The within- and between-batch precision were within the acceptable limits as per Food and Drug Administration guidelines. The validated method was successfully applied to plasma protein binding and in vitro metabolism studies. Compound 20–223 was highly bound to mouse plasma proteins (>98% bound). Utilizing mouse S9 fractions, in vitro intrinsic clearance (CL_int) was 24.68 ± 0.99 μL/min/mg protein. A total of 12 phase I and II metabolites were identified with hydroxylation found to be the major metabolic pathway. The validate method required a low sample volume, was linear from 0.2 to 500 ng/mL, and had acceptable accuracy and precision.     

辛烷基二甲基苄基季铵盐离子液体对Q235钢的缓蚀性能

利用失重分析、 极化曲线、 电化学阻抗谱和扫描电子显微镜等研究了辛烷基二甲基苄基季铵盐离子液体(ODBA)对1 mol/L盐酸溶液中Q235钢的缓蚀性能, 并分析了其在Q235钢表面的吸附行为. 失重分析结果表明, 随着ODBA浓度的增加, 缓蚀效率逐渐提高, 在ODBA质量浓度为0.2 g/L、 温度为30 ℃时, 缓蚀效率可达95.53%; 电化学测试结果与失重分析结果一致; 热力学研究结果表明, ODBA在碳钢表面的吸附是放热过程, 且遵循Langmuir吸附等温线, 是以化学吸附为主的混合型吸附; 同步热分析测试表明ODBA具有良好的热稳定性.     

Systematic Profiling and Evaluation of Structure-based Kinase–Inhibitor Interactome in Cervical Cancer by Integrating In Silico Analyses and In Vitro Assays at Molecular and Cellular Levels

Various protein kinases are implicated in the pathogenesis of human cervical cancer and many kinase inhibitors have been used to regulate the activity of protein kinases involved in the disease signaling networks. In the present study, a systematic kinase–inhibitor interactome is created for various small-molecule inhibitors across diverse cervical cancer-related kinases by using ontology enrichment, molecular docking, dynamics simulation and energetics analysis. The interactome profile is examined in detail with heatmap analysis and heuristic clustering to derive promising inhibitors that are highly potential to target the kinome of human cervical cancer in a multi-target manner. A number of hit and unhit inhibitors are selected and their cell-suppressing effects are tested against human cervical carcinoma HeLa, from which several inhibitor compounds with high cytotoxicity are successfully identified. A further kinase assay confirms that these inhibitors can generally target their noncognate kinases HER3 and BRaf in cervical cancer with a high or moderate activity; the activity profile are comparable with or even better than that of cognate kinases inhibitors, with IC₅₀ values ranging between 4.8 and 340.6 nM for HER3 and between 37.2 and 638.2 nM for BRaf. This work would help to identify those unexpected kinase–inhibitor interactions in human cervical cancer and to develop new and efficient therapeutic strategy combating the disease.     

甲基丙烯酸二甲氨基乙酯类离子液体 对Q235钢的缓蚀性能

以甲基丙烯酸二甲氨基乙酯为母体、 对氯甲基苯乙烯为季铵化试剂, 合成了一种具有疏水结构的甲基丙烯酸二甲氨基乙酯型离子液体(DEMA). 通过失重实验、 电化学分析、 原子力显微镜(AFM)、 接触角测试和量子化学计算等研究了DEMA在1 mol/L盐酸中对Q235钢的缓蚀性能, 并揭示了其在Q235钢表面的吸附行为和吸附机理. 失重实验结果表明, DEMA在盐酸中对Q235钢具有优异的缓蚀效果, 且在较高温度(60 ℃)下也能保持高效吸附; 电化学实验结果与失重测试结果一致; 接触角测试结果表明, DEMA可明显增强Q235钢表面的疏水性; 分析热力学参数可知, DEMA在Q235钢表面的吸附为自发、 放热过程, 符合Langmuir等温式, 且以化学吸附为主; 量子化学计算结果证实DEMA的结构中包含大量吸附活性位点.     

A bioactive new protostane-type triterpenoid from Alisma plantago-aquatica subsp. orientale (Sam.) Sam.

A new protostane-type triterpenoid, 5β,29-dihydroxy alisol A (1) was isolated from Alisma plantago-aquatica subsp. orientale (Sam.) Sam. as well as 12-deoxyphorbol-13α-pentadecanoate (2). We first report the presence of compound 2 in the genus Alisma. Their structures were established on the basis of 1D and 2D NMR, and HRESIMS spectroscopic analyses. All the isolated compounds were assayed for their inhibitory effects against human carboxylesterase 2 (HCE-2). Compounds 1 and 2 displayed inhibitory activities against HCE-2 with IC₅₀ values of 29.2 and 4.6 μM, respectively. The interaction mechanisms of HCE-2 with compounds 1 and 2 were investigated by molecular docking, respectively.     

Phytochemical compounds and anti-corrosion activity of Veronica rosea

The aim of this work is the phytochemical study of the butanolic extract of the aerial parts of Veronica rosea. Four compounds 1–4 have been isolated using different chromatographic methods. The structures of these compounds were determined by NMR spectral analysis and mass spectroscopy. The adsorption and anticorrosion effects of this extract were investigated towards the corrosion of copper in 1 M HNO₃ aqueous by the weight loss technique and potentiodynamic polarization. The results showed that the butanolic extract is a good inhibitor and the inhibition efficiency increases with increasing of concentration of the inhibitor. The adsorption of this extract on the copper specimen surface was spontaneous and obeyed the Langmuir’s adsorption isotherm. Large value of adsorption equilibrium Constant (K _ads = 35 L g^?1) was obtained. The polarization experiments confirmed the data obtained by gravimetric weight-loss. Tafel plot of polarization curves indicates that the extract acts as a mixed type inhibitor.     

Synthesis of Novel Triazole Incorporated Thiazolone Motifs Having Promising Antityrosinase Activity through Green Nanocatalyst CuI-Fe3O4@SiO2 (TMS-EDTA)

In the present work, novel 5-((1-benzyl-1,2,3-triazol-4-yl)methoxybenzylidene)-2-(arylamino)thiazol-4-one thiazolone incorporated triazole derivatives have been designed as tyrosinase inhibitors. The compounds were synthesized through click reaction in good yield. Moreover, the antityrosinas activity of the synthesized derivatives was evaluated. In the search for establishing a click copper-catalyzed azide/alkyne cycloaddition (CuAAC) reaction under strict conditions, in terms of a novel air-stable, a recyclable and efficient magnetic catalyst was planned for new triazole derivatives as a well-organized copper iodide supported on the functionalized Fe₃O₄@SiO₂ core-shell (CuI/Fe₃O₄@SiO₂(TMS-EDTA) nanoparticles). The engineered nanocatalyst synthesized for the first time and characterized by different methods, including FT-IR spectroscopy, XRD, FESEM, EDX, TEM, TGA, and BET analysis. The excellent catalytic performance in ethanol with high surface area (351.7 m²g⁻¹) and short reaction time for diverse functional groups (120–200 min), no use of toxic solvents, reusability of the catalyst, and using eco-friendly conditions are the advantageous of this work. Moreover,the nanocatalyst can be used at least five times without any significant decrease in the yield of the reaction. The thiazolidine-triazole derivatives 9a , 9c , 9e , and 9 g showed promising tyrosinase inhibitory activity with IC₅₀ values in the range of 5.90–9.81 μM. The compounds were found to be considerably more potent tyrosinase inhibitors than the reference inhibitor kojic acid (IC₅₀ = 18.36 μM).     

Design and synthesis of cyclic acylguanidines as BACE1 inhibitors

Based on the lead compound 1 reported in literature, a series of novel BACE1 inhibitors were designed and synthesized, among which compound 11 exhibited a 14-fold improvement in potency over the lead compound 1. This represents a good lead for the discovery of more promising BACE1 inhibitors for the potential treatment of AD.     

Kinetics of oxidation of benzyl alcohols with molecular oxygen catalyzed by N-hydroxyphthalimide: Role of hydroperoxyl radicals

A kinetic study of the initiated oxidation of benzyl alcohol and cumene by molecular oxygen was performed. The oxidation rate was more enhanced with N-hydroxyphthalimide (NHPI) in the case of cumene than that of benzyl alcohol. HOOH inhibits cumene oxidation and does not affect the rate of oxidation of benzyl alcohol. It was shown that termination chain reactions of phthalimid-N-oxyl radicals (PINO^•) does not occur with RОО^• and proceeds with HOO^•. A kinetic scheme of the process and an equation describing the kinetics of oxidation of benzyl alcohol in the presence of NHPI are proposed. Using the PM7 method, the thermodynamic characteristics of elementary steps of oxidation explaining the obtained results were calculated.     

Rational Design of a Cocktail of Inhibitors against Aβ Aggregation

It has been reported that many molecules could inhibit the aggregation of Aβ (amyloid-β) through suppressing either primary nucleation, secondary nucleation, or elongation processes. In order to suppress multiple pathways of Aβ aggregation, we screened 23 small molecules and found two types of inhibitors with different inhibiting mechanisms based on chemical kinetics analysis. Trp-glucose conjugates ( AS2 ) could bind with fibril ends while natural products ( D3 and D4 ) could associate with monomers. A cocktail of these two kinds of molecules achieved co-inhibition of various fibrillar species and avoid unwanted interference.