Synthesis and biological evaluation of new series of quinazoline derivatives as EGFR/HER2 dual-target inhibitors.

It is generally believed that EGFR/HER2 dual-target inhibitors may overcome the resistance of EGFR TKIs caused by HER2 overexpression. The structure-based synthesis and biological evaluation of quinazoline derivatives as EGFR/HER2 dual-target inhibitors has been studied in this paper. II-1, II-2, III-3, III-4 displayed comparable inhibitory potency against EGFR and HER2 and II-1 showed remarkable antiproliferative activities against NCI-H358/PC-9/Calu-3/NCI-H1781 (EGFR IC50 = 0.30 nM, HER2 IC50 = 6.07 nM, NCI-H358 GI50 = 23.30 nM, PC-9 GI50 = 1.95 nM, Calu-3 GI50 = 23.13 nM NCI-H1781 GI50 = 41.61 nM).

Chicoric Acid Prevents Neuroinflammation and Neurodegeneration in a Mouse Parkinson's Disease Model: Immune Response and Transcriptome Profile of the Spleen and Colon.

Chicoric acid (CA), a polyphenolic acid compound extracted from chicory and echinacea, possesses antiviral, antioxidative and anti-inflammatory activities. Growing evidence supports the pivotal roles of brain-spleen and brain-gut axes in neurodegenerative diseases, including Parkinson's disease (PD), and the immune response of the spleen and colon is always the active participant in the pathogenesis and development of PD. In this study, we observe that CA prevented dopaminergic neuronal lesions, motor deficits and glial activation in PD mice, along with the increment in striatal brain-derived neurotrophic factor (BDNF), dopamine (DA) and 5-hydroxyindoleacetic acid (5-HT). Furthermore, CA reversed the level of interleukin-17(IL-17), interferon-gamma (IFN-γ) and transforming growth factor-beta (TGF-ß) of PD mice, implicating its regulatory effect on the immunological response of spleen and colon. Transcriptome analysis revealed that 22 genes in the spleen (21 upregulated and 1 downregulated) and 306 genes (190 upregulated and 116 downregulated) in the colon were significantly differentially expressed in CA-pretreated mice. These genes were functionally annotated with GSEA, GO and KEGG pathway enrichment, providing the potential target genes and molecular biological mechanisms for the modulation of CA on the spleen and gut in PD. Remarkably, CA restored some gene expressions to normal level. Our results highlighted that the neuroprotection of CA might be associated with the manipulation of CA on brain-spleen and brain-gut axes in PD.

Neuroprotection of chicoric acid in a mouse model of Parkinson's disease involves gut microbiota and TLR4 signaling pathway.

Chicoric acid (CA), a polyphenolic acid obtained from chicory and purple coneflower (Echinacea purpurea), has been regarded as a nutraceutical to combat inflammation, viruses and obesity. Parkinson's disease (PD) is a common neurodegenerative disorder, and the microbiota-gut-brain axis might be the potential mechanism in the pathogenesis and development of PD. The results obtained in this study demonstrated that oral pretreatments of CA significantly prevented the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced motor dysfunctions and death of nigrostriatal dopaminergic neurons along with the inhibition of glial hyperactivation and the increment in striatal neurotrophins. 16S rRNA sequence results showed that CA significantly reduced MPTP-induced microbial dysbiosis and partially restored the composition of the gut microbiota to normal, including decreased phylum Bacteroidetes and genera Parabacteroide, as well as increased phylum Firmicutes, genera Lactobacillus and Ruminiclostridium. Besides, CA promoted colonic epithelial integrity and restored normal SCFA production. We also observed that proinflammatory cytokines such as TNF-α and IL-1ß in the serum, striatum and colon were reduced by CA, indicating that CA prevented neuroinflammation and gut inflammation, in which the suppression of the TLR4/MyD88/NF-κB signaling pathway might be the underlying molecular mechanism. These findings demonstrated that CA had neuroprotective effects on MPTP-induced PD mice possibly via modulating the gut microbiota and inhibiting inflammation throughout the brain-gut axis.

Evaluation of the molluscicidal activities of arylpyrrole on Oncomelania hupensis, the intermediate host of Schistosoma japonicum.

The snail Oncomelania hupensis is the only intermediate host of the highly invasive parasite Schistosoma japonicum. Molluscicide is often used to curb transmission of S. japonicum. Niclosamide, the only World Health Organization (WHO) recognized molluscicide, presents major drawbacks, including high cost and toxicity towards aquatic animals. In the present study, a number of aryl pyrrole derivatives (ADs) were synthesized to serve as potential molluscicides and were tested on O. hupensis. To uncover the underlying mechanisms, adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels were assessed in the soft body of ADs-exposed O. hupensis, using high performance liquid chromatography (HPLC). The effect of C6 on key points of energy metabolism (the activities of complexes I, III, IV and the membrane potential) was determined. We demonstrated that the Compound 6 (C6, 4-bromo-1-(bromomethyl)-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile) exerted the strongest molluscicidal activity against adult O. hupensis at LC50 of 0.27, 0.19, and 0.13 mg/L for 24, 48, and 72 h respectively. Moreover, we found that the bromide on the pyrrole ring of C6 was essential for molluscicidal activity. Furthermore, the ATP content reduced from 194.46 to 139.75 µg/g after exposure to 1/2 LC50, and reduced to 93.06 µg/g after exposure to LC50. ADP, on the other hand, remained the same level before and after C6 exposure. We found that C6, at 1/2 LC50, reduced the membrane potential of O. hupensis, while no significant changes were observed in the activities of complexes I, III, and IV. C6 was identified with excellent activities on O. hupensis. The obtained structure-activity relationship and action mechanism study results should be useful for further compound design and development.

The TDs/aptamer cTnI biosensors based on HCR and Au/Ti3C2-MXene amplification for screening serious patient in COVID-19 pandemic.

The accurate assay of cardiac troponin I (cTnI) is very important for acute myocardial infarction (AMI), it also can be employed as an effective index for screening serious patients in COVID-19 pandemic before fatal heart injury to reduce the mortality. A ratiometric sensing strategy was proposed based on electrochemiluminescent (ECL) signal of doxorubicin (Dox)-luminol or the electrochemical (EC) signal of methylene blue (MB) vs. referable EC signal of Dox. The bio-recognitive Tro4-aptamer ensures the high specificity of the sensor by affinity binding to catch cTnI, and the tetrahedral DNA (TDs) on Au/Ti3C2-MXene built an excellent sensing matrix. An in situ hybrid chain reaction (HCR) amplification greatly improved the sensitivity. The ratiometric sensing responses ECLDox-luminol/CurrentDox or CurrentMB/CurrentDox linearly regressed to cTnI concentration in the range of 0.1 fM-1 pM or 0.1 fM-500 fM with the limit of detection (LOD) as 0.04 fM or 0.1 fM, respectively. Served as the reference signal, CurrentDox reflected the variation of sensor, it is very effective to ensure the accuracy of detection to obviate the false results. The proposed biosensors show good specificity, sensitivity, reproducibility and stability, have been applied to determine cTnI in real samples with satisfactory results. They are worth looking forward to be used for screening serious patient of COVID-19 to reduce the mortality, especially in mobile cabin hospital.

Discovery and Validation of a Novel Target of Molluscicides against Oncomelania hupensis, the Intermediate Host of Schistosoma japonicum.

In this study, 196 strains of actinomycetes isolated from marshland soil samples were tested for molluscicidal activity against Oncomelania hupensis. Five strains demonstrated molluscicidal activity, of which the molluscicidal efficiency of Actinomycetes strain A183 was the maximum. After the fermentation supernatant of actinomycetes A183 was extracted with ethyl acetate (EWEA), the LC50 of the EWEA after leaching for 48 h and 72 h were 0.2688 and 0.2195 mg/L, respectively. The effect of EWEA on the key points of energy metabolism was determined. We noted that 1 mg/L of EWEA (A813) significantly reduced the activity of mitochondrial respiratory chain complex I (P < 0.05), while no significant changes were observed in the activities of complexes II, III, and IV. In addition, EWEA (A813) could decrease the membrane potential of O. hupensis purified mitochondria in vitro. The LC50 of the 3 uncoupler (FCCP, DNP, and Tyrphostin A9) after immersion for 24 h were 0.065, 0.135, and 0.110 mg/L, respectively; LC50 after 48 h treatment was 0.064, 0.124, and 0.082 mg/L, respectively; LC50 after 72 h treatment was 0.063, 0.129, and 0.061 mg/L, respectively, and all uncoupler showed strong molluscicidal activities, demonstrating that the mitochondrial membrane potential uncoupling is a potential target for molluscicides against O. hupensis. Moreover, the molluscicidal active substance of strain A183 needs to be further isolated, purified, and structurally characterized considering its promising potential applications.

A New γ-Glutamyltranspeptidase-Based Intracellular Self-Assembly of Fluorine-18 Labeled Probe for Enhancing PET Imaging in Tumors.

γ-Glutamyltranspeptidase (GGT) is a cell -membrane-associated enzyme which has been recognized as a promising biomarker for the diagnosis of many malignant tumors. Herein, we rationally designed a fluorine-18 labeled small-molecule probe, [18F]γ-Glu-Cys(StBu)-PPG(CBT)-AmBF3 (18F-1G), by applying a biocompatible CBT-Cys condensation reaction and ingeniously decorating it with a GGT-recognizable substrate, γ-glutamate (γ-Glu), for enhancing PET imaging to detect GGT level of tumors in living nude mice. The probe had exceptional stability at physiological conditions, but could be efficiently cleaved by GGT, followed by a reduction-triggered self-assembly and formation of nanoparticles (NPs) progressively that could be directly observed by transmission electron microscopy (TEM). In in vitro cell experiments, 18F-1G showed GGT-targeted uptake contrast of 2.7-fold to that of 18F-1 for the detection of intracellular GGT level. Moreover, the higher uptake in GGT overexpressed HCT116 tumor cells (∼4-fold) compared to GGT-deficient L929 normal cells demonstrated that 18F-1G was also capable of distinguishing some tumor cells from normal cells. In vivo PET imaging revealed enhanced and durable radioactive signal in tumor regions after 18F-1G coinjecting with 1G, thus allowing real-time detection of endogenous GGT level with high sensitivity and noninvasive effect. We anticipated that our probe could serve as a new tool to investigate GGT-related diseases in the near future.

Isoliquiritigenin-induced vasodilation by activating large-conductance Ca2+ -activated K+ channels in mouse mesenteric arteries.

Isoliquiritigenin (ISL) is a flavonoid substance with a chalcone structure, which exerts anti-tumour, anti-oxidation and anti-inflammatory activity. The large-conductance calcium-activated potassium channel (BKCa ) is an important potassium channel with negative feedback regulation on the vascular smooth muscle cells (VSMCs) membrane. The activation of BKCa channel causes the hyperpolarization of VSMCs. It plays an important role in relaxation of blood vessels. Previous studies have shown that ISL causes the relaxation of the aorta and the basilar artery of the rat. However, there have not been studies on regulation of ISL in mesenteric arteries. To examine whether ISL causes the relaxation of the mesenteric artery of mice, we recorded vasodilation of mouse mesenteric arterial rings with a myograph. After contraction of arterial rings with phenylephrine, we added ISL to the arterial rings and measured its relaxation effect. To further examine which channel was involved in this relaxation effect, we tested the effects of ISL on endothelium-dependent and endothelium-independent vasodilation. Then we used BKCa channel blockers tetraethylammonium and iberiotoxin, to detect whether the BKCa channel is involved in ISL-induced vasodilation. Mesenteric arterial smooth muscle cells were isolated by enzyme digestion. Bis-(1, 3-dibutylbarbituric acid) trimethine oxonol staining was used to measure membrane potential of mesenteric arterial smooth muscle cells. We identified a vasodilation effect caused by ISL on mouse mesenteric arterial rings pre-contracted by phenylephrine in a concentration-dependent manner, with an EC50 of 13.71 ± 1.1 µmol/L. The vasodilation effect of ISL is endothelium-independent. K+ channel inhibitors tetraethylammonium and iberiotoxin reduced the vasodilation induced by ISL which suggested the involvement of BKCa channel.

Discovery and biological evaluation of novel G protein-coupled receptor 119 agonists for type 2 diabetes.

G protein-coupled receptor 119 (GPR119) is a member of the GPCR family promising to be the target for type 2 diabetes mellitus (T2DM) treatment. In this work, 30 novel compounds were designed, synthesized, and evaluated by in vitro cAMP activation assay, where compounds II-14 and II-18 showed the best potency with EC50 values of 69 and 99 nM, respectively. In the oral glucose tolerance test, compound II-18 showed even more efficacious activity in lowering blood excursions than MBX-2982 at a fixed dose of 30 mg/kg. Here, we report that compound II-18 with its excellent agonistic activity and its orally effective activity in decreasing blood glucose deviations may serve as a potent GPR119 agonist for the treatment of T2DM.

Design, synthesis, and evaluation of a series of novel phenylpropanoic acid derivatives agonists for the FFA1.

Free fatty acid 1 (FFA1/GPR40) has attracted extensive attention as a novel target for the treatment of type 2 diabetes for its role in the enhancement of insulin secretion with glucose dependency. Aiming to develop novel potent FFA1 agonists, a new series of phenylpropionic acid derivatives were designed and synthesized on the basis of the modification of chemical cement of TAK-875, AMG-837, and LY2881835. Among them, most promising compounds 7, 14, and 15 were obtained with EC50 values of 82, 79, and 88 nM, exhibiting a powerful agonistic activity compared to TAK-875 (95.1 nM). During Oral glucose tolerance test in normal mice, compound 7, 14, and 15 had significant glucose-lowering effect at the dose of 50 mg/kg. Furthermore, compound 15 (50 mg/kg) also significantly improved in glucose tolerance in type 2 diabetic mice. Herein, we reported the discovery and optimization of a series of potent FFA1 agonists. The discovery supported further exploration surrounding this scaffold.

Design, synthesis, and biological evaluation of 2-(4-(methylsulfonyl)phenyl)pyridine derivatives as GPR119 agonists.

This study describes the design, synthesis, and biological evaluation of a series of novel small molecule GPR119 agonists with improved potency and moderate physiochemical characteristics. Among them, the most promising compounds 19 and 20 were obtained with EC50 values of 75 and 25 nM, respectively, in vitro cAMP assays and effectively decreased blood glucose excursion in oral glucose tolerance test (OGTT) of normal mice. Furthermore, in OGTT with type 2 diabetic mice induced by streptozotocin and high-fat diet, compound 19 also showed significant reduction in blood glucose level compared to vehicle control group, which demonstrated an attractive in vitro and in vivo profile for further development.

Determination of an isonicotinylhydrazide derivative, a novel positive inotropic compound, in mouse plasma by LC-MS/MS and its application to a pharmacokinetics study.

Heart failure (HF) is one of the most serious health problems worldwide. A new positive inotropic compound, an isonicotinylhydrazide derivative (AF-HF001) was designed recently. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of the target analyte in mouse plasma. Samples were prepared by one step precipitation with ethyl acetate and stored in acetonitrile. Chromatographic analysis was carried out on a Hypersil Gold C18 column (2.1 mm × 50 mm, 3 µm) with a gradient mobile phase consisting of acetonitrile and 0.1% aqueous formic acid. The analyte was detected by selective reaction monitoring (SRM) mode with target quantitative ion pair of m/z 292.1 → 148.2, using praziquantel as the internal standard (IS) m/z 313.1 → 203.2. Good linearity (r = 0.995) was observed over a wide concentration range. The validation of method showed acceptable recovery and precision. The method has been then applied to a very first pharmacokinetic assay of AF-HF001 in mice.

Synthesis and biological evaluation of novel 5,6-dihydropyrimido[4,5-f]quinazoline derivatives as potent CDK2 inhibitors.

As serine/threonine kinase, the cyclin dependent kinase 2 (CDK2) is a promising target for various diseases such as cerebral hypoxia, cancer, and neurodegenerative diseases. Here we reported the structure-based synthesis and biological evaluation of novel 5,6-dihydropyrimido[4,5-f]quinazoline derivatives as CDK2 inhibitors, which exhibited potent CDK2 inhibitory activities, as well as anticancer activities in low concentration against two human cancer cell lines (MCF-7 and HCT116). In particular, compounds 11a and 11f (IC50 values of 0.11 and 0.09 µM for CDK2, respectively) have demonstrated significantly inhibitory potency against CDK2 and have showed great inhibitory activities against MCF-7 and HCT116 cell lines.

Synthesis and SAR of 4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline derivatives as potent and selective CDK4/6 inhibitors.

CDK4/6 pathway is an attractive target for development of anti-cancer drugs. Herein, we reported the design and synthesis of a series of 4,5-dihydro-1H-pyrazolo [4,3-h]quinazoline derivatives as selective CDK4/6 inhibitors. Applied with the optimizing strategy to the initial scaffold, it is found that compound 13n is able to selectively inhibit CDK4 and CDK6 with IC50 values 0.01 and 0.026 µM, respectively. The compound showed good anti-proliferative activity when tested in a panel of tumor cell lines with CDK4/6 related mechanism of action, the results clearly suggest that compound 13n works much better than Ly2385219 which is a selective CDK4/6 inhibitor. This compound was also found to have favorable pharmacokinetic parameters. Taken together, compound 13n could be selected for further preclinical evaluation.

Transition-Metal-Free Trifluoromethylation of Aldehyde Derivatives with Sodium Trifluoromethanesulfinate.

A metal-free and cost-effective synthetic protocol for the trifluoromethylation of N,N-disubstituted hydrazones with Langlois's reagent (CF3SO2Na) to afford the corresponding functionalized trifluoromethyl ketone hydrazones has been established. It is proposed that a radical/SET mechanism proceeding via a trifluoroalkyl radical may be involved in the reaction. Applications of the methodology in industry will be found and the development of new methods for trifluoromethylation with Langlois's reagent will be continued in our laboratory.

Interleukin 10 protects primary melanocyte by activation of Stat-3 and PI3K/Akt/NF-κB signaling pathways.

Vitiligo is a common melanocytopenic disorder of the skin, with acquired focal depigmentation. Normal human skin relies on melanocytes to provide photoprotection and thermoregulation by producing melanin. Interleukin 10 (IL-10) is a pleiotropic immunoregulatory cytokine drawing more and more researchers' attention. The present study was conducted to investigate the effects of IL-10 on melanocytes and elucidate the underlying mechanisms. We proved that IL-10 play no role in regulating melanogenesis of normal human foreskin-derived epidermal melanocytes (NHEM). IL-10 stimulation activated the JAK/Stat-3 and PI3K/Akt signaling pathways. Moreover, IL-10 treatment increased translocation of p65 NF-κB into the nuclear compartment, and up-regulated expression of the pro-survival proteins Bcl-2 and Bcl-xL. IL-10 restored anti-apoptotic proteins expression and suppressed cytochrome c release in H2O2-induced apoptosis. In conclusion, IL-10 may provide pro-survival cues to melanocytes and be applied in the treatment of vitiligo and other depigmenting disorders.

Cross-talk between 5-hydroxytryptamine and substance P in the melanogensis and apoptosis of B16F10 melanoma cells.

Skin pigmentation is a complex process controlled by many different factors. Substance P (SP) regulates many biological functions, including melanogenesis and stress. Our previous study indicated that regulation of SP on melanocyte function was mediated by neurokinin 1 receptor (NK1 receptor). Substantial evidence has accumulated that psychological stress can be associated with skin pigmentation, so that the impact of 5-hydroxytryptamine (5-HT), one of the important factors participating in stress process, on melanogenesis has also been concerned. It has been reported that 5-HT induces melanin synthesis via 5-HT2A receptor. Furthermore, 5-HT2A receptor and NK1 receptor are G-protein coupled receptors (GPCRs) and both expressed on melanocyte, the present study was designed to investigate whether SP has influence on the adjustment function of 5-HT. Our data demonstrated that, SP inhibited 5-HT2A receptor expression to neutralize the pro-melanogenesis effect of 5-HT on B16F10 cells. The up-regulation of NK1 receptor expression was simultaneous with the down-regulation of 5-HT2A receptor treated by SP. This inhibition of 5-HT2A receptor expression by SP could be reversed by NK1 receptor antagonist Spantide I. Our studies indicated that SP could directly induce B16F10 cells apoptosis in vitro. 5-HT and 5-HT2A receptor agonist could mitigate this apoptotic effect of SP. It is the strong evidence of possible cross-talk between GPCRs and giving enlightenments when screening desirable drugs for target receptors.

Oxadiazole-2-oxides may have other functional targets, in addition to SjTGR, through which they cause mortality in Schistosoma japonicum.

BACKGROUND: Schistosomiasis is one of the world's major public health problems. Besides praziquantel (PZQ), there is currently no other effective treatment against schistosomiasis. The development of new antischistosomal agents to curb the emergence of PZQ resistance should be a high priority. Oxadiazole-2-oxides have been identified as potential antischistosomal reagents, with thioredoxin glutathione reductase (TGR) being one of their molecular targets. METHODS: To develop novel treatment reagents against Schistosoma japonicum, 30 novel oxadiazole-2-oxides were synthesised and their antischistosomal activities on juvenile and adult S. japonicum were evaluated in vitro and in vivo. Their inhibitory activities against S. japonicum thioredoxin glutathione reductase (SjTGR) were also analysed. RESULTS: Most of the oxadiazole-2-oxides showed good juvenile and adult S. japonica killing activities in vitro. However, the antischistosomal effects of these compounds were not positively correlated with either their inhibition of SjTGR, or with nitric oxide (NO) release. Compounds 4a, 4b, 7c, 13, 16 and 20 resulted in 87.7%, 83.1%, 87.1%, 84.6%, 90.8% and 69.5%, respectively, mortality in the adult worms, when used to treat infected mice at schistosomula stage. These mortality rates were similar to or higher than that of artemisinin. Furthermore, compounds 4a and 16 resulted in 66.7% and 69.4% reductions in the worm burdens, respectively, when infected mice were treated at the adult worm stage. These treatment effects were similar to PZQ. No differences in activity of the oxadiazole-2-oxides against female and male adult worms were observed. The toxicity of the oxadiazole-2-oxides on mammalian cells appeared to be similar to, or less than, that of PZQ. CONCLUSIONS: The antischistosomal activity of the oxadiazole-2-oxides does not depend on NO production or the inhibition of SjTGR activity. There may be other functional targets of the oxadiazole-2-oxides in S. japonicum. Several of the novel oxadiazole-2-oxides synthesised in this study could be used to develop novel antischistosomal drugs and explore potential molecular targets.

Iron-catalyzed direct α-arylation of α-amino carbonyl compounds with indoles.

A mild and general α-arylation of α-amino carbonyls with indoles catalyzed by Fe(ClO4)3 has been developed. C-H activation is smoothly fulfilled by using TBHP as the oxidant with good yields. Two hydrogen dissociations make this transformation more environmentally benign because of high atom efficiency.

Gene Expression Profiling of H9c2 Cells Subjected to H2O2-Induced Apoptosis with/without AF-HF001.

Heart failure represents a major health problem. The development of new drugs to treat this condition is essential. We previously discovered that AF-001 attenuates the cardiac defects caused by heart failure in zebrafish. In this paper, we report the identification of AF-HF001, an AF-001 derivative, and its effects on live cardiomyocytes subjected to oxidative damage. The in vitro results demonstrated that AF-HF001 attenuates the production of reactive oxygen species (ROS) and the myocardial cell apoptosis. A DNA microarray was performed to broadly analyze gene expression after H2O2 treatment with or without AF-HF001. Hierarchical clustering analysis revealed that AF-HF001 modifies the expression of certain genes (Ndufs2, Ndufb6, Ndufb8, Ndufa13, Ndufs3, Ndufs5, TPM1, MYH14, RyR1, and TIMP4) related to ROS production, cardiac contractility and extracellular matrix remodeling. AF-HF001 ameliorates oxidative damage, which may be related to the mitogen-activated protein kinase (MAPK) family and the intrinsic mitochondrial pathway. Altogether, this study suggests that AF-HF001 exhibits potential as a clinical drug candidate for the treatment of heart failure.