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A series of pyrazole-thiophene derivatives exhibiting good Akt inhibitory activities were obtained on the basis of conformational restriction strategy, leading to the discovery of compound 1d and 1o which showed excellent in vitro antitumor effect against a variety of hematologic cancer cells and their potential of inducing apoptosis, blocking the cell cycles at S phase and significantly inhibiting the phosphorylation of downstream biomarkers of Akt kinase of cancer cells. Amongst, compound 1o also exhibited good PK profiles and inhibited about 40% tumor growth in MM1S xenograft model. Compound 1o might be a potential candidate for further development.

Purpose In order to get novel EGFR inhibitors exerting more potency in tumor hypoxia than in normoxia. Methods A series of 4-[(2-nitroimidazole-1H-alkyloxyl)aniline]-quinazolines were designed and synthesized, and their in vitro cytotoxicity and EGFR inhibitory activity were evaluated. Molecule docking study was performed for the representative compound. Results The structure-activity relationship (SAR) studies revealed that compounds bearing both meta-chloride and para-(2-nitroimidazole-1H-alkyloxy) groups on the aniline displayed potent inhibitory activities both in enzymatic and cellular levels. The most promising compound 16i potently inhibited EGFR with an IC50 value of 0.12 μM. Meanwhile, it manifested more potent cytotoxicity than the positive control lapatinib under tumor normoxia and hypoxia conditions (IC50 values of 1.59 and 1.09 μM against A549 cells, 2.46 and 1.35 μM against HT-29 cells, respectively). The proposed binding model of 16i in complex with EGFR was displayed by the docking results. Conclusion This study provides insights for developing hypoxia-activated kinase inhibitors.

A series of 3,4-disubstituted piperidine derivatives were obtained based on a conformational restriction strategy and a lead compound, A12, that exhibited potent in vitro and in vivo antitumor efficacies; however, obvious safety issues limited its further development. Thus, systematic exploration of the structure-activity relationship of compound A12, involving the phenyl group, hinge-linkage, and piperidine moiety, led to the discovery of the superior 3,4,6-trisubstituted piperidine derivative E22. E22 showed increased potency in Akt1 and cancer cell inhibition, remarkably reduced human ether-a-go-go-related gene blockage, and significantly improved safety profiles. Compound E22 also exhibited good kinase selectivity, had a good pharmacokinetic profile, and displayed very potent in vivo antitumor efficacy, with over 90% tumor growth inhibition in the SKOV3 xenograft model. Further mechanistic studies were conducted to demonstrate that compound E22 could significantly inhibit the phosphorylation of proteins downstream of Akt kinase in cells and tumor tissue from the xenograft model.

Through virtual screening, we identified the lead compound MCL1020, which exhibited modest CHK1 inhibitory activity. Then a series of 5-(pyrimidin-2-ylamino)picolinonitrile derivatives as CHK1 inhibitors were discovered by further rational optimization. One promising molecule, (R)-17, whose potency was one of the best, had an IC50 of 0.4 nM with remarkable selectivity (>4300-fold CHK1 vs. CHK2). Compound (R)-17 effectively inhibited the growth of malignant hematopathy cell lines especially Z-138 (IC50: 0.013 μM) and displayed low affinity for hERG (IC50 > 40 μM). Moreover, (R)-17 significantly suppressed the tumor growth in Z-138 cell inoculated xenograft model (20 mg/kg I.V., TGI = 90.29%) as a single agent with body weight unaffected. Taken together, our data demonstrated compound (R)-17 could be a promising drug candidate for the treatment of hematologic malignancies.

Multiple sclerosis (MS) is a disease of the autoimmune-mediated disorder in the central nervous system, for which no effective therapeutic agent is currently available. The regulation of macrophage polarization toward M2 is a general benefit for treating MS. The gene biomarker-based phenotypic screening approach was developed, and 3,4-disubstituted piperidine derivative S-28 was identified as a lead compound modulating macrophage M2 polarization. Further SAR studies resulted in the discovery of the most potent modulator D11 that showed good oral bioavailability and significant in vivo therapeutic effects. Mechanistic studies demonstrated that the M2 polarization macrophages modulated by D11 mainly functioned through inhibiting the proliferation of T-cells and activating the phosphorylation of Stat3 and Akt. Therefore, the gene biomarker-based phenotypic screening was demonstrated as a promising tool for the discovery of novel macrophage M2 polarization modulators. Compound D11 may serve as a promising starting point for the development of therapeutics to treat MS.

The potential of specific proteasome inhibitors to act as anti-cancer agents has attracted intensive investigations. The proteasome can be covalently inhibited by epoxyketone derivatives via a two-step reaction. Several computational approaches have been developed to mimic the covalent binding event. Compound 1 composed of a six-membered heterocyclic ring was designed by using covalent docking. With a possible different binding mode from the clinical compound Carfilzomib, it occupied the S5 pocket of 20S proteasome and showed favorable inhibitory activity. Subsequently optimization and evaluation were taken place. Among these compounds, 11h demonstrated extraordinary in vitro inhibitory activity and selectivity, and good in vivo proteasome inhibitory activity, a favorable pharmacokinetic profile and xenograft tumor inhibition. The possible binding pattern of compound 11h against proteasome was further fully explored via calculations, providing a theoretical basis for finding potent proteasome inhibitors.

Macrocyclization has been frequently utilized for optimizing peptide or peptidomimetic-based compounds. In an attempt to obtain potent, metabolically stable, and orally available proteasome inhibitors, 30 oprozomib-derived macrocyclic peptides with structural diversity in their N-terminus and linker were successively designed and synthesized for structure–activity relationship (SAR) studies. As a consequence, the macrocyclic peptides with N-methyl-pyrazole (24p, 24x), imidazole (24t), and pyrazole (24v) as their respective N-termini exhibited favorable in vitro activity and metabolic stability, which translated into their potent in vivo proteasome inhibitory activity after oral administration. In particular, compound 24v, as the most distinguished one among this series, displayed excellent chymotrypsin-like (ChT-L, β5) inhibitory potency (IC50 = 16 nM), low nanomolar antiproliferative activity against all three of the tested cell lines, and superior metabolic stability in mouse liver microsome (MLM), as w...

New catalytic systems that contain incompatible catalytic sites were constructed by the in situ polymerization of acidic and basic polymers into metal-organic frameworks, which resulted in highly porous, recyclable, and durable catalytic composites with excellent compartmentalization, so that opposing agents were spatially isolated. These synthesized hybrid catalysts exhibited excellent catalytic activity for one-pot "wolf and lamb" reactions (deacetalization/Knoevenagel or Henry), which was attributed to their unique characteristic of having a locally homogeneous, but globally heterogeneous, structure.

CXCR1 and CXCR2 are CXC chemokine receptors (CXCRs), corresponding to cytokines of the CXC chemokine family. CXCR2 was found to be 77% homologous to CXCR1. Antagonism of the chemokine receptor CXCR2 has been proposed as a new strategy for the treatment of metastatic cancer. In order to find a CXCR2 selective antagonist, a bicyclo[2.2.1]heptane containing N,N′-diarylsquaramide (compound 2e) was identified by introducing a bridge ring system into the N,N′-diarylsquaramide skeleton, and it exhibited good CXCR2 antagonistic activity (CXCR2IC50 = 48 nM) and good selectivity (CXCR1IC50/CXCR2IC50 = 60.4). Furthermore, an in vitro biological assay of compound 2e also demonstrated its good anti-cancer metastatic effect against the pancreatic cancer cell line CFPAC1. In addition, compound 2e showed an extremely high stability in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF), as well as in rat and human plasma, but not in rat and human liver microsomes. In vivo pharmacokinetic studies in rats indicated that 2e has an excellent PK profile (10 mg kg−1 po, Cmax = 2863 ng mL−1, t1/2 = 2.58 h). Moreover, molecular docking was further implemented to propose the preponderant configuration of compound 2e, providing important and useful guidelines for further development.

A series of novel α-terpineol derivatives were designed and synthesized through structural derivatization of the tertiary hydroxyl moiety or reduction of the double bond. Of the resulting compounds, eight compounds enhanced relaxation of airway smooth muscle (ASM) compared to the α-terpineol precursor, and four compounds (4a, 4d, 4e, and 4i)were superior or comparable to aminophylline at a concentration of 0.75 mmol/L. Assays for 3′-5′-Cyclic adenosine monophpsphate (cAMP) activation revealed that some representative α-terpineol derivatives in this series were capable of upregulating the level of cAMP in ASM cells. Further in vivo investigation using the asthmatic rat model, illustrated that treatment with the compounds 4a and 4e resulted in significantly lowered lung resistance (RL) and enhanced dynamic lung compliance (Cldyn), two important parameters for lung fuction. Moreover, treatment with 4e downregulated the levels of both IL-4 and IL-17. Due to its several favorable physiological functions, including ASM relaxation activity, cAMP activation capability, and in vivo anti-asthmatic efficacy, 4e is a promising remedy for bronchial asthma, meriting extensive development.

Metal–organic framework (MOF)-based asymmetric heterogeneous catalysts have attracted increasing attention; however, some challenges need to be addressed, such as the rigidity of chiral auxiliary groups within MOFs and the lack of a versatile methodology for the facile construction of chiral MOFs. To address this issue, in this study, a mechanistically distinct approach was developed for heterogenizing linear chiral catalysts in the MOF cavities, rather than the synthetic modification of MOFs. This strategy involves the facile in situ polymerization of pre-impregnated chiral monomers within MOFs, affording the hybrid composites featuring a locally homogeneous and globally heterogeneous structure. The introduced chiral catalytic sites would be flexible in the pores, offering an opportunity to exploit its cooperative effect with the nearby catalytic metal nodes. The advantages of the chiral polymer/MOF composites were clarified by their excellent diastereo- and enantioselectivities and recycling capacity for catalyzing the asymmetric Aldol reaction, which were superior to those of individually heterogeneous and homogeneous catalysts.

S-nitrosylation is a posttranslational modification of protein cysteine residues leading to the formation of S-nitrosothiols and its detection is crucial to understanding of redox regulation and NO-based signaling. Prototypical detection methods for S-nitrosylation are always carried out ex situ. However, the reversible nature and the tendency of transnitrosylation highlight the necessity of its probing in intact live biological contexts. Herein we provide a fluorogenic chemical probe for the detection of S-nitrosylation in live endothelial cells. The probe is weakly emissive alone and becomes highly fluorescent only after undergoing a reaction with S-nitrosothiols in live cellular environments. This probe features high degrees of specificity and desirable sensitivity. Furthermore, it has been successfully applied to image the dynamic change of protein S-nitrosylation in live endothelial cells. The applicability of the probe in complex biological systems has been additionally verified by imaging a known target of S-nitrosylation, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), in live cells. Due to the versatility exemplified, this probe holds great promise for exploring the role of protein S-nitrosylation in the pathophysiological process of a variety of vascular diseases.

Natural products remain the largest resources of lead compounds that can be used to develop novel anticancer drug candidates. Based on deacetylisovaltratum, a natural product with promising anticancer activity, herein we designed and synthesized of a series of valepotriate derivatives with a novel skeleton from commercially available genipin. In addition, a structure–activity relationship study demonstrated the importance of an epoxy group on the C1-position and the preferable size of the sidechain ((5-methylhexanoyl)oxy) on the C-7 position of valepotriates for their cytotoxic activities. The most potent compound 1e showed moderate to good IC50 values against various cancer cells, ranging from 10.7 to 50.2 μM, which are comparable to that of deacetylisovaltratum. Additionally, we demonstrate that mitochondrion-mediated apoptosis would be its mechanism of action, thus enlightening the further development of novel valepotriate derivatives.

Based on our previous work, a series of N-phenyl-3-methoxy-4-pyridinone derivatives were designed as orally bioavailable dual functional agents for therapy of Alzheimer’s disease, through introducing alkyloxy moiety into 4-pyridinone ring to avoid the possible phase II metabolism of 3-hydroxy-4-pyridinone in lead compound 3-hydroxy-2-methyl-1-(4-(3-(pyrrolidin-1-yl)propoxy)phenyl)-pyridin-4(1H)-one (4). In vitro studies indicated that most of these compounds exhibit excellent H3 receptor antagonistic activities and potent self-induced Aβ1-40/Aβ1-42 aggregation inhibitory activities. In particular, 3-methoxy-1-(4-(3-(pyrrolidin-1-yl)propoxy)phenyl)-pyridin-4(1H)-one (7i) demonstrated IC50 value of 0.52 nM in H3R antagonism and good selectivity over other histamine receptor subtypes. The transmission electron microscopy (TEM) images showed that compound 7i can inhibit self-mediated Aβ1-40/Aβ1-42 aggregation efficiently. As expected, it exhibited desirable pharmacokinetic properties in plasma and good BBB permeability. Furthermore, compound 7i can efficiently block (R)-α-methylhistamine- induced dipsogenia and reverse scopolamine-induced learning deficits of rats. All above results indicated that compound 7i was a promising orally bioavailable dual functional agents with potential use in the treatment of Alzheimer’s disease.

A novel series of 2-subsituted benzothiazole derivatives as MTDLs were designed and synthesized for AD therapy using pharmacophore-combine strategy. The benzothiazole moiety from ThT and the HPO moiety from deferiprone were connected with vinyl linker to achieve target compounds. The biological evaluation results revealed that the majority of them demonstrated desirable triple functions by interfering with Aβ aggregation, oxidative stress and metal dyshomeostasis simultaneously. The two most attractive compounds 9c and 9i exhibited excellent self-Aβ1–42 aggregation inhibitory activity, efficient ABTS˙+ scavenging activity, potent biometals chelating properties, as well as disaggregation activity against previous formed Aβ1–42 fibrils. In addition to these advantages, both of them displayed no cytotoxicity to human glioma U251 cells up to 50 μM, thereby meriting further investigation.

Herein, we reported the preparation and in vitro development of a novel series of quinoline-based mTOR inhibitors, some of which were obtained via introducing a ring-opening strategy. As for enzymatic activity, more than half of these quinoline derivatives exhibited moderate to potent inhibition against mTOR. Among them, six compounds showed IC50 values below 50 nM. In particular, several quinolines exhibited remarkably enhanced anti-proliferative activities against all the three tested tumor cell lines in contrast to the initial lead 9. As a representative in this series, compound 24 demonstrated IC50 values of 0.11, 0.17 and 0.04 μM against HCT-116, PC-3 and MCF-7 cell lines, respectively. Besides, compounds 17 and 24 were identified to be selective over class I PI3Ks. Further Western blot analysis validated the dual inhibition of mTORC1 and mTORC2 as a result of compound 24 treatment in the MCF-7 cell line, which was beneficial for conquering the S6K/IRS1/PI3K negative feedback loop. Moreover, acceptable stability was displayed by compound 17, another representative of this series, in simulated intestinal fluid (SIF), simulated gastric fluid (SGF), as well as rat liver microsome (RLM). By virtue of the favorable biological profiles, several quinolines merit further in vivo investigation.

With the aim of overcoming the instability and poor membrane permeability of epigallocatechin-3-gallate (EGCG), a series of prodrugs of EGCG and its derivatives (pro-EGCGs) were designed and synthesized, and their protective effect on melanocytes against H2O2-induced cell damage was biologically evaluated. The enhanced potency of pro-EGCGs could be clearly observed, and the most potent compound, 3c, showed excellent protective effect of melanocytes against H2O2-induced cell death, and good effect on lactate dehydrogenase (LDH) release from melanocytes under oxidant stress. In addition, compounds 14b and 14c, which are the parent compounds of 3b and 3c, also showed good inhibitory activities against JAK1, JAK2 and JKA3, which are potential therapeutic targets for anti-vitiligo agents, demonstrating the promising perspective of 3b and 3c as both anti-oxidant and immuno-related agents for anti-vitiligo treatment.

A series of quinoline derivatives featuring the novelty of introducing intra-molecular hydrogen bonding scaffold (iMHBS) were designed, synthesized and biologically evaluated for their mTOR inhibitory activity, as well as anti-proliferative efficacies against HCT-116, PC-3 and MCF-7 cell lines. As a result, six compounds exhibited significant inhibition against mTOR with IC50 values below 35nM. Compound 15a, the most potent mTOR inhibitor reported herein (IC50=14nM), also displayed the most favorable cellular activities, with the IC50 values of 0.46, 0.61 and 0.24μM against HCT-116, PC-3 and MCF-7, respectively. Besides, several compounds in this series were identified to be selective over class I PI3Ks. Further western blot analysis of 16b, a representative compound in this series, highlighted their advantage in surmounting the S6K/IRS1/PI3K negative feedback loop upon dual inhibition of mTORC1 and mTORC2. In addition to the remarkable activity, 15a demonstrated acceptable stability in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and liver microsome, thereby being valuable for extensive in vivo investigation.

Accumulating evidence suggests that formation of peroxynitrite (ONOO(-)) in the cerebral vasculature contributes to the progression of ischemic damage, while the underlying molecular mechanisms remain elusive. To fully understand ONOO(-) biology, efficient tools that can realize the real-time tracing of endogenous ONOO(-) fluxes are indispensable. While a few ONOO(-) fluorescent probes have been reported, direct visualization of ONOO(-) fluxes in the cerebral vasculature of live mice remains a challenge. Herein, we present a fluorescent switch-on probe (NP3) for ONOO(-) imaging. NP3 exhibits good specificity, fast response, and high sensitivity toward ONOO(-) both in vitro and in vivo. Moreover, NP3 is two-photon excitable and readily blood-brain barrier penetrable. These desired photophysical and pharmacokinetic properties endow NP3 with the capability to monitor brain vascular ONOO(-) generation after injury with excellent temporal and spatial resolution. As a proof of concept, NP3 has enabled the direct visualization of neurovascular ONOO(-) formation in ischemia progression in live mouse brain by use of two-photon laser scanning microscopy. Due to these favorable properties, NP3 holds great promise for visualizing endogenous peroxynitrite fluxes in a variety of pathophysiological progressions in vitro and in vivo.

A novel series of 4-alkynyl-quinoline derivatives were designed, synthesized and biologically evaluated for their PI3Kα inhibitory activities and anti-proliferative effects against two cancer cell lines PC-3 and HCT-116. Most of them showed potent PI3Kα inhibitory activities with IC50 values at low nanomolar level and good to excellent anti-proliferative effects against both cell lines. Among them, compound 15d, the most potent one, was selected for further biological evaluation. As a result, 15d displayed strong inhibitory activity against other class I PI3K isoforms (PI3Kβ, PI3Kγ and PI3Kδ) and mTOR with an acceptable kinase selectivity profile. Moreover, the western blot assay indicated that the phosphorylation of Akt, another downstream effector of PI3K, can be remarkably suppressed by 15d at cellular level. All these experimental results suggested that 15d is a potent PI3K/mTOR dual inhibitor and could serve as a promising lead compound for the development of anticancer agents.

A novel series of 3-(pyrrolopyridin-2-yl)indazole derivatives were synthesized and biologically evaluated for their anti-proliferative effects on five human cancer cell lines. As a result, all of them exhibited vigorous potency against HL60 cell line with IC50 values ranging from singe digital nanomolar to micromolar level. Besides, a majority of them displayed modest to good antiproliferative activities against the other four cell lines, including KB, SMMC-7721, HCT116, and A549. Particularly, compound 2y, as the most distinguished one in this series, demonstrated IC50 values of 8.3nM and 1.3nM against HL60 and HCT116 cell lines, respectively. Afterwards, for exploring the molecular target, compounds2d, 2g and 2y were further selected to evaluate the inhibitory activities against a panel of kinases. Finally, they were identified to be targeting Aurora A kinase with significant selectivity over other kinases, such as CHK1, CDK2, MEK1, GSK3β, BRAF, IKKβ and PKC.

Autophagy is an important basic metabolic mechanism by engulfing and degrading the unnecessary or dysfunctional cellular components within double-membered autolysosomes to maintain cellular homeostasis. Autophagy has sparkled great interest for its complicated functions in different stages of cancer, and is regarded as a potential target for anticancer therapy. As a suppressor pathway, autophagy prevents tumor initiation and as a survival pathway, autophagy contributes to tumor growth and progression by attenuating cellular metabolic stress and resisting therapeutic agents-induced cell death. Many autophagy regulators have been identified as potential cancer therapeutic agents and some cytotoxic anticancer drugs also induce autophagy. Combination regimen of autophagy regulators with other anticancer agent exhibits desirable efficacy and several protocols are underway in clinical trials. This review delineates the possible role of autophagy in anticancer therapy, and discusses reported potent autophagy regulators in cancer treatment.

We report herein a reaction-based fluorescent switch-on sulfide sensor, azo3, for the quantification of endogenous sulfides in rat tissues. The sensor was exploited based on the novel azo-sulfide chemistry and designed by locking the rhodol fluorophore into its nonfluorescent form with an azo group. However, the azo group would undergo a specific and biocompatible reaction with sulfides, triggering significant fluorescence increasements which were linear to the concentrations of sulfides. Azo3 distinguished by its high sensitivity (148-fold fluorescent switch-on response), good selectivity (22-fold more selective towards sulfides than other bio-thiol species) and low detection limit (500nM). Moreover, the azo3-based assay for biological sulfides displayed the unique advantage of being insusceptible to ultraviolet (UV) irradiation. Azo3 has been successfully applied to the quantification of endogenous sulfides in rat plasma and tissues including heart, brain, liver, spleen, lung and kidney. In addition to providing azo3 as a valuable tool to analyze sulfides in biological samples, we also discussed the influences of the electron effect on the sensitivity of the probes, which would shed some light on the design of future reaction-based probes.

Three series of novel 2-methylpiperazine derivatives were designed and synthesized using a fragment-assembly strategy. Among them, six compounds (13, 16, 18, 22, 33, and 36) showed potent activity against CCR5 comparable to that of the positive control, maraviroc, in calcium mobilization assay. Moreover, some compounds were selected and further tested for their antiviral activity in HIV-1 single cycle assay. As a result, four compounds (13, 16, 33, and 36) showed antiviral activity at the nanomolar level. Additionally, the potent four compounds showed no cytotoxicity at a concentration of 10 μM.

A novel support vector machine (SVM) classification model was established for distinguishing potent and weak/inactive insecticides. Classification model-based rational design of novel tetronic acid derivatives was then performed to choose the preferable site of spirotetramat for chemical modification. Afterwards, eleven C5′-oxime ether-derived spirotetramat analogues, which are indicated as “potent class”, were synthesized and validated by biological assays, revealing that theoretical estimates are significantly consistent with experimental activities of these compounds. To be of interest, the most promising compound 91b exhibited excellent insecticidal and acaricidal activities. Moreover, molecular docking was further implemented to propose the possible interaction mode of acetyl-CoA carboxylase (ACCase) and compounds 91b, 91j, and 91k, providing some important and useful guidelines for further development.

We report herein a fluorescence switch-on probe suitable for the detection of hydrogen sulfide (H2S) in complex biological systems. The probe features a straightforward synthesis, high sensitivity and good selectivity. As a proof of concept, its capability for detecting biological H2S has been illustrated by imaging H2S in live cells.

Hypoxia inducible factor-1 (HIF-1) is the key transcription factor of cellular response to hypoxia and plays a critical role in tumor metastasis. We describe here the discovery and a structure–activity relationship study of a series of 3-aryl-5-indazole-1,2,4-oxadiazole derivatives as novel HIF-1 inhibitors. The two most promising compounds 4g and 4h inhibit HIF-1 transcription with IC50 values of 0.62 and 0.55 μM in vitro, respectively, and they exhibit more efficient HIF-1 inhibition in xenograft tumors than YC-1, a potential anticancer drug targeting HIF-1. In addition, they also remarkably prevent the hypoxia-driven migration of SKOV3 cells in vitro and tumor metastasis in vivo. Further investigation of the mechanism revealed that the two inhibitors could decrease HIF-1α and VEGF expression. These results suggest that our newly synthesized HIF-1 inhibitors 4g and 4h are potential therapeutic agents with which to treat tumor metastasis.

A novel series of 4-anilinoquinazoline derivatives (19a-19t) were designed and synthesized through incorporation of the 2-nitroimidazole moiety into the 4-anilinoquinazoline scaffold of EGFR inhibitors. The most promising compound 19h displayed potent EGFR inhibitory activity with the IC50 value of 0.47 nM. It also strongly suppressed the proliferation of A549 and HT-29 cells with sub-micromolar IC50 values both under normoxia and hypoxia, which were several folds more potent than gefitinib and erlotinib. Further reductive mimic investigation revealed that 19h could be reductive activated under hypoxia and was fully consistent with the results of cell apoptotic assay and in vitro metabolism evaluation. Our results suggest that the incorporation of hypoxia-activated moiety into EGFR inhibitor scaffold might be a tractable strategy to overcome the tumor hypoxia.

A new approach employing a combination of pyrethroid and repellent is proposed to improve the protective efficacy of conventional pyrethroid-treated fabrics against mosquito vectors. In this context, the insecticidal and repellent efficacies of commonly used pyrethroids and repellents were evaluated by cone tests and arm-in-cage tests against Stegomyia albopicta (=Aedes albopictus) (Diptera: Culicidae). At concentrations of LD50 (estimated for pyrethroid) or ED50 (estimated for repellent), respectively, the knock-down effects of the pyrethroids or repellents were further compared. The results obtained indicated that deltamethrin and DEET were relatively more effective and thus these were selected for further study. Synergistic interaction was observed between deltamethrin and DEET at the ratios of 5 : 1, 2 : 1, 1 : 1 and 1 : 2 (but not 1 : 5). An optimal mixing ratio of 7 : 5 was then microencapsulated and adhered to fabrics using a fixing agent. Fabrics impregnated by microencapsulated mixtures gained extended washing durability compared with those treated with a conventional dipping method. Results indicated that this approach represents a promising method for the future impregnation of bednet, curtain and combat uniform materials.

The epidermal growth factor receptor (EGFR) family includes four structurally related receptor tyrosine kinases, termed as HER1 (EGFR, erbB1), HER2 (erbB2), HER3 (erbB3), and HER4 (erbB4). Given its intimate role in the development of several solid tumors, excessive HER signaling provides a unique opportunity for anticancer intervention. Along with extensive pharmacological studies validating the therapeutic potential of targeting the EGFR family for cancer therapy, kinase inhibitors of this family are continuously coming up and entering clinical studies. Herein, we review the EGFR family small molecule kinase inhibitors which have been approved or progressed into clinical studies, mainly focusing on their mechanisms of action, structure-activity relationships, binding modes, synthetic routes, and clinical status.

A series of thienopyridinone derivatives was designed and synthesized as inhibitors of checkpoint kinase 1 (Chk1). Most of them exhibited moderate to good Chk1 inhibitory activities. Among them, compounds 8q, 8t, and 8w with excellent Chk1 inhibitory activities (IC50 values of 4.05, 6.23, and 2.33nM, respectively) displayed strong synergistic effects with melphalan, a DNA-damaging agent in the cell-based assay. Further kinase profiling indicated that compound 8t was highly selective against CDK2/cyclinA, Aurora A, and PKC.

A series of novel 2-methoxy-phenyl dimethyl-carbamate derivatives were designed, synthesized and evaluated as site-activated MTDLs based on rivastigmine and curcumin. Most of them exhibited good to excellent AChE and BuChE inhibitory activities with sub-micromolar IC50 values. Among all the compounds, 6a demonstrated the most potent AChE inhibition with IC50 value of 0.097μM, which is about 20-fold than that of rivastigmine. In addition, the three selected compounds 5a, 6a and 6e demonstrated inhibitory activity against Aβ self-aggregation similar to cucurmin in TEM assay, which is obviously different from the weak activity of rivastigmine. Moreover, the hydrolysate of 6a (compound 7) also showed potent ABTS(+) scavenging and moderate copper ion chelating activity in vitro.

DPP-4 specifically degrades the incretin hormone GLP-1 and GIP, both of which are vital modulators of blood glucose homeostasis. Attributed to its potential biological function, DPP-4 inhibition has presently represented an attractive therapeutic strategy for treating diabetes and aroused a significant interest in the pharmaceutical industry. Chemical stability, selectivity and pharmacokinetic properties have been continuously emphasized during the long journey of R&D centered on DPP-4 inhibitors. The current landscape of the development of DPP-4 inhibitors is outlined in this review, with a focus on rational drug design and structural optimization to pursue chemical stability, selectivity and favorable pharmacokinetic properties. In addition, the structure–activity relationships, based on reported DPP-4 inhibitors, will be discussed.

Hypoxia-inducible factor 1 (HIF-1), a heterodimeric transcription factor that mediates the adaptation of tumor cells and tissues to the hypoxic microenvironment, has attracted considerable interest as a potential therapeutic target. Recently, HIF-1α has been recognized as the critical target of cardiac glycosides for cancer therapy, but the molecular mechanism of cardiac glycosides' inhibition of HIF-1α is still poorly understood. In the present study, we observed that neither HIF-1α mRNA levels nor HIF-1α protein degradation are affected by Ouabain. However, Ouabain was found to be associated with the regulation of HIF-1α translation. Basing on in silico, in vitro and ex vivo models of translation processing, further studies revealed that eIF4E plays a critical role in the inhibitory effect of Ouabain on HIF-1α protein synthesis, rather than mTORC1, eIF2α signaling or Na(+)/K(+)-ATPase inhibition. Mechanistically, Ouabain directly binds eIF4E, disrupts eIF4E/eIF4G association (200 μM, Inhibit rate =61 ± 3%) but not the eIF4E/mRNA complex formation (200 μM, Inhibit rate =18 ± 5%) both in vitro and in cells, thereby inhibiting the intracellular cap-dependent translation. The association between Ouabain and eIF4E not only raises the hope of using cardiac glycosides for cancer therapeutics more rational, but also offers a pharmacologic means for developing novel anti-cancer HIF-1α antagonists.

A set of forty-seven Akt1 inhibitors was used for the development of molecular docking based QSAR model by using nonlinear regression. The integration of docking scores, key interaction profiles and molecular descriptors remarkably improved the accuracy of the QSAR models, providing reasonable statistical parameters (Rtrain2 = 0.948, Rtest2 = 0.907 and Qcv2 = 0.794). The established MD-SVR model based structural modification of new 4-amino-pyrimidine derivatives was further performed, and six compounds 56a,b and 60a–d with good prediction activities were synthesized and biologically evaluated. All of these compounds exhibited promising Akt1 inhibitory and antiproliferative activities, suggesting the reliability and good application value of the established MD-SVR model in the development of Akt1 inhibitors.

A series of diphenylmethylamine derivatives were rationally designed, synthesized and biologically evaluated. Most of them exhibited moderate to good Akt1 inhibitory activities, as well as promising anti-proliferative efficacy against cancer cell lines. Besides, molecular docking studies were carried out to probe their binding modes with Akt1. Further kinase selectivity studies of compound 22c were performed, indicating its excellent selectivity against Aurora A, Drak, IKKβ, GSK3β, SYK and JAK2, and moderate selectivity against PKC and BRAF. Finally, a refined pharmacophore model was generated using the most active compounds 2, 12c and 22c via application of HipHop program.

A highly sensitive and specific fluorescent probe has been developed for the rapid detection of H2S in living cells. This probe exhibits the unique qualities of quick response, low detection limit, excellent water solubility and good membrane permeability. Its potential for biological applications has been demonstrated by imaging H2S in living cells.