Three-Dimensional Polyoxometalate Organic Frameworks with One-Dimensional Channels Constructed by Multiple Helical Chains Based on 22-Core Ln/Mn/Mo Clusters for Proton Conduction.

Two unique 22-core sandwich {[Mn6Mo6O37]Ln3[MnMo6O24]} (Ln = La or Pr) units have been assembled, featuring an undisclosed {Mn6Mo6} cluster. This assembly is subsequently integrated into two three-dimensional polyoxometalate organic frameworks, which exhibit one-dimensional hydrophilic hexagonal channels formed by six intertwined 63 helical chains, leading to effective proton conduction primarily facilitated by an abundance of water molecules within the channels.

Synthesis and antitumor activities of novel 3-(6-aminopyridin-3-yl)benzamide derivatives: Inducing cell cycle arrest and apoptosis via AURKB transcription inhibition.

Here, a series of 3-(6-aminopyridin-3-yl) benzamide derivatives were designed and synthesized. Cell viability assay indicated that most compounds exhibited potent antiproliferative activity against all the tested cancer cells. Among them, compound 7l displayed the best antiproliferative activity particularly in A549 cells, with an IC50 value of 0.04 ± 0.01 µM. RNA-seq analysis was employed to explore the potential pathways related to the antiproliferative activity of compound 7l. The data revealed that 7l exerted antiproliferative activity mainly by regulating cell cycle, DNA replication and p53 signaling pathway. Indeed, compound 7l induced G2/M phase arrest by AURKB transcription inhibition and resulted in cell apoptosis via p53 signaling pathway. Most importantly, compound 7l demonstrated potent antitumor activity in A549 xenograft tumor model. Collectively, 7l might be a promising lead compound for the development of new therapeutic agents for AURKB overexpressed or mutated cancers.

Electron-transferring flavoprotein and its dehydrogenase contributed to growth development and virulence in Beauveria bassiana.

Electron-transferring flavoprotein (Etf) and its dehydrogenase (Etfdh) are integral components of the electron transport chain in mitochondria. In this study, we characterize two putative etf genes (Bbetfa and Bbetfb) and their dehydrogenase gene Bbetfdh in the entomopathogenic fungus Beauveria bassiana. Individual deletion of these genes caused a significant reduction in vegetative growth, conidiation, and delayed conidial germination. Lack of these genes also led to abnormal metabolism of fatty acid and increasing lipid body accumulation. Furthermore, the virulence of Bbetfs and Bbetfdh deletion mutants was severely impaired due to decreasing infection structure formation. Additionally, all deletion strains showed reduced ATP synthesis compared to the wild-type strain. Taken together, Bbetfa and Bbetfb, along with Bbetfdh, play principal roles in fungal vegetative growth, conidiation, conidial germination, and pathogenicity of B. bassiana due to their essential functions in fatty acid metabolism.

Bbhox2 is a key regulator for conidiation and virulence in Beauveria bassiana.

Beauveria bassiana, a well-known filamentous biocontrol fungus, is the main pathogen of numerous field and forest pests. To explore the potential factors involved in the fungal pathogenicity, Bbhox2, an important and conserved functional transcription factor containing homeodomain was carried out by functional analysis. Homologous recombination was used to disrupt the Bbhox2 gene in B.bassiana. The conidia yield of the deletant fungal strain was significantly reduced. The conidial germination was faster, and stress tolerance to Congo red and high osmotic agents were decreased compared with that in the wildtype. Additionally, ΔBbhox2 showed a dramatic reduction in virulence no matter in topical inoculations or in intra-hemolymph injections against Galleria mellonella larvae, which is likely due to the failure of appressorium formation and the defect in producing hyphal body. These results indicate that the Bbhox2 gene markedly contributes to conidiation and pathogenicity in B. bassiana.

Structure optimization, synthesis, and biological evaluation of 6-(2-amino-1H-benzo[d]imidazole-6-yl)-quinazolin-4(3H)-one derivatives as potential multi-targeted anticancer agents via Aurora A/ PI3K/BRD4 inhibition.

Aurora A (Aurora kinase A), a critical regulator of cell mitosis, is frequently overexpressed in many malignant cancers, and has been considered as a promising drug target for cancer therapy. Likewise, Phosphatidylinositol 3-kinase alpha (PI3Kα) is also regarded as one of the most important targets in cancer therapy by mediating the cell growth and angiogenesis of various human cancers. In addition, Bromodomain-containing protein 4 (BRD4) modulates oncogene expressions of Myc, Aurora kinase and various RTKs. Recently, accumulating evidences indicated that hyperactivated or abnormally expressed Aurora A, PI3Kα or BRD4 are closely associated with drug resistance and poor prognosis of non-small cell lung cancer (NSCLC). Hence, simultaneous inhibition of Aurora A, PI3Kα, and BRD4 is expected to be a new strategy for NSCLC therapy. In this study, we performed further structure optimization of 6-(2-amino-1H-benzo[d]imidazole-6-yl)-quinazolin-4(3H) -one based on previous study to obtain a series of derivatives for discovering potential Aurora A, PI3Kα and BRD4 multi-targeted inhibitors. MTT assay showed that most of the newly synthesized compounds exhibited an evident anticancer activity against the NSCLC cells. Among them, the IC50 values of the most potent compound 9a were 0.83, 0.26 and 1.02 µM against A549, HCC827 and H1975 cells, respectively. In addition, 9a markedly inhibited the Aurora A and PI3Kα kinase activities with IC50 values of 10.19 nM and 13.12 nM. Compound 9a induced G2/M phase arrests and apoptosis of HCC827 cells by simultaneous inhibition of Aurora A/PI3K/ BRD4 signaling pathways. Collectively, our studies suggested that 9a might be a potential multi-targeted inhibitor for NSCLC therapy.

Design, synthesis, and biological evaluation of 6-(imidazo[1,2-a] pyridin-6-yl) quinazolin-4(3H)-one derivatives as potent anticancer agents by dual targeting Aurora kinase and ROR1.

ROR1 and Aurora kinase were overexpressed in various cancers and essential for cell proliferation, survive and metastasis. Pharmaceutical inhibition of ROR1 and Aurora kinase abrogated the activation of downstream signaling and induced cancer cell apoptosis. Hence, ROR1 and Aurora kinase considered as attractive therapeutic targets for the development of anticancer drugs. In the present work, three series of novel 6-(imidazo[1,2-a] pyridin-6-yl)-quinazolin-4(3H)-one derivatives were designed and synthesized via bioisosterism and scaffold-hopping strategies guided by FLF-13, an Aurora kinase inhibitor we discovered earlier. Most of compounds in series 2 and series 3 showed submicromolar to nanomolar inhibitory activity against multiple cancer cell lines. More importantly, compounds 12d and 12f in series 3 showed nanomolar inhibitory activity against all test cancer cells. The most promising compound 12d exhibited potent inhibitory activity against Aurora A and Aurora B with IC50 values of 84.41 nM and 14.09 nM, respectively. Accordingly, compounds 12d induced G2/M phase cell cycle arrest at 24 h and polyploidy at 48 h. It's worth noting that 12d also displayed inhibitory activity against ROR1 and induce cell apoptosis. Furthermore, 12d could significantly inhibit the tumor growth in SH-SY5Y xenograft model with tumor growth inhibitory rate (IR) up to 46.31 % at 10 mg/kg and 52.66 % at 20 mg/kg. Overall, our data suggested that 12d might serve as a promising candidate for the development of therapeutic agents for cancers with aberrant expression of ROR1 and Aurora kinases by simultaneously targeting ROR1 and Aurora kinase.

Three New Constituents with Anti-Inflammatory and Antimicrobial Activities in Vitro from the Roots of Capsicum annuum L.

Three new compounds, including two new sesquiterpenes (1-2), named Annuumine E-F, and one new natural product, 3-hydroxy-2,6-dimethylbenzenemethanol (3), together with seventeen known compounds (4-20) were isolated from the ethanol extract of the roots of Capsicum annuum L. Among them, five compounds (4, 5, 9, 10 and 20) were isolated from this plant for the first time. The structures of new compounds (1-3) were determined via detailed analysis of the IR, HR-ESI-MS and 1D and 2D NMR spectra. The anti-inflammatory activities of the isolated compounds were evaluated by their ability to reduce NO release by LPS-induced RAW 264.7 cells. Notably, compound 11 exhibited moderate anti-inflammatory activity (IC50 =21.11 µM). Moreover, the antibacterial activities of the isolated compounds were also evaluated.

Cytostatic Activity of Sanguinarine and a Cyanide Derivative in Human Erythroleukemia Cells Is Mediated by Suppression of c-MET/MAPK Signaling.

Sanguinarine (1) is a natural product with significant pharmacological effects. However, the application of sanguinarine has been limited due to its toxic side effects and a lack of clarity regarding its molecular mechanisms. To reduce the toxic side effects of sanguinarine, its cyanide derivative (1a) was first designed and synthesized in our previous research. In this study, we confirmed that 1a presents lower toxicity than sanguinarine but shows comparable anti-leukemia activity. Further biological studies using RNA-seq, lentiviral transfection, Western blotting, and flow cytometry analysis first revealed that both compounds 1 and 1a inhibited the proliferation and induced the apoptosis of leukemic cells by regulating the transcription of c-MET and then suppressing downstream pathways, including the MAPK, PI3K/AKT and JAK/STAT pathways. Collectively, the data indicate that 1a, as a potential anti-leukemia lead compound regulating c-MET transcription, exhibits better safety than 1 while maintaining cytostatic activity through the same mechanism as 1.

Design, Synthesis and Biological Evaluation of 6-(Imidazo[1,2-a]pyridin-6-yl)quinazoline Derivatives as Anticancer Agents via PI3Kα Inhibition.

Aberrant expression of the phosphatidylinositol 3-kinase (PI3K) signalling pathway is often associated with tumourigenesis, progression and poor prognosis. Hence, PI3K inhibitors have attracted significant interest for the treatment of cancer. In this study, a series of new 6-(imidazo[1,2-a]pyridin-6-yl)quinazoline derivatives were designed, synthesized and characterized by 1H NMR, 13C NMR and HRMS spectra analyses. In the in vitro anticancer assay, most of the synthetic compounds showed submicromolar inhibitory activity against various tumour cell lines, among which 13k is the most potent compound with IC50 values ranging from 0.09 µΜ to 0.43 µΜ against all the tested cell lines. Moreover, 13k induced cell cycle arrest at G2/M phase and cell apoptosis of HCC827 cells by inhibition of PI3Kα with an IC50 value of 1.94 nM. These results suggested that compound 13k might serve as a lead compound for the development of PI3Kα inhibitor.

Design, Synthesis, and Evaluation of the COX-2 Inhibitory Activities of New 1,3-Dihydro-2H-indolin-2-one Derivatives.

Thirty-three 1,3-dihydro-2H-indolin-2-one derivatives bearing α, ß-unsaturated ketones were designed and synthesized via the Knoevenagel condensation reaction. The cytotoxicity, in vitro anti-inflammatory ability, and in vitro COX-2 inhibitory activity of all the compounds were evaluated. Compounds 4a, 4e, 4i-4j, and 9d exhibited weak cytotoxicity and different degrees of inhibition against NO production in LPS-stimulated RAW 264.7 cells. The IC50 values of compounds 4a, 4i, and 4j were 17.81 ± 1.86 µM, 20.41 ± 1.61 µM, and 16.31 ± 0.35 µM, respectively. Compounds 4e and 9d showed better anti-inflammatory activity with IC50 values of 13.51 ± 0.48 µM and 10.03 ± 0.27 µM, respectively, which were lower than those of the positive control ammonium pyrrolidinedithiocarbamate (PDTC). Compounds 4e, 9h, and 9i showed good COX-2 inhibitory activities with IC50 values of 2.35 ± 0.04 µM, 2.422 ± 0.10 µM and 3.34 ± 0.05 µM, respectively. Moreover, the possible mechanism by which COX-2 recognized 4e, 9h, and 9i was predicted by molecular docking. The results of this research suggested that compounds 4e, 9h, and 9i might be new anti-inflammatory lead compounds for further optimization and evaluation.

Characterization of a fungal competition factor: Production of a conidial cell-wall associated antifungal peptide.

Competition is one of the fundamental driving forces of natural selection. Beauveria bassiana is a soil and plant phylloplane/root fungus capable of parasitizing insect hosts. Soil and plant environments are often enriched with other fungi against which B. bassiana competes for survival. Here, we report an antifungal peptide (BbAFP1), specifically expressed and localized to the conidial cell wall and is released into the surrounding microenvironment inhibiting growth of competing fungi. B. bassiana strains expressing BbAFP1, including overexpression strains, inhibited growth of Alternaria brassicae in co-cultured experiments, whereas targeted gene deletion of BbAFP1 significantly decreased (25%) this inhibitory effect. Recombinant BbAFP1 showed chitin and glucan binding abilities, and growth inhibition of a wide range of phytopathogenic fungi by disrupting membrane integrity and eliciting reactive oxygen species (ROS) production. A phenylalanine residue (F50) contributes to chitin binding and antifungal activity, but was not required for the latter. Expression of BbAFP1 in tomato resulted in transgenic plants with enhanced resistance to plant fungal pathogens. These results highlight the importance of fungal competition in shaping primitive competition strategies, with antimicrobial compounds that can be embedded in the spore cell wall to be released into the environment during the critical initial phases of germination for successful growth in its environmental niche. Furthermore, these peptides can be exploited to increase plant resistance to fungal pathogens.

Construction of Water-Stable Rare-Earth Organic Frameworks with Ambient High Proton Conductivity Based on Zirconium Sandwiched Heteropolytungstate.

Water-stable proton-conducting materials owning excellent performances at ambient temperatures are currently one of the crucial challenges. Herein, four water-stable three-dimensional polyoxometalate-based rare-earth organic frameworks have been successfully synthesized and formulated as H{Ln4(L)2(H2O)21[Zr3(OH)3(PW9O34)2]}·15H2O (1-3) (Ln = La (1), Ce (2), Pr (3); L = 3,5-pyridine dicarboxylic acid), which are the first examples of MOFs constructed by a zirconium sandwiched polyoxoanion. There are abundant coordinated water molecules functionalizing the PrIII centers, and simultaneously, plenty of lattice water molecules are fitted into the channel of the framework. A continuous H-bonding network is found between the architectures and plays an important role in stabilizing the structure. Benefiting from the consecutive H-bonding networks, compounds 1-3 showed high proton conductivities at ambient temperature (up to 1.05 × 10-3 S·cm-1 under 98% RH) by a synergistic effect of the combined components.

Sphingolipid synthesis inhibitor fumonisin B1 causes verticillium wilt in cotton.

Verticillium wilt caused by Verticillium dahliae is a major disease of cotton. Acidic protein-lipopolysaccharide complexes are thought to be the toxins responsible for its symptoms. Here, we determined that the sphingolipid biosynthesis inhibitor fumonisin B1 (FB1) acts as a toxin and phenocopies the symptoms induced by V. dahliae. Knocking out genes required for FB1 biosynthesis reduced V. dahliae pathogenicity. Moreover, we showed that overexpression of a FB1 and V. dahliae both downregulated gene, GhIQD10, enhanced verticillium wilt resistance by promoting the expression of brassinosteroid and anti-pathogen genes. Our results provide a new strategy for preventing verticillium wilt in cotton.

Manipulation of host ecdysteroid hormone levels facilitates infection by the fungal insect pathogen, Metarhizium rileyi.

Entomopathogenic fungi such as Metarhizium rileyi and Beauveria bassiana are widely used insect biological control agents. Little, however, is known concerning genetic or enzymatic factors that differentiate the mechanisms employed by these two fungal pathogens to infect target hosts. Infection by either of these organisms is known to increase levels of the growth and molting hormone, ecdysone, which also regulates the expression of a number of innate immune pathways. M. rileyi, but not B. bassiana, has apparently evolved an ecdysteroid-22-oxidase (MrE22O) that inactivate ecdysone. We show that deletion of MrE22O impaired virulence compared with the wild-type strain, with an increase in ecdysone titer seen in hosts that was coupled to an increase in the expression of antimicrobial genes. An M. rileyi strain engineered to overexpress MrE22O (MrE22OOE ), as well as trans-expression in B. bassiana (Bb::MrE220OE ) resulted, in strains displaying enhanced virulence and dampening of host immune responses compared with their respective wild-type parental strains. These results indicate that ecdysone plays an important role in mediating responses to fungal infection and that some insect pathogenic fungi have evolved mechanisms for targeting this hormone as a means for facilitating infection.

The secondary metabolite regulator, BbSmr1, is a central regulator of conidiation via the BrlA-AbaA-WetA pathway in Beauveria bassiana.

The filamentous fungus Beauveria bassiana, an insect fungal pathogen, is widely used for pest biocontrol. Aerial conidia are infectious propagules, and their yield and viability greatly affect the field application of this fungus; however, little is known about the molecular regulatory mechanism of the triggered conidiation. In the present study, we find that the secondary metabolite regulator BbSmr1 is involved in the regulation of asexual conidiation development and stress response in B. bassiana. A deficiency in Bbsmr1 results in a prominent fluffy-like phenotype on solid medium, decreased conidial yield, accelerated conidial germination, as well as increased tolerance to H2 O2 stress and cell wall inhibitors. The deletion of Bbsmr1 also leads to thickened conidial cell walls and changed cell epitopes. Overexpressing either BbbrlA or BbabaA in the ∆Bbsmr1 strain can rescue the phenotypes of conidial development and stress response. BbSmr1 activates BbbrlA transcription by directly binding to the A4GA3 sequence of the BbbrlA promoter. BbBrlA in turn binds to the promoter of Bbsmr1 and negatively regulates the expression of Bbsmr1. These results indicate that BbSmr1 positively regulates conidial development in B. bassiana by activating the central development pathway BrlA-AbaA-WetA and provides insights into the developmental regulatory mechanism of entomopathogenic fungi.

Ergosterol-targeting fusion antifungal peptide significantly increases the Verticillium wilt resistance of cotton.

Increasing the targeting ability of antifungal proteins towards specific components of fungal cells has the potential to improve their antifungal activity and reduce harmful effects to nontarget cells. To obtain effective disease resistance genes against cotton Verticillium wilt, we constructed several fusion genes, in which binding domains targeting chitin, sphingolipid or ergosterol in the fungal cell wall or cell membrane were individually fused to the antifungal peptide BbAFP1 from entomopathogenic fungus Beauveria bassiana. Transient expression of fusion genes in cotton cotyledons indicated that the BbAFP1::ErBD fusion peptide with an ergosterol binding domain exhibited better disease resistance against V. dahliae than wild-type BbAFP1 and other fusion genes. BbAFP1::ErBD and BbAFP1 transgenic cotton were obtained and verified by Southern and Western blotting. Compared with BbAFP1-expressing cotton, BbAFP1::ErBD-expressing cotton showed higher disease resistance against V. dahliae, with smaller lesion areas (0.07 cm2 vs. 0.16 cm2 ) on the leaves and a lower disease index (23.9 vs. 34.5). Overexpression of BbAFP1::ErBD by transgenic tobacco also showed enhanced disease resistance against V. dahliae compared with that of the wild-type gene. These results indicated that construction of fusion antifungal peptides that target fungal cells is a powerful strategy to obtain new anti-disease genes, and the obtained fusion gene BbAFP1::ErBD has the potential to defend against plant fungal diseases.

Design, synthesis, and biological evaluation of novel 6-(pyridin-3-yl) quinazolin-4(3H)-one derivatives as potential anticancer agents via PI3K inhibition.

Abnormal activation of the PI3K/Akt pathway is demonstrated in most of human malignant tumors via regulation of proliferation, cell cycle, and apoptosis. Therefore, drug discovery and development of targeting the PI3K/Akt pathway has attracted great interest of researchers in the development of anticancer drugs. In this study, fifteen 6-(pyridin-3-yl) quinazolin-4(3H)-one derivatives were designed and synthesized. Anticancer activities of the synthetic compounds were evaluated and the potential mechanisms were explored. Several compounds showed certain proliferation inhibitory activity against the tested cancer cells including human non-small cell lung cancer (NSCLC) HCC827, human neuroblastoma SH-SY5Y and hepatocellular carcinoma LM3 cells. Among them, compound 7i and 7m showed the best inhibitory activity against all the cancer cell lines and more active against HCC827 cells with IC50 values of 1.12 µM and 1.20 µM, respectively. In addition, 7i and 7m showed lower inhibitory activity against H7702 cells (human normal liver cells) with IC50 values of 8.66 µM and 10.89 µM, respectively, nearly 8-fold lower than that in HCC827 cells. These results suggested that compounds 7i and 7m had certain selectivity to tumor cells, compared to human normal cells. Further biological studies indicated 7i induced G2/M phase arrests and cell apoptosis of HCC827 cells via PI3K/Akt and caspase dependent pathway. Together, these novel 6-(pyridin-3-yl) quinazolin-4(3H)-one derivatives such as compound 7i and 7m might be lead compounds for development of potential anti-cancer drugs.

Thiamine-biosynthesis genes Bbpyr and Bbthi are required for conidial production and cell wall integrity of the entomopathogenic fungus Beauveria bassiana.

Beauveria bassiana is an important entomopathogenic fungus used to control a variety of insect pests. Conidia are the infective propagules of the fungus. However, some important factors that influence conidiation are still to be investigated. In this study, a mutant with decreased conidial production and hyphal growth was identified from a random T-DNA insertional library of B. bassiana. The corresponding gene (Bbthi) for this mutation encodes a putative thiazole synthase. Thiazole and pyrimidine are structural components of thiamine (vitamin B1), which is an essential nutrient for all forms of life. Disruption of Bbthi, Bbpyr, a putative pyrimidine synthetic gene, or both in B. bassiana results in a significant decrease of thiamine content. Loss of Bbthi and Bbpyr function significantly decreased the conidial production and hyphal growth, as well as disrupted the integrity of conidial cell wall. However, the defect of Bbpyr and Bbthi does not decrease the virulence of B. bassiana. Our results indicate the importance of thiamine biosynthesis in conidiation of B. bassiana, and provide useful information to produce conidia of entomopathogenic fungi for biocontrol of insect pests.

Expression of a Beauveria bassiana chitosanase (BbCSN-1) in Pichia pastoris and enzymatic analysis of the recombinant protein.

Chitosanase (EC 3.2.1.132) is an important chitosan-degrading enzyme involved in industrial applications. In this study, a chitosanase gene (BbCSN-1) from Beauveria bassiana, an insect fungal pathogen, was cloned and expressed in Pichia pastoris. The amount of BbCSN-1 in the fermentation broth of P. pastoris gradually increased after induction with methanol from one to 6 d, reaching 398 µg/ml on the 6th day. The molecular characteristics of BbCSN-1 were measured with colloidal chitosan as a substrate. The purified BbCSN-1 exhibited optimum activity at pH 5 and 30 °C and was stable at pH 2-8 and below 40 °C. The Km value of BbCSN-1 was approximately 0.8 mg/ml at 30 °C (pH 6.0). The activity of BbCSN-1 was significantly enhanced by Mn2+ but inhibited by Co2+ and Cu2+. These results indicated that BbCSN-1 from B. bassiana could be easily expressed in P. pastoris, which provided a basis for further study on its application.

The PI3Kα inhibitor DFX24 suppresses tumor growth and metastasis in non-small cell lung cancer via ERK inhibition and EPHB6 reactivation.

EPHB6 is a metastasis inhibitory gene that is frequently decreased or deficiency in non-small cell lung cancer (NSCLC), which contributed to the subsequent development of distant metastasis. These suggested the possibility that reactivation of EPHB6 might prevent the metastasis of NSCLC. Nevertheless, EPHB6 expression might also promote cancer cell growth and inhibit cell apoptosis by activating Akt and ERK pathway, apart from inhibition of migration and invasion. In the present study, we developed a novel quinazolin-4(3H)-one analog (DFX24) as a potential PI3Kα inhibitor, which inhibited both cell proliferation and metastasis of NSCLC cell lines. Investigation to the molecular mechanisms revealed DFX24 inhibited the cell growth and metastasis via inhibition of PI3Kα and ERK activity, as well as the increase in EPHB6 expression. In addition, DFX24 also induced cell cycle arrest and tumor cell apoptosis by inhibiting PI3K/Akt pathway and activating mitochondria-dependent pathway, respectively. These findings suggested that DFX24 might be considered as a novel drug candidate and may provide a potential therapy for NSCLC.