Design, synthesis, and biological evaluation of naphthalene imidazo[1,2-b]pyridazine hybrid derivatives as VEGFR selective inhibitors.

The vascular endothelial growth factor receptor (VEGFR) is a receptor tyrosine kinase that is regarded as an emerging target for abnormal angiogenesis diseases. In this study, novel naphthalene imidazo[1,2-b]pyridazine hybrids as VEGFR selective inhibitors were designed and synthesized using a scaffold hopping strategy based on ponatinib, a multitarget kinase inhibitor. Among the evaluated compounds, derivative 9k (WS-011) demonstrated the most potent inhibitory potency against VEGFR-2 (IC50 = 8.4 nM) and displayed superior VEGFR selectivity over a panel of 70 kinases compared with ponatinib. Furthermore, 9k possessed good cytotoxic effects on various cancer cell lines, especially the colon cancer HT-29 cells, with an acceptable oral bioavailability. Moreover, 9k significantly inhibited the migration and invasion of human umbilical vein endothelial cells (HUVEC) cells and induced apoptosis through the upregulation of apoptotic proteins in HT-29 cells. 9k also effectively suppressed the activation of VEGFR-2 signaling pathways, which in turn inhibited the growth of HT-29 cells and the tube formation of HUVECs in vitro. All of the findings revealed that 9k could be considered a promising antiangiogenesis lead that merits further investigation.

Targeting the pyruvate dehydrogenase complex/pyruvate dehydrogenase kinase (PDC/PDK) axis to discover potent PDK inhibitors through structure-based virtual screening and pharmacological evaluation.

Proliferating cancer cells are characterized by the Warburg effect, a metabolic alteration in which ATP is generated from cytoplasmic glycolysis instead of oxidative phosphorylation. The pyruvate dehydrogenase complex/pyruvate dehydrogenase kinase (PDC/PDK) axis plays a crucial role in this effect and has been identified as a potential target for anticancer drug development. Herein, we present the discovery and pharmacological evaluation of potent PDK inhibitors targeting the PDK/PDC axis. We successfully identified 6 compounds from a small molecule library through a structure-based virtual screening campaign and evaluated their enzymatic inhibitory potencies for PDK1-4. Our results indicated that compound 1 exhibited submicromolar inhibitory activities against PDK1-3 (IC50 = 109.3, 135.8, and 458.7 nM, respectively), but is insensitive to PDK4 (IC50 = 8.67 µM). Furthermore, compound 1 inhibited the proliferation of A549 cells with an EC50 value of 10.7 µM. In addition, compound 1 induced cell apoptosis, arrested the cell cycle at the S phase, and reduced cell invasion and migration, while showing low in vivo toxicity at a high dose. Based on these observations, it can be concluded that compound 1 is a promising anti-PDK1-3 lead that merits further investigation.

PTEN inhibition leads to the development of resistance to novel isoquinoline derivative TNBG-5602 in human liver cancer cells.

TNBG-5602, a new synthesized derivative of tetrazanbigen, is a potential chemotherapeutic agent against cancer. However, its underlying mechanism is complex and still unknown. In this investigation, the anticancer effects of TNBG-5602 were determined in vitro and in vivo. Small RNA retroviral library plasmids that overexpress 19-bp fragments were used to generate TNBG-5602-resistant cells. After validation, the overexpressed 19-bp fragments were sequenced using next-generation sequencing (NGS) in the drug-resistant cells. Furthermore, the relationship of TNBG-5602, phosphatase and tensin homolog deleted on Chromosome 10 (PTEN), and the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathway was explored. The results showed that TNBG-5602 can effectively inhibit cancer cell proliferation and induce apoptosis in vitro and in vivo. Drug-resistant cells were screened using the small RNA library. Compared with naïve cells, drug-resistant cells were more resistant to TNBG-5602 in vitro and in vivo. NGS results revealed that the second highest overexpressed 19-bp fragment perfectly matched the PTEN gene, so the expression of PTEN in various cells and tissues was verified. Further research showed that exogenous overexpression of PTEN strengthened the anticancer effects of TNBG-5602 on p-Akt expression, whereas silencing of PTEN weakened these effects in naïve cells. Taken together, by using this library, we confirmed that PTEN is the target gene to the anticancer effects of TNBG-5602 via the PI3K/Akt pathway.

Aloe-emodin derived azoles as a new structural type of potential antibacterial agents: design, synthesis, and evaluation of the action on membrane, DNA, and MRSA DNA isomerase.

As serious global drug resistance motivated the exploration of new structural drugs, we developed a type of novel structural aloe-emodin azoles as potential antibacterial agents in this work. Some target aloe-emodin azoles displayed effective activity against the tested strains, especially tetrazolyl aloe-emodin 4b showed a low MIC value of 2 µg mL-1 towards MRSA, being more efficient than the reference drug norfloxacin (MIC = 8 µg mL-1). Also, the active molecule 4b exhibited low cytotoxicity against LO2 cells with no distinct tendency to induce the concerned resistance towards MRSA. The tetrazolyl derivative 4b was preliminarily investigated for the possible mechanism; it was revealed that tetrazolyl derivative 4b could both disrupt the integrity of MRSA membrane and form 4b-DNA supramolecular complex by intercalating into DNA. Moreover, tetrazolyl aloe-emodin 4b could bind with MRSA DNA isomerase at multiple sites through hydrogen bonds in molecular simulation.

Tetrazanbigen Derivatives as Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) Partial Agonists: Design, Synthesis, Structure-Activity Relationship, and Anticancer Activities.

Tetrazanbigen (TNBG) is a novel sterol isoquinoline derivative with poor water solubility and moderate inhibitory effects on human cancer cell lines via lipoapoptosis induction. Herein, we developed a series of novel TNBG analogues with improved water solubility and antiproliferative activities. The CCK-8 assay enabled us to identify a novel compound, 14g, which strongly inhibited HepG2 and A549 cell growth with IC50 values of 0.54 and 0.47 µM, respectively. The anticancer effects might be explained by the partial activation and upregulation of PPARγ expression, as indicated by the transactivation assay and western blotting evaluation. Furthermore, the in vitro antiproliferative activity was verified in an in vivo xenograft model in which 14g strongly reduced tumor growth at a dose of 10 mg/kg. In line with these positive observations, 14g exhibited an excellent water solubility of 31.4 mg/mL, which was more than 1000-fold higher than that of TNBG (4 µg/mL). Together, these results suggest that 14g is a promising anticancer therapeutic that deserves further investigation.

Design and biological evaluation of a novel type of potential multi-targeting antimicrobial sulfanilamide hybrids in combination of pyrimidine and azoles.

This work explored a novel type of potential multi-targeting antimicrobial three-component sulfanilamide hybrids in combination of pyrimidine and azoles. The hybridized target molecules were characterized by 1H NMR, 13C NMR and HRMS spectra. Some of the developed target compounds exerted promising antimicrobial activity in comparison with the reference drugs norfloxacin and fluconazole. Noticeably, sulfanilamide hybrid 5c with pyrimidine and indole could effectively inhibit the growth of E. faecalis with MIC value of 1 µg/mL. The active molecule 5c showed low cell toxicity and did not obviously trigger the development of resistance towards the tested bacteria strains. Mechanism exploration indicated that compound 5c could not only exert efficient membrane permeability, but also intercalate into DNA of resistant E. faecalis to form 5c-DNA supramolecular complex, which might be responsible for its antimicrobial action. The further investigation showed that this molecule could be effectively transported by human serum albumins through hydrogen bonds and van der Waals force.

TNBG-5602, a novel derivative of quinoxaline, inhibits liver cancer growth via upregulating peroxisome proliferator-activated receptor γ in vitro and in vivo.

OBJECTIVES: TNBG-5602 is a newly synthesized compound with an isoquinoline structure. In the present study, we demonstrated the anticancer effect of TNBG-5602 in in-vitro and in-vivo models and investigated its possible anticancer mechanism. METHODS: The antiproliferation effect of TNBG-5602 in vitro was evaluated in human liver cancer cell line QGY-7701. The acute toxicity of TNBG-5602 was evaluated in mice. The anticancer activity of TNBG-5602 in vivo was assessed in a xenograft model of human liver cancer cell line QGY-7701. KEY FINDINGS: The results of CCK-8 assay showed that TNBG-5602 can effectively inhibit the proliferation of liver cancer cells in vitro. The acute toxicity test in mice showed that the LD50 of TNBG-5602 was 172 mg/kg. In a xenograft liver cancer model, TNBG-5602 could remarkably inhibit the growth of tumours. During in-vitro and in-vivo studies, we noted that TNBG-5602 could induce lipid accumulation in cancer cells and tissues. Further study indicated that the anticancer effect of TNBG-5602 may be exerted through activating peroxisome proliferator-activated receptor γ (PPARγ) and downregulating proliferating cell nuclear antigen (PCNA). CONCLUSIONS: Our results suggested that TNBG-5602 might exert potent anticancer activity through increasing the expression of PPARγ.

Discovery of novel 9H-purin derivatives as dual inhibitors of HDAC1 and CDK2.

HDAC and CDK inhibitors have been demonstrated to be synergistically in suppressing cancer cell proliferation and inducing apoptosis. In this work, we incorporated the pharmacophore groups of HDACs and CDKs inhibitors into one molecule to design and synthesize a series of purin derivatives as HDAC/CDK dual inhibitors. The lead compound 6d, showing good HDAC1 and CDK2 inhibitory activity with IC50 values of 5.8 and 56 nM, respectively, exhibited attractive potency against several cancer cell lines in vitro. This work may lead to the discovery of a novel scaffold andpotentialdual HDAC/CDK inhibitors.

Design, synthesis and antimicrobial evaluation of novel benzimidazole-incorporated sulfonamide analogues.

A novel series of benzimidazole-incorporated sulfonamide analogues were designed and synthesized with an effort to overcome the increasing antibiotic resistance. Compound 5c gave potent activities against Gram-positive bacteria and fungi, and 2,4-dichlorobenzyl derivative 5g showed good activities against Gram-negative bacteria. Both of these two active molecules 5c and 5g could effectively intercalate into calf thymus DNA to form compound-DNA complex respectively, which might block DNA replication to exert their powerful antimicrobial activity. Molecular docking experiments suggested that compounds 5c and 5g could insert into base-pairs of DNA hexamer duplex by the formation of hydrogen bonds with guanine of DNA. The transportation behavior of these highly active compounds by human serum albumin (HSA) demonstrated that the electrostatic interactions played major roles in the strong association of active compounds with HSA, and which was also confirmed by the full geometry calculation optimizations.

New Progress in Azole Compounds as Antimicrobial Agents.

The increasing incidence of microbial resistance and newly emerging pathogens have become a serious challenge for public health. More and more efforts have been directed to the development of new antimicrobial agents with distinct mechanisms from the well-known classes of clinical drugs. The extensive clinical utilization of azole-based medicinal drugs has evoked numerous attentions, and their researches and developments have been a quite rapid developing and active highlight topic with an infinite space. Consideration of our researches on azole compounds and other literature in recent three years, this review scientifically reviewed the new progress of azole derivatives as antibacterial, antifungal, antitubercular and antiviral agents, including mono-nitrogen azoles (oxazoles, thiazoles and carbazoles), bis-nitrogen azoles (imidazoles, pyrazoles and benzimidazoles) and tri-nitrogen azoles (triazoles and benzotriazoles) as well as tetrazole derivatives. It was hoped that this review would be helpful for the design and development of highly efficient azole derivatives with high bioactivity and low toxicity.

Recent Researches in Metal Supramolecular Complexes as Anticancer Agents.

The research and development of metal supramolecular complexes as anticancer supramolecular drugs, which are aggregates mainly formed by one or more inorganic metal compounds with one or more either inorganic or organic molecules in general via coordination bonds, has been a quite rapidly developing, increasingly active and newly rising highlight interdisciplinary field. Numerous efforts have been directed toward metal supramolecular complexes as potential anticancer agents and the unprecedented progress has been made. This has opened up a wholly new and infinite space to create novel metal-based bioactive supermolecules. More importantly, metal-based complex supermolecules as potential anticancer agents with wide potential applications have become highlight topics in recent years, and are becoming increasingly useful and important in preventing and treating cancer diseases. In view of the rapid progress in metal complex anticancer supermolecules with rich variation of structural types, this work systematically reviewed the recent research and development of the whole range of metal-based supramolecular complexes as anticancer agents mainly in 2009. The perspectives of the foreseeable future and potential application of metal supramolecular complexes in cancer therapy were also presented. It is hoped that this review will serve as a stimulant for new thoughts in the quest for rational designs of more active and less toxic metal supramolecular complex anticancer drugs.

Recent researches in metal supramolecular complexes as anticancer agents.

The research and development of metal supramolecular complexes as anticancer supramolecular drugs, which are aggregates mainly formed by one or more inorganic metal compounds with one or more either inorganic or organic molecules in general via coordination bonds, has been a quite rapidly developing, increasingly active and newly rising highlight interdisciplinary field. Numerous efforts have been directed toward metal supramolecular complexes as potential anticancer agents and the unprecedented progress has been made. This has opened up a wholly new and infinite space to create novel metal-based bioactive supermolecules. More importantly, metal-based complex supermolecules as potential anticancer agents with wide potential applications have become highlight topics in recent years, and are becoming increasingly useful and important in preventing and treating cancer diseases. In view of the rapid progress in metal complex anticancer supermolecules with rich variation of structural types, this work systematically reviewed the recent research and development of the whole range of metal-based supramolecular complexes as anticancer agents mainly in 2009. The perspectives of the foreseeable future and potential application of metal supramolecular complexes in cancer therapy were also presented. It is hoped that this review will serve as a stimulant for new thoughts in the quest for rational designs of more active and less toxic metal supramolecular complex anticancer drugs.

Synthesis, antibacterial and antifungal activities of some carbazole derivatives.

A series of N-substituted carbazole derivatives were synthesized and evaluated for antibacterial and antifungal activities against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Bacillus proteus, Candida albicans and Aspergillus fumigatus by two fold serial dilution technique. Some of the synthesized compounds displayed comparable or even better antibacterial and antifungal activities than reference drugs fluconazole, chloramphenicol and norfloxacin against tested strains.

Synthesis, antibacterial and antifungal activities of novel 1,2,4-triazolium derivatives.

A series of novel 1,2,4-triazolium derivatives was synthesized starting from commercially available 1H-1,2,4-triazole, 2,4-dichlorobenzyl chloride, or 2,4-difluorobenzyl bromide. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Bacillus proteus, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans ATCC 76615, and Aspergillus fumigatus. All structures of the new compounds were confirmed by NMR, IR, and MS spectra, and elemental analyses. The antimicrobial tests showed that most of synthesized triazolium derivatives exhibit significant antibacterial and antifungal activities in vitro. 1-(2,4-Difluorobenzyl)-4-dodecyl-1H-1,2,4-triazol-4-ium bromide and 1-(2,4-Dichlorobenzyl)-4-dodecyl-1H-1,2,4- triazol-4-ium bromide were the most potent compounds against all tested strains with the MIC values ranging from 1.05 to 8.38 microM. They exhibited much stronger activities than the standard drugs chloramphenicol and fluconazole which are in clinical use. The results also showed that the antimicrobial activities of triazolium derivatives depend upon the type of substituent, the length of the alkyl chain, and the number of triazolium rings.

Review on supermolecules as chemical drugs.

Supramolecular medicinal chemistry field has been a quite rapidly developing, increasingly active and newly rising interdiscipline which is the new expansion of supramolecular chemistry in pharmaceutical sciences, and is gradually becoming a relatively independent scientific area. Supramolecular drugs could be defined as medicinal supermolecules formed by two or more molecules through non-covalent bonds. So far a lot of supermolecules as chemical drugs have been widely used in clinics. Supermolecules as chemical drugs, i.e. supramolecular chemical drugs or supramolecular drugs, which might have the excellences of lower cost, shorter period, higher potential as clinical drugs for their successful research and development, may possess higher bioavailability, better biocompatibility and drug-targeting, fewer multidrug-resistances, lower toxicity, less adverse effect, and better curative effects as well as safety, and therefore exhibit wide potential application. These overwhelming advantages have drawn enormous special attention. This paper gives the definition of supramolecular drugs, proposes the concept of supramolecular chemical drugs, and systematically reviews the recent advances in the research and development of supermolecules, including organic and inorganic complex ones as chemical drugs in the area of antitumor, anti-inflammatory, analgesic, antimalarial, antibacterial, antifungal, antivirus, anti-epileptic, cardiovascular agents and magnetic resonance imaging agents and so on. The perspectives of the foreseeable future and potential application of supramolecules as chemical drugs are also presented.