Yuanyuan Shan

Synthesis and preliminary biological evaluation of novel taspine derivatives as anticancer agents.

Antiangiogenic therapy might represent a new promising anticancer therapeutic strategy. Taspine can significantly inhibit cell proliferation of human umbilical vein endothelial cells (HUVECs) induced by vascular endothelial growth factor-165, which is crucial for angiogenesis. In this study, a series of novel taspine derivatives were synthesized and screened for in vitro anticancer and antiangiogenesis activities. The majority of the derivatives demonstrated a moderate degree of cytotoxicity against human cancer cell lines. One of them (14) exhibited much better antiproliferative activity against CACO-2 (IC(50)=52.5microM) and ECV304 (IC(50)=2.67microM) cells than taspine did. Some of them were also effective in antiproliferative assays against HUVECs. The in silico estimate of solubility of title compounds were higher than that of taspine.

Development of 5-Fluorouracil derivatives as anticancer agents.

5-Fluorouracil (5-FU) is one of the most potent antimetabolites which have been widely used in the treatment of advanced solid tumors. As an anticancer agent, because of its low efficacy and high toxicity, numerous modifications of 5-FU structure have been performed. A great number of novel 5-FU derivatives have been developed with highly efficient and much less toxic. In this paper, the recent development of novel 5-FU derivatives as potent antitumor agents is reviewed and discussed.

Molecular Docking, 3D-QSAR Studies, and In Silico ADME Prediction of p-Aminosalicylic Acid Derivatives as Neuraminidase Inhibitors

Neuraminidase (NA) is a major glycoprotein of influenza virus which is essential for viral infection. It offers a potential target for antiviral drug design and discovery. To develop novel potent neuraminidase inhibitors (NAI), Surflex‐Dock was employed to dock 40 hydrophobic p‐aminosalicylic acid derivatives into the active site of NA. The 3D‐quantitative structure–activity relationship studies involving comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were carried out on 40 molecules. Both CoMFA (q2 = 0.628, r2 = 0.697) and CoMSIA (q2 = 0.746, r2 = 0.816) gave reasonable results. A preliminary pharmacokinetic profile of these NAI was also performed on the basis of Volsurf predictions. The results obtained from this study will be useful in the design of novel potent NAI.

Recent Advances in Antiangiogenic Agents with VEGFR as Target

Angiogenesis is required for invasive tumor growth and metastasis and constitutes an important point in the control of cancer progression. Its inhibition may be a valuable approach to cancer therapy. Antiangiogenic agents are designed to attack the tumor vasculature and cut off the tumors supply of nutrients. Systemic blockade of angiogenesis has been recently approved for the treatment of several types of human cancers. Antiangiogenic therapy presents various advantages as compared to conventional treatment. Vascular endothelial growth factor (VEGF) is considered to be one of the most important regulators of angiogenesis and a key target in anticancer treatment. VEGF binding to its receptor (VEGFR) leads to cell proliferation and new vascular formation by tyrosine kinase (TK) pathway. VEGF/VEGFR pathway is becoming attractive target for anticancer drug design. It is believed to be important in the control of angiogenesis. Antiangiogenic therapy based on inhibition of VEGFR was reported to be powerful clinical strategies. In this review, the authors describe the existing literature regarding VEGFR inhibitors in the last few years. We attempt to cover all essential publications on the medicinal chemistry in terms of chemical structure, pharmacological profile and structure-activity relationships.

Discovery of biphenyl-based VEGFR-2 inhibitors. Part 3: Design,synthesis and 3D-QSAR studies

VEGFR-2 plays an essential role in angiogenesis and is a central target for anticancer drug discovery. In order to develop novel VEGFR-2 inhibitors, we designed and synthesized 33 biphenyl amides based on our previously reported lead compound. The biological results indicated that four compounds (18b, 20e, 20h and 20j) are potent VEGFR-2 inhibitors which are comparable to positive control. Compound 18b displayed the most potent VEGFR-2 inhibition with IC50 value of 2.02nM. Moreover, it exhibited promising antiproliferative activity against MCF-7 and SMMC-7721 cells with IC50 values of 1.47μM and 5.98μM, respectively. Molecular docking and 3D-QSAR studies were also carried out. The results indicated that these biphenyl amides could serve as promising leads for further optimization as novel VEGFR-2 inhibitors.

Discovery of novel VEGFR-2 inhibitors. Part 5: Exploration of diverse hinge-binding fragments via core-refining approach.

Pathological angiogenesis plays a critical role in numerous diseases including malignancy. VEGFR-2 is the central regulators in angiogenesis and has become a promising target for anticancer drug design. We have identified a novel biphenyl-aryl urea incorporated with salicyladoxime (BPS-7) as potent VEGFR-2 inhibitor. As a continuation to our previous research, various aromatic-heterocyclic were introduced as hinge-binding fragment via a core-refining approach. Interestingly, many compounds exhibited comparable VEGFR-2 inhibition to Sorafenib. In particular, 12e and 12o displayed excellent VEGFR-2 inhibitory activity with IC₅₀ values of 0.50 nM and 0.79 nM, respectively. Several title compounds showed considerable antiproliferative activity against A549 and SMMC-7721 cells. In addition, molecular docking was performed to rationalize the efficiency of the better compounds. These results will be instructive for further inhibitor design and optimization.

Discovery of novel anti-angiogenesis agents. Part 6: Multi-targeted RTK inhibitors

Angiogenesis is modulated by a multitude of pro-angiogenic factors including VEGFR-2, Tie-2, and EphB4. Moreover, their crosstalk also had been well elaborated. We have identified several diarylurea-based VEGFR-2 inhibitors as potential anti-angiogenesis agents. As a continuation to our previous research, two series of diaryl malonamide and diaryl thiourea derivatives have been developed as multiplex VEGFR-2/Tie-2/EphB4 inhibitors. Interestingly, the biological evaluation indicated that several compounds bearing trifluoromethyl or trifluoromethoxyl exhibited promising multiplex inhibition against angiogenesis-related VEGFR-2, Tie-2, and EphB4. The representative compound (18a) displayed both potent multi-targeted RTK inhibition and considerable antiproliferative activities against human umbilical vein endothelial cells (EA.hy926). These results will contribute to the discovery of novel muti-targeted anti-angiogenesis agents.

Recent advances in the structure-based design of neuraminidase inhibitors as antiinfluenza agents.

Influenza is an infection of the upper respiratory tract caused by influenza virus. Neuraminidase (NA) plays an essential role in replication and infection of influenza virus. It is considered as a suitable target for antivirus agents development. Several potent NA inhibitors (NAIs) developed by using structure-based rational design have been widely used in clinic for treatment of influenza. However, the emergence of NA inhibitor-resistant virus mutations significantly limit their effectiveness. The molecular basis of virus resistance to NAIs has been a focus of intensive research. This review highlights recent progress in rational design and resistance mechanism of NAIs. We hope this review will be useful to not only researchers who are interested in developing novel NAIs but also clinical pharmacists.

Discovery of novel anti-angiogenesis agents. Part 8: Diaryl thiourea bearing 1H-indazole-3-amine as multi-target RTKs inhibitors

VEGFR-2, TIE-2, and EphB4 are essential for both angiogenesis and tumorigenesis. Herein, we designed and prepared three classes of multi-target inhibitors based on the extensive sequence homology along the kinase domain of angiogenic RTKs. Biological evaluation indicated that these multi-target inhibitors exhibited considerable potential as novel anti-angiogeneic and anticancer agents. Among them, a diaryl thiourea bearing 1H-indazole-3-amine (16a) displayed the most potent RTK inhibition and excellent selectivity. It also showed inhibition on viability of human umbilical vein endothelial cells and anti-proliferation against a broad spectrum of cancer cells. Therefore, 1H-indazole-3-amine could serve as a promising hinge binding group for multi-target inhibitors of VEGFR-2, Tie-2, and EphB4.

Discovery and evaluation of triple inhibitors of VEGFR-2, TIE-2 and EphB4 as anti-angiogenic and anti-cancer agents

Receptor tyrosine kinases (RTKs), especially VEGFR-2, TIE-2, and EphB4, play a crucial role in both angiogenesis and tumorigenesis. Moreover, complexity and heterogeneity of angiogenesis make it difficult to treat such pathological traits with single-target agents. Herein, we developed two classes of multi-target RTK inhibitors (RTKIs) based on the highly conserved ATP-binding pocket of VEGFR-2/TIE-2/EphB4, using previously reported BPS-7 as a lead compound. These multi-target RTKIs exhibited considerable potential as novel anti-angiogenic and anticancer agents. Among them, QDAU5 displayed the most promising potency and selectivity. It significantly suppressed viability of EA.hy926 and proliferation of several cancer cells. Further investigations indicated that QDAU5 showed high affinity to VEGFR-2 and reduced the phosphorylation of VEGFR-2. We identified QDAU5 as a potent multiple RTKs inhibitor exhibiting prominent anti-angiogenic and anticancer potency both in vitro and in vivo. Moreover, quinazolin-4(3H)-one has been identified as an excellent hinge binding moiety for multi-target inhibitors of angiogenic VEGFR-2, Tie-2, and EphB4.