Publications by authors named "Alexander Kiselyov"

Doublecortin-like kinase 1 (DCLK1) is a cancer stem cell marker that is highly expressed in various types of human cancer, and a protein kinase target for cancer therapy that is attracting increasing interest. However, no drug candidates targeting DCLK1 kinase have been developed in clinical trials to date. XMD-17-51 was found herein to possess DCLK1 kinase inhibitory activities by cell-free enzymatic assay.

View Article and Find Full Text PDF

Mutant huntingtin (mHTT) protein carrying the elongated N-terminal polyglutamine (polyQ) tract misfolds and forms protein aggregates characteristic of Huntington's disease (HD) pathology. A high-affinity ligand specific for mHTT aggregates could serve as a positron emission tomography (PET) imaging biomarker for HD therapeutic development and disease progression. To identify such compounds with binding affinity for polyQ aggregates, we embarked on systematic structural activity studies; lead optimization of aggregate-binding affinity, unbound fractions in brain, permeability, and low efflux culminated in the discovery of compound , which exhibited target engagement in autoradiography (ARG) studies in brain slices from HD mouse models and postmortem human HD samples.

View Article and Find Full Text PDF

In an effort to develop potent, orally bioavailable compounds for the treatment of neoplastic diseases, we developed a class of dual VEGFR-2 kinase and tubulin inhibitors. Targeting the VEGFR receptor kinase and tubulin structure allows for inhibition of both tumor cells and tumor vasculature. Previously, a combination of two compounds, a VEGF receptor tyrosine kinase inhibitor and tubulin agent, was demonstrated to produce an enhanced antitumor response in animal studies.

View Article and Find Full Text PDF

Derivatives of (1,2,3-triazol-4-yl)benzenamines are described as potent and ATP-competitive inhibitors of vascular endothelial growth factor receptors I and II (VEGFR-1/2). A number of compounds exhibited VEGFR-2 and VEGFR-1 inhibitory activity comparable to that of Vatalanib in both HTRF enzymatic and cellular assays.

View Article and Find Full Text PDF
Article Synopsis
  • Novel isothiazole derivatives are identified as strong inhibitors of vascular endothelial growth factor receptors VEGFR-1 and VEGFR-2, showing promise in treating diseases related to these pathways.
  • Some of these compounds demonstrate VEGFR-2 inhibitory activity similar to Vatalanib in both enzymatic and cellular tests.
  • Certain derivatives have a 4- to 8-fold preference for inhibiting VEGFR-2 over VEGFR-1 and display good permeability across cell layers, which is essential for drug development.
View Article and Find Full Text PDF

A series of arylphthalazine derivatives were synthesized and evaluated as antagonists of VEGF receptor II (VEGFR-2). IM-094482 57, which was prepared in two steps from commercially available starting materials, was found to be a potent inhibitor of VEGFR-2 in enzymatic, cellular and mitogenic assays (comparable activity to ZD-6474). Additionally, 57 inhibited the related receptor, VEGF receptor I (VEGFR-1), and showed excellent exposure when dosed orally to female CD-1 mice.

View Article and Find Full Text PDF

We have discovered novel inhibitors of VEGFR-2 kinase with low nanomolar potency in both enzymatic and cell-based assays. Active series are heteroaryl-ketone compounds containing a central aromatic ring with either an indazolyl or indolyl keto group in the ortho orientation to the benzylic amine group (Fig. 1).

View Article and Find Full Text PDF

Novel derivatives of 1,2,4-triazoles are described as potent ATP-competitive inhibitors of vascular endothelial growth factor receptors I and II (VEGFR-1/2). A number of compounds display VEGFR-2 inhibitory activity comparable to that of Vatalanib and Vandetanib in both homogenous time-resolved fluorescence enzymatic and cellular assays. Several active molecules feature high intrinsic permeability (>30 x 10(-5) cm/min) across Caco-2 cell monolayer.

View Article and Find Full Text PDF

We have developed a series of novel potent 1-(2-(pyridin-4-yl)ethyl)-1H-azole-5-carboxamides active against kinases VEGFR-2 and -1. Both specific and dual ATP-competitive inhibitors of VEGFR-2 were identified. Kinase selectivity could be controlled by varying the 5-carboxamide substituent at the azole ring.

View Article and Find Full Text PDF

We have developed a series of novel potent ortho-substituted azole derivatives active against kinases VEGFR-1 and VEGFR-2. Both specific and dual ATP-competitive inhibitors of VEGFR-2 were identified. Kinase activity and selectivity could be controlled by varying the arylamido substituents at the azole ring.

View Article and Find Full Text PDF

Novel potent derivatives of phthalazine are described as ATP-competitive inhibitors of vascular endothelial growth factor receptors I and II (VEGFR-1/2). A number of compounds display VEGFR-2 inhibitory activity reaching that of Vatalanib 3 (IC50 < 100 nm) in an HTRF enzymatic assay. Several derivatives also show good potential for the development as VEGFR-2 specific inhibitors showing 15-20-fold selectivity over VEGFR-1.

View Article and Find Full Text PDF

Novel potent derivatives of phthalazine are described as an adenosine triphosphate-competitive inhibitors of vascular endothelial growth factor receptors I and II. A number of compounds display vascular endothelial growth factor receptor II inhibitory activity reaching that of Vatalanib A (IC(50): < 50 nm) in an homogenous time-resolved fluorescence enzymatic assay.

View Article and Find Full Text PDF

Novel tricyclic derivatives containing an oxazepine, thiazepine, or diazepine ring were studied for their EGFR tyrosine kinase inhibitory activity. While the oxazepines were in general more potent than thiazepines, the diazepines displayed somewhat different structure-activity relationships. Moreover, the diazepines, in contrast to the oxazepines, showed appreciable inhibitory activity against the KDR tyrosine kinase.

View Article and Find Full Text PDF

Identification of antimitotic molecules that affect tubulin dynamics is a multistep procedure. It includes in vitro tubulin polymerization assay, studies of a cell cycle effect, and general cytotoxicity assessment. To simplify this lengthy screening protocol, we have introduced and validated an assay system based on the sea urchin embryos.

View Article and Find Full Text PDF

Estrogen is a hormone critical in the development, normal physiology and pathophysiology of numerous human tissues. The effects of estrogen have traditionally been solely ascribed to estrogen receptor alpha (ERalpha) and more recently ERbeta, members of the soluble, nuclear ligand-activated family of transcription factors. We have recently shown that the seven-transmembrane G protein-coupled receptor GPR30 binds estrogen with high affinity and resides in the endoplasmic reticulum, where it activates multiple intracellular signaling pathways.

View Article and Find Full Text PDF

We have developed a series of novel potent ((pyridin-4-yl)ethyl)pyridine derivatives active against kinases VEGFR-1 and -2. Both specific and dual ATP-competitive inhibitors of VEGFR-2 were identified. Kinase selectivity could be controlled by varying the arylamino substituent at the 1,3,4-oxadiazole ring.

View Article and Find Full Text PDF

A novel class of pyrimido[4,5-b]-1,4-benzoxazepines is described as inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinase. Two compounds display potent EGFR inhibitory activity of less than 1 microM in cellular phosphorylation assays (IC(50) 0.47-0.

View Article and Find Full Text PDF

A novel class of 1-(isoquinolin-5-yl)-4-arylamino-phthalazines is described as inhibitors of vascular endothelial growth factor receptor II (VEGFR-2). Many compounds display VEGFR-2 inhibitory activity with an IC(50) as low as 0.017 microM in an HTRF enzymatic assay.

View Article and Find Full Text PDF

Oxadiazole derivatives were synthesized and evaluated for their ability to inhibit tubulin polymerization and to cause mitotic arrest in tumor cells. The most potent compounds inhibited tubulin polymerization at concentrations below 1 microM. Lead analogs caused mitotic arrest of A431 human epidermoid cells and cells derived from multi-drug resistant tumors (10, EC(50)=7.

View Article and Find Full Text PDF

Novel potent derivatives of (azol-1-yl)methyl-N-arylbenzamides with improved solubility (>3mM) are described as ATP-competitive inhibitors of vascular endothelial growth factor receptor 2 (VEGFR-2). Many compounds display VEGFR-2 inhibitory activity reaching IC(50)<100 nM in the enzymatic assay. The compounds also inhibit the related tyrosine kinase, VEGFR-1, with similar potencies.

View Article and Find Full Text PDF

A novel potent derivatives of hetaryl imidazoles were described as inhibitors of vascular endothelial growth factor receptor II (VEGFR-2). Several compounds display VEGFR-2 inhibitory activity reaching IC(50)<100 nM in both enzymatic and cellular assays. The compounds also inhibit the related tyrosine kinase, VEGFR-1.

View Article and Find Full Text PDF

This tutorial review deals with developments in the chemistry of N-fluoropyridinium salts in the past decade, including both synthetic and mechanistic aspects. Three distinct types of transformations including: i) fluorination reactions, ii) carbenoid behavior and iii) cine-/tele- substitution involving N-fluoropyridinium cation are exemplified. Procedures for fluorination of carbanions and benzenoid aromatics along with hetarylation processes yielding 2- and 4-substituted pyridines are referenced.

View Article and Find Full Text PDF

Novel potent derivatives of N-(aryl)-4-(azolylethyl)thiazole-5-carboxamides are described as inhibitors of vascular endothelial growth factor receptor II (VEGFR-2). Several compounds display VEGFR-2 inhibitory activity reaching IC(50)<100 nM in both enzymatic and cellular assays. The compounds also inhibit the related tyrosine kinase, VEGFR-1.

View Article and Find Full Text PDF

[Reaction: see text]. A synthesis of the title compounds, which have found use as inhibitors of certain receptor tyrosine kinases, was achieved using a Pictet-Spengler cyclization as a key step.

View Article and Find Full Text PDF

A novel class of 1-[4-(1H-benzoimidazol-2-yl)-phenyl]-3-[4-(1H-benzoimidazol-2-yl)-phenyl]-ureas are described as potent inhibitors of heparanase. Among them are 1,3-bis-[4-(1H-benzoimidazol-2-yl)-phenyl]-urea (7a) and 1,3-bis-[4-(5,6-dimethyl-1H-benzoimidazol-2-yl)-phenyl]-urea (7d), which displayed good heparanase inhibitory activity (IC(50) 0.075-0.

View Article and Find Full Text PDF