ABSTRACT
BACKGROUND AND PURPOSE: Rho-kinase (ROCK) has been implicated in the pathophysiology of altered vasoregulation leading to hypertension. Here we describe the pharmacological characterization of a potent, highly selective and orally active ROCK inhibitor, the derivative of a class of azaindoles, azaindole 1 (6-chloro-N4-{3,5-difluoro-4-[(3-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy]-phenyl}pyrimidine-2,4-diamine). EXPERIMENTAL APPROACH: Pharmacological characterization of azaindole 1 was performed with human recombinant ROCK in vitro. Vasodilator activity was determined using isolated vessels in vitro and different animal models in vivo. KEY RESULTS: This compound inhibited the ROCK-1 and ROCK-2 isoenzymes with IC50 s of 0.6 and 1.1 nM in an ATP-competitive manner. Although ATP-competitive, azaindole 1 was inactive against 89 kinases (IC50>10 microM) and showed only weak activity against an additional 21 different kinases (IC50=1-10 microM). Only the kinases TRK und FLT3 were inhibited by azaindole 1 in the sub-micromolar range, albeit with IC50 values of 252 and 303 nM, respectively. In vivo, azaindole 1 lowered blood pressure dose-dependently after i.v. administration in anaesthetized normotensive rats. In conscious normotensive and spontaneously hypertensive rats azaindole 1 induced a dose-dependent decrease in blood pressure after oral administration without inducing a significant reflex increase in heart rate. In anaesthetized dogs, azaindole 1 induced vasodilatation with a moderately elevated heart rate. CONCLUSIONS AND IMPLICATIONS: Azaindole 1 is representative of a new class of selective and potent ROCK inhibitors and is a valuable tool for the elucidation of the role of ROCK in the cardiovascular system.
Subject(s)
Cardiovascular System/drug effects , Diamines/pharmacology , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacology , rho-Associated Kinases/antagonists & inhibitors , Administration, Oral , Animals , Apoptosis Regulatory Proteins/antagonists & inhibitors , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Binding Sites/drug effects , Blood Pressure/drug effects , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Calcium-Calmodulin-Dependent Protein Kinases/genetics , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cells, Cultured , Computer Simulation , Death-Associated Protein Kinases , Dogs , Dose-Response Relationship, Drug , Female , Humans , Injections, Intravenous , Male , Mice , Models, Animal , Models, Molecular , Organ Culture Techniques , Phosphorylation , Polymerase Chain Reaction/methods , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Rabbits , Rats , Rats, Inbred SHR , Rats, Wistar , Recombinant Proteins/antagonists & inhibitors , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Time Factors , Vasodilator Agents/administration & dosage , Vasodilator Agents/chemistry , Vasodilator Agents/pharmacology , rho-Associated Kinases/genetics , rho-Associated Kinases/metabolismABSTRACT
A highly convergent synthetic approach was developed to obtain alpha-galactosyl cerebroside O-(alpha-D-galactopyranosyl)-2-hexacosylamino-D-ribo-1,3,4-octa decantriol, which has previously been demonstrated to have immunostimulatory activity. Known 4,6-O-benzylidene galactose was the starting material for both the required alpha-galactosyl and the phytosphingosine building blocks O-(2,3-di-O-benzyl-4,6-O-benzylidene-D-galactopyranosyl) trichloroacetimidate (4) and 2-O-methanesulfonyl-D-arabino-1,2,3,4-octadecantetrol (5). The key step of the synthetic strategy is the highly regio- and stereoselective O-galactosylation of 1,3,4-O-unprotected phytosphingosine acceptor 5 using known 4 as donor. The total synthesis required only 11 synthetic steps starting from galactose.
Subject(s)
Galactosylceramides/chemical synthesis , Adjuvants, Immunologic/chemical synthesis , Antineoplastic Agents/chemical synthesis , Killer Cells, Natural/chemistry , Ligands , Receptors, Antigen, T-CellABSTRACT
As part of a continuing study aimed to achieve improved monoclonal antibodies against carcinoembryonic antigen (CEA) carbohydrate fragments, the synthesis of a sialyl-(2-->6)-lactosamine trisaccharide with a 5-amino-3-oxapentyl spacer group at C-1I has been developed. Two different routes to access this target are described. For this purpose 5-azido-3-oxapentyl 6-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranoside (4) was selectively beta-galactosylated in 81% yield using the crystalline 2,3-di-O-acetyl-4,6-O-benzylidene-alpha-D-galactopyranosyl trichloroacetimidate as the donor, taking advantage of the bulky phthalimido group at C-2 of 4. On the other hand, galactosylation of the suitable protected acceptor 5-azido-3-oxapentyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranoside with the crystalline 2,3-di-O-acetyl-4,6-O-benzylidene-alpha-D-galactosyl bromide renders the corresponding disaccharide in a moderate 58% yield. Despite the fact that the first strategy, unlike the second one, requires a hydrazinolysis-acetylation reaction at the disaccharide stage, it was found to be more convenient to access the disaccharide acceptor. Sialylation was performed using a thiophenyl donor under an NIS-TfOH activation procedure in acetonitrile to give a mixture of alpha and beta trisaccharides in 49 and 16% yields, respectively.
