ABSTRACT
The highly enantioselective aza-Michael reaction of tert-butyl ß-naphthylmethoxycarbamate to cyclic enones has been accomplished by using a new cinchona alkaloid derived C(9)-urea ammonium catalyst under phase-transfer catalysis conditions with up to 98% ee at 0 °C. The resulting aza-Michael adducts can be converted to versatile intermediates by selective deprotection and the cyclic 1,3-aminoalcohols by diastereoselective reduction with up to 32:1, which have been widely used as important pharmacophores in pharmaceutical development.
ABSTRACT
Lysine methyltransferases are important regulators of epigenetic signaling and are emerging as a novel drug target for drug discovery. This work demonstrates the positioning of novel 1,5-oxaza spiroquinone scaffold into selective SET and MYND domain-containing proteins 2 methyltransferases inhibitors. Selectivity of the scaffold was identified by epigenetic target screening followed by SAR study for the scaffold. The optimization was performed iteratively by two-step optimization consisting of iterative synthesis and computational studies (docking, metadynamics simulations). Computational binding studies guided the important interactions of the spiro[5.5]undeca scaffold in pocket 1 and Lysine channel and suggested extension of tail length for the improvement of potency (IC50: up to 399 nM). The effective performance of cell proliferation assay for chosen compounds (IC50: up to 11.9 nM) led to further evaluation in xenograft assay. The potent compound 24 demonstrated desirable in vivo efficacy with growth inhibition rate of 77.7% (4 fold decrease of tumor weight and 3 fold decrease of tumor volume). Moreover, mirosomal assay and pharmacokinetic profile suggested further developability of this scaffold through the identification of major metabolites (dealkylation at silyl group, reversible hydration product, the absence of toxic quinone fragments) and enough exposure of the testing compound 24 in plasma. Such spiro[5.5]undeca framework or ring system was neither been reported nor suggested as a modulator of methyltransferases. The chemo-centric target positioning and structural novelty can lead to potential pharmacological benefit.
Subject(s)
Aza Compounds/pharmacology , Enzyme Inhibitors/pharmacology , Epigenesis, Genetic/drug effects , Histone-Lysine N-Methyltransferase/antagonists & inhibitors , Quinones/pharmacology , Spiro Compounds/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Aza Compounds/chemical synthesis , Aza Compounds/chemistry , Cell Survival/drug effects , Crystallography, X-Ray , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Epigenesis, Genetic/genetics , Female , HEK293 Cells , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Humans , Male , Mammary Neoplasms, Experimental/drug therapy , Mammary Neoplasms, Experimental/metabolism , Mammary Neoplasms, Experimental/pathology , Mice , Mice, Inbred BALB C , Mice, Inbred ICR , Mice, Nude , Microsomes, Liver/chemistry , Microsomes, Liver/metabolism , Molecular Docking Simulation , Molecular Structure , Quinones/chemical synthesis , Quinones/chemistry , Spiro Compounds/chemical synthesis , Spiro Compounds/chemistry , Structure-Activity RelationshipABSTRACT
A novel nitration (via C(sp3)-N breaking/C(sp2)-N formation with CH3NO2) mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA) is described. The NO2 transfer from CH3NO2 to the aromatic group of the substrate is possible with careful selection of the solvent, NaX, and oxidant. In addition, the solvent-controlled C(sp2)-H functionalization can shift to an α-C(sp3)-H functionalization (cyanation or oxygenation) of the α-C(sp3)-H of cyclic amines.
ABSTRACT
Here we first time report an unprecedented and unnatural six-membered 1,5-oxaza spiroquinone scaffold with structural novelty, a convenient and efficient synthetic route was developed for the synthesis of new 1,5-oxaza spiroquinone derivatives (1a-1r) in high yields from readily available starting materials. The logic of the present work consists of (1) the identification of a promising unprecedented scaffold from privileged scaffolds of biological active molecules through our 'Chemistry-oriented Synthesis' (ChOS) approach, a compensatory strategy for target-based drug discovery, (2) the positioning of the identified 1,5-oxaza spiroquinone scaffold on neuroinflammation and neurodegenerative disease through nitric oxide (NO) inhibitory activity without cytotoxicity in hyper-activated microglia (IC50 of NO production: 0.07-1.82⯵M) to establish structure-activity relationship (SAR), (3) the investigation on the possibility as a selective kinase inhibitor related to neurodegenerative diseases (eg. JNK1, CDK2, DAPK1) through kinase full panel screening of the most potent compound 1n, and (4) the evaluation on in vivo efficacy of the compound 1n through Y-maze test.