﻿iMOSFLM: a new graphical interface for diffraction-image processing with MOSFLM

﻿iMOSFLM: a new graphical interface for diffraction-image processing with MOSFLM. to patients, but also to their caretakers, the economy, and to global health in general. Effective treatments for neurodegenerative diseases are limited, and the development of novel therapeutics to treat neurodegeneration is a highly desirable unmet medical need. Neuronal nitric oxide synthase (nNOS) is an enzymatic target under investigation for the treatment of neurodegenerative disorders (as well as other conditions characterized by neuronal damage, such as stroke, ischemic events, cerebral palsy, and neuropathic pain).1 Three NOS isoenzymes produce nitric oxide (NO), a free-radical second-messenger molecule, in the human body: endothelial NOS (eNOS) produces the NO employed in blood pressure regulation and smooth muscle tone, inducible NOS (iNOS) plays a role in immune activation, and in the CNS, the NO produced by nNOS is required for normal neuronal signaling.2 Under neuroinflammatory or neurodegenerative phenotypes, however, nNOS can become overactive or overexpressed, and NO levels surge several orders of magnitude, where NO can cause damage or combine to form other damaging species like peroxynitrite. 3 These species can cause protein nitration and aggregation, 4 depletion of cellular energy and glutathione reserves,5,6 damage to various cellular structures, and Piperonyl butoxide the eventual apoptosis or necrosis of neurons, leading progressively to the symptoms characteristic of neurodegeneration. Studies have shown that hyperactive nNOS Piperonyl butoxide and dysfunctional nitrergic signaling are affiliated with or directly implicated in the pathology of many neurodegenerative disorders7,8, 9, 10 making nNOS a desirable target for therapeutic intervention.9, 11, 12 nNOS functions by converting l-arginine to l-citrulline and NO an electron relay proceeding through five cofactors. nNOS is only functional as a homodimer with each monomer made up of an oxygenase domain name and a reductase domain name that are joined by a linker domain name where calmodulin, in response to elevated calcium levels, binds and activates the enzyme. Once activated, electron flow proceeds from the reductase domain-bound reduced nicotinamide adenine dinucleotide phosphate (NADPH), to flavin adenine dinucleotide (FAD), to flavin mononucleotide (FMN), and then from the FMN subdomain of one monomer to the other monomer’s oxygenase domain name,13 through (6pharmacokinetics.17 Unfortunately, 2 was selective for rat nNOS (rnNOS) over human nNOS (hnNOS), displayed low selectivity for human nNOS over human eNOS (heNOS), caused toxic side effects in Piperonyl butoxide rats, and was extremely promiscuous in CNS counterscreens. The second-generation,18 rearranged phenyl ether 4 (optimized from lead 3), preserved the potency and selectivity of 1 1 and 2 while drastically decreasing the off-target binding, but this compound had significantly decreased Caco-2 permeability, low human nNOS activity, and similarly low selectivity for hnNOS over heNOS. Open in a separate window Physique 1 Previous use of 2-aminoquinolines as nNOS inhibitors. We chose to continue investigating Piperonyl butoxide this cleaner-binding phenyl ether scaffold in an attempt to improve n/e selectivity, hnNOS inhibitory potency, and possibly cellular permeability. First, the 5-position of the phenyl ring (Physique 2) was substituted with a variety of groups, leading to analogues 5-9. Previously, the 1,3,5-trisubstituted phenyl or pyridyl moieties of 2-aminopyridine inhibitors19, 20, 21 were able to access nNOS-specific residues such as Asp597 (Asp602 in hnNOS), or other nNOS-specific regions, and lead to high n/e selectivity. It was proposed that analogous substituents around the phenyl ether scaffold could reach potentially similar nNOS-specific regions that could improve hnNOS potency, such as the hnNOS-specific residue ARHGDIG His342. Open in a separate window Physique 2 Design strategy utilized and compounds synthesized in this study. All molecules have a CLogP between 2.5-4 (lower for cyano compounds and higher for deoxy compounds), and tPSA (total polar surface area) of 50-83 ?2 (higher for cyano compounds and lower for deoxy compounds). Second, it was previously reported that for 2-aminopyridines, installation of a methyl group at the 4-position of the pyridine could drastically improve potency, and in some cases, selectivity.22 A fragment screen then showed that 2-amino-4-methylquinoline bound nearly 7-fold tighter (aminoquinoline 52,30 was converted into desmethyl 7-bromoquinoline 53 (Scheme 4A). Next, suitable Sonogashira coupling partners were prepared. To prepare 14, 3-iodobenzyl bromide (54, Scheme 4B) was Piperonyl butoxide converted to carbamate 55, and coupling with ethynyltrimethylsilane afforded 56 in excellent yields, which was then desilylated to yield 57. Synthesis of cyanated analogues 15 and 16 began with bromination of commercially available cyanotoluene 58 (Scheme 4C);.