Unravelling the fine structure of stacked bipyridine diamine-derived C(3)-discotics as determined by x-ray diffraction, quantum-chemical calculations, fast-mas nmr and cd spectroscopy

An in depth investigation of the fine structure adopted by the helical stacks of C(3)-discotics 1 incorporating three 3,3%27-diamino-2,2%27-bipyridine units is described. In the bulk the molecules display liquid crystalline behaviour in a temperature window of >300 K and an ordered rectangular columnar mesophase (Col(ro)) with an inter-disc distance of 3.4 angstrom is assigned. X-Ray diffraction on aligned samples has also revealed a helical superstructure in the liquid crystalline state, and a rotation angle of 13-16 degrees between consecutive discs. The proposed superstructure in the bulk phase has been further substantiated by a combination of quantum-chemical calculations and solid-state NMR spectroscopy. Dilute solution NMR spectroscopy and elaborate CD spectroscopy on aggregated samples have revealed an isodesmic growth pattern of the C(3)-discotics. From the combined results it has become evident that the fine tuning interaction responsible for the highly ordered helical architectures is not weak intermolecular hydrogen bonding, but rather rigidification, due to propeller formation after preorganisation by pi-pi interactions. Although all the techniques used underpin the structural features proposed, none of them individually is able to point to a unique structure. However, together the techniques give very strong evidence for a confined ship-screw arrangement in which all amidic carbonyl oxygens point in one direction

Synthesis, Biological Evaluation, and Molecular Modeling of 1-Benzyl-1H-imidazoles as Selective Inhibitors of Aldosterone Synthase (CYP11B2)

Reducing aldosterone action is beneficial in various major diseases such as heart failure. Currently, flits is achieved with mineralocorticoid receptor antagonists, however, aldosterone synthase (CYP11B2) inhibitors may offer a promising alternative. In this study, WC used three-dimensional modeling of CYP11B2 to model the binding modes of the natural substrate 18-hydroxycorticosterone and the recently published CYP11B2 inhibitor R-fadrozole as a rational guide to design 44 structurally simple and achiral 1-benzyl-1H-imidazoles. Their syntheses, in vitro inhibitor potencies, and in silico docking are described. Some promising CYP11B2 inhibitors were identified, with our novel lead MOERAS115 (4-((5-phenyl-1H-imidazol-1-y1)methyl)benzonitrile) displaying an IC50 for CYP11B2 of 1.7 nM, and a CYP11B2 (versus CYP11B1) selectivity of 16.5, comparable to R-fadrozole (IC50 for CYP11B2 6.0 nM. Selectivity 19.8). Molecular docking of the Inhibitors in the models enabled us to generate posthoc hypotheses oil their binding modes, providing a Valuable basis for future Studies and further design of CYP11B2 inhibitors