1-Acetyl-2-r,6-c-bis­(4-chloro­phen­yl)-3-methyl-1,2,5,6-tetra­hydro­pyridin-4-yl acetate

In the title compound, C22H21Cl2NO3, the pyridine ring adopts a half-chair conformation and the 4-chloro­phenyl groups occupy axial positions. The 4-chloro­phenyl groups are almost perpendicular to the plane of the tetra­hydro­pyridine ring forming dihedral angles 84.62 (6) and 85.55 (5)°; the dihedral angle between the two 4-chloro­phenyl rings is 12.16 (4)°. The crystal structure is stabilized by inter­molecular C—H⋯O inter­actions

Feedback control of Wnt signaling based on ultrastable histidine cluster co-aggregation between Naked/NKD and Axin.

Feedback control is a universal feature of cell signaling pathways. Naked/NKD is a widely conserved feedback regulator of Wnt signaling which controls animal development and tissue homeostasis. Naked/NKD destabilizes Dishevelled, which assembles Wnt signalosomes to inhibit the β-catenin destruction complex via recruitment of Axin. Here, we discover that the molecular mechanism underlying Naked/NKD function relies on its assembly into ultra-stable decameric core aggregates via its conserved C-terminal histidine cluster (HisC). HisC aggregation is facilitated by Dishevelled and depends on accumulation of Naked/NKD during prolonged Wnt stimulation. Naked/NKD HisC cores co-aggregate with a conserved histidine cluster within Axin, to destabilize it along with Dishevelled, possibly via the autophagy receptor p62, which binds to HisC aggregates. Consistent with this, attenuated Wnt responses are observed in CRISPR-engineered flies and human epithelial cells whose Naked/NKD HisC has been deleted. Thus, HisC aggregation by Naked/NKD provides context-dependent feedback control of prolonged Wnt responses

7H-1-Benzofuro[2,3-b]carbazole

In the title compound, C18H11NO, the carbazole and benzofuran rings are almost co-planar, making a dihedral angle of 3.31 (3)°. The crystal structure is stabilized by weak C—H⋯π inter­actions

3-(4-Methoxy­benz­yl)-1-benzothio­phene

In the title compound, C16H14OS, the dihedral angle between the benzothio­phene ring system and the benzene ring is 72.41 (12)°. A weak inter­molecular C—H⋯π inter­action from the benzene ring to the benzothio­phene ring system is observed in the crystal structure

Tribenzoatobismuth(III): a new ­polymorph

A new polymorph (β) was obtained for an active pharmaceutical ingredient, bis­muth tribenzoate, [Bi(C6H5CO2)3]. The new β-polymorph is 1.05 times denser than the previously known polymorph [Rae et al. (1998 ▶). Acta Cryst. B54, 438–442]. In the β-polymorph, the Bi atom is linked with three benzoate anions, each of them acting as a bidentate ligand, and these assemblies with C 3 point symmetry can be considered as ‘mol­ecules’. The structure of the β-polymorph has no polymeric chains, in contrast to the previously known polymorph. The ‘mol­ecules’ in the β-polymorph are stacked along [001], so that the phenyl rings of the neighbouring mol­ecules are parallel to each other. Based on the pronounced difference in the crystal structures, one can suppose that two polymorphs should differ in the dissolution kinetics and bioavailability

(E)-3-Hydr­oxy-13-methyl-16-[4-(methyl­sulfan­yl)benzyl­idene]-7,8,9,11,12,13,15,16-octa­hydro-6H-cyclo­penta­[a]phen­an­­­­thren-17(14H)-one

In the title compound, C26H28O2S, the dihedral angles between the mean plane of the five membered ring and the 4-(methyl­sulfan­yl)benzyl­idine ring in the two crystallographically independent mol­ecules are 34.05 (10) and 40.53 (15)°. The packing is stabilized by inter­molecular O—H⋯O and C—H⋯O inter­actions

A Method for Measuring the Weak Value of Spin for Metastable Atoms

A method for measuring the weak value of spin for atoms is proposed using a variant of the original Stern–Gerlach apparatus. A full simulation of an experiment for observing the real part of the weak value using the impulsive approximation has been carried out. Our predictions show a displacement of the beam of helium atoms in the metastable 2 3S1 state, ∆w, that is within the resolution of conventional microchannel plate detectors indicating that this type of experiment is feasible. Our analysis also determines the experimental parameters that will give an accurate determination of the weak value of spin. Preliminary experimental results are shown for helium, neon and argon in the 23S1 and 3P2 metastable states, respectivel

3,4-Dibromo-2,5-dimethyl-1-phenyl­sulfonyl-1H-pyrrole

In the title compound, C12H11Br2NO2S, the dihedral angle between the two rings is 78.79 (12)°. The crystal packing features C—H⋯π inter­actions

The 293 K structure of tetradehydrohaliclonacyclamine A

The polycyclic title compound {systematic name: (1S,16S,17S,31S)-3,20- diaza-tetra-cyclo-[15.15.0.1.1] tetra-tria-conta-6,8,23,25-tetra-ene}, CHN , has recently been isolated and characterized structurally, in solution by NMR spectroscopy and in the solid state by X-ray crystallography. At 130 K the structure is monoclinic (P21, Z = 4) and comprises two mol-ecules in the asymmetric unit with distinctly different conformations in the twelve-C-atom bridging chains. We report that, at 250 K, a phase change from monoclinic to ortho-rhom-bic (P22121, Z = 4) occurs. The higher-temperature phase is structurally characterized herein at 293 K. The two different conformers resolved in the monoclinic low-temperature form merge to give a single disordered mol-ecule in the asymmetric unit of the high-temperature phase

(S)-2-Amino-2-(2-chloro­phen­yl)cyclo­hexa­none

The crystal structure of the title compound, C12H14ClNO, was determined in order to confirm that the chiral center of the mol­ecule has an S configuration. The cyclo­hexa­none ring adopts a chair conformation. The 2-chloro­phenyl ring is slightly twisted from the axial C—N bond, with a N—C—C—C torsion angle of −5.7 (2)°. In the crystal, an inter­molecular N—H⋯O hydrogen bond links adjacent mol­ecules into an infinite chain, which propagates in the b-axis direction