Crystallization and characterization of an inflammatory lectin purified from the seeds of Dioclea wilsonii

DwL, a lectin extracted from the seeds of Dioclea wilsonii, is a metalloprotein with strong agglutinating activity against rabbit and ABO erythrocytes, inhibited by glucose and mannose. DwL was purified by affinity chromatography on a Sephadex G-50 column and ion exchange chromatography on a HiTrap SP XL column. SDS-PAGE revealed three electrophoretic bands corresponding to the α (25,634 ± 2 Da), β (12,873 ± 2 Da) and γ (12,779 ± 2 Da) chains. Protein sequencing was done by Tandem Mass Spectrometry. The primary sequence featured 237 amino acids and was highly homologous to other reported Diocleinae lectins. A complete X-ray dataset was collected at 2.0 ? for X-Man-complexed DWL crystals produced by the vapor diffusion method. The crystals were orthorhombic and belonged to the space group I222, with the unit-cell parameters a = 59.6, b = 67.9 and c = 109.0 ?. DWL differed in potency from other ConA-like lectins and was found to induce neutrophil migration in rats, making it particularly useful in structural/functional studies of this class of proteins.     

Conformations of diester triphenylphosphonium ylides with an ylidic ester or keto and ester ylidic groups

The structures of three related keto diester and diester ylides, namely diethyl 3‐oxo‐2‐(triphenylphosphoranylidene)glutarate, C₂₇H₂₇O₅P, (I), diethyl 3‐oxo‐2‐(triphenylphosphoranylidene)glutarate acetic acid monosolvate, C₂₇H₂₇O₅P·C₂H₄O₂, (II), and diethyl 2‐(triphenylphosphoranylidene)succinate, C₂₆H₂₇O₄P, (III), are presented. The syn‐keto anti‐ester conformations in the crystalline keto diesters are governed by electronic delocalization between the P—C and ylidic bonds and an acyl group, and by intra‐ and intermolecular interactions. There are also intramolecular attractive and repulsive interactions of different types (C—H...O and C—H...π) controlling the molecular conformations. The mono‐ylidic diester (III) has an anti‐ester conformation, while those for (I) and (II) are related to pyrolytic formation of acetylene derivatives. The terminal nonylidic ester group in (I) was disordered over two sets of almost equally populated positions.     

Use of xenon as a mobile phase for on–line capillary supercritical fluid chromatography–fourier transform infrared spectrometry

Xenon is investigated as a mobile phase for on-line capillary supercritical fluid chromatography-Fourier transform infrared spectrometry (SFC-FTIR). Polycyclic aromatic hydrocarbons, aromatic isocyanates, and epoxy acrylate oligomers are analyzed as examples to show that xenon has similar selectivities and solvating powe to CO₂. Its optical transparency makes it ideal for IR detection. A stop flow system is constructed to increase the sensitivity of spectra measured from compounds which are weak IR absorbers.     

Zur Bestimmung des Kalis und Natrons in Pflanzenaschen und ?hnlichen Substanzen

Ohne Zusammenfassung     

Anisotropy of electromagnetically induced left-handedness in atomic three-level media based upon bianisotropic polarizabilities and tensor character

A three-level atomic system, configured as either a gaseous medium or a solid state material, with a driving field establishing a Rabi frequency of control, is tested by a probe field. The medium has bianisotropic microscopic polarizability and magnetizability, from which the permittivity and permeability tensors are derived. Non-isotropy and polarization dependence for left-handedness (negative index of refraction) is demonstrated through examination of tensor components in the detuning frequency spectrum. These results have important implications for use in optical or electronic devices.