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The optically pure 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid was obtained through the chalcone route. The structure of 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid was first elucidated by single crystal X-ray analysis: triclinic, space group, triclinic ( P-1) with a = 8.1379(13) Å, b = 8.9831(14) Å, c = 13.198(2) Å, α = 88.413(2)°, β = 74.908(2)°, γ = 72.987(2)°. V = 889.5(2) Å3, Z = 2. The structure was solved by direct methods and refined to a final R = 0.0413 for 1630 reflections with I > 2 σ( I). The crystal structure is stabilized by O–H···O and C–H···O hydrogen bondings and π–π stacking interactions. The titled compound, 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid dimethylformamide solvate, was linked to one-dimensional molecular ribbons via intermolecular O–H···O and C–H···O hydrogen bondings.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: A novel polymeric complex NaCo(o-pba)3(H2O)3 (o-Hpba=2-(1-oxo-1H-2,3-dihydroisoindol-2-yl)benzonic acid) based on racemic N-arylphthalimidine ligand has been prepared and characterized by elemental analysis, spectroscopic and X-ray crystallography methods. In the compound, each Co(II) cation is coordinated by six O atoms from three carboxyl groups of o-pba− and three water molecules in fac-MA3B3 model forming a chiral tripodal Co(o-pba)3(H2O)3 − anion-complex, enantiomeric pairs of which are alternately arranged in head-to-head and tail-to-tail orientations giving rise to a meso-one-dimensional chain-like structure. The compound exhibits high stability and unusual triple-peak luminescence in DMSO solution at room temperature. [Copyright &y& Elsevier]

Highlights: [•] This paper described the preparation and full characterization of a new phthalimidin derivative. [•] The compound exhibits blue–green emission with peaks at 354.5 and 486.5nm. [•] Second harmonic generation (SHG) property was investigated at the first time for this kind of compound. [•] The compound has moderate antibacterial and antifungi activities. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two pairs of rac- and meso-diastereomers were successfully separated. [•] Photolysis of (CMe2)(C9H7)(η 5-C9H6)Re(CO)3 (1) yielded the novel product (CMe2)[(η 5-C9H6)(η 2-C9H7)]Re(CO)2 (3). [•] Molecular structures of all compounds were determined by X-ray diffraction. [ABSTRACT FROM AUTHOR]

Eukaryotic 1,4-β-endoglucanases (EC 3.2.1.4) have shown great potentials in many commercial applications because they effectively catalyze hydrolysis of cellulose, the main component of the plant cell wall. Here we expressed a glycoside hydrolase family (GH) 5 1,4-β-endoglucanase from Aspergillus niger (AnCel5A) in Pichia pastoris , which exhibits outstanding pH and heat stability. In order to further investigate the molecular mechanism of AnCel5A, apo-form and cellotetraose (CTT) complex enzyme crystal structures were solved to high resolution. AnCel5A folds into a typical (β/α) 8 -TIM barrel architecture, resembling other GH5 members. In the substrate binding cavity, CTT is found to bind to −4 – −1 subsites, and several polyethylene glycol molecules are found in positive subsites. In addition, several unique N -glycosylation motifs that may contribute to protein higher stability were observed from crystal structures. These results are of great importance for understanding the molecular mechanism of AnCel5A, and also provide guidance for further applications of the enzyme. [ABSTRACT FROM AUTHOR]