Crystal Structure and Binding Properties of a New Molecular Clip Based on Diethoxycarbonyl Glycoluril: C_(42)H_(36)N_6O_6

A new molecular clip based on diethoxycarbonyl glycoluril 5： C42H36N6O6, has been synthesized and characterized by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group Pbca with a = 12.7639（5）, b = 16.9727（7）, c = 34.2069（14） A, V = 7410.5（5） A3, Z = 8, Dc= 1.292 g/cm3, p（MoKa） = 0.088 mm-1, F（000） = 3024, the final R = 0.0655 and wR = 0.1566 for 5123 observed reflections with I 〉 2tr（/）. The crystal structural analysis shows that intermolecular C-H...O and C-H...N hydrogen bonds stabilized the whole crystal structure. The binding study by fluorescence spectroscope titration showed that the title molecule can selectively recognize Fe3~ with fluorescence quenching.

Synthesis,Crystal Structure and Binding Properties of 6H,7H,13H,14H-5a,6a,7a,12a,13a,14a-Hxaazbenz[f]indeno[2,1,8-ija]naphth[2,3-f]azulene-14b,14c-dicarboxylic-5,8,12,15-tetrahydro-6,8,14-trioxo-diethyl Ester

The title compound 6H,7H,13H,14H-5a,6a,7a,12a,13a,14a-hxaazbenz[f]indeno[2,1,8- ija]naphth[2,3-f]azulene- 14b, 14c-dicarboxylic-5,8,12,15-tetrahydro-6,8,14-trioxo-diethyl ester （C27H26N6OT, Mr = 546.54） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P211c with a = 8.8129（6）, b = 17.9883（13）, c = 16.2623（11）A, β = 98.770（2）°, V = 2547.9（3）A3, Z = 4, De= 1.425 g/cm3, p（MoKa） = 0.105 mm-1, F（000） = 1144, the final R = 0.0672 and wR = 0.1162 for 2275 observed reflections with I 〉 2σ（I）. The crystal structural analysis shows that intermolecular C-H...O hydrogen bonds and π-π stacking interactions result in a three-dimensional framework. The binding study by fluorescence spectroscopy titration showed that he title compound can selectively recognize Fe3＋ with fluorescence quenching.

Crystal Structure and Binding Properties of a New Diethoxycarbonyl Glycoluril Derivative:C_(46)H_(34)Cl_4N_4O_8

A new clip molecule 1 based on diethoxycarbonyl glycoluril, C46H34ChN4O8, has been synthesized and characterized by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P1 with a = 11.3674（8）, b = 11.3674（8）, c = 16.9704（12） A, a = 70.0690（10）, β= 72.2310（10）, y = 78.0880（10）°, V= 1993.2（2） A3, Z = 2, Dc = 1.521 g/cm3, μ（MoKa） = 0.361 mml, F（000） = 940, the final R = 0.0422 and wR = 0.1144 for 22997 observed reflections with 1 〉 2o（I）. The crystal structural analysis shows that C-H……O and C-H……Cl hydrogen bonds, C-H-……π, C-CI……π supramolecular interactions, andπ-π packing interaction stabilized the whole crystal structure. The binding study by fluorescence spectroscope titration showed that the title molecule can selectively recognize Fe3＋ with fluorescence quenching.

MIMUMUM DEGREE AND BINDING NUMBER FOR k-FACTORS WITH PRESCRIBED PROPERTIES

Let integer k≥1, G be a graph of order n,n≥max {4k - 6, 4} and kn=0 (mod 2). Assume that the binding number of G is more than 2-2/n or the minimum degree of G is more than n/2. We prove that (i) G hasa k-fartor that contains a given edge; (ii) G has a k-factor that does not contain a given edge.

Study on Synthesis of Multivalent Neoglycoproteins and Their Binding Properties to Hepatic Stellate Cells

Neoglycoproteins of human serum albumin (HSA) modified with some kind of carbohydrates were synthesized. Their molecular weight and purification were determined by HPSEC and SDS-PAGE, respectively. The binding properties of these conjugates to hepatic stellate cells (HSCs) were evaluated by confocal fluorescence microscopy. The bioactivity revealed that compound 4a (HSA modified with glucose) showed high binding affinity.

Anticancer activity and DNA binding property of the trimers of triphenylethylene-coumarin hybrids

Novel trimers of triphenylethylene-coumarin hybrid containing two amino side chains （5a-d and 6a-d） were designed and synthesized by the condensation of 1,3,5-benzenetricarboxylic acid with the varied amino monomeric hybrids catalyzed by HATU and DIPEA at room temperature. The extended trimeric compound 6a （R = piperidinyl） exhibited significant anti-proliferative activity against three cancer cells at IC5o of near 10 μmol/L. UV-vis, fluorescence （lifetime） and thermal denaturation exhibited that 6a had significant interaction with Ct-DNA by the intercalative mode of binding. The order of their anti- proliferative activities was 6（a, d） 〉 5（a, d） and （5-6）a 〉 （5-6）d, respectively, in accordance with that of their DNA binding properties, which suggested that the prolonged linker （six carbons） and piperidinyl ~roun on the side chains are beneficial to DNA binding and the anti-tumor activity.

Rapid characterization of the binding property of HtrA2/Omi PDZ domain by validation screening of PDZ ligand library

HtrA2/Omi is a mammalian mitochondrial serine protease, and was found to have dual roles in mam- malian cells, not only acting as an apoptosis-inducing protein but also maintaining mitochondrial ho- meostasis. PDZ domain is one of the most important protein-protein interaction modules and is in- volved in a variety of important cellular functions, such as signal transduction, degradation of proteins, and formation of cytoskeleton. Recently, it was reported that the PDZ domain of HtrA2/Omi might regulate proteolytic activity through its interactions with ligand proteins. In this study, we rapidly characterized the binding properties of HtrA2/Omi PDZ domain by validation screening of the PDZ ligand library with yeast two-hybrid approach. Then, we predicted its novel ligand proteins in human proteome and reconfirmed them in the yeast two-hybrid system. Finally, we analyzed the smallest networks bordered by the shortest path length between the protein pairs of novel interactions to evaluate the confidence of the identified interactions. The results revealed some novel binding proper- ties of HtrA2/Omi PDZ domain. Besides the reported Class II PDZ motif, it also binds to Class I and Class III motifs, and exhibits restricted variability at P?3, which means that the P?3 residue is selected according to the composition of the last three residues. Seven novel ligand proteins of HtrA2/Omi PDZ domain were discovered, providing significant clues for further clarifying the roles of HtrA2/Omi. Moreover, this study proves the high efficiency and practicability of the newly developed validation screening of candidate ligand library method for binding property characterization of peptide-binding domains.

Synthesis, Crystal Structure of the Receptor Derived from Diethoxycarbonyl Glycoluril for Aromatic Amide Guest

The receptor derived from the diethoxycarbonyl glycoluril was synthesized and characterized by IR,^(1)H NMR,MS techniques and X-ray single crystal analysis.Single crystal X-ray diffraction reveals that the receptor remains monomeric because of its bulky t-Bu groups on the side walls.Its unique binding properties for aromatic amides were studied through ^(1)H NMR and IR techniques.