Crystallization and Preliminary Crystallographic Studies of Luffaculin 1, a Ribosome-inactivating Protein from the Seeds of Luffa Acutangula

1 INTRODUCTION The ribosome-inactivating proteins (RIPs) are RNA N-glycosidases[1, 2] which inactivate ribosomes by cleaving a single N–C glycosidic bond between adenine and ribose at A4324 in the 28s rRNA of rat. Because of the removal of one adenine from rRNA, elongation factorⅡ(EF-2) can not bind to the 60S subunit, so RIPs can arrest protein synthesis. RIPs can be classified into three types based on the struc- tures of genes and mature proteins[3]. Type 1 RIPs with molec…     

Studies on the Reaction Mechanism of Br2 ＋ I2 = 2IBr

1 INTRODUCTION Interhalogen compounds have played an impor- tant role in environment and chemical engineering production. During the course of ozone exhaustion induced by sunlight in polar region, Br2, BrCl and HOBr are all precursors of Br atom[1]. Lately, scien- tists have detected that the content of BrCl in polar region sunlight was 35 ppt, larger than that of Br2 (25 ppt). Previous studies suggested that the con- centration of BrCl and O3 exhibits obvious negative correlation: w…     

Synthesis and Crystal Structural Characterization of a Thiosemicarbazone Derived from 4-Acylpyrazolone

1 INTRODUCTION Pyrazol-5-one derivatives form an important class of organic compounds due to their structural che- mistry and biological activities as analgesic, antipy- retic, anti-inflammatory and hyperglycemic agents[1～4]. Even the simplest pyrazol-5-one derivatives like antipyrine and amidopyrine are widely used in anal- gesic medicine[5, 6]. On the other hand, thiosemicar- bazones, especially heterocyclic thiosemicarbazones, have been the subject of extensive investigations be- cause…     

Synthesis, Crystal Structure, Fluorescent and Thermal Properties of Sodium Tridecafluorodizirconate Na5Zr2F13 Compound

1 INTRODUCTION Considerable research effort on the heavy metal fluoride glasses like barium, zirconium fluoride and a series of rare-earth fluorozirconate compounds du- ring the last two decades was initiated by the broad optical transmission window of these glasses and thereby the potential for ultralow-loss optical fi- bers[1~10]. The fluorozirconate of alkali metals was first reported in 1938[11], and most of the sodium and potassium fluorozirconates were reported amongthe 1940s and 19…     

Synthesis and Crystal Structure of a New Zn(II) Nitronyl Nitroxide Complex [Zn(NIT4Py)(PDA)(H2O)3]

1 INTRODUCTION Nitronyl nitroxides, independently or in combina- tion with metal ions, have been one of the most wi- dely studied systems in molecular magnetism for understanding radical-radical or metal-radical inte- ractions as well as for synthesizing organic ferroma- gnets and metal-radical magnetic materials[1～4]. Up to now, lots of metal-radical complexes have been reported[5～8]. On the other hand, cooperative inter- molecular interactions, such as coordination bonds, hydrogen bon…     

Correlation Study on Sweetness of Amino Acid with Different Configurations and Quantum Chemical Parameters

1 INTRODUCTION Since the introduction of QSAR by Hansch and Fujita in 1964, Deutsch and Hansch have quickly used it in the study of nitrophenylamine sweet reagents. They found good correlation between their distribution coefficients in octanol/water system and sweetness degree. Subsequently, they detected that vibration of aroma-substituent compounds has so- mething to do with sweetness. Henceforth, statistic correlations between structure and sweetness ofseries compounds have been inv…     

Synthesis and Crystal Structure of 4-Phenyl-5-(1''''t-butyl-5''''-methyl-4''''-pyrazolyl)-1,2,4-triazol-3-thione

COOEtCOCH3(CH3)2NNHNH2NNCH3OOEtNH2NH2NNCH3ONHNH2PhNCSNNCH3ONHNHCNHSOH-NNCH3NNHNPhS12345 1 INTRODUCTION A large number of 1,2,4-triazole derivatives have been synthesized in recent years[1～4]. Many of them are reported to exhibit broad spectrum biologi-…     

A New Synthesis Method and Crystal Structure of 2-Phenyl-5,6,7,8-tetrahydro-6,6-dimethyl-5,7-methano-8-quinolinol

The title compound 2-phenyl,5,6,7,8-tetrahydro-6,6-dimethyl-5,7-methano-8- quinolinol 1 has been synthesized by the oxidation of corresponding anion with 02. The oxidation gave a convenient method for synthesizing pyridylalcohol 1 in good yield. The suitable single crystals for X-ray diffraction were obtained by recrystallization from a mixture of solvents （ether and ethyl acetate）. The configuration of C6 in the title compound is in R form and there are strong face-to-face offset π-π interactions between pyridine rings. Crystallographic data for 1： C18H19NO, Mr = 265.34, monoclinic, space group P21/c with a = 13,4073（4）, b = 10.2866（3）, c = 10,5570（3）A, β = 108.413（2）°, V = 1381.43（7） A^3, Z = 4, De= 1.276 g/cm^3, μ = 0.078 mml, F（000） = 568, R = 0.0721 and wR = 0.2054 for 2241 observed reflections （I〉 2σ（I））.     

Synthesis and Crystal Structure of (L)_2W(CO)_4·CH_3COCH_3 (L=1-Phenacylimidazole)

1 INTRODUCTION Due to their variability in binding modes, five- membered heterocyclic ligands such as pyrazole[1] and 1,2,4-triazole[2] have been drawn much attention. Consequently, there are numerous reports on their derivatives. Imidazoles resemble pyrazoles, and they are isomeric five-membered heterocyclic molecules containing two nitrogen atoms. Furthermore, imida- zole is also a ring component of adenine and purine, one of the most versatile binding sites in biological systems, so th…     

Synthesis and Structure of a New Bicadmium （Ⅱ） Complex with Macrocyclic Hexaaza Bearing Hydroxyethyl Pendants

1 INTRODUCTION The cadmium(??) complexes have been exten-sively studied because of their potentially usefulproperties, such as toxicity research[1], catalysis[2],magnetism[3] and nonlinear optics[4]. A lot of studieson binuclear cadmium(??) pendant-ar…