Synthesis and NHE1 inhibitory activity of ligustrazine derivatives

A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, 1H NMR and MS. The results of NHE1 inhibitory activity test showed that compounds I2, I3, I4, I6, and I7 possess more potent NHE1 inhibitory activity than cariporide.     

Two new epimeric pairs of iridoid from mangrove plant Scyphiphora hydrophyllacea

Two new epimeric pairs of iridoid scyphiphin A_1(1a),A_2(1b) and scyphiphin B_1(2a),B_2(2b) were isolated from Scyphiphora hydrophyllacea Gaertn.F.Their structures were elucidated by spectroscopic methods.The mixture of scyphiphin B_1 and scyphiphin B_2 showed moderate cytotoxicity against human hepatoma SMMC-7721 cell line in vitro by MTT method.     

Some addition reactions of bisgermavinylidene

The reaction of bisgermavinylidene [(Me₃SiN?PPh₂)₂C?Ge→Ge?C(PPh₂?NSiMe₃)₂] ( 1 ) with AdNCO (Ad = Adamantyl) afforded the [2 + 2] cycloadditon product [(Me₃SiN?PPh₂)₂CGeC(O) NAd] ( 2 ). Similar reaction of 1 with Ph₃SiOH in tetrahydrofuran (THF) yielded the base‐stabilized germanium(II) triphenylsiloxide [H₂C(PPh₂?NSiMe₃)₂Ge(OSiPh₃)₂] ( 3 ). The results suggested that reactive germavinylidene may exist in solution and is capable of forming addition reaction products. The X‐ray structures of 2 and 3 were determined. Copyright © 2007 John Wiley & Sons, Ltd.     

Ⅱ-Ⅵ族应变层超晶格的X射线衍射分析

本文报导了用计算机控制的衍射仪(CuKα辐射)测量的金属有机化学汽相沉淀(MOCVD)方法生长的Ⅱ-Ⅵ族应变层超晶格的X射线衍射曲线,观察到了超晶格结构的多级卫星峰,且卫星峰的强度随角度呈周期性变化.对这种卫星峰形成包络的衍射曲线,用X射线运动学衍射理论进行了分析和讨论,这种讨论有助于理解X射线衍射曲线中卫星峰的形成.同时用光致发光和包络峰宽度的方法估算了样品的结构参数.     

A new two-dimensional approach to quantitative prediction for collision cross-section of more than 110 singly protonated peptides by a novel moecular electronegativity-interaction vector through quantitative structure-spectrometry relationship studies

Based on two-dimensional topological characters, a novel method called molecular electronegativity-interaction vector (MEIV) is proposed to parameterize molecular structures. Applying MEIV into quantitative structure-spectrometry relationship studies on ion mobility spectrometry collision cross-sections of 113 singly protonated peptides, three models were strictly obtained, with correlative coefficient r and leave-one-out cross-validation q of 0.983, 0.979, 0.981, 0.979 and 0.980, 0.978, respectively. Thus, the MEIV is confirmed to be potent to structural characterizations and property predictions for organic and biologic molecules. Translated from Chinese Journal of Analytical Chemistry, 2006, 34(6) (in Chinese)     

Theoretical Study on the Kinetics of Electron Transfer for Bond—breaking Reaction

ＩｎｔｒｏｄｕｃｔｉｏｎＦｒｅｅｒａｄｉｃａｌｆｏｒｍａｔｉｏｎｆｒｏｍｈａｌｏｇｅｎａｔｅｄｈｙｄｒｏｃａｒｂｏｎｓｈａｓｒｅｃｅｉｖｅｄｃｏｎｓｉｄｅｒａｂｌｅａｔｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｉｔｓｓｃｉｅｎｔｉｆ ｉｃａｎｄｅｎｖｉｒｏｎｍｅｎｔａｌｒｅｌｅｖａｎｃｅ .1 6 Ｔｈｉｓｒｅａｃｔｉｏｎｓｅｅｍｓｔｏｐｌａｙａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｖａｒｉｏｕｓｐｒｏｃｅｓｓｅｓ .Ｂｏｎｄ ｂｒｅａｋ ｉｎｇｒｅａｃｔｉｏｎｉｓａｐｏｗｅｒｆｕｌｓｙｎｔｈｅｔｉｃｔｏｏｌｔｏｐｒｏｖ…     

凸二次交叉规划的等价形式

利用参数规划逆问题考虑凸二次交叉规划与多目标规划的关系 ,把交叉规划转变为同变量规划组 ,再把同变量规划组变为多目标规划 ,证明了凸二次交叉规划的均衡解与多目标规划的最优解的关系。     

Application of Genetic Algorithm to the QSAR Research of Pyrrolobenzothiazepinones and Pyrrolobenzoxazepinones-Novel and Specific Non-Nucleoside HIV-1 Reverse Transcription Inhibitors

Quantitativestructure-activityrelationship(QSAR)modelingprovidesarationalbasisforunderstandingmechanismsofbiologicalperformanceandformodifyingchemicalstfucturetoimProveperformancebyaltCringchemicalstIuctllre.Itiswellknownthatoneofthemostimportantanddiffcultproblemintraditionalquantitativestructure-activityrelationshipistheproperchoiceoftheadequatefeaturesforbuildingtheregressionmodels.Recentlysomereportssuggestthatgeneticalgorithms(GA)maybeusefulinQSARanalysis.WehavedevelopedaQSARprogra…     

Three New Urea Derivatives from Pliocene‐Fossil Pinus armandii

Three new urea derivatives, isolated from the Pliocene lignified wood of Pinus armandii, were identified as carbonylbis[imino(6‐methyl‐3,1‐phenylene)]bis[carbamic acid] dimethyl ester ( 1 ), and as the corresponding dibutyl ester 2 and bis(2‐methylpropyl) ester 3 . Their structures were elucidated by spectroscopic methods, including MS and 1D‐ and 2D‐NMR techniques.     

Synthesis and light‐emitting properties of platinum‐containing oligoynes and polyynes derived from oligo(fluorenyleneethynylenesilylene)s

A series of blue‐light‐emitting oligo(fluorenyleneethynylenesilylene)s (OFESs) of the general formula HC?CRC?C(EC?CRC?C)_mEC?CRC?CH (E = SiPh₂, SiMe₂, or SiMe₂? SiMe₂; m = 0–2; R = 9,9‐dihexylfluorene‐2,7‐diyl) and their phosphorescent platinum‐containing oligoynes and polyynes were synthesized and characterized. The solution properties and regiochemical structures of this new structural class of organosilicon‐based polyplatinayne polymers {trans‐[? Pt(PBu₃)₂C ?CRC?C(EC?CRC?C)_mEC?CRC?C? ]_n} were studied with IR and NMR (¹H, ¹³C, ²⁹Si, and ³¹P) spectroscopy. The optical absorption and photoluminescence spectra of these metallopolymers were examined and compared with their discrete oligomeric model complexes. Our studies led to a novel approach of using the sp³‐silyl moiety as a conjugation interrupter to limit the effective conjugation length in metal polyynes, which could boost the phosphorescence decay rates essential for light‐energy harvesting from the triplet excited state. The influence of the heavy platinum atom and the group 14 silyl unit possessing different side‐group substituents on the thermal and phosphorescence properties was investigated in detail. We also established the goal of studying the evolution of the lowest singlet and triplet excited states with chain length m of OFESs and the nature of E in these metallopolymers. This work indicated that the phosphorescence emission efficiency harnessed through the heavy‐atom effect of platinum in the main chain did not change very much with oligomer chain length m but generally decreased with the E group in the order SiMe₂ > SiMe₂? SiMe₂ > SiPh₂. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4804–4824, 2006