用于同步辐射光源的成像板粉末衍射系统

报道了我们研制的一套成像板粉末衍射装置,对其误差来源进行了详细的分析讨论,并与衍射仪进行了比较.该装置的半径为143.3mm,最大测量角度范围不160°，最大角度(2q )偏差小于0.03°,这些性能指标已被实验所证实,完全可应用于粉末衍射全谱的测量.     

{Cu[H_2NC(CH_2OH)_3]_2}{Pic}_2·H_2O的合成与晶体结构

三羟甲基氨基甲烷与苦味酸(Pic)铜在乙醇水混合液中反应,制得少见的不对称氢键连接的超分子化合物{Cu[H2NC(CH2OH)3]2}{Pic}2?H2O。晶体属三斜晶系,空间群为P ,晶胞参数为a = 6.894(1),b = 8.219(1),c = 13.543(3) ? ?= 79.290(1),?= 8 3.36(2), ?= 84.590(1)埃轿狢20H30CuN8O22,V = 746.9(2) 3,Z = 1,Dc = 1.774 g/cm3,F(000) = 411,?= 0.844 mm-1,R = 0.0334,Rw = 0.0863。在配合物的结构单元中, Cu2+位于对称中心,分别与2个四齿配体(三羟甲基氨基甲烷)中的2个OH,1个NH2,三齿配位,呈笼状螯合。而另一个OH,因配体和中心离子构型的限制,不参与配位。     

Fluorescent sensors for the enantioselective recognition of mandelic acid: signal amplification by dendritic branching

Novel chiral bisbinaphthyl compounds have been synthesized for the enantioselective fluorescent recognition of mandelic acid. By introducing dendritic branches to the chiral receptor unit, the fluorescence signals of the receptors are significantly amplified because of the light-harvesting effect of the dendritic structure. This has greatly increased the sensitivity of the sensors in the fluorescent recognition. Study of the three generation sensors demonstrates that the generation zero sensor is the best choice for the recognition of mandelic acid because of its greatly increased fluorescence signal over the core and its high enantioselectivity. This sensor is potentially useful for the high throughput screening of chiral catalysts for the asymmetric synthesis of alpha-hydroxycarboxylic acids.     

小分子胺直接有效催化合成α-苯硒基酮

用有机小分子胺, 如辛可尼啶, L-脯胺酸和N-取代的手性1,2-环己二胺等直接催化酮与苯硒基氯反应, 通过这一简单有效的方法, 高收率合成了一些α-苯硒基酮.     

Natural products of the medicinal fungus Ganoderma lucidum: occurrence,biological activities,and pharmacological functions

Ganoderma lucidum, a fungus used in traditional Chinese medicine, produces polysaccharides and oxygenated triterpenoids with a very broad spectrum of biological activities and pharmacological functions. Among the Ganoderma triterpenoids, many pairs of C-3 alpha/beta stereoisomers and C-3/C-15 positional isomers have been identified. Biosynthetic study has indicated that the C-3alpha series of oxygenated triterpenoids is derived from the C-3beta series via an oxidation-reduction pathway. The interaction of Ganoderma triterpenoids with human platelets in the induction of aggregation and inhibition of agonist-induced aggregation and signal transduction has been elucidated. Reduction of cellular mevalonate content to a stage in which cholesterol synthesis is strongly inhibited and cell growth is marginally arrested sensitizes hepatoma cells to the oxygenated triterpenoids. A combination treatment of lovastatin and Ganoderma triterpenoids in animal studies has exhibited a potential anticancer effect.     

Crystal Structure, Thermal Stability and Luminescence of Coordination Polymer [Cd（BBP）（p-PDOA）]n

Hydrothermal reaction of Cd（NO3）2·4H2O with bbp and p-PDOAH2 at 140 ℃ yielded a novel 1D cadmium（Ⅱ） coordination polymer, [Cd（bbp）（p-PDOA）]n （bbp=2,6-bis（benzimidazol-2-yl）pyridine, p-PDOA=p-phenylenedioxydiacetate dianion）, in which CdN3O4 pentagonal bipyramids were linked by p-PDOA ligands in a bis-bidentate mode to construct a zigzag chain with the adjacent Cd…Cd distance of 1.14（1） nm, There exists a 2D supramolecular network linked by π-π stacking with a face-to-face distance of 0.35（1） nm between the 2,6-bis（benzimidazol-2-yl） pyridine ligands and hydrogen-bonding interactions （0.27（4） nm）. A 3D supramolecular network was further constructed by these non-covalent interactions between the zippers. The TG/DTG showed that its chain skeleton was thermally stable up to 389 ℃ and the blue fluorescent emission of the complex was determined at 428 nm in a solid state with its long decay lifetime of 7.24 ns.     

Syntheses of Novel Isopenam and Isocephem Antibiotics. Preparation of a retinamido derivative of a highly strained β-lactam as potent anticancer agent

Syntheses of the cis-configurated isopenam 9 (Scheme 1), isocephem 14 (Scheme 2), and isocephem 19 (Scheme 3) are described. The key step in the preparation of 14 and 19 involved a Pummerer-type rearrangement of the corresponding sulfoxides 12 and 18 . These β-lactams were found to possess biological activity against several pathogenic microorganisms in vitro. The electronic activation of the lactam moiety of 19 remarkably enhanced its biological activity. A retinoic moiety was attached to 19 via an amino linker. The resultant retinamido-β-lactam 21 showed significant cytostatic activity in tracheal organ cultures obtained from vitamin-A-deficient hamsters.     

Benzolignanoid and Polyphenols from Origanum Vulgare

A new dihydrobenzodioxane derivative, origalignanol ( 10 ), together with nine polyphenolic compounds, salvianolic acid A ( 1 ), salvianolic acid C ( 2 ), lithospermic acid ( 3 ), apigenin 7‐O‐β‐D‐glucuronide ( 4 ), apigenin 7‐O‐β‐D‐(6″‐methyl)glucuronide ( 5 ), luteolin, ( 6 ), luteolin 7‐O‐β‐D‐glucopyranoside ( 7 ), luteolin 7‐O‐β‐D‐glucuronide ( 8 ), and luteolin 7‐O‐β‐D‐xylopyranoside ( 9 ), were isolated from the aqueous ethanolic extract of the aerial parts of Origanum vulgare for the first time. The structure of new compound 10 was determined on the basis of spectroscopic methods. Compound 5 is probably an artifact formed during the isolation. Compounds 1, 2 and 3 showed strong DPPH radical scavenging activity with an EC₅₀ of 7.2 ± 0.4, 9.6 ± 0.9, and 9.5 ± 0.7 μM, respectively, and protected rat hepatocytes from CCl₄‐damage at 100 μM.     

Crystal-to-crystal transformations of a microporous metal-organic laminated framework triggered by guest exchange, dehydration and readsorption

Single crystals of a neutral, microporous, laminated metal-organic framework (MOF)[Fe(pydc)(4,4'-bipy)]xH(2)O (1xH(2)O)(H(2)pydc = 2,5-dicarboxypyridine, 4,4'-bipy = 4,4'-bipyridine) were generated by hydrothermal synthesis, and its crystal structure was determined. 1xH(2)O retains the framework robustness to ca. 370 degrees C and is insoluble in common organic solvents. By soaking in MeOH and EtOH solutions, 1xH(2)O was transformed directly from the parent single crystals into single crystals of 1xMeOH or 1xEtOH, respectively. Meanwhile, 1xH(2)O shrank to the guest-free framework (h) or (v), respectively, under appropriate heating (up to 160 degrees C in N(2)) or vacuum treatment (10 mmHg) at room temperature. Compared to that of 1xH(2)O, the unit-cell volume of 1xEtOH slightly increases by 2.9%, whereas those of (h) or (v) are reduced by 8.2 and 6.6%, respectively. The anhydrous (v) was found to be highly chemically reactive, taking up ethanol vapor to furnish the solvated crystal structure of an 'expanded' framework 1xEtOH. In a mixture of ethanol-DMF or ethanol-benzene, a selective exchange process was observed, with only ethanol molecules exchanged into the structure due to the limited free size of the channels in the framework of. All the transformed crystals have also been characterized by X-ray single-crystal diffraction to understand the crystal-to-crystal transformation, which have different free volumes (6.5-20.4%).     

联苯菊酯酶联免疫吸附分析方法研究

建立了定量测定联苯菊酯的间接竞争酶联免疫吸附分析方法(ic-ELISA)。利用联苯菊酯的代谢物联苯醇合成了联苯菊酯的半抗原LBc(2-甲基-3-苯基苄基氧基羰基丙酸)和LBy(2-甲基-3-苯基苯甲酸)。通过碳二亚胺法将LBc交联于牛血清蛋白(BSA)作为免疫抗原(LBc-BSA),通过活泼酯法将LBc和LBy分别交联于卵清蛋白(OVA)作为包被抗原(LBc-OVA和LBy-OVA),LBc-BSA为免疫原制备了联苯菊酯的兔抗血清,间接非竞争酶联免疫吸附分析方法测得其效价达5.12×104。通过同源异源分析,发现异源分析的灵敏度较高,对pH值、离子强度、甲醇含量等影响因素进行了研究,0.3mol/L钠离子强度的磷酸缓冲液(pH7.5)和30%的甲醇确定为联苯菊酯间接竞争酶联免疫吸附分析方法的最佳工作条件,该方法的IC50为2.16±0.32mg/L,检出限(LDL)为0.016±0.002mg/L。对大部分拟除虫菊酯,如三氟氯氰菊酯、溴氰菊酯、氯氰菊酯、氰戊菊酯、甲氰菊酯和拟除虫菊酯的代谢物3-苯氧基苯甲酸没有明显的交叉反应。