Sesquiterpenoids and Phenylpropane Derivatives from Sonchus uliginosus

Six new compounds were isolated from the whole plant of Sonchus uliginosus, including three eudesmane‐type sesquiterpenoids (1β,6α)‐1,6,14‐trihydroxyeudesm‐3‐en‐12‐oic acid γ‐lactone ( 1 ), (1β,6α)‐1,6,14‐trihydroxyeudesma‐3,11(13)‐dien‐12‐oic acid γ‐lactone ( 2 ), and (1β,6α)‐1,6‐dihydroxy‐14‐O‐[(4‐hydroxyphenyl)acetyl]eudesma‐3,11(13)‐dien‐12‐oic acid γ‐lactone ( 3 ), and three phenylpropane derivatives, 4‐hydroxy‐γ,3,5‐trimethoxybenzenepropanol ( 6 ), γ,3,4,5‐tetramethoxybenzenepropanol ( 7 ), and γ,3,4,5‐tetramethoxybenzenepropanol acetate ( 8 ), together with the two known compounds 4 and 5 . The new structures were elucidated by means of spectroscopic methods, such as IR, EI‐MS, HR‐ESI‐MS, 1D‐ and 2D‐NMR, and by comparison of the spectroscopic data with those reported for structurally related compounds.     

Triterpenoids from Rhaponticum Uniflorum

The isolation and identification of twenty‐one components (including four new triterpenoid saponins and one new triterpenoid acid) from the root of Rhaponticum uniflorum (L.) DC. (Compositae) are described. Their structures were determined on the basis of spectral analysis and chemical trans formation. The new compounds were identified as 3‐O‐α‐L‐arabinopyranosyl‐urs‐12,18(19)‐dien‐28‐oic acid β‐D‐glucopyranosyl ester, 3β‐ hydroxyurs‐12,18(19)‐dien‐28‐oic acid β‐D‐glucopyranosyl ester, 3β‐hydroxyurs‐12,19(29)‐dien‐28‐oic acid β‐D‐glucopyranosylester, 3‐O‐α‐L‐arabinopyranosyl‐urs‐9(11),12‐dien‐28‐oic acid β‐D‐glucopyranosyl ester and 2 α,3 α, 19α,25‐tetrahydroxyurs‐12‐en‐23,28‐dioic acid.     

Synthesis and properties of novel polyurethanes containing 3,4‐dioxybenzylidenecyanoacetate group as a nonlinear optical chromophore

Methyl 3,4‐di‐(2′‐hydroxyethoxy)benzylidenecyanoacetate ( 3 ) was prepared by hydrolysis of methyl 3,4‐di‐(2′‐vinyloxyethoxy)benzylidenecyanoacetate ( 2 ). Diol 3 was condensed with 2,4‐toluenediisocyanate, 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate, and 1,6‐hexamethylenediisocyanate to yield polyurethanes 4 – 6 containing the nonlinear optical chromophore 3,4‐dioxybenzylidenecyanoacetate. The resulting polyurethanes 4 – 6 were soluble in common organic solvents such as acetone and dimethylformamide. Polymers 4 – 6 indicated thermal stability up to 300 °C in thermogravimetric thermograms with glass‐transition temperature values obtained from differential scanning calorimetric thermograms in the range of 78–102 °C. The second‐harmonic generation coefficients (d₃₃) of the poled polymer films were around 6.9 × 10^?9 esu. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1742–1748, 2002     

4‐[3‐(3,4‐Di­methoxy­phenyl)­prop‐2‐enoyl]­phenyl methacryl­ate and 4‐[3‐(2‐bromo­phenyl)­prop‐2‐enoyl]­phenyl methacryl­ate

Chalcones (α,β‐unsaturated ketones) are effective antitumour agents. It has been proved that having halogen or methoxy groups substituted in various positions of the phenyl ring enhances the activity of chalcones many times. The title compounds, C₂₁H₂₀O₅ and C₁₉H₁₅BrO₃, respectively, were chosen for crystallographic study in order to determine their structures and conformations. In both compounds, the keto group is in the s‐cis conformation and is almost planar. There are weak intramolecular interactions in both structures.     

微量元素锌与反复呼吸道感染的相关性

对28例反复呼吸道感染患儿(下称复感儿)及26例健康儿进行微量元素发锌测定。发现前者发锌平均值为(92.3±14.7)×10~(-6),后者为(132.5±21.5)×10~(-6),P<0.01,差异非常显著。对复感儿进行口服锌治疗,观察其疗效及治疗前后发锌变化。治疗前发锌平均值为(92.3±14.7)×10~(-6),治疗后为(137.5±20.2)×10~(-6),P<0.01差异非常显著。有效率达85.7％。故缺锌可能是复感儿患病的影响因素之一,锌治疗小儿反复呼吸道感染是十分必要的。     

X‐Ray Single Crystal Refinement and Superconductivity of La3Ni2B2N3

Crystalline samples of La₃Ni₂B₂N₃ were synthesized using solid state metathesis reactions from combinations of La, LaCl₃, NiCl₂ together with Li₃BN₂. The structure was determined by single crystal X‐ray diffraction (I4/mmm (No. 139), a = 372.95(2) pm, c = 2056.3(2) pm, R₁ = 0.027, wR₂ = 0.062) and confirmed earlier results from neutron powder diffraction. La₃Ni₂B₂N₃ contains BN units capping square planar Ni layers. Isolated nitrogen atoms reside in La₆ octahedra. Magnetic measurements on several bulk samples exhibit superconductivity at temperatures below 14.6 K.     

A New 18(13 → 12β)‐abeo‐Lanostadiene Triterpenoid from Ganoderma fornicatum

A new triterpenoid, fornicatin C (= (3β)‐3‐hydroxy‐18(13 → 12β)‐abeo‐lanosta‐13(17),24‐dien‐18‐oic acid; 1 ), was isolated from the fruiting bodies of Ganoderma fornicatum, together with the known compounds fornicatin A ( 2 ) and fornicatin B ( 3 ), among other constituents. The structure of 1 was elucidated by means of spectroscopic techniques, and those of 2 and 3 were identified by comparing their spectroscopic data with those reported in the literature.     

N,N′‐Bis(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide and N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide

The mol­ecules of N,N′‐bis­(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyl­dicarboxamide, [Fe(C₁₂H₁₁N₂O)₂], contain intra­molecular N—H⋯N hydrogen bonds and are linked into sheets by three independent C—H⋯O hydrogen bonds. The mol­ecules of the isomeric compound N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide lie across inversion centres, and the mol­ecules are linked into sheets by a combination of N—H⋯N hydrogen bonds and π–π stacking inter­actions between pyridyl groups.     

酚醛基活性炭纤维孔结构及其电化学性能研究

利用水蒸汽活化法制备了酚醛基活性炭纤维(ACF-H2O), 对其比表面积、孔结构与在LiClO4/PC(聚碳酸丙烯酯)有机电解液中的电容性能之间的关系进行了探讨. 用N2(77 K)吸附法测定活性炭纤维的孔结构和比表面积, 用恒流充放电法和交流阻抗技术测量双电层电容器(EDLC)的电容量及内部阻抗. 研究表明, 在LiClO4/PC有机电解液中, ACF-H2O电极的可用孔径(d)应在0.7 nm以上. 随着活化时间的延长, ACF-H2O的孔容和比表面不断增大, 但微孔(0.7 nm ＜ d ＜ 2.0 nm)和中孔(d ＞ 2.0 nm)率变化很小, 活化过程中孔的延伸和拓宽同步进行, 但过度活化则造成孔壁塌陷, 孔容和比表面迅速下降. 因此, 除活化过度的样品外, 电容量随比表面积呈线性增长, 最高达到109. 6 F•g-1. 但中孔和微孔的孔表面对电容的贡献不同, 其单位面积电容分别为8.44 μF•cm-2和4.29 μF•cm-2, 中孔具有更高的表面利用率. ACF-H2O电极的电容量、阻抗特性和孔结构密切相关. 随着孔径的增大, 时间常数减小, 电解液离子更易于向孔内快速迁移, 阻抗降低, 电极具有更好的充放电倍率特性. 因此, 提高孔径和比表面积, 减少超微孔(d ＜ 0.7 nm), 是提高 EDLC能量密度和功率密度的重要途径. 然而仅采用水蒸汽活化, 只能在小中孔以下的孔径范围内进行调孔, ACF-H2O电极电容性能的提高受限.     

New Clerodane Diterpenoids from Casearia membranacea

Bioassay‐guided fractionation of an AcOEt extract of Casearia membranacea resulted in the isolation of six new clerodane diterpenes, caseamembrins G–L ( 1 – 6 ). The structures of the new compounds, including their relative configurations, were established by an extensive study of their spectral data, especially 2D NMR. The cytotoxic activities of the isolated diterpenes against human oral epidermoid (KB), cervical epitheloid (Hela), and liver (Hep59T/VGH) carcinoma cell lines were investigated.