Two New Diterpene Alkaloids from the Roots of Spiraea japonica var. Acuta

Spiraea japonica L. (Rosaceae) is widely distributed in Yunnan Provence, P. R. China. Previous chemical investigations on S. japonica and its varieties have led to the report of 7 new atisane-type diterpenoids and 38 new diterpene alkaloids of atisine- and hetisine-type1-11. This paper describes the isolation and structure elucidation of two new diterpene alkaloids named spiratines A and B (1-2). Their structures were elucidated on the basis of 1D and 2D NMR experiments (HMQC, HMBC, 1…     

Surface‐initiated atom transfer radical polymerization from porous poly(tetrafluoroethylene) membranes using the C?F groups as initiators

This work reports the surface‐initiated atom transfer radical polymerization (ATRP) from hydrogen plasma‐treated porous poly(tetrafluoroethylene) (PTFE) membranes using the C? F groups as initiators. Hydrogen plasma treatment on PTFE membrane surfaces changes their chemical environment through defluorination and hydrogenation reactions. With the hydrogen plasma treatment, the C? F groups of the modified PTFE membrane surface become effective initiators of ATRP. Surface‐initiated ATRP of poly(ethylene glycol) methacrylate (PEGMA) is carried out to graft PPEGMA chains to PTFE membrane surfaces. The chain lengths of poly(PEGMA) (PPEGMA) grafted on PTFE surfaces increase with increasing the reaction time of ATRP. Furthermore, the chain ends of PPEGMA grown on PTFE membrane surfaces then serve as macroinitiators for the ATRP of N‐isopropylacrylamide (NIPAAm) to build up the PPEGMA‐b‐PNIPAAm block copolymer chains on the PTFE membrane surfaces. The chemical structures of the modified PTFE membranes are characterized using X‐ray photoelectron spectroscopy. The modification increases the surface hydrophilicity of the PTFE membranes with reductions in their water‐contact angles from 120° to 60°. The modified PTFE membranes also show temperature‐responsive properties and protein repulsion features owing to the presence of PNIPAAM and PPEGMA chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2076–2083, 2010     

Study on the Structure of Supramolecular Inclusion Complex of β-Cyclodextrin with Retinoic Acid

The importance of Vitamin A for human health has been stressed in resent studies1, meanwhile its derivative so-called retinoic acid (RA) has been widely used as pharmaceutical to treat several types of skin disease and cancer2,3. However the application of retinoic acid is restrained for its poor water solubility, unstability and side effect on the human body.Cyclodextrins (CDs) are macrocyclic oligosaccharides built up from 6, 7, or 8 glucopyranose units called (, (, and (-CD, respectively…     

Taxayuntin I from Thous Yunnanensis

Sinceexcellentantitumoractivityanduniquemechanismofactionofpaclitaxel(taxol@)werediscovered,chemicalstudiesonTaxusspecieshavebeenextensivelycarriedoutl'2.About300taxoidshavebeenisolatedfromGeneraTaxusandAustrotaxusplants'.Insearchforbioactivetaxoidsa...     

3,6‐Bis(2‐pyridyl)di‐1,2,4‐triazolo­[3,4‐a:4′,3′‐c]­phthalazine

The title compound, C₂₀H₁₂N₈, (I), has been prepared by the reaction of 1,4‐dihydrazinophthalazine and pyridine‐2‐carbox­aldehyde, followed by an oxidative cyclization by treatment with bromine. In the solid state, the mol­ecules of (I) are discrete, comprising a fused and twisted four‐ring system with an overall helical appearance. The distance between the two intramolecular pyridyl N atoms is 3.075 (2) Å, this short contact distance suggesting a π–π interaction.     

荧光相位成像的光束扫描法

利用计算机控制振镜进行光束扫描，用锁相放大器进行增益调制与相位调节，最后再用计算机重建图像，实现钛宝石和红宝石的相位成像。分别完成了激发光和荧乐相移为π／１２、π／１４和７π／１２的成像，分析了系统的时间分辨率和空间分辨率，提出了实用化发展的方向。     

Relativistic orbital perturbations in a weak gravitational field

With the general third-order equations of motion for a test particle, Synge's third-order orbital equations at great distance in the weak gravitational field generated by a massive body are derived. The body has an axis of symmetry around which is rotating steadily. The results found for the advance of perihelion using first integrals of motion for the general equations show that the effect due to the inner stress of the body can be derived for orbits with inclination with respect to the equator of the body. Then, by means of the variation of the parameters method, we obtain with the equations at great distance the corresponding perturbations on the elements of such orbits in the field considered. These perturbations result to be of second order with regard to the mass of the body (the basis of the approximation).     

多亚甲基桥连双巴比妥的合成及鉴定

在ＰＴＣ条件下合成了多亚甲基桥连的双巴比妥类化合物１～３，并通过了元素分析，ＩＲ及＾１ＨＮＭＲ予以鉴定。