5-二乙氨甲基-6-甲基嘧啶-2,4-二酮的合成及抗炎活性

经由6-甲基嘧啶-2,4-二酮(6-甲基尿嘧啶)在无水乙醇中与甲醛和二乙胺反应,得到5-二乙氨甲基-6-甲基嘧啶-2,4-二酮;研究了影响反应收率的各种因素;利用质谱和核磁共振谱对产品进行了结构鉴定;同时利用小鼠耳肿胀试验测定了产物的抗炎活性.结果表明,所制备的5-二乙氨甲基-6-甲基嘧啶-2,4-二酮具有显著的抗炎活性.     

(4-甲基-1,3-二噻烷-2-亚甲基)-1,7-二芳基-1,6-二烯-3,5-二酮的合成

从2,4-戊二酮和1,2,3-三溴丙烷出发合成了一类新的α-羰基二硫缩烯酮类化合物,并以其为底物合成了(4-甲基-1,3-二噻烷-2-亚甲基)-1,7-二芳基-1,6-二烯-3,5-二酮类化合物,通过IR和1H NMR方法对其进行了表征.     

2,6-二甲基-3,5-二乙氧羰基-1,4-二氢吡啶的二-π甲烷光重排反应

合成了2,6-二甲基-3,5-二乙氧羰基-1,4-二氢吡啶,并研究了它在紫外光(366nm)照射下的光化学反应。结果表明,主要的光化产物为2,6-二甲基-3,5-二乙氧羰基吡啶(占95%)其次是少量的二-π甲烷光重排产物,1,3-二甲基-2-氮杂-4,5-二乙氧羰基-双环-[3、1、0]-己烯-3(占5%)。     

5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2,5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮的合成

报道俘精酸酐类化合物(E/Z)4-二环丙亚甲基-3-[1-(2,5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2,5-酮的拆分,及(E)和(Z)-5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2,5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮4(E)和4(Z)的合成,并对它们的光致变色特性进行了初步研究。     

5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2, 5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮的合成

报道俘精酸酐类化合物(E/Z)4-二环丙亚甲基-3-[1-(2, 5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2, 5-酮的拆分, 及(E)和(Z)-5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2, 5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮 4(E)和4(Z)的合成, 并对它们的光致变色特性进行了初步研究。     

N,N′-二-(3,5-二甲基苯基)-3,6-二甲基-1,4-二氢-1,2,4,5-四嗪-1,4-二甲酰胺的合成

1,2,4,5-四嗪衍生物具有抗肿瘤,杀菌,杀虫等活性,我们曾合成了具有抗肿瘤活性的N,N′-二苯基-3,6-二甲基-1,4-二氢-1,2,4,5-四嗪-1,4-二甲酰胺(3a)[1,2,3],合成路线见图1.研究它们的抗肿瘤活性时发现该化合物的苯环间位若以N,N-二甲基取代,对小鼠白血病细胞(P-388)和人肺腺癌细胞(A-549)有很强的抗肿瘤活性.     

二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基的合成

以1,4-环己二酮、丙二酸二乙酯及多元醇等为原料, 经过两次“一锅煮”法合成了六种二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基螺环树形化合物, 其中烷氧基为异戊氧基、三羟甲基甲氧基、2,2-二溴甲基-3-羟丙氧基、2,2-二羟甲基丙氧基、二羟甲基膦甲氧基和(N-羟甲基-N-二羟甲基氨基乙基)甲氧基. 利用IR, NMR, MS和元素分析对合成的化合物进行了结构认证, 对影响反应的因素进行了讨论.     

环状碳酸酯5,5-二甲基-1,3-二噁烷-2-酮的合成

在三乙胺存在下,2,2-二甲基-1,3-丙二醇和氯甲酸乙酯反应合成了环状碳酸酯5,5-二甲基-1,3-二噁烷-2-酮,其结构经1H NMR和IR表征。提出了可能的反应机理。     

无溶剂超声辐射下琥珀酸二酰亚胺磺酸铈催化合成5-[(3-吲哚基)-甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物

在琥珀酸二酰亚胺磺酸铈催化下,吲哚、醛和2,2-二甲基-1,3-二噁烷-4,6-二酮在无溶剂条件下超声辐射合成了10种5-[(3-吲哚基)-甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物.当催化剂的用量为3%(摩尔分数)时,30℃反应30~60 min,收率为68.9%~96.7%.此外,还探讨了琥珀酸二酰亚胺磺酸铈的催化机理.该方法具有条件温和,反应时间短且收率高的优点.催化剂邻琥珀酸二酰亚胺磺酸铈对环境友好且可循环利用.     

1,1-二氨基-2,2-二硝基乙烯的合成研究进展

1,1-二氨基-2,2-二硝基乙烯（FOX-7）是一种低感度高能量的新型含能材料.现有的1,1-二氨基-2,2-二硝基乙烯的合成包括以2-甲基咪唑、盐酸乙脒与乙二酸二乙酯、2-甲基-4,6-二羟基嘧啶为前体的三条合成路线.使用硫酸/硝酸体系硝化2-甲基-4,6-二羟基嘧啶可得到2-二硝基亚甲基-5,5-二硝基嘧啶-4,6-二酮,然后水解可得到FOX-7,正相硅胶薄层色谱可对该反应进行监测.使用曲拉通X-100/正己烷体系的反相微乳法可制备FOX-7球形纳米晶;FOX-7球形纳米晶具有良好的应用前景,对其合成工艺与路线进行探索和研究具有一定的意义.     

Total synthesis, structure revision, and absolute configuration of (+)-yatakemycin

The total synthesis of the reported structure 2 for yatakemycin, an exceptionally potent, naturally occurring antitumor agent disclosed in 2003, and its lack of correlation with the natural product are detailed. On the basis of spectroscopic distinctions between 2 and yatakemycin, the natural product structure was reformulated as 3, now bearing a thiomethyl ester versus thioacetate in the left-hand subunit. Total synthesis of 3 provided a compound nearly identical to but still subtly distinct from the natural product. A second reformulation of the yatakemycin structure as 1, incorporating the alternatively substituted right-hand subunit as well as the initial thiomethyl ester reformulation, was confirmed by total synthesis of both (+)- and ent-(-)-1 in studies that also unambiguously established the absolute configuration of the natural product.     

Total synthesis, structure revision, and absolute configuration of (-)-brevenal

Total synthesis of structure 1 originally proposed for brevenal, a nontoxic polycyclic ether natural product isolated from the Florida red tide dinoflagellate, Karenia brevis, was accomplished. The key features of the synthesis involved (i) convergent assembly of the pentacyclic polyether skeleton based on our developed Suzuki-Miyaura coupling chemistry and (ii) stereoselective construction of the multi-substituted (E,E)-dienal side chain by using copper(I) thiophen-2-carboxylate (CuTC)-promoted modified Stille coupling. The disparity of NMR spectra between the synthetic material and the natural product required a revision of the proposed structure. Detailed spectroscopic comparison of synthetic 1 with natural brevenal, coupled with the postulated biosynthetic pathway for marine polyether natural products, suggested that the natural product was most likely represented by 2, the C26 epimer of the proposed structure 1. The revised structure was finally validated by completing the first total synthesis of (-)-2, which also unambiguously established the absolute configuration of the natural product.     

Dysidin,ein neuartiger,chlorhaltiger Naturstoff aus dem Schwamm Dysidea herbacea

Dysidin, a novel chlorine containing natural product from the sponge Dysidea herbacea Dysidin ( 1 ) has been isolated from the marine sponge Dysidea herbacea. It structure has been determined by degradation studies and spectroscopic methods. The synthesis of a degradation product is described. The relative and absolute configuration is established by X-ray diffraction methods.     

Exploiting predisposition in the stereoselective synthesis of mono-, bi- and tetracyclic oxygen heterocycles: equilibration between,and trapping of,alternative di- and tetraacetals

The desymmetrisation of 1,4-difuran-2-ylbutane-1,4-diol by Sharpless asymmetric oxidation gave the corresponding desymmetrised product in > 96% ee. However, the product existed as a mixture of two interconverting isomers, both of which were mixtures of anomers. The product could be trapped in high yield with a range of reagents to give stable adducts with embedded pyran-3-one, 1,6-dioxaspiro[4.5]decane or pyrano[3,2-b]pyran ring systems. The strategy was also applied in the interconversion between alternative tetracycles and, under acidic conditions, this process was thermodynamically controlled. The selectivity of the process was rationalised by molecular modelling using the HF/6-31G* parameter set.     

SYNTHESIS OF SODIUM MONO(2,4,4'-TRIMETHYLPENTYL) PHOSPHINATE. OPTIMIZATION,PURIFICATION, AND SURFACTANT PROPERTIES.

Sodium mono(2,4,4'-trirnethylpentyl)phosphinate has been obtained as a main product with good yield from the reaction between diisobutylene and sodium hypophosphite. The procedure is defined by a set of operating conditions which enable obtaining the product with optimum yield. Empirical relationships between the product quality and the operative conditions have been found. The purity of the mono(2,4,4',trimethylpentyl)phosphinic acid was checked by 1R and ³¹P NMR spectroscopy and determined by potentiometric titration of an ethanol/water solution. Finally the critical micelle concentration of sodium mono(2,4,4'-trunethylpentyl)phosphinate and sodium mono(n-octyl)phospninate has been determined.     

羧甲基牛膝多糖的制备、结构及生物活性研究

在NaOH水溶液中,以ClCH_2COOH为羧甲基化试剂,对牛膝多糖(AbPS)进行了羧 甲基化,粗产物经DEAE-Cellulose及Sephadex G-25两次柱层析纯化,得到羧甲基 牛膝多糖(CM-AbPS)纯品,经高效液相法（HPLC）及毛细管电泳法（CE）检测表明 具有较好的均一性,并通过样品甲基化和GC-MS分析,对羧甲基牛膝多糖链中羧甲 基的分布进行了研究,结果表明羧甲基牛膝多糖中羧甲基主要取代的糖链中呋喃果 糖的4-位上。该产物具有抗肿瘤活性。     

THE HYDROSILYLATION REACTION OF LADDERLIKE POLYVINYLSILSESQUIOXANE WITH 1, 1, 3, 3-TETRAMETHYLDISILOXANE

The hydrosilylation reaction of ladderlike polyvinylsilsesquioxane (Vi-T)with 1, 1, 3, 3-tetramethyldisiloxane (H- MM ) catalyzed by dicyclopentadienyl-dichloroplat-inium (Cp_2PtCl_2) was carried out well in tetrahydrofuran (THF) to produce a soluble whitesolid. This product was characterized by IR, ~1H-NMR, ~(13)C-NMR, ~(29)Si-NMR, DSC, X-raydiffraction method, gel permeation chromatography (GPC), vapour pressure osmometry(VPO), atomic force microscopy (AFM) and molecular simulation. These results provethat the product contains nanoscale tubular structure.     

Design, synthesis, and characterization of conifer-shaped dendritic architectures

An elongated structural design leading to more conical-shaped dendritic architectures by using a combination of 1-->3, 1-->(2+1), and 1-->(2+1 Me) C-branched monomers is presented. Synthesis of the conifer-shaped macromolecule was achieved by reaction between isocyanate 20 and amine 26 in dry CH2Cl2. A resultant extended focal adamantane-modified dendron was deprotected to generate the water-soluble product, which was subsequently complexed with beta-cyclodextrin in D2O to create the desired tree-like product. Host-guest interactions of the adamantane moiety with the beta-cyclodextrin cavity were monitored by 1H NMR spectroscopy. All monomers, key intermediates, and final products were fully characterized by 1H and 13C NMR spectroscopy, ESI or MALDI-TOF mass spectrometry, and IR spectroscopy.     

Determination of Product Inhibition of CBH1, CBH2, and EG1 Using a Novel Cellulase Activity Assay

The hydrolysis of lignocellulosic biomass by degrading enzymes (cellulases) has emerged as a promising process within the bio-ethanol industry. Yet, understanding all the intricacies of how these enzymes work has been a challenging task. Substrate–enzyme interaction in complex feed mixtures, the recalcitrance of the crystalline structure of cellulose and enzyme inactivation by product inhibition, nonproductive binding to lignin, and process stress are only some of the problems standing in the way of creating an effective and efficient process to bio-ethanol production. This study focuses on the product inhibition of cellobiohydrolases and endoglucanases. Here, we present a method of studying product inhibition by measuring the decrease in substrate, utilizing the fluorescent properties of a calcofluor dye.     

Fluorescein–formaldehyde oligomeric pH indicator: Facile synthesis,characterization, and potential application

A kind of fluorescent oligomeric pH indicator (fluorescein–formaldehyde product) was synthesized by the reaction of fluorescein with formaldehyde under alkaline conditions by a one‐pot method. The synthesized product was fully characterized with Fourier transform infrared, ¹H NMR, ultraviolet–visible spectra, luminescence spectra, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectra. The results indicated that the reaction was a typical phenol–formaldehyde reaction and that the fluorescein–formaldehyde product contained dimer, trimer, tetramer, and even a little octamer. Visible spectra and luminescence spectra showed that the fluorescein–formaldehyde product could still provide pH sensitivity similar to that of fluorescein. In addition, the oligomeric pH indicator immobilized poly(vinyl alcohol) membranes could be easily fabricated and achieved better long‐term stability and fast equilibrium response. Thus, they are promising transparent membranes for optical pH sensors of a wide pH range (0.0–10.0) based on absorption and fluorescence. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3447–3453, 2005