聚四氢呋喃三元醇的合成及表征

合成了一种新的三元引发剂[C₂H₅C(CH₂OCH₂CH₂CO+ClO₄^-)₃],并用于制备聚四氢呋喃三元醇.用¹HNMR,FTIR和GPC法对聚合物的结构进行了表征.结果表明,产物中环状齐聚物的含量极低.对聚合物水解产物的分子量及分子量分布测定结果表明,产物为预期的三元醇,聚合反应过程中链转移可以忽略,聚合物的分子量可控.     

Biochemical,Kinetic and Biological Properties of Group V Phospholipase A2 from Dromedary

Secretory group V phospholipase A2 (PLA₂-V) is known to be involved in inflammatory processes in cellular studies, nevertheless, the biochemical and the enzymatic characteristics of this important enzyme have been unclear yet. We reported, as a first step towards understanding the biochemical properties, catalytic characteristics, antimicrobial and cytotoxic effects of this PLA₂, the production of PLA₂-V from dromedary. The obtained DrPLA₂-V has an absolute requirement for Ca²⁺ and NaTDC for enzymatic activity with an optimum pH of 9 and temperature of 45 °C with phosphatidylethanolamine as a substrate. Kinetic parameters showed that K_cat/Km_app is 2.6 ± 0.02 mM⁻¹ s⁻¹. The enzyme was found to display potent Gram-positive bactericidal activity (with IC50 values of about 5 µg/mL) and antifungal activity (with IC50 values of about 25 µg/mL)in vitro. However, the purified enzyme did not display a cytotoxic effect against cancer cells.     

Asymmetric Synthesis of Calyculin C. 1. Synthesis of the C(1)-C(25) Fragment

We report our synthesis of the C(1)-C(25) fragment of serine/threonine phosphatase PP1 and PP2A inhibitor, calyculin C. Synthetic efforts were directed initially toward the synthesis of a spiroketal core fragment (7), which culminated in completion of the bottom half of the natural product. The synthesis of fragment 7 and subsequent elaboration relied on an allylboration strategy for introduction of chirality. The C(1)-C(8) fragment representing the potentially unstable tetraene moiety was introduced as a separate entity.     

O-(1-甲硫基乙叉胺基)磷酰胺酯(或磷酸酯)的合成及其生物活性研究

首次合成了30种新型O-(1-甲硫基乙叉胺基)磷酰胺酯及磷酸酯类化合物,生物活性测定表明,部分化合物具有一定的杀菌和除草活性,化合物(R¹O)₂P(O)-ON＝C(SCH₃)CH₃(V)具有一定的杀虫活性.     

Synthesis and Photosensitive Properties of Poly(aryl imino) Containing Azobenzene Group (PAI-A)

Using 4,4′‐dibromobenzophenone and 4,4′‐diaminoazobenzene as monomers, poly(aryl imino) containing azobenzene unit (PAI‐A) was synthesized via palladium‐catalyzed amination, and structurally characterized by means of FT‐IR, ¹H NMR spectra and elemental analysis, the results of which show an agreement with the proposed structure. The UV absorption spectra were tested under different conditions. Additionally, differential scanning calorimetry (DSC) and thermogravimetric (TG) measurements show that PAI‐A possesses high glass transition temperature (T_g>176°C) and good thermal stability with high decomposition temperatures in nitrogen atmosphere (T_D>410°C).     

Total Synthesis of Everninomicin 13,384-1-Part 1: Synthesis of the A(1)B(A)C Fragment

The powerful antibiotic everninomicin 13,384-1 (1, Ziracin) has been prepared for the first time through a total synthesis. The 1-->1'-disaccharide and the two orthoesters of this target molecule were introduced by new methodologies using a tin acetal and 1,2-phenylseleno migrations. The reaction sequence also relies on stereoselective glycosidations and subtle manipulations of protecting groups. In addition to the introduction of new synthetic methodologies, this total synthesis should allow the preparation of combinatorial libraries of semisynthetic analogues of this highly promising antibiotic for biological screening purposes.     

O-芳基-O-烷基-O-(1-甲硫基乙叉胺基)磷酸酯的合成及其生物活性研究

以盐酸羟胺、乙醛、取代酚类及烷氧基磷酰二氯为原料,合成了22个O-芳基-O-烷基-O-(1-甲硫基乙叉胺基)磷酸酯化合物,采用元素分析、红外光谱和1H NMR谱对其进行了表征.初步生物活性测定结果表明,部分化合物具有一定的杀菌、除草活性,许多化合物具有优良的杀虫活性.     

Synthesis and Properties of Pentafluorosulfanyl Group (SF5)-Containing Meta-Diamide Insecticides

Herein, we describe novel pentafluorosulfanyl (SF₅) group-containing meta-diamide insecticides. For the facile preparation of the SF₅-based compounds 4a–d, practical synthetic methods were applied. Among newly synthesized compounds, 3-benzamido-N-(2,6-dimethyl-4-(pentafluoro-λ⁶-sulfanyl)phenyl)-2-fluorobenzamide 4d showed (i) a high insecticidal activity, (ii) an excellent selectivity to insects, and (iii) good levels of water solubility and log P values. In this study, we demonstrated that the pentafluorosulfanyl moiety could serve as an attractive functionality for the discovery of a new scope of crop-protecting agents.     

Ni(II) Ternary Complex Based on Antimicrobial Drug Enoxacin: Synthesis and Biological Properties

First Ni(II) ternary complex using the quinolone antibacterial agent enoxacin (HEn) as ligand and 1,10‐phenanthroline as co‐ligand has been synthesized and characterized. It is a mononuclear structure, in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom. The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants (6.40×10⁴ and 7.12×10⁴, respectively). The investigation of the interaction of the complex with calf‐thymus (CT) DNA has been performed with UV and circular dichroism (CD) spectroscopies, indicating that they bind to CT DNA probably by the intercalative binding mode. The binding constant (K_b) of the complex with CT DNA calculated with UV is 2.03×10⁵, which is higher than that of free enoxacin drug (2.09×10⁴) and even higher than that of typical intercalation indicator (1.23×10⁵) of ethidium bromide (EB). Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA‐bound EB using the intercalative binding site. In addition, the antimicrobial activity showed that the complex exhibited a little bit good inhibition (MIC=1.843 (g·mL^?1) against B. subtilis than free HEn.     

Synthesis and Biological Activities of C (5)-N-Spin-Labeled Uridines and Related Derivatives

Direct introduction of a N-atom in one step at C (5) of 5-hydroxyuridine (4a) or 5-hydroxy-2′-deoxyuridine (4b) by certain primary amines led to the synthesis of two novel C(5)-N-spin-labeled nucleoside analogs and to several C(5)-N-aryl adducts. Substitution by 4-amino-2,2,6,6-tetramethylpiperidinooxyl (3) at C(5) of 4a or 4b led to the spin-labeled nucleosides 5-[(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)amino]uridine and -2′-deoxyuridine ( 2a and 2b , respectively). The analogous C(5)-substituted aniline adducts 5-anilino uridine (5a) and 5-anilino-2′-deoxyuridine (5b) and the p-toluidine adducts 5-(p-toluidino)uridine (6a) and 5-(p-toluidino)-2-deoxyuridine (6b) were also prepared. In addition, results of the antiviral and antimetabolic activity of some of these analogs are reported.     

9-咔唑-羧酸化合物的微波合成及其生物活性研究

9-咔唑 -羧酸化合物不但是医药[1] 、有机光导材料[2 ] 的中间体 ,而且其本身亦具有干扰素诱导能力[3] .近年来 ,我们[4 ] 应用 9-咔唑 -乙酸和丙酸作为高效液相色谱分析氨基酸、胺和醇类的衍生化试剂 .目前所合成的此类化合物很少 .近 1 5年以来 ,微波在有机合成中的应用已发展成为一个新的研究领域[5] ,许多反应已在微波炉中高产率快速地实现了 .本文采用微波辐照法快速合成了系列 9-咔唑 -羧酸化合物 3 a— 3 m,优化了反应条件 ,并测试了它们的生物活性 .反应式如下 :丷4R5丯HR3 R2R1( 1) +Br R6COOC2 H5( 2 ) 丷4R5丯R6COOHR3 R…     

Synthesis and Properties of Poly(1,6-Heptadiyne) Derivatives Containing Hydroxy Functional Group

Abstract

1,6-Heptadiyne derivatives containing hydroxy and aromatic substituents, 4-hydroxy-4-phenyl-l,6-heptadiyne (HPHD), 4-hydroxy-4-(4′-methylphenyl)-l,6-heptadiyne (HMHD), and 4-hydroxy-4-(4′-methoxy-phenyl)-l,6-heptadiyne (HMOHD), were prepared and polymerized by various transition metal catalyst systems. A molybdenum complex was found to be the most effective catalyst for the cyclopolymerization of 4-hydroxy-l,6-heptadiyne derivatives. Polymerization of 4-hydroxy-l,6-heptadiyne derivatives by MoCl₅-based catalysts gave soluble and highly colored polymers. HMOHD containing the methoxy functional group showed the highest reactivity in cyclopolymerization. The structures of the resulting polymers were elucidated with IR, ¹H- and ¹³C-NMR, and UV-visible spectroscopies. The present polymers were thermally and oxidatively more stable and had higher number-average molecular weights (M_n) of 2 × 10⁴ to 3 ×10⁴ than the corresponding 4-hydroxy-1,6-heptadiyne derivatives containing aliphatic substituents.     

Synthesis of C(1)-C(11) oxygen-bridged pregnanes

A general procedure for the synthesis of 1α,11α- and 1β,11α-epoxysteroids is described, using an intramolecular remote functionalization reaction involving the photolysis of 11α-hydroxysteroids in the presence of diacetoxyiodobenzene and iodine. Three 1,11-epoxypregnanes were prepared, two of them (compounds 10 and 14) are conformationally constrained analogues of steroidal hormones, compound 13 is a synthetic precursor of neurosteroids.     

Triol Crystalline Hosts Derived from Malic Acid. Synthesis,Inclusion Formation and X-ray Crystal Structures of a Free Host and its Inclusion Compound with Ethanol (1:1)

Abstract

Four new host compounds 1–3 (a, b) derived from malic acid as different optical species and having particular lateral substituents were synthesized. Their properties in crystalline inclusion formation were studied and discussed. Crystal structures of a free host compound 1 and its ethanol inclusion complex [1·EtOH (1:1)] have been determined by X-ray analysis [1: orthorhombic, P2₁2₁2₁, a = 9.304(3), b = 14.950(3), c = 15.712(3) Å, Dc = 1.248 Mg·m^?3, Z = 4, R = 0.039 for 2474 reflexions; 1·EtOH (1:1): triclinic, P 1; a = 11.945(3), b = 14.080(3), c = 16.029(4) Å, α = 106.82(2), β = 97.74(2), γ = 89.93(2)°, D_c = 1.187 Mg·m³, Z = 4, R = 0.096 for 10404 data]. Spontaneous resolution occurs during crystallization in crystals of 1. An interesting H-bonding pattern develops that probably is responsible for the inclusion formation with ethanol in the associate crystal.     

Synthesis,Structure and Properties of C(X)NHP(Y) Fragment Containing Compounds

Abstract

N-(thio)carbonyl(thio)amidophosphate, their open-chain and crown-containing analogues with a C (X) NHP (Y) fragments are associated with intermolecular hydrogen bonds as C=X…H-N and P=Y…H-N or intramolecular hydrogen bonds of N-H…O(macrocycle). These compounds easily enter into alkylation reaction, are added according to C=N bonds of activated imines, take part in O → S and S → O exchanging reactions.     

C(3)-乙烯基的化学修饰与含氧基团取代的叶绿素-a衍生物的合成

以焦脱镁叶绿酸-a甲酯为起始原料, 通过加成和氧化反应将其3-位上的乙烯基转化为羟乙基、溴乙基、二羟乙基、二溴乙基和溴羟乙基, 再经过二甲亚砜/乙酸酐或者高钌酸四丙基铵(TPAP)/N-甲基吗啉-N-氧化物所组成的混合氧化剂的氧化反应, 得到多种C(3)-多酮基取代的二氢卟吩衍生物. 其单羟基作为离去基团与不同的活泼亚甲基化合物经过重排过程, 得到相应的酮基取代的二氢卟吩衍生物. 所得新叶绿素衍生物的化学结构均经UV, IR, ¹H NMR及元素分析得以证实, 并对相应的反应提出可能的反应机理.     

碳核苷的合成及生物活性研究

通过呋喃汞盐与溴代木糖的偶合，合成５个新碳核甙；经过元素分析，＾１ＨＮＭＲ，＾１３ＣＮＭＲ，ＭＳ，ＩＲ确定了它们的结构；并检验了其中两个化合物对α－及β－硫代葡糖苷酶的抑制活性。