丹皮酚希夫碱及其铜配合物的合成与抗菌活性

采用水蒸汽蒸馏法从牡丹皮中提取并精制得丹皮酚(1);1与硫代氨基脲经缩合反应制得新化合物丹皮酚希夫碱(2),收率61%;2与二水氯化铜反应合成了丹皮酚希夫碱铜配合物(3),收率53%,其结构经UV-Vis,1H NMR,13C NMR,IR和元素分析表征。抗菌活性测试结果表明,2和3对大肠埃希氏菌、金黄色葡萄球菌、绿脓假单胞菌及白假丝酵母菌均有较强的抑菌和杀菌作用,尤其是3对金黄色葡萄球菌的抑制和灭活作用较显著,MIC和MBC分别为2.20μg·m L-1和8.60μg·m L-1。     

Total Synthesis of a Dimeric Thymol Derivative Isolated from Arnica sachalinensis

The total synthesis of a dimeric thymol derivative (thymarnicol) isolated from Arnica sachalinensis was accomplished in 6 steps. A key biomimetic Diels–Alder dimerization was found to occur at ambient temperature and the final oxidative cyclization occurs when the substrate is exposed to air and visible light. These results indicate that this natural product is likely the result of spontaneous (non‐enzyme‐mediated) reactivity.     

Stilbenes and Its Derivative from Gnetum Cleistostachyum

Gnetum cleistostachyum C. Y. Cheng grows in the southern of Yunnan province of China, and is not recordedin the folk medicine. However, some Chinese Gnetum species, such as G. parvifolium and G. montanum, have been used for treatment of rheumatic arthritis and bronchitis in folk medicine.     

A Facile Generation of a Cyclopropylzinc Compound from an Alkenylzinc Derivative and Its Reaction with Electrophiles

The one-pot synthesis of cyclopropyl compounds from 1-alkynes has been achieved by direct cyclopropanation of a 1-alkenylzinc species upon treatment with iodomethylzinc and trapping of the cyclopropylzinc intermediate with allyl bromide in the presence of CuCN⋅2 LiCl (see reaction scheme). This method proceeds under mild conditions and in good yield.     

New Kendomycin Derivative Isolated from Streptomyces sp. Cl 58-27

In the course of screening new streptomycete strains, the strain Streptomyces sp. Cl 58-27 caught our attention due to its interesting secondary metabolite production profile. Here, we report the isolation and characterization of an ansamycin natural product that belongs structurally to the already known kendomycins. The structure of the new kendomycin E was elucidated using NMR spectroscopy, and the corresponding biosynthetic gene cluster was identified by sequencing the genome of Streptomyces sp. Cl 58-27 and conducting a detailed analysis of secondary metabolism gene clusters using bioinformatic tools.     

Identification and Fibrinolytic Evaluation of an Isoindolone Derivative Isolated from a Rare Marine Fungus Stachybotrys longispora FG216

An isoindolone derivative, Fungi fibrinolytic compound (R)‐2,5‐bis((2R,3R)‐2‐((E)‐4,8‐dimethylnona‐3,7‐dien‐1‐yl)‐3,5‐dihydroxy‐2‐methyl‐7‐oxo‐3,4,7,9‐tetrahydropyrano[2,3‐e]isoindol‐8(2H)‐yl)pentanoic acid (FGFC1, Fungi fibrinolytic compound 1 ), was isolated from a rare marine microorganism strain Stachybotrys longispora FG216. The structure of FGFC1 was elucidated by ¹H NMR, ¹³C NMR, IR, and MS data; moreover, it was also evaluated for fibrinolytic activity in vitro and in vivo. The results showed that 0.1–0.4 mmol/L of FGFC1 could stimulate generation of plasmin activity (increased by 2.05–11.44 folds) by measuring Glu‐plasminogen and Lys‐plasminogen activation in vitro. The experiment of fluorescein isothiocyanate (FITC)‐fibrinogen degradation indicated that the effect of FGFC1 on fibrinolytic activity was mediated by plasminogen and scuPA. In addition, FGFC1 (10 mg/kg) could dissolve most of pulmonary thrombus of Wistar rat in vivo. It is possible that FGFC1 is a potential thrombolytic agent in the future.     

A New Eudesmanolide and a New Aromatic Derivative from Carpesium cernuun

Carpesium cernuun L. has long been used as chinese folk medicine for its anti-inflammatory, pain-relief, and detoxication properties1. Up to now, no phytochemical studies of Carpesium cernuun has been carried out. Here we report the structure elucidation of a new eudesmanolide 1 and a new aromatic derivative 2, which were obtained from this plant. Compound 1 was isolated as colorless gum, [(]+128.4 (c 0.43, CHCl3). Its EIMS revealed a molecular ion peak m/z 248. Together with the support …     

C60乙二胺衍生物铂配合物的合成及其催化硅氢化性能

C₆₀与乙二胺反应,再与氯亚铂酸钾配位,得到了一种以C₆₀衍生物为基的Pt(Ⅱ)配合物,并研究了其在烯烃与三乙氧基硅烷的硅氢加成反应中的催化性能。结果表明,该配合物为硅氢加成反应的高效催化剂,并对苯乙烯有独特的催化性能,以近100%的区域选择性得到α-加成产物。     

Complex Forming Ability of a Family of Isolated Cyclosophoraoses with Ergosterol and Its Monte Carlo Docking Computational Analysis

Neutral cyclosophoraoses (unbranched cyclic -1,2-d-glucans) produced by the Rhizo-bium meliloti 2011 were prepared by size exclusion and anion-exchange chromatographic techniques. The degree of polymerization (DP) of isolated cyclosophoraoses was determined by matrix associated laser desorption/ionization mass spectrometry (MALDI/MS) techniques. A family of purified neutral cyclosophoraoses (DP 17–27) was used as a host for the inclusion complexation with hardly soluble ergosterol. High performance liquid chromatographic (HPLC) analysis showed that it induced much enhanced solubility of ergosterol compared to -cyclodextrin. In order to understand the molecular basis of the complex forming ability of cyclosophoraoses, a Monte Carlo (MC) docking-minimization method was used for host-guest complex formation of cyclosophoraoses or -cyclodextrin with ergosterol. From the MC simulation we propose the `hand-shake' mechanism for complexation of cyclosophoraoses with ergosterol.     

A New Compound Isolated from a Bioactive Streptomycete

A new compound, named (S)-α-acetylamino-β-(3-indole)propano1 (1) was isolated, along with two known compounds teleocidin B 1 and emycin B from culture broth of a streptomycete strain YIM33176 (streptomyces pleomorphus). The structure of 1 was determined by detailed spectroscopic investigation.     

A Diruthenium Complex of an N-Pyridyl-o-aminophenol Derivative: A Route to Mixed Valency

An N-pyridyl-o-aminophenol derivative that stabilises mixed-valence states of ruthenium ions is disclosed. A diruthenium complex, [(L_IQ⁰)Ru₂Cl₅] ⋅ MeOH ( 1⋅ MeOH) is successfully isolated, in which L_IQ⁰ is the o-iminobenzoquinone form of 2-[(3-nitropyridin-2-yl)amino]phenol (L_APH₂). In 1 , L_IQ⁰ oriented towards one ruthenium centre is a non-innocent NO-donor redox ligand, whereas another oriented towards another ruthenium centre is an innocent pyridine-donor redox ligand. Complex 1 is a diruthenium(II,III) mixed-valence complex, [Ru^II(L_IQ⁰)(μ-Cl)₂Ru^III], with a minor contribution from the diruthenium(III,III) state. [Ru^III(L_ISQ^.−)(μ-Cl)₂Ru^III] contains L_ISQ^.−, which is the o-iminobenzosemiquinonate anion radical form of the ligand. Complexes 1 ⁻ and 1 ⁺ are diruthenium(II,II), [Ru^II(L_IQ⁰)(μ-Cl)₂Ru^II], and diruthenium(III,III), [Ru^III(L_IQ⁰)(μ-Cl)₂Ru^III], complexes, respectively, of L_IQ⁰. Complex 1 ²⁻ is a diruthenium(II,II) complex of the o-iminobenzosemiquinonate anion radical (L_ISQ^.−), [Ru^II(L_ISQ^.−)(μ-Cl)₂Ru^II], with a minor contribution from the diruthenium(III,II) form, [Ru^III(L_AP²⁻)(μ-Cl)₂Ru^II]. Complex 1 ²⁺ is a diruthenium(III,IV) mixed-valence complex of L_IQ⁰, [Ru^III(L_IQ⁰)(μ-Cl)₂Ru^IV]. Complexes 1 and 1 ²⁺ exhibit inter-valence charge-transfer transitions at λ=1300 and 1370 nm, respectively.     

北五味子中一种新的莽草酸衍生物的分离纯化及其含量测定

从北五味子中提取分离得到一种新的莽草酸衍生物, 经一维、二维核磁共振波谱(1D NMR, HMQC, HMBC)等数据解析, 鉴定为莽草酸正丁酯. 并采用ZORBAX Extend C18柱, 以乙腈-0.05%磷酸为流动相进行梯度洗脱, 检测波长为215 nm, 流速1.0 mL/min, 建立了北五味子中莽草酸正丁酯含量的高效液相色谱分析方法. 结果表明, 莽草酸正丁酯在2~65 μg/mL浓度范围内线性关系良好, 相关系数r=0.9999, 平均回收率为98.25%, 相对标准偏差(RSD)为1.55%, 表明本法简单准确, 重复性好.     

A Novel Oxazolidine Derivative from Xylose and Urea

Abstract

Reaction of equiraolecular amounts of xylose and urea in D₂O at 68 °C, monitored by ¹³C NMR, gave a six carbon xylofuranosyl derivative as the major product. No intermediate in the formation of this monomeric compound was detected. The xylofuranosyl derivative was subsequently isolated and purified from a six week 0.1 molar reaction of xylose and urea in H₂O. Its structure, α-d-xylo-furano[1,2-d]oxazolidin-2-one 1, was confirmed by elemental analysis, ¹H coupled and decoupled ¹³C NMR, ¹H NMR, IR and DCI-MS. The ¹H NMR and GC-MS (El, DCI) of the N-acetyl-di-O-acetyl derivative 2 were in agreement with structure 1.     

A New Glycine Derivative and a New Indole Alkaloid from the Fermentation Broth of the Plant Endophytic Fungus Pestalotiopsis podocarpi Isolated from the Chinese Podocarpaceae Plant Podocarpus macrophyllus

A new glycine derivative, podocarpiamide ( 1 ), a new indole alkaloid, 1‐methoxy‐1H‐indol‐3‐ethanol ( 2 ), together with two known compounds, 1‐methoxy‐1H‐indole‐3‐acetic acid ( 3 ) and methyl 1‐methoxy‐1H‐indole‐3‐acetate ( 4 ), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis podocarpi. Their structures were elucidated by extensive spectroscopic analysis including 1D‐ and 2D‐NMR (HSQC, HMBC, and COSY) and MS experiments. Compound 1 has an interesting unusual carbamic acid structure.