Trichodermatides A-D, novel polyketides from the marine-derived fungus Trichoderma reesei

Four new polyketide derivatives, Trichodermatides A-D (1-4) were isolated from the marine-derived fungus Trichoderma reesei. Trichodermatide A (1) is an unprecedented example of a polyketide with a ketal-containing pentacyclic skeleton. The chemical structures and absolute configurations of compounds 1-4 were elucidated by extensive spectroscopic methods, especially 2D NMR and CD spectral analysis, and supported by their proposed biosynthesis pathway. The cytotoxicity of 1-4 was evaluated against A375-S2 human melanoma cell line.     

流动注射编结反应器在线分离富集技术在原子光谱中的应用

综述了流动注射编结反应器在线富集技术在原子光谱中的研究进展,重点突出编结反应器富集的相关机理和不同富集方式的实际分析应用,并对流动注射编结反应器富集分离的应用前景进行了展望。引用文献59篇。     

导电氧化物AZO对尖晶石型LiMn2O4高温性能的改善及研究

采用溶胶凝胶法对尖晶石型LiMn₂O₄正极材料进行铝掺杂氧化锌(AZO)包覆改性,并通过XRD、SEM、EDS、TEM、EIS、ICP -AES和充放电测试等手段对其结构,形貌及电化学性能进行表征。研究结果表明,AZO包覆层有效的阻止了LiMn₂O₄颗粒和电解液的直接接触,抑制了高温下锰溶解,明显改善了LiMn₂O₄的高温循环性能。1.5wt% AZO包覆的LiMn₂O₄正极材料在高温(55℃)1C时,首次放电比容量为114 mAh·g^-1,经过100次循环后,容量保持率仍高达95.4%,远高于未包覆LiMn₂O₄的70.6%。此外,1.5wt% AZO包覆的LiMn₂O₄表现出了优越的大倍率放电性能,在10C下放电比容量能达到99 mAh·g^-1。     

铋对铅铋合金表面氧化膜生成的影响

铋对铅铋合金表面氧化膜生成的影响;铋;PbO;PbO+PbO·PbSO4;PbO2;蓄电池     

The Concentration of Hydrogen Peroxide Generated during Aggregation of a-Synuclein in vitro Is Lower than 5 nmol/L

Introduction a-Syn is a major component of Lewy bodies and Lewy neurites in the brains of patients with neurode-generative diseases, such as Parkinson抯 disease, the Lewy body variant of Alzheimer抯 disease, dementia with Lewy bodies and multiple system atrophy.1,2 a-Syn is prone to aggregate in vitro and the aggregates appear to be toxic to neurons, though the reason for the cyto-toxicity remains unclear.3-6 Previous studies by electron spin resonance (ESR) showed that a-Syn could liberat…     

Determination of aluminum in environmental and biological samples by reversed-phase high-performance liquid chromatography via pre-column complexation with morin

Morin was used as a pre-column reagent for the determination of aluminum by RP-HPLC with fluorescence detection. This method has been successfully applied to direct determination of trace Al in environmental and biological samples. The response was linear from 6 x 10(-9) to 6 x 10(-5) M with a detection limit of 2 x 10(-9) M. In addition, the different Al complexes with morin were separated by the proposed HPLC procedure and their coordination ratios were depicted by molar-ratio method. The results showed that 1:1 and 2:1 Al-morin complexes formed.     

Deep Eutectic Solvent-Based HS-SME Coupled with GC for the Analysis of Bioactive Terpenoids in Chamaecyparis obtusa Leaves

Headspace-solvent microextraction (HS-SME) was developed as a solvent-minimized extraction technique, but few studies have examined the applications of deep eutectic solvents (DESs) to the HS-SME of bioactive compounds. In this study, HS-SME was developed for the extraction of bioactive compounds using DESs as extraction solvents. DESs, which were prepared by mixing choline chloride (ChCl) with ethylene glycol (EG) at different ratios, were applied to the extraction of three terpenoids from Chamaecyparis obtusa leaves by HS-SME. The ChCl/EG ratio in the DESs, HS-SME conditions, such as the extraction temperature and extraction time, and sample/DES ratio were optimized. All extracts were analyzed by GC. Under optimized conditions, the limits of detection were 2.006 ng mL^?1 for linalool, 3.150 ng mL^?1 for α-terpineol and 2.129 ng mL^?1 for terpinyl acetate. The relative standard deviations were in the range of 2.1–6.8 %. The recoveries of the three terpenoids were in the range of 79.4–103 %. HS-SME is simple and rapid compared to heat reflux extraction and ultrasonic extraction. Moreover, DESs can be used in HS-SME for the extraction of a range of bioactive and volatile compounds.     

导电氧化物AZO对尖晶石型LiMn_2O_4高温性能的改善及研究

采用溶胶凝胶法对尖晶石型LiMn2O4正极材料进行铝掺杂氧化锌(AZO)包覆改性,并通过XRD、SEM、EDS、TEM、EIS、ICP-AES和充放电测试等手段对其结构,形貌及电化学性能进行表征。研究结果表明,AZO包覆层有效的阻止了LiMn2O4颗粒和电解液的直接接触,抑制了高温下锰溶解,明显改善了LiMn2O4的高温循环性能。1.5wt%AZO包覆的LiMn2O4正极材料在高温(55℃)1C时,首次放电比容量为114 mAh·g-1,经过100次循环后,容量保持率仍高达95.4%,远高于未包覆LiMn2O4的70.6%。此外,1.5wt%AZO包覆的LiMn2O4表现出了优越的大倍率放电性能,在10C下放电比容量能达到99 mAh·g-1。     

两个基于呋喃-3-酮配体的钯(Ⅱ)化合物的合成、晶体结构和光谱性质

合成了2个钯（Ⅱ）化合物Pd（L¹）₂（1）和Pd（L²）₂（2）,（L¹=（Z）-4-（（对甲苯胺基）亚甲基）-2,2,5,5-四甲基二氢呋喃-3（2H）-酮,L²=（Z）-4-（（对甲苯胺基）亚甲基）-2,2,5,5-四甲基二氢呋喃-3（2H）-酮）,并利用元素分析,红外光谱,核磁共振氢谱,紫外光谱和X射线单晶衍射等手段对其结构进行了表征。X射线单晶衍射表明,化合物1和2中包含多种弱相互作用。在化合物1中,呋喃环上氧原子和苯环上的甲基氢原子之间形成氢键,氢键桥联分子形成了一条平行于c轴方向的一维链结构,一维链之间通过C-H…H-C和C-H…C弱相互作用形成了三维超分子结构。在化合物2中,分子之间通过C-H…H-C和C-H…C弱相互作用形成了一个二维层状结构。