Three New Phenyl Ether Derivatives from Aspergillus carneus HQ889708

Three new phenyl ether derivatives, 3‐hydroxy‐5‐(3‐hydroxy‐5‐methylphenoxy)benzoic acid ( 1 ), 3,4‐dihydroxy‐5‐(3‐hydroxy‐5‐methylphenoxy)benzoic acid ( 2 ), 3‐[3‐hydroxy‐5‐(hydroxymethyl)phenoxy]‐5‐methylphenol ( 3 ), and three known compounds 4 – 6 were obtained from the fermentation broth of Aspergillus carneus HQ889708, which was isolated from sea water from South China Sea. The structures of compounds 1 – 3 were established on the basis of spectroscopic methods including ESI‐MS and NMR. Compounds 4 – 6 were reported before as synthesized products, herein, they are reported from nature for the first time.     

Prognostic Metabolite Biomarkers for Soft Tissue Sarcomas Discovered by Mass Spectrometry Imaging

Metabolites can be an important read-out of disease. The identification and validation of biomarkers in the cancer metabolome that can stratify high-risk patients is one of the main current research aspects. Mass spectrometry has become the technique of choice for metabolomics studies, and mass spectrometry imaging (MSI) enables their visualization in patient tissues. In this study, we used MSI to identify prognostic metabolite biomarkers in high grade sarcomas; 33 high grade sarcoma patients, comprising osteosarcoma, leiomyosarcoma, myxofibrosarcoma, and undifferentiated pleomorphic sarcoma were analyzed. Metabolite MSI data were obtained from sections of fresh frozen tissue specimens with matrix-assisted laser/desorption ionization (MALDI) MSI in negative polarity using 9-aminoarcridine as matrix. Subsequent annotation of tumor regions by expert pathologists resulted in tumor-specific metabolite signatures, which were then tested for association with patient survival. Metabolite signals with significant clinical value were further validated and identified by high mass resolution Fourier transform ion cyclotron resonance (FTICR) MSI. Three metabolite signals were found to correlate with overall survival (m/z 180.9436 and 241.0118) and metastasis-free survival (m/z 160.8417). FTICR-MSI identified m/z 241.0118 as inositol cyclic phosphate and m/z 160.8417 as carnitine.

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Single-Molecule Photoactivation FRET: A General and Easy-To-Implement Approach To Break the Concentration Barrier

Single-molecule fluorescence resonance energy transfer (sm-FRET) has become a widely used tool to reveal dynamic processes and molecule mechanisms hidden under ensemble measurements. However, the upper limit of fluorescent species used in sm-FRET is still orders of magnitude lower than the association affinity of many biological processes under physiological conditions. Herein, we introduce single-molecule photoactivation FRET (sm-PAFRET), a general approach to break the concentration barrier by using photoactivatable fluorophores as donors. We demonstrate sm-PAFRET by capturing transient FRET states and revealing new reaction pathways during translation using μm fluorophore labeled species, which is 2–3 orders of magnitude higher than commonly used in sm-FRET measurements. sm-PAFRET serves as an easy-to-implement tool to lift the concentration barrier and discover new molecular dynamic processes and mechanisms under physiological concentrations.     

1,5-二取代六氢三嗪-2-N-硝基亚胺的合成和杀虫活性的测定

以S-甲基-N-硝基异硫脲、取代苄胺为原料,依次经过亲核取代反应,Mannich反应合成了12个未见文献报道的1,5-二取代六氢三嗪-2-N-硝基亚胺(2a～21),结构经1H NMR,IR和元素分析确证.初步的杀虫活性测试表明,该类化合物在500mg/L时对稻飞虱具有较好的杀虫活性.     

Surface modification of PDMS by surface-initiated atom transfer radical polymerization of water-soluble dendronized PEG methacrylate

The current paper reports the synthesis of a highly hydrophilic, antifouling dendronized poly(3,4,5-tris(2-(2-(2-hydroxylethoxy)ethoxy)ethoxy)benzyl methacrylate) (PolyPEG) brush using surface initiated atom transfer radical polymerization (SI-ATRP) on PDMS substrates. The PDMS substrates were first oxidized in H₂SO₄/H₂O₂ solution to transform the Si-CH₃ groups on their surfaces into Si-OH groups. Subsequently, a surface initiator for ATRP was immobilized onto the PDMS surface, and PolyPEG was finally grafted onto the PDMS surface via copper-mediated ATRP. Various characterization techniques, including contact angle measurements, attenuated total reflection infrared spectroscopy, and X-ray photoelectron spectroscopy, were used to ascertain the successful grafting of the PolyPEG brush onto the PDMS surface. Furthermore, the wettability and stability of the PDMS-PolyPEG surface were examined by contact angle measurements. Anti-adhesion properties were investigated via protein adsorption, as well as bacterial and cell adhesion studies. The results suggest that the PDMS-PolyPEG surface exhibited durable wettability and stability, as well as significantly anti-adhesion properties, compared with native PDMS surfaces. Additionally, our results present possible uses for the PDMS-PolyPEG surface as adhesion barriers and anti-fouling or functional surfaces in biomedical applications.     

Coordination assembly and characterization of red-emitting europium (III) organic/inorganic polymeric hybrids

Novel luminescent ternary organic-inorganic-polymeric hybrid material has been assembled by Eu(3+) complex incorporating into poly (methyl methacrylate) (PMMA) matrix. The functionalized silylated precursor PDC-Si derived from PDC (2,6-pyridinedicarboxylic acid chloride) behaves as the coordination units of Eu(3+) ion. The organic polymer was introduced into the system by directly dissolving PMMA in solution of Eu(PDC-Si)(3) complex and N-N-Dimethyl Formamide (DMF) with subsequent addition of tetraethoxysilane to promote hydrolysis and condensation. The structure and photophysical properties of the resulting hybrids are characterized by Fourier transform infrared spectra, X-ray diffraction (XRD), scanning electronic microscopy and photoluminescence spectra. The luminescence quantum yield was calculated based on the emission spectra and luminescence lifetimes. XRD reveals its amorphous structure. Efficient energy transfer process occurs between PMMA and Eu(3+), and replacement of water molecule by PMMA in the first coordination sphere was confirmed by comparing with the binary hybrid.     

以微孔β沸石为硅铝源合成强酸性介孔分子筛

以微孔β沸石为硅铝源,通过碱处理和以十六烷基三甲基溴化铵为模板剂,合成了具有较强酸性的六方结构介孔分子筛材料B-MCM-41,并采用XRD、N₂吸附脱附、FT-IR、²7Al MAS NMR、HRTEM和水热处理等手段对其进行了结构表征,采用NH₃-TPD对其进行了酸性表征。实验结果表明,B-MCM-41具有明显强于常规介孔分子筛的酸性,且在C⁺₁0混合芳烃加氢脱烷基化反应中表现出了良好的催化性能。这主要是由于碱溶液将β沸石降解为沸石结构单元,在表面活性剂作用下五元环次级结构单元被引入了介孔铝硅酸盐B-MCM-41的结构。     

Fragmentation patterns of novel dithiocarbamate derivatives with pharmaceutical activity under electrospray ionization tandem mass spectrometry conditions

The fragmentation patterns of a novel series of dithiocarbamate derivatives with pharmaceutical activity were investigated by positive ion electrospray ionization mass spectrometry in conjunction with tandem mass spectrometry (ESI-MS(n)). In the gas phase, the dithiocarbamate protonated molecules containing the piperazinium moiety undergo losses of bromide to form the piperazinium cation by ionization, followed by subsequent losses of methyl bromide, ring opening and rearrangement of piperazinium. Furthermore, the dithiocarbamate derivatives and their intermediates both undergo cleavage of the C-S bond to produce two common fragment ions. The different fragmentation observed for these compounds facilitated their identification and could be valuable in the further study of their metabolic pathways as prodrugs.     

SSZ-33分子筛的合成、表征及其对汽车尾气中碳氢化合物的捕集性能

采用碘化N,N,N-三甲基-8-氨基-三环[5.2.1.02.6]癸烷为结构导向剂, 通过过程控制方法, 经3-4 d成功合成了高性价比的B-SSZ-33分子筛. 以B-SSZ-33为母体, 经过Al(NO3)3溶液后处理制得了Al-SSZ-33分子筛. 采用X射线衍射(XRD), 傅里叶变换红外(FT-IR)光谱, 扫描电子显微镜(SEM), 热重(TG)分析, 电感耦合等离子体原子发射光谱(ICP-AES), N2吸附/脱附, 27Al核磁共振(27Al NMR)和NH3程序升温脱附(NH3-TPD)等手段对合成的B-SSZ-33、Al-SSZ-33样品进行了物理化学性能表征. 并以甲苯作为汽车尾气中碳氢化合物的探针分子, 通过甲苯程序升温脱附测试来考察样品的碳氢捕集性能. 结果表明: 后处理过程中Al同晶取代B, 从而制得了含骨架Al的Al-SSZ-33; 在甲苯的程序升温脱附测试中, 由于Al-SSZ-33相对于B-SSZ-33具有较强的酸性位, 且表面孔口由于骨架外硅铝物种的修饰, 限制了甲苯的扩散, 致使脱附速率最大时的温度(Tmax)和脱附最终的温度(Tend)均升高, 从而形成了新型汽车尾气捕集催化剂的雏形.