Laminar flow mediated continuous single-cell analysis on a novel poly(dimethylsiloxane) microfluidic chip

A novel microfluidic chip with simple design, easy fabrication and low cost, coupled with high-sensitive laser induced fluorescence detection, was developed to provide continuous single-cell analysis based on dynamic cell manipulation in flowing streams. Making use of laminar flows, which formed in microchannels, single cells were aligned and continuously introduced into the sample channel and then detection channel in the chip. In order to rapidly lyse the moving cells and completely transport cellular contents into the detection channel, the angle of the side-flow channels, the asymmetric design of the channels, and the number, shape and layout of micro-obstacles were optimized for effectively redistributing and mixing the laminar flows of single cells suspension, cell lysing reagent and detection buffer. The optimized microfluidic chip was an asymmetric structure of three microchannels, with three microcylinders at the proper positions in the intersections of channels. The microchip was evaluated by detection of anticancer drug doxorubicin (DOX) uptake and membrane surface P-glycoprotein (P-gp) expression in single leukemia K562 cells. An average throughput of 6–8 cells min⁻¹ was achieved. The detection results showed the cellular heterogeneity in DOX uptake and surface P-gp expression within K562 cells. Our researches demonstrated the feasibility and simplicity of the newly developed microfluidic chip for chemical single-cell analysis.     

DBU: An Efficient Base Catalyst for Synthesis of the New Oxazolo[5,4-d]pyrimidine Derivatives

New types of oxazolo[5,4-d]pyrimidines were synthesized via 1,8-diazabicyclo[5,4,0]undec-7-ene-catalyzed heteroannulation of 2-substituted 5-amino-4-cyano-1,3-oxazoles with various isothiocyanates.     

Synthesis,Characterization, and Biological Evaluation of Some Novel Thiosemicarbazones as Possible Antibacterial and Antioxidant Agents

Abstract

The synthesis and characterization of 18 novel thiosemicarbazones have been investigated as part of a research program on development of compounds with antibacterial and antioxidant activities. Among the tested compounds, 2-(4-hydroxybenzylidene)-N-[4-(trifluoromethoxy)phenyl]hydrazine carbothioamide (3g) and 2-(thiophen-2-ylmethylidene)-N-[4-(morpholin-4-yl)phenyl]hydrazine carbothioamide (4b) showed excellent inhibition potency at low concentration (0.5 μg/mL) against Gram-positive pathogens (Enterococcus faecalis and Staphylococcus aureus). All tested compounds were also found to possess antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.]     

Synthesis and Crystal Structure of Methyl 2-(Diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate

The title compound, methyl 2-(diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, 1H- and 13C-NMR spectroscopy and elemental analysis. These experimental studies were supported by quantum mechanical calculations. The structure was solved in monoclinic, space group P21/c with a = 9.573(3), b = 19.533(7), c = 9.876(3), β = 92.35(4)°, V = 1845.2(10)3, T = 85(2) K, Z = 4, R = 0.040 and wR = 0.089 for 6424 observed reflections withI>2σ(I).     

Facile synthesis of thiourea derivatives in ionic liquid

The synthesis of cinnamoyl thiourea derivatives from cinnamoyl isothiocyanate (CIT) with substituted aniline (RC6H4NH2) was investigated in the mostly used ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4]. Significant enhance-ments in reactivity, yield and reaction rate were achieved. The products could be recovered by simple filtration. [Bmim][BF4] couldbe recycled simply by removing water under vacuum and reused at least 9 times without significant decrease in activity.     

2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖基异硫氰酸酯的合成及晶体结构

采用葡萄糖作原料经乙酰化、溴化和硫氰酸化三步合成了2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖基异硫氰酸酯,培养出了单晶,用X射线衍射分析了其晶体结构.结果表明,晶体为正交晶系,P212121空间群,a=0.72624(2)nm,b=1.17508(2)nm,c=2.17210(5)nm,α=β=γ=90°,V=1.85365(7)nm,Z=4,R=0.0531,wR=0.1359.     

Direct Route to a New Class of Acrylamide Thioglycosides and Their Conversions to Pyrazole Derivatives

A new method for preparation of a new class of acrylamide thioglycosides via a one-pot reaction of potassium 2-cyanoethylene-1-thiolate salts with 2,3,4,6-tetra-O-acetyl-α-D-gluco- and galactopyranosyl bromides has been studied. The E-configuration of these thioglycosides were proven by their transformations to the corresponding 5-aminopyrazoles.     

超高效液相色谱-串联质谱法定性和高效液相色谱法定量分析天南星中氨基酸成分

为建立中药材中氨基类极性非紫外活性成分的定性与定量分析方法,以中药材天南星为研究对象,采用柱前衍生化技术,以异硫氰酸苯酯(PITC)为衍生化试剂,经C₁₈色谱柱(100 mm×2.1 mm, 3.5 μm)分离和超高效液相色谱-串联质谱(UHPLC-MS/MS)分析,共解析了天南星中20个成分,包括18个氨基酸和2个胺类化合物。经优化衍生化条件,应用高效液相色谱法(HPLC),以Diamonsil C₁₈色谱柱(250 mm×4.6 mm, 5 μm)分离,以乙腈和0.05 mol/L醋酸铵-醋酸缓冲液(pH 6.5)为流动相,梯度洗脱,在254 nm下检测,建立了同时测定15种氨基酸含量的方法,经方法学考察符合含量测定要求。谷氨酸、色氨酸在2~100 mg/L范围内、精氨酸在6~300 mg/L范围内、其余各氨基酸在0.8~40 mg/L范围内均呈良好的线性关系,相关系数均不小于0.9995;平均回收率在95%~105%之间,RSD均小于3%;并成功应用于12批中药材的测定。本方法简便、灵敏、准确,具有可操作性,可用于快速鉴定中药中的氨基类成分以及进行含量测定。