电子对生物分子DNA损伤可能性的分析

目的研究电子在人体组织等效材料中形成的“簇点”能量分布情况，以及簇点的产生对生物效应发生的意义。方法针对电子与人体组织等效介质作用的物理机理，利用蒙特卡罗(MC)方法，按一个个相互作用事件(电离、激发、弹性散射、Auger电子发射)方式真实模拟电子在介质中的径迹，通过对这些事件进行统计分析，得到相关结论。结果电子在穿过介质过程中，主要以簇点(大于30％)形式沉积能量，并且80％以上的簇点中的能量沉积在50eV以上；簇点的密集程度与电子能量、簇点直径密切相关，簇点中能量沉积也取决于辐射类型和能量。结论簇点中的能量沉积是诱发组织细胞核内DNA分子各种损伤的最主要因素。     

槲寄生毒素研究进展

槲寄生毒素是药用植物槲寄生中非常重要的抗肿瘤成分之一,是一类相对分子质量在5 000左右的含有46个氨基酸残基的碱性毒性多肽,富含半胱氨酸。这类多肽对多种肿瘤细胞系具有细胞毒活性,并具有免疫调节功效,还有显著的降压、抗心律失常等作用。着重对槲寄生毒素的结构、功能、构效关系等方面的研究结果与进展进行综述。     

Regioselective O/C phosphorylation of α-chloroketones: a general method for the synthesis of enol phosphates and β-ketophosphonates via Perkow/Arbuzov reaction

A regioselective O/C phosphorylation of α-chloroketones with trialkyl phosphites was performed for the first time, which employed solvent-free Perkow reaction and NaI-assisted Arbuzov reaction under mild conditions respectively. Versatile enol phosphates were prepared in good to excellent yields as well as β-ketophosphinates.

A highly regioselective O/C phosphorylation of α-chloroketones with trialkyl phosphites was developed in the preparation of enol phosphates and β-ketophosphonates.     

Probing the weak interaction of proteins with neutral and zwitterionic antifouling polymers

Protein–polymer interactions are of great interest in a wide range of scientific and technological applications. Neutral poly(ethylene glycol) (PEG) and zwitterionic poly(sulfobetaine methacrylate) (pSBMA) are two well-known nonfouling materials that exhibit strong surface resistance to proteins. However, it still remains unclear or unexplored how PEG and pSBMA interact with proteins in solution. In this work, we examine the interactions between two model proteins (bovine serum albumin and lysozyme) and two typical antifouling polymers of PEG and pSBMA in aqueous solution using fluorescence spectroscopy, atomic force microscopy and nuclear magnetic resonance. The effect of protein:polymer mass ratios on the interactions is also examined. Collective data clearly demonstrate the existence of weak hydrophobic interactions between PEG and proteins, while there are no detectable interactions between pSBMA and proteins. The elimination of protein interaction with pSBMA could be due to an enhanced surface hydration of zwitterionic groups in pSBMA. New evidence is given to demonstrate the interactions between PEG and proteins, which are often neglected in the literature because the PEG–protein interactions are weak and reversible, as well as the structural change caused by hydrophobic interaction. This work provides a better fundamental understanding of the intrinsic structure–activity relationship of polymers underlying polymer–protein interactions, which are important for designing new biomaterials for biosensor, medical diagnostics and drug delivery applications.     

3-甲基-4-丁酰胺基-5-硝基苯甲酸甲酯合成方法改进

目的:合成抗高血压药替米沙坦的重要中间体3-甲基-4-丁酰胺基-5-硝基苯甲酸甲酯.方法:以3-甲基-4-胺基苯甲酸甲酯为原料,在氯仿中与丁酰氯反应得-3-甲基-4-丁酰胺基苯甲酸甲酯,将此反应液简单干燥后,直接滴入-10℃～-5℃的95%发烟硝酸中进行硝化.结果:改进了目标化合物3-甲基-4-丁酰胺基-5-硝基苯甲酸甲酯的硝化方法,两步收率达88%.结论:本方法操作简单,可实现连续放大生产,提高了收率和效率.     

Adsorption capacity of kelp-like electrospun nanofibers immobilized with bayberry tannin for uranium(vi) extraction from seawater

The extraction of uranium(vi) from seawater is of paramount interest to meet the rapid expansion of global energy needs. A novel gelatin/PVA composite nanofiber band loaded with bayberry tannin (GPNB-BT) was used to extract uranium(vi) from simulated seawater in this study. It was fabricated by electrostatic spinning and crosslinking, and characterized by SEM, EDX, FTIR, and XPS. Batch experiments were carried out to investigate the adsorption of uranium(vi) onto GPNB-BT. Simultaneously, the regeneration–reuse process of the GPNB-BT was determined and illustrated here. The GPNB-BT exhibited excellent adsorption and regeneration performance, and a maximum adsorption capacity of 254.8 mg g⁻¹ toward uranium(vi) was obtained at 298.15 K, pH = 5.5. Further, the regeneration rate for uranium did not decrease significantly after five cycles. Moreover, even at an extremely low initial concentration of 3 μg L⁻¹ in the simulated seawater for 24 h, GPNB-BT showed an ultrahigh adsorption rate of more than 90% and adsorption capacity of 7.2 μg g⁻¹ for uranium. The high density of adjacent phenolic hydroxyl groups and the specific surface area of GPNB-BT improved the adsorption ability of GPNB-BT for uranium. Therefore, the GPNB-BT was shown to have an application prospect for the effective extraction of uranium(vi) from seawater.

A novel kelp-like gelatin/PVA composite nanofiber band loaded with bayberry tannin was fabricated for the extraction of uranium(vi) from seawater.     

回回蒜子正丁醇部位化学成分研究

目的对中草药回同蒜子(Rannunculus chinensis Bunge)的正丁醇部位进行化学成分研究.方法采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱和制备薄层等方法进行分离纯化,根据波谱数据和理化性质进行结构鉴定.结果分离鉴定出9个单体化合物,分别为:对羟基苯甲酸(1)、咖啡酸(2)、tachiosi...     

双抗体夹心生物素-亲和素ELISA法检测相思子毒素

目的 建立相思子毒素(abrin)的酶联免疫检测方法,为abrin临床诊断、中毒治疗、法医学鉴定等应用领域提供技术基础和参考依据.方法采用双抗体夹心生物素-亲和素ELISA法来检测微量abrin.结果该法检测abrin线性范围为0.125～31.25 μg/L,线性回归方程为y=0.52369X 0.51632(r=0.9816,P＜0.0001,n=9),检测限为0.125 μg/L.不同浓度蓖麻毒素(ricin)、葡萄球菌肠毒素(SEB)对检测结果基本无干扰,表明该法检测abrin具有很好的特异性.该法能用于abrin毒素污染水样、土样、食品、血液等模拟样品的分析,相对标准差为2.35%～4.14%,具有较好的重现性.结论 成功建立了夹心BA-ELISA法检测abrin,巧妙地将多克隆抗体的强富集能力、单克隆抗体的特异性以及生物素-亲和素系统的放大作用结合起来,达到了提高检测的灵敏度和特异性的目的 ,可适用于各种微量abrin样品的分析.     

兔血浆中纳曲酮LC-MS/MS分析方法的建立及其在纳曲酮-3-O-辛酸酯药动学研究中的应用

目的建立快速灵敏的液相色谱-串联质谱法,研究纳曲酮-3-O-辛酸酯在兔体内的药动学。方法纳曲酮辛酸酯进入体内后可快速水解为纳曲酮,因此纳曲酮-3-O-辛酸酯在兔体内的药动学参数可基于纳曲酮的血浆样品浓度检测而获得。血浆样品预处理采用甲基叔丁基醚液液萃取方法,以纳洛酮为内标。采用Agilent Zorbax SB-C18(100 mm×2.1 mm,3.5μm)型色谱柱,以甲醇/0.1%甲酸水溶液(50∶50,V/V)作为流动相,流速0.2 mL·min^-1;正离子多反应监测模式:纳曲酮(m/z 342.2→324.1),内标纳洛酮(m/z 328.1→310.2);选用12只新西兰大耳白兔,分别im给予等摩尔剂量的纳曲酮和纳曲酮-3-O-辛酸酯,于给药前及给药后不同时间点取血,所得的血药浓度数据采用非房室模型计算主要药动学参数。结果血浆内源性物质均不干扰样品峰,建立的LC-MS/MS体内分析测定方法的绝对回收率>76%,线性范围为0.5~100μg·L^-1(r²>0.999)。兔im给予纳曲酮1.0 mg·kg^-1后纳曲酮的主要药动学参数为:Tmax为(6.7±2.6)min,Cmax为(681±153)μg·L^-1,T_1/2为(40.0±7.5)min,AUC0-t为(25850±4642)μg·min·L^-1,MRTtn为(43.7±6.1)min。兔im给予等摩尔剂量的纳曲酮辛酸酯1.2 mg·kg^-1后,纳曲酮的主要药动学参数为:Tmax为(240.0±120.0)min,Cmax为(61.3±10.6)μg·L^-1,T_1/2为(295.7±133.0)min,AUC0-t为(30650±6775)μg·min·L^-1,MRTtn为(406.1±5.0)min。结论本研究建立的LC-MS/MS方法灵敏度高,适用于纳曲酮-3-O-辛酸酯的药动学研究。与im等摩尔剂量的纳曲酮相比,纳曲酮-3-O-辛酸酯的达峰时间和半衰期显著延长,达峰浓度显著降低。     

一种新槲寄生蛋白A链的基因克隆及序列分析

目的克隆槲寄生蛋白具有N-糖苷酶活性的毒性A链。方法利用硫酸铵沉淀、亲和色谱和离子交换色谱法,从吉林产槲寄生[Viscum coloratum(Komar．)Nakai]中提取、分离、纯化其中具有半乳糖结合活性的蛋白质成分。采用SDS-PAGE分析纯化的蛋白样品,蛋白条带转印至PVDF膜后,Edman降解法测定肽链的N端序列。由测序结果设计引物,利用RT-PCR方法克隆一种蛋白A链的基因。结果从槲寄生中纯化出两种高毒性的蛋白质新成分CM-1、CM-2,其中CM-1 A链被克隆并测序,其与白果槲寄生蛋白A链的同源性较高。结论一种新槲寄生蛋白A链的基因被成功克隆。