分散固相萃取-液相色谱-串联质谱法同时快速测定化妆品中81种糖皮质激素

建立了分散固相萃取-液相色谱-串联质谱同时快速测定化妆品中81种非法添加糖皮质激素(GCs)的分析方法。样品用水分散后加乙腈超声提取,经十八烷基键合硅胶(C18)和N-丙基乙二胺(PSA)净化,待测物选用具有多重色谱保留模式的Poroshell 120 PFP色谱柱(100 mm×2.1 mm,2.7μm)分离,以0.2%(v/v)乙酸水溶液-乙腈为流动相梯度洗脱,在电喷雾正离子模式下以动态多反应监测方式测定,内标法定量。81种待测物在各自的浓度范围内线性关系良好,相关系数均大于0.99,在3个不同的添加水平下,平均回收率为68.8%~105.3%,RSD为2.9%~13.1%(n=6),方法的检出限(S/N≥3)和定量限(S/N≥10)分别为0.002~0.006μg/g和0.005~0.020μg/g。筛查了137个化妆品样品,发现16个阳性样品,含量为16.9~158μg/g。结果表明,该法简便快速,灵敏可靠,适用于化妆品中81种GCs的同时快速定性定量筛查分析。     

气相色谱-串联质谱法同时测定卷烟滤嘴中15种多环芳烃

建立了气相色谱-串联质谱同时检测卷烟滤嘴中15种多环芳烃的方法。卷烟滤嘴用二氯甲烷振荡萃取后,经0.22μm有机相滤膜过滤,采用DB-5MS色谱柱(30 m×0.25 mm,0.25μm)进行分离,电子轰击源、正离子模式下以多反应监测模式进行检测,内标法进行定量。15种多环芳烃(苊烯、苊、芴、菲、蒽、荧蒽、芘、苯并[a]蒽、屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、二苯并[a,h]蒽、苯并[g,h,i]苝和茚并[1,2,3-c,d]芘)的线性关系良好,相关系数(R~2)为0.991 4~0.999 9。15种多环芳烃在低、中、高3个添加水平下的平均回收率为81.6%~111.2%;除了芴在低添加水平时相对标准偏差为19.2%外,其他相对标准偏差均小于16%。15种多环芳烃的检出限为0.02~0.24 ng/滤嘴,定量限为0.04~0.80 ng/滤嘴。方法前处理简便,具有快速、准确、灵敏度高及重复性好的优点,适用于卷烟滤嘴中多环芳烃的分析。     

L-苯丙氨酸衍生物的一锅法合成及其抗/促凝活性

氨基酸及其衍生物在止血/抗凝活性方面有一定的应用。以L-苯丙氨酸为起始原料,经磺化引入磺酸基,再与甲醇、乙醇、丙醇、异丙醇和正丁醇脱水酯化,一锅法合成了6种未见报道的L-苯丙氨酸的磺酸酯类衍生物(L1~L6),以期获得具有的较强血液生理活性的潜在药物。实验中采用了质谱、核磁共振进行结构表征。该合成方法产率高(78%~95%),后处理简单,不失为合成该类衍生物的好方法。衍生物的凝血四项实验表明:抗促凝效果是内源性和外源性凝血途径共同作用的结果。血浆复钙实验表明:衍生物均具有一定的抗凝活性,其抗凝效果随浓度变化而变化,但是随R链的长度增加,抗凝效果并未见规律性。衍生物的抗凝活性主要受磺酸基及酯基的影响,因此在设计合成抗血栓化合物时可以考虑引入磺酸基及酯类基团。     

四氯化碳液相催化加氢制氯仿多元金属催化剂的制备及其催化性能

以贵金属M(=Pd,Pt)为主要活性成分,掺加过渡金属Fe和Ni作为助剂,采取浸渍和氢气还原法制备了椰壳活性炭(ACcs)负载的单元金属(M/ACcs)、二元金属(M-Ni/ACcs、M-Fe/ACcs)和三元金属(M-Ni-Fe/ACcs)系列催化剂;通过CC_l4液相催化加氢制氯仿反应考察了这些催化剂的催化活性和选择性。结果表明,Pd基催化剂的催化活性明显高于Pt基催化剂,但后者对氯仿的选择性优于前者;在前5 h加氢反应时段,两系列催化剂的活性顺序为:Pd-Ni-Fe/ACcsPd-Fe/ACcsPd/ACcsPd-Ni/ACcs和Pt/ACcs≈Pt-Fe/ACcsPt-Ni/ACcsPt-Ni-Fe/ACcs;总体上,引入Fe对于催化性能的改善效果要优于Ni,Ni的单独引入则会不同程度地降低催化活性。综合考量成本、活性和选择性等因素,优选Pd-Ni-Fe/ACcs作为催化剂,在393 K下反应5 h,可实现CC_l497.6%的转化率以及接近100%氯仿的选择性。     

4-甲基-4-氮杂-21E-苯亚甲基-5-孕烯-3,20-二酮类化合物的合成

报道了一种以KF/Al_2O_3催化合成4-甲基-4-氮杂-21E-苯亚甲基-5-孕烯-3,20-二酮类化合物的方法。以黄体酮为原料,经NaIO_4/KMnO_4氧化裂解、胺解关环得到重要中间体4-甲基-4-氮杂-5-孕烯-3,20-二酮,后者在KF/Al_2O_3催化下经克莱森缩合得到目标产物。考察了不同的催化剂、反应温度、催化剂用量对目标产物的影响。条件优化的结果为:n(3)∶n(KF/Al_2O_3)=1∶1,回流状态下反应4 h,产率为56%~68%。此方法适用性好,为4-氮杂甾体苯亚甲基衍生物的合成提供了一种方便而有效的方法。     

高效液相色谱-飞行时间质谱联用法分析人参及人参皂苷与山楂配伍过程中的水解行为

利用高效液相色谱-飞行时间质谱联用的方法,分别对人参配伍山楂前后人参皂苷的变化进行分析,同时对人参皂苷Re、Rg1、Rb1、Rd与山楂配伍的水解规律进行系统研究,并与单独煎煮液、仿山楂配伍pH值煎煮液的水解产物进行比较,结果发现人参与山楂配伍后人参皂苷Rg1、Rb1含量明显减少,而人参皂苷Re、Rd、Rg2、Rg3、F2、Rh1含量明显增加,其中人参皂苷Re与山楂配伍后水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2,仿山楂配伍pH值水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2、Rg4、Rg6;人参皂苷Rg1与山楂配伍后水解产物为20(S)-Rh1、20(R)-Rh1,仿山楂pH值水解产物为20(S)-Rh1、20(R)-Rh1、Rh4、Rk3;人参皂苷Rb1与山楂配伍后水解产物为Rd、20(S)-Rg3,仿山楂pH值水解产物为F2、20(S)-Rg3;人参皂苷Rd与山楂配伍后水解产物为F2、20(S)-Rg3、20(R)-Rg3,仿山楂pH值水解产物为20(S)-Rg3、20(R)-Rg3。研究表明,不同人参皂苷和山楂配伍后与仿山楂pH值的水解产物并不相同,人参与山楂配伍改变了人参皂苷成分的种类及含量。本研究为临床方剂中人参与山楂配伍后成分的变化提供物质基础数据。     

Precisely installing gold nanoparticles at the core/shell interface of micellar assemblies of triblock copolymers

Two reduction-cleavable ABA triblock copolymers possessing two disulfide linkages, PMMA-ss-PMEO₃MA-ss-PMMA and PDEA-ss-PEO-ss-PDEA were synthesized via facile substitution reactions from homopolymer precursors, where PMMA, PMEO₃MA, PDEA, and PEO represent poly(methyl methacrylate), poly(tri(ethylene glycol) monomethyl ether methacrylate, poly(2-(diethylamino)ethyl methacrylate), and poly(ethylene oxide), respectively. Spherical micelles were obtained through supramolecular self-assembly of these two triblock copolymers in aqueous solutions. The resultant micelles with abundant disulfide bonds could serve as soft templates and precisely accommodate gold nanoparticles in the core/shell interface as a result of the formation of Au-S bonds.     

Polyethylene glycol phospholipids encapsulated silicon 2,3-naphthalocyanine dihydroxide nanoparticles (SiNcOH-DSPEPEG(NH2) NPs) for single NIR laser induced cancer combination therapy

Currently, the combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a powerful technique for cancer treatment. However, most examples of combined PTT and PDT reported use multi-component nanocomposites under excitation of separate wavelength, resulting in complex treatment process. In this work, a novel theranostic nanoplatform (SiNcOH-DSPE-PEG(NH₂) NPs) has been successfully developed by coating silicon 2,3-naphthalocyanine dihydroxide (SiNcOH) with DSPE-PEG and DSPE-PEG-NH₂ for photoacoustic (PA) imaging-guided PTT and PDT tumor ablation for the first time. The as-prepared single-agent SiNcOH-DSPE-PEG(NH₂) NPs not only have good water solubility and biocompatibility, but also exhibit high photothermal conversion efficiency and singlet oxygen generation capability upon 808 nm NIR laser irradiation. In addition, owing to their high absorption at NIR region, the SiNcOH-DSPE-PEG(NH₂) NPs can also be employed as an effective diagnostic nanoagent for photoacoustic (PA) imaging. In vitro and in vivo experimental results clearly indicated that the simultaneously combined PTT and PDT under the guidance of PA imaging with single NIR laser excitation can effectively kill cancer cells or eradicate tumor tissues. Taking facile synthesis and high efficiency in cancer treatment by SiNcOH-DSPE-PEG(NH₂) NPs into consideration, our study provides a promising strategy to realize molecular imaging-guided combination therapy.     

Hydrothermal synthesis of peony-like CuO micro/nanostructures for high-performance lithium-ion battery anodes

The peony-like CuO micro/nanostructures were fabricated by a facile hydrothermal approach. The peonylike CuO micro/nanostructures about 3-5 μm in diameter were assembled by CuO nanoplates. These CuO nanoplates, as the building block, were self-assembled into multilayer structures under the action of ethidene diamine, and then grew into uniform peony-like CuO architecture. The novel peony-like CuO micro/nanostructures exhibit a high cycling stability and improved rate capability. The peony-like CuO micro/nanostructures electrodes show a high reversible capacity of 456 mAh/g after 200 cycles, much higher than that of the commercial CuO nanocrystals at a current 0.1 C. The excellent electrochemical performance of peony-like CuO micro/nanostructures might be ascribed to the unique assembly structure, which not only provide large electrode/electrolyte contact area to accelerate the lithiation reaction, but also the interval between the multilayer structures of CuO nanoplates electrode could provide enough interior space to accommodate the volume change during Li~+ insertion and de-insertion process.     

Hβ/Al-SBA-15介微孔复合分子筛负载Ni-W催化剂对萘加氢裂化制BTX的催化性能

采用后合成法制备Hβ/Al-SBA-15复合分子筛,利用XRD、N_2吸附、Py-IR、NH_3-TPD、SEM和TEM等手段进行表征。用浸渍法将Ni-W活性组分担载在Hβ/Al-SBA-15载体上,制备Ni-W/Hβ/Al-SBA-15催化剂,以萘为模型化合物,考察该催化剂的加氢裂化性能。结果表明,所合成的Hβ/Al-SBA-15复合分子筛既有介孔结构又有微孔结构,并同时具有B酸和L酸中心,酸性强于SBA-15。具有适度酸性位和介微孔结构的Ni-W/Hβ/Al-SBA-15催化剂,对萘加氢裂化具有较高的萘转化率和BTX选择性,分别为96%和61.1%。