MALDI质谱技术在酶活性分析中的应用

酶作为生物催化剂参与很多重要的生理过程,同时也是一类重要的生物分子。酶的活性分析对于疾病诊断和治疗具有重要意义。基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)具有操作简单、分析速度快、灵敏度高和易于实现高通量分析的特点,已被广泛用于各种组学研究和生物分子的检测,在酶的检测和活性分析中亦发挥了重要作用。该文综述了国内外利用MALDI-TOF MS分析酶活性和进行药物筛选的策略,总结了各种方法的优缺点,提出了MALDI质谱技术在酶活性分析领域存在的问题和挑战,并对其发展前景进行了展望。     

罂粟碱检测方法研究进展

罂粟碱和中药罂粟壳作为临床上的常见药物及作为食品添加剂的非法使用,吸引了众多研究人员对罂粟碱检测方法的研究.本文概述了罂粟碱的结构特点和作为药物的使用情况,系统介绍了与其相关的各种检测方法,包括化学分析方法、光谱分析方法、电化学分析方法、色谱和毛细管电泳分离分析方法和免疫分析方法等,并对其检测方法的发展趋势进行了评述和展望.     

Ultrasonic assisted extraction,characterization and gut microbiota-dependent anti-obesity effect of polysaccharide from Pericarpium Citri Reticulatae 'Chachiensis'

Pericarpium Citri Reticulatae 'Chachiensis' (PCRC), the premium aged pericarps of Pericarpium Citri Reticulatae, is widely used in traditional Chinese medicines with a diversity of promising bioactivity. Herein we report the extraction, characterization and underlying mechanism of anti-metabolic syndrome of an arabinan-rich polysaccharide from PCRC (PCRCP). This polysaccharide was obtained in a 7.0% yield by using ultrasound-assisted extraction under the optimized conditions of 30 mL/g liquid-to-solid ratio, 250 W ultrasound power for 20 min at 90 °C with pH 4.5. The PCRCP with an average molecular weight of 122.0 kDa, is mainly composed of D-galacturonic acid, arabinose and galactose, which may link via 1,4-linked Gal(p)-UA, 1,4-linked Ara(f) and 1,4-linked Gal(p). Supplementation with PCRCP not only effectively alleviated the weight gain, adiposity and hyperglycemia, but also regulated the key metabolic pathways involved in the de novo synthesis and β-oxidation of fatty acid in high-fat diet (HFD)-fed mice. Furthermore, PCRCP treatment caused a significant normalization in the intestinal barrier and composition of gut microbiota in mice fed by HFD. Notably, PCRCP selectively enriched Lactobacillus johnsonii at the family-genus-species levels, a known commensal bacterium, the level of which was decreased in mice fed by HFD. The depletion of microbiome induced by antibiotics, significantly compromised the effects of anti-metabolic syndrome of PCRCP in mice fed by HFD, demonstrating that the protective phenotype of PCRCP against anti-obesity is dependent on gut microbiota. PCRCP is exploitable as a potential prebiotic for the intervention of obesity and its complications.     

二氯氧锆比色法测定陈皮中的总黄酮

建立陈皮中总黄酮的含量测定方法,以控制其质量.以橙皮苷为对照品,采用ZrOCl2比色法测定陈皮中总黄酮的含量,测定波长为312.5nm.在浓度0.0044-0.022mg/mL范围内,吸光度与浓度呈良好的线性关系（r-0.9999）,平均回收率为100.69％,RSD为1.64％（n=6）.本法操作简单,具有良好的稳定性和重现性,适用于陈皮中总黄酮的含量测定和评价.     

高效毛细管电泳法测定罂粟壳中生物碱的含量

采用高效毛细管电泳法测定罂粟壳中可待因、吗啡和罂粟碱的含量,结果表明可待因的加样回收率为９６．６１％,吗啡为９５．９０％,罂粟碱为９５．３７％。方法简便、准确、重现性好,可作为生物碱的质量控制方法。     

在线提取-高效液相色谱-二极管阵列检测-四极杆飞行时间质谱法快速鉴定陈皮中黄酮类化合物

建立了简便、高效的在线提取-高效液相色谱-二极管阵列-四极杆飞行时间质谱法（OLE-HPLC-DAD-QTOF-MS）快速提取和分离鉴定陈皮中黄酮类化合物。在线提取体系中,将填有陈皮粉末样品（2.0 mg）的固相萃取小柱取代样品环连接在手动进样阀上,样品直接被流动相提取并进入HPLC-DAD-QTOF-MS系统分析,无需额外的样品前处理步骤。与传统的溶剂回流提取法相比,在线提取法具有较高的提取率。通过分析化合物的紫外谱图、色谱保留时间和质谱信息,共鉴定出24种黄酮类化合物,其中新圣草次苷、柠檬黄素-3-O-（3-羟基-3-甲基戊二酸）-葡萄糖苷及其异构体首次在陈皮中报道。建立的方法为中药复杂体系中活性成分的快速分离鉴定提供了新的研究思路。     

高速逆流色谱分离制备陈皮中的黄酮类化合物

应用高速逆流色谱法分离制备了陈皮中3种黄酮类化合物。以石油醚-乙酸乙酯-甲醇-水(体积比为2∶4∶3∶3)为两相溶剂系统,在主机转速850 r/min、流动相流速1.7 mL/min、检测波长280 nm条件下进行分离制备,6 h内从4.0 g陈皮粗提物中一步分离制备得到橙皮苷10.1 mg、桔皮素49.8 mg和5-羟基-6,7,8,3′,4′-五甲氧基黄酮50.6 mg,纯度均达97.0%以上,各化合物结构经质谱和核磁共振氢谱、碳谱鉴定。利用该方法可以对陈皮中的黄酮类化合物进行快速的分离和纯化。     

Multi‐criteria optimization for ultrasonic‐assisted extraction of antioxidants from Pericarpium Citri Reticulatae using response surface methodology,an activity‐based approach

An activity‐based approach to optimize the ultrasonic‐assisted extraction of antioxidants from Pericarpium Citri Reticulatae (Chenpi in Chinese) was developed. Response surface optimization based on a quantitative composition‐activity relationship model showed the relationships among product chemical composition, antioxidant activity of extract, and parameters of extraction process. Three parameters of ultrasonic‐assisted extraction, including the ethanol/water ratio, Chenpi amount, and alkaline amount, were investigated to give optimum extraction conditions for antioxidants of Chenpi: ethanol/water 70:30 v/v, Chenpi amount of 10 g, and alkaline amount of 28 mg. The experimental antioxidant yield under the optimum conditions was found to be 196.5 mg/g Chenpi, and the antioxidant activity was 2023.8 μmol Trolox equivalents/g of the Chenpi powder. The results agreed well with the second‐order polynomial regression model. This presented approach promised great application potentials in both food and pharmaceutical industries.     

紫外分光光度法分析陈皮中微量元素硒

采用紫外分光光度法,在检测波长为335 nm,以邻苯二胺做显色剂,分析了中药陈皮中微量元素硒。结果表明,广东、陕西城固、四川陈皮中硒元素平均含量分别为5.3754,2.9008;2.7570μg/g。     

气相色谱-串联质谱动态多反应监测模式测定陈皮中88种农药残留

该文采用改进的QuEChERS结合气相色谱-串联质谱(GC-MS/MS)建立了陈皮中88种农药残留在动态多反应检测(dMRM)模式下的检测方法。对样品提取方式进行筛选优化,采用乙腈为提取剂,加入无水硫酸镁4.0 g、无水乙酸钠1.0 g、陶瓷均质子提取,以PSA 200 mg、C_(18)100 mg、GCB 30 mg净化,通过基质匹配外标法校正,减弱了陈皮中基质效应对目标化合物定量准确性的影响。结果表明,88种农药在一定浓度范围内的线性关系良好,相关系数(r~2)均不低于0.996 3,以3倍信噪比(S/N=3)计算得方法检出限(LOD)为0.001 0～0.050 0 mg/kg,以S/N=10计算得定量下限(LOQ)为0.002～0.100 0 mg/kg;在低、中、高3个加标浓度下的平均回收率为60.1%～118%,相对标准偏差(RSD)为0.30%～13%(n=6)。方法快速高效、灵敏可靠,适用于陈皮中农药残留的快速筛查及日常检测。