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.     

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。     

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.     

液相色谱-串联四极杆质谱法测定罂粟壳主要成分在止咳药中的含量

采用液相色谱-电喷雾串联四极杆质谱仪,用多离子反应检测(MRM)定量法检测,通过对样品SPE净化预处理、色谱条件、质谱参数等的优化选择和方法学验证,建立了定量检测止咳药中的罂粟壳含量的理想方法。吗啡、可待因、罂粟碱、那可丁的母离子质荷比分别为286.2、300.2、340.7、413.4、289.3;定量用子离子分别为165.0、215.1、202.5、324.7、220.0、201.1,另一组子离子分别为181.1、165.1、324.7、353.1、165.0。本方法灵敏度高、操作简单、定量准确。吗啡、可待因、罂粟碱、那可丁的检出限LOD分别为0.073、0.024、0.003和0.0009μg/L(进样量10μL),定量限LOQ分别是0.24、0.08、0.01和0.003μg/L。回收率为95%~110%。     

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.     

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。     

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。     

陈皮挥发油的气相色谱/质谱分析

用ＧＣ／ＭＳ分析复方制剂平胃散中的一种单味药材陈皮的挥发油化学成分及其相对含量,对色质联用仪产生的二维数据借助直观推导式演进特征投影法来分辨以得到组分的纯色谱和质谱,根据组分的色谱保留时间和质谱对组分进行定性,继而用总体积积分法定量。本文分离出５３个组分,其中鉴定了３４个组分,约占其挥发油总量的９６．０８％。     

Nontargeted urine metabolomics analysis of the protective and therapeutic effects of Citri Reticulatae Chachiensis Pericarpium on high-fat feed-induced hyperlipidemia in rats

In this study, we focused on studying the changes in urine metabolites in hyperlipidemic rats using ultra-performance liquid chromatography coupled with quadrupole time-of-fight mass spectrometry (UPLC–Q-TOF/MS) and metabolomics, as well as the effect of Citri Reticulatae Chachiensis Pericarpium (CRCP) on hyperlipidemia. These urine samples were examined by UPLC–Q-TOF/MS to obtain MS data. The MS data were analyzed by principal component analysis and partial least squares-discriminant analysis to identify the differential metabolites. CRCP reduced the body weight and levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol and abnormally decreased high-density lipoprotein cholesterol in hyperlipidemic rats, which were significantly raised by a high-fat diet. Twenty-seven potential biomarkers were identified within the complex sample matrix of urine. Fourteen biomarkers increased in the hyperlipidemia rats compared with normal rats. Meanwhile, 13 biomarkers decreased. CRCP reversed abnormal changes in biomarkers, including 5-l -glutamyl-taurine, 5-aminopentanoic acid, cis-4-octenedioic acid and 2-octenedioic acid. These biomarkers show that hyperlipidemia is related to the metabolic pathways of taurine and hypotaurine metabolism, fatty acid biosynthesis , and arginine and proline metabolism . CRCP mainly prevents hyperlipidemia by intervening in these metabolic pathways.     

Fingerprinting alterations of secondary metabolites of tangerine peels during growth by HPLC-DAD and chemometric methods

Tangerine peels are herbal materials of two coupled traditional Chinese medicines, Pericarpium Citri Reticulatae (PCR) and Pericarpium Citri Reticulatae Viride (PCRV). In this paper, high-performance liquid chromatographic fingerprints of tangerine peels during growth were firstly measured for deliberately collected 34 samples from three species (Citrus reticulata ‘Chachi’, Citrus reticulata ‘Dahongpao’ and Citrus erythrosa Tanaka). After sixteen characteristic components which have similar change trends in the grown process were screened out with the help of heuristic evolving latent projection (HELP) method, score plots of principal component analysis (PCA) successfully presented the grown footprints of tangerine peels. It implied that July might be the best harvest time for PCRV, November and December were better for PCR. Furthermore, hesperidin, nobiletin and tangeretin were screened as chemical markers by loadings of PCA. The HPLC-HELP-PCA strategy has shown its potential in optimization of harvest time and chemical markers’ screening, which will have wide perspective in the analysis of “coupled TCMs”.