牛蒡子中牛蒡苷和牛蒡苷元的测定

目的：测定牛蒡子中牛蒡苷和牛蒡苷元的含量。方法采用 Agilent-C18（4.6mm ×250mm,5μm）色谱柱;流动相：甲醇-水二元梯度洗脱,流速0.8mL· min －1,检测波长280nm。结果牛蒡苷和牛蒡苷元分别在0.36～2.8μg（r＝0.9995）,0.006～0.56μg（r＝0.9996）范围内线性关系良好。平均回收率牛蒡苷为100.3％,RSD为2.3％;牛蒡苷元为99.5％,RSD为2.9％。结论该方法简便、准确,实验结果可为牛蒡子的质量控制提供参考。     

RP-HPLC法测定牛蒡子中木脂素的含量

用RP-HPLC法分离并测定了牛蒡子中5种2,3-二苄基丁内酯型木脂素——牛蒡甙(Ⅰ)、牛蒡酚A(Ⅱ)、牛蒡酚F(Ⅲ)、牛蒡甙元(Ⅳ)、牛蒡素B(Ⅴ)。以安定为内标,分析柱C₁₈,甲醇-水-乙腈-四氢呋喃(57:49:11:1)为流动相,梯度流速,1.0～1.5m1/min。检测波长220nm,线性范围0.029～0.242μg,相关系数r=0.9993～0.9999,回收率96.14～104.99%。本法简便、快速、灵敏。     

牛蒡子化学成分的研究

从牛蒡(Arctium lappa L.)子乙醚和丙酮提取物中,经硅胶柱层析,低压柱层析和制备性薄层层析分离到一个甾体化合物,胡萝卜甙(daucosterol,Ⅰ)和四个已知木脂素:牛蒡子甙元(arctigenin,Ⅱ)、牛蒡子甙(arctiin,Ⅲ)、罗汉松脂素(matairesinol,Ⅳ)和牛蒡酚F(lappaol F,Ⅴ)。一个新木脂素,命名为新牛蒡素乙(neoarctin B,Ⅵ)。根据光谱(UV,IR,¹H-NMR,¹³C-NMR,DEPT,2D-NMR和MS)分析,推定了其化学结构为式Ⅵ。     

牛蒡子水煎液、牛蒡苷和牛蒡苷元体外抗菌实验

目的:对照研究牛蒡子水煎液、牛蒡苷和牛蒡苷元的体外抗菌作用.方法:采用系统溶剂提取法提取牛蒡苷,再用水浴水解法制得牛蒡苷元,以双黄连粉针为对照,用纸片扩散法进行抗菌实验.结果:牛蒡苷元和双黄连粉针的抑菌圈直径均大于15 mm,对5种菌株均有高度敏感,具有很强的抑菌能力.牛蒡苷的抑菌圈稍小,直径为10～14 mm,但也比较明显,属于中等敏感,抑菌能力良好.浓度为2:1、1:1和1:2的牛蒡子水煎液的抑菌圈较小,直径均小于10mm,属于低度敏感,抑菌能力较差.稀释至1:4的牛蒡子水煎液,对试验菌株基本无抑菌效果.结论:牛蒡子具有一定的抗菌作用,可以开发为一种新型的抗感染药物.     

不同牛蒡子中牛蒡苷的鉴别及含量考察

目的:采用薄层色谱法和高效液相色谱法对牛蒡子、炒牛蒡子及其免煎剂中主要成分牛蒡苷进行鉴别及含量测定。方法:鉴别采用TLC法,含量测定采用HPLC法。色谱柱:Diamonsil C₁₈柱（200 mm×4.6 mm,5μm）;流动相:甲醇-水（1:1.1）;柱温:30℃;流速:1 ml·min^-1;检测波长280 nm。结果:TLC图谱显示,斑点清晰。含量测定方法学考察结果,平均回收率为97.56%,RSD为1.41%（n=6）。牛蒡子生品与炮制品中牛蒡苷的含量均符合药典限度要求,免煎剂中牛蒡苷含量仅为炮制品中的1/3。结论:该实验方法简便、准确、专属性强,可用于牛蒡子及其制剂的质量控制;牛蒡子免煎剂的生产提取工艺有待于进一步完善。     

牛蒡子化学成分的研究

目的：研究牛蒡子化学成分。方法采用硅胶柱色谱,Sephadex LH-20等方法对牛蒡子进行分离纯化,通过理化性质和核磁图谱数据鉴定化合物结构。结果从牛蒡子中分离鉴定13种化合物,分别为牛蒡苷元,油酸,棕榈油酸,十四烷酸,14-二十八烯烃,β-谷甾醇,咖啡酸,咖啡酸乙酯,对羟基苯甲酸,反式对羟基肉桂酸,罗汉松脂素,牛蒡酚B,络石苷元。结论化合物3,4,5,7,8,9,10为首次从牛蒡子中分离得到,为牛蒡子的进一步研究提供参考依据。     

牛蒡子水煎液及牛蒡苷、牛蒡苷元体外抗菌实验研究

目的：探讨牛蒡子的抗茵作用。方法：取牛蒡子作为研究对象，对其有效成分进行提取、分离，考察牛蒡子水煎液、提取产物牛蒡苷、牛蒡苷元体外对8种细菌的抗茵作用。结果：牛蒡苷元、牛蒡苷、牛蒡子水煎液2：1与1：1浓度与阳性对照药双黄连相比的效果较好。结论：牛蒡子具有一定的抗茵作用，可以开发为一种新型的抗感染药物。     

RP－HPLC法测定牛蒡子中木脂素的含量

用ＲＰ－ＨＰＬＣ法分离并测定了牛蒡子中５种２，３－二苄基丁内酯型木脂素——牛蒡甙（Ⅰ）、牛蒡酚Ａ（Ⅱ）、牛蒡酚Ｆ（Ⅲ）、牛蒡甙元（Ⅳ）、牛蒡素Ｂ（Ⅴ）。以安定为内标，分析柱Ｃ１８，甲醇－水－乙腈－四氢呋喃（５７：４９：１１：１）为流动相，梯度流速，１．０～１．５ｍ１／ｍｉｎ。检测波长２２０ｎｍ，线性范围０．０２９～０．２４２μｇ，相关系数ｒ＝０．９９９３～０．９９９９，回收率９６．１４～１０４．９９％。本法简便、快速、灵敏。     

牛蒡子化学成分的分离与鉴定

目的:分离与鉴定牛蒡子中的化学成分。方法:采用硅胶柱色谱、SephadexLH-20等手段对牛蒡子进行分离纯化,通过理化性质鉴别与各种波谱学方法鉴定其结构。结果:从牛蒡子中分离鉴定出10个化学成分,分别为β-谷甾醇(1)、牛蒡子苷元(2)、罗汉松脂素(3)、牛蒡酚B(4)、牛蒡酚A(5)、牛蒡酚F(6)、牛蒡子苷(7)、8-hydroxypinoresino(l8)、(+)-Fraxiresino(l9)、胡萝卜苷(10)。其中,化合物8、9为首次从牛蒡子中获得。结论:本试验结果可为牛蒡子的进一步研究提供依据。     

转化牛蒡子苷牛蒡内生菌的分离及L2菌株的鉴定

从牛蒡(Arctium lappa L.)的根、茎、叶、总苞、种子中分离纯化了57株内生菌。以牛蒡子粉为底物,采用高效液相色谱法定量测定转化培养液中牛蒡子苷和牛蒡子苷元的含量,筛选得到6株转化牛蒡子苷的内生菌。其中L2的转化率最高,可达76.9%。利用LC-MS方法对其转化产物牛蒡子苷元进行了验证。L2经过形态观察、生理生化特征分析及16S rDNA序列分析,鉴定为氧化微杆菌(Microbacterium oxydans)。本试验结果为探索牛蒡内生菌转化牛蒡子苷成主要药效成分牛蒡子苷元技术提供了科学依据。     

Plasma pharmacokinetics and tissue distribution of arctiin and its main metabolite in rats by HPLC-UV and LC-MS

The pharmacokinetic profile of arctiin, the major active lignan in fruits of Arctium lappa L., was investigated. Its main meta"bolite arctigenin was identified by an LC-MS method, and an HPLC-UV technique was developed for the simultaneous quantification of the metabolite and arctiin in plasma and organs. Chromatographic separation was performed on an Agilent? C?? HPLC column with acetonitrile and water by linear gradient elution. Arctiin and arctigenin were identified on-line by LC-MS. The pharmacokinetics and tissue distribution of arctiin and arctigenin were determined for the first time by using a simple, selective, and accurate HPLC method. The AUC0-t values of arctigenin were larger compared with arctiin after oral administration of arctiin. The concentration of the metabolite was significantly higher than the concentration of arctiin in the stomach and small intestine in rats after oral administration of arctiin, indicating that the stomach and small intestine were the major organs of arctiin metabolism. These findings could provide support for the clinical studies conducted with Fructus Arctii.     

牛蒡子浸膏的稳定性研究

目的确定牛蒡子浸膏的干燥条件。方法在不同的干燥温度和时间下,测定牛蒡子浸膏中有效成分牛蒡苷的含量。结果在80℃干燥48h后,牛蒡子浸膏有效成分牛蒡苷的损失较小,而在100℃烘48h后牛蒡苷的含量约下降了20．00％。结论牛蒡子浸膏的干燥温度应控制在80℃以下。     

中药牛蒡子主要活性成分微生物转化研究进展

牛蒡子为菊科草本植物牛蒡的干燥成熟果实,具有抗炎、抗病毒、抗糖尿病等多种药理功能。目前已知,牛蒡苷和牛蒡苷元是中药牛蒡子的主要活性成分,摄入体内的牛蒡苷或牛蒡苷元可进一步被肠道菌群转化为去甲基牛蒡苷元、肠二醇、肠内酯等多种代谢产物。现有研究表明,牛蒡苷或牛蒡苷元的微生物转化产物具有比牛蒡苷元更高、更广的生物学活性。综述不同产地牛蒡子主要活性成分含量、药代动力学及肠道菌群代谢差异,旨在为牛蒡子主要活性成分微生物转化产物的研究与开发提供参考。     

Arctigenin isolated from the seeds of Arctium lappa ameliorates memory deficits in mice

The seeds of Arctium lappa L. (AL, family Asteraceae), the main constituents of which are arctiin and arctigenin, have been used as an herbal medicine or functional food to treat inflammatory diseases. These main constituents were shown to inhibit acetylcholinesterase (AChE) activity. Arctigenin more potently inhibited AChE activity than arctiin. Arctigenin at doses of 30 and 60?mg/kg (p.?o.) potently reversed scopolamine-induced memory deficits by 62?% and 73?%, respectively, in a passive avoidance test. This finding is comparable with that of tacrine (10?mg/kg p.?o.). Arctigenin also significantly reversed scopolamine-induced memory deficits in the Y-maze and Morris water maze tests. On the basis of these findings, arctigenin may ameliorate memory deficits by inhibiting AChE.     

Structural transformation of lignan compounds in rat gastrointestinal tract.

Structural transformation of arctiin and tracheloside, major components of seeds of Arctium lappa and Carthamus tinctorius, were investigated using rat gastric juice (pH 1.2-1.5) and rat large intestinal flora in vitro. Quantitative analysis of lignans and their metabolites was carried out by high performance liquid chromatography. Both lignans were stable in rat gastric juice and arctiin was rapidly transformed to arctigenin in rat large intestinal flora, followed by conversion to the major metabolite, 2-(3",4"-dihydroxybenzyl)-3-(3',4'-dimethoxybenzyl)-butyrolactone. On the other hand, tracheloside also decreased dependently with time and was converted to trachelogenin and its major metabolite, 2-(3",4"-dihydroxybenzyl)-3-(3',4'-dimethoxybenzyl)-2-hydroxybutyrola ctone. These experiments suggest that in the course of metabolism of lignans, firstly a cleavage of the glycosidic bond occurred and then demethylation of the phenolic methoxy group in the alimentary tract followed.     

甘肃牛蒡不同部位总木脂素及牛蒡苷的含量测定

目的对甘肃临洮产牛蒡不同部位所含总木脂素及牛蒡苷含量进行测定。方法利用牛蒡子中总木脂素与牛蒡苷在同一峰位有吸收的特点,以牛蒡苷为对照品,以280 nm为测定波长,紫外分光光度法测定牛蒡不同部位总木脂素含量,同时采用HPLC测定其牛蒡苷含量。结果牛蒡苷浓度在0.005 7～0.079 5 mg.mL 1内,吸收度与浓度呈良好线性关系,线性方程为Y=9.244 9X+0.017 2,r=0.999 6,平均回收率98.2%,RSD=1.61%。以牛蒡苷计,牛蒡子中总木脂素含量为12.27%,牛蒡根、牛蒡叶、牛蒡茎中总木脂素的含量均在6%左右。牛蒡子中牛蒡苷的含量为6.19%(n=3),牛蒡根、牛蒡茎、牛蒡叶样品均未检测到牛蒡苷。结论采用紫外分光光度法和HPLC分别测定牛蒡不同部位总木脂素和牛蒡苷含量的方法快速、简捷,可全面控制牛蒡的质量。     

Tumor specific cytotoxicity of arctigenin isolated from herbal plant Arctium lappa L.

The effectiveness of cancer chemotherapy is often limited by the toxicity to other tissues in the body. Therefore, the identification of non-toxic chemotherapeutics from herbal medicines remains to be an attractive goal to advance cancer treatments. This study evaluated the cytotoxicity profiles of 364 herbal plant extracts, using various cancer and normal cell lines. The screening found occurrence of A549 (human lung adenocarcinoma) specific cytotoxicity in nine species of herbal plants, especially in the extract of Arctium lappa L. Moreover, purification of the selective cytotoxicity in the extract of Arctium lappa L. resulted in the identification of arctigenin as tumor specific agent that showed cytotoxicity to lung cancer (A549), liver cancer (HepG2) and stomach cancer (KATO III) cells, while no cytotoxicity to several normal cell lines. Arctigenin specifically inhibited the proliferation of cancer cells, which might consequently lead to the induction of apoptosis. In conclusion, this study found that arctigenin was one of cancer specific phytochemicals, and in part responsible for the tumor selective cytotoxicity of the herbal medicine.     

Arctigenin suppresses cell proliferation via autophagy inhibition in hepatocellular carcinoma cells

Autophagy is a catabolic process that degrades dysfunctional proteins and organelles and plays critical roles in cancer development. Our preliminary screening identified that extracts of the fruits of Arctium lappa and the fruits of Forsythia suspensa notably suppressed the proliferation of hepatocellular carcinoma HepG2 cells and downregulated the autophagy. In this study, we explored the effect of arctigenin (ARG), a bioactive lignan in both extracts, on cell proliferation and autophagy-related proteins in HepG2 cells. ARG inhibited the proliferation of HepG2 cells. Analysis of autophagy-related proteins demonstrated that ARG might block the autophagy that leads to sequestosome 1/p62 (p62) accumulation. The stage of inhibition in autophagy by ARG differed from those by the autophagy inhibitors 3-methyladenine (3-MA) or chloroquine (CQ). ARG could also inhibit starvation-induced autophagy. Further analysis of apoptosis-related proteins indicated that ARG did not affect caspase-3 activation and PARP cleavage, suggesting that the antiproliferative effect of ARG can occur independently of apoptosis. In summary, our study showed that ARG suppresses cell proliferation and inhibits autophagy, and might lead to the development of agents for autophagy research and cancer chemoprevention.