柱前衍生化HPLC法测定黄芪中黄芪甲苷的含量

目的：建立黄芪中黄芪甲苷的柱前衍化高效液相色谱测定法,并用该法对不同产地黄芪中黄芪甲苷的含量进行比较,方法：以吡啶－苯甲酰氯（２．５：１）为衍生化试剂,对黄芪甲苷分子中的羟基进行苯甲酰化,以甲醇－四氢呋喃－水（９０：４：６,０．２％三乙胺）为流动相,ＶＤ３为内标物,在２３０ｎｍ波长处检测。结果黄芪甲苷在０．００４－０．０８０ｍｇ．ｍＬ＾－１范围内呈线性,相关系数为０．９９９９,平均回收率为９４．７     

黄芪化学成分与生态因子的相关性

以主成分分析(PCA)和相关性分析(CA)法研究黄芪中主要有效成分与生态因子的相关性,探究影响黄芪主要成分积累的生态因子.结果表明: 山西产地黄芪中的黄芪甲苷、毛蕊异黄酮苷、芒柄花苷、山奈酚和黄芪多糖的含量显著高于内蒙古和甘肃两地.影响黄芪化学成分含量的气候因子主要为年均相对湿度、年日照时数及7月均温.影响黄芪化学成分含量的土壤元素主要为钙,且钙在一定范围内与毛蕊异黄酮苷、山柰酚、芒柄花苷、槲皮素、黄芪多糖的含量呈负相关.     

黄芪种衣剂对黄芪品质的影响

通过以不同用量（种子干重的2%,4%,6%和8%）的黄芪种衣剂包衣种子为处理组,以ND牌种衣剂（种子干重的8%）包衣和空白种子为双对照组,比较研究在不同种子处理条件下,膜荚黄芪植物中黄芪甲苷含量、总黄酮含量及农药残留量发生变化情况。研究结果表明,黄芪种衣剂包衣处理后,明显增加了黄芪中有效成分黄芪甲苷、总黄酮的含量,且包衣所产生的农药残留可随植物生长完全降解掉,研究结果表明黄芪种衣剂的使用可以提高中药材黄芪的品质。     

HPLC-ELSD法测定消栓通颗粒中黄芪甲苷的含量

目的:建立测定消栓通颗粒中黄芪甲苷含量的新方法.方法:采用高效液相色谱-蒸发光散射检测法测定,色谱柱为kromasilC18柱,以乙腈-水(32:68)为流动相,流速为1.0ml/min,ELSD条件为飘逸管温度为105℃,载气流速为2.5L/min;测定消栓通颗粒中黄芪甲苷的含量.结果:黄芪甲苷在1.08μg-6.48μg范围内与峰面积线性关系良好(r=0.9999),平均加样回收率为100.2%,RSD为0.93%.结论:方法灵敏、可靠、准确、重复性好,可作为消栓通颗粒的质量控制方法.     

高效液相色谱法测定黄芪注射液中黄芪甲甙的含量

本文报道用高效液相色谱法测定黄芪注射液中黄芪甲甙的含量。色谱柱为:NOVA-PAK C_(18)4μm(4.6mm×250mm);流动相:乙腈-0.1％磷酸(33:67),205nm检测,外标定量。结果表明,建立的方法完全适用于黄芪注射液中黄芪甲甙的含量测定。其方法快速、灵敏、重现性好。     

干旱胁迫对蒙古黄芪生长和生理生化指标及其黄芪甲苷积累的影响

以二年生蒙古黄芪实生苗为试验材料,采用盆栽模拟自然界干旱的方法,连续控水14d,分析持续性干旱胁迫对蒙古黄芪实生苗生长、生理生化指标及其黄芪甲苷的影响。结果显示:(1)随着土壤相对含水量的降低,黄芪叶片相对含水量逐渐降低,而其中丙二醛含量升高,其根茎干重也降低。(2)随着胁迫时间的延长,黄芪根叶中抗氧化酶类SOD、POD、CAT、APX和GR活性呈先增加后降低的趋势,根中最高值较对照分别增加了72.1%、108.6%、178.0%、299.4%和303.4%,且根叶中渗透调节物质脯氨酸和可溶性糖含量也逐渐升高。(3)黄芪甲苷积累量在干旱胁迫第12天达到最大,比对照增加了53.0%,随后降低。研究表明,随着干旱胁迫程度的加深,黄芪苗生长受到一定程度抑制,但能通过调节自身保护酶活性和渗透调节物质含量来减轻干旱的损伤,最大程度地维持植株的正常代谢;适度水分胁迫有利于黄芪甲苷的积累,而重度胁迫不利于其积累。     

黄芪甲苷在大鼠体内的药代动力学和组织分布研究

建立了固相萃取-HPLC-MS测定大鼠血浆中黄芪甲苷含量的方法,并对其在大鼠体内的药代动力学和组织分布进行了研究。分别以1,2,4 mg/kg的剂量对大鼠静脉给药,给药后2,10,20,30,60 min和1.5,2,3,4,6,8 h采集血样,同时以2 mg/kg的剂量对大鼠静脉给药,给药后20,60,240 min采集各组织,测定血浆样品和组织样品中的黄芪甲苷浓度。血药浓度-时间曲线按二室模型拟合最佳,t1/2(α)分别为12.36,7.05,15.98 min,t1/2(β)分别为69.14,73.28,95.24 min,AUC分别为277.36,415.36,623.15μg.min/mL,AUC与剂量的线性方程为y=113.64x 173.47(r=0.997),表明黄芪甲苷在大鼠体内呈线性消除。组织分布研究表明黄芪甲苷在体内分布较广。     

大孔树脂吸附法纯化黄芪总皂苷的工艺研究

采用大孔树脂吸附法富集纯化黄芪总皂苷,以HPLC-ELSD法测定黄芪甲苷的含量作为考察指标,筛选了树脂型号、吸附流速、洗脱溶剂、洗脱流速以及洗脱溶剂用量等工艺条件.结果表明:最佳工艺为选择D101型大孔树脂,吸附流速为2 BV·h-1,洗脱流速为4 BV·h-1,收集5 BV的70％乙醇部分,得到的黄芪总皂苷纯化效果最好,黄芪甲苷的转移率可达93.21％.     

HPLC-UV-ELSD法同时测定黄芪中黄芪皂苷和黄酮类成分

建立HPLC-UV-ELSD法同时测定黄芪中黄芪皂苷Ⅰ、黄芪皂苷Ⅱ、黄芪皂苷Ⅲ、黄芪甲苷、毛蕊异黄酮葡萄糖苷、刺芒柄花苷、毛蕊异黄酮的含量,并比较四种不同供试液中7种成分的含量差异,实验采用Agilent 5 TC-C_(18)色谱柱(250 mm×4.6 mm,5μm),0.3%甲酸水溶液-乙腈进行梯度洗脱,流速为1.0 mL/min,检测波长254 nm;柱温30℃,漂移管温度70℃。在该色谱条件下,黄芪中7种成分能得到较好的分离,稳定性,重复性及精密度良好。本方法能简便、快捷、有效的测定黄芪药材中多种成分含量。大孔树脂制备供试品中黄芪皂苷和黄酮类成分更高,说明碱化处理对黄芪中的成分含量产生了一定影响。     

茯苓、黄芪复方免疫成分的最佳制备工艺研究

以茯苓、黄芪提取液中多糖和甲苷的含量及出膏率为指标,优选了提取工艺,并考察了两种精制工艺对复方免疫成分的影响。结果为浸泡细粉药材12h,提取1次,料水比1:15,为最佳提取工艺,采用每100mL提取液中加入25mL1%壳聚糖液的精制工艺效果最佳。     

Inhibitory effects of astragaloside IV on ovalbumin-induced chronic experimental asthma

Astragaloside IV, a new cycloartane-type triterpene glycoside extract of Astragalus membranaceus Bunge, has been identified for its potent immunoregulatory, antiinflammatory, and antifibrotic actions. Here we investigated whether astragaloside IV could suppress the progression of airway inflammation, airway hyperresponsiveness, and airway remodeling in a murine model of chronic asthma. BALB/c mice sensitized to ovalbumin (OVA) were chronically challenged with aerosolized OVA for 8 weeks. Astragaloside IV was orally administered at a dose of 50 mg x kg-1 x day-1 during each OVA challenge. Astragaloside IV treatment resulted in significant reduction of eosinophilic airway inflammation, airway hyperresponsiveness, interleukin (IL)-4 and IL-13 levels in bronchoalveolar lavage fluid, and total immunoglobulin E levels in serum. Furthermore, astragaloside IV treatment markedly inhibited airway remodeling, including subepithelial fibrosis, smooth muscle hypertrophy, and goblet cell hyperplasia. In addition, the expression of transforming growth factor-beta1 in the lung was also reduced by astragaloside IV. These data indicate that astragaloside IV may mitigate the development of characteristic features in chronic experimental asthma.     

Quantitative determination of Astragaloside IV, a natural product with cardioprotective activity, in plasma, urine and other biological samples by HPLC coupled with tandem mass spectrometry

Astragaloside IV is a novel cardioprotective agent extracted from the Chinese medical herb Astragalus membranaceus (Fisch) Bge. This agent is being developed for treatment for cardiovascular disease. Further development of Astragaloside IV will require detailed pharmacokinetic studies in preclinical animal models. Therefore, we established a sensitive and accurate high performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (LC/MS/MS) quantitative detection method for measurement of Astragaloside IV levels in plasma, urine as well as other biological samples including bile fluid, feces and various tissues. Extraction of Astragaloside IV from plasma and other biological samples was performed by Waters OASIS(trade mark) solid phase extraction column by washing with water and eluting with methanol, respectively. An aliquot of extracted residues was injected into LC/MS/MS system with separation by a Cosmosil C18 5 microm, 150 mm x 2.0 mm) column. Acetonitrile:water containing 5 microM NaAc (40:60, v/v) was used as a mobile phase. The eluted compounds were detected by tandem mass spectrometry. The average extraction recoveries were greater than 89% for Astragaloside IV and digoxin from plasma, while extraction recovery of Astragaloside IV and digoxin from tissues, bile fluid, urine and fece ranged from 61 to 85%, respectively. Good linearity (R2>0.9999) was observed throughout the range of 10-5000 ng/ml in 0.5 ml rat plasma and 5-5000 ng/ml in 0.5 ml dog plasma. In addition, good linearity (R2>0.9999) was also observed in urine, bile fluid, feces samples and various tissue samples. The overall accuracy of this method was 93-110% for both rat plasma and dog plasma. Intra-assay and inter-assay variabilities were less than 15.03% in plasma. The lowest quantitation limit of Astragaloside IV was 10 ng/ml in 0.5 ml rat plasma and 5 ng/ml in 0.5 ml dog plasma, respectively. Practical utility of this new LC/MS/MS method was confirmed in pilot pharmacokinetic studies in both rats and dogs following intravenous administration.     

Preclinical pharmacokinetics and tissue distribution of a natural cardioprotective agent astragaloside IV in rats and dogs

Astragaloside IV, a natural product purified from the Chinese medical herb Astragalus membranaceus (Fisch) Bge, is now being developed as a cardioprotective agent for treating cardiovascular diseases. The purpose of the present study was to examine in vivo pharmacokinetics and tissue distribution in both rats and dogs by using an established high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry quantitative detection method. Astragaloside IV showed moderate to fast elimination; the elimination half-life of astragaloside IV was 98.1, 67.2 and 71.8 min in male rats, and 34.0, 66.9 and 131.6 min in female rats at doses of 0.75, 1.5 and 3.0 mg/kg, respectively. There was no significant difference in systemic clearance at three dose levels, suggesting that astragaloside IV may have linear pharmacokinetic characteristics in rats within the dose ranges tested. The highest concentration of astragaloside IV was detected in the lung and liver. However, limited distribution to the brain, indicates that astragaloside IV may have difficulty penetrating the blood brain barrier. In addition, only about 50% of the parent astragaloside IV was recovered in both urine and feces. These results indicate that there was about 83% astragaloside IV binding to plasma protein and that the binding to the plasma is linear at the concentration range of 250-1000 ng/ml. As in rats, astragaloside IV may have linear pharmacokinetic characteristics in dogs within the dose ranges tested. Astragaloside IV was slowly cleared via hepatic clearance with a systemic clearance (CL) of about 0.004 l/kg/min. Based on the favorable pharmacokinetic properties in both rats and dogs, astragaloside IV warrants further investigation for the prevention of cardiovascular diseases.     

A Study on the Constituents of Stems and Leaves of Astragalus membranaceus

A new saponin was isolated from stems and leaves of Astragalus membranaceus Bunge. On the basis of chemical reaction and spectroscopic (MS, NMR)analysis, it is identified as cycloastragenol 3-O-β-D-glucoside.     

黄芪复合体(豆科)核型资料的聚类分析

在平均欧氏距离系数基础上,运用UPGMA法,对黄芪复合体5个类群11个居群的核型资料进行了Q型聚类分析,结果表明,膜荚黄芪Astragalus membranaceus和A. penduliflorus的不同居群在核型上存在明显的差异,但二者之间以及它们与民和黄芪、淡紫花黄芪的居群之间具有一定的连续性。蒙古黄芪在核型上与其它类群均存在一定的差异,且存在明显的间断。因此,本文作者认为:A. penduliflorus应视为膜荚黄芪的异名,黄芪复合体应包括2种:膜荚黄芪(A. membranaceus(Fisch)Bunge)和蒙古黄芪(A. monghulicus Bunge)、2亚种:膜荚黄芪(A. membranaceus spp. membranaceus)、民和黄芪(A. membranaceus spp. minhensis)和1变种:淡紫花黄芪(A. membranaceus var. purpurinus Y.C.Ho)。黄芪复合体核型的进化趋势是从对称向不对称发展,与Stebbins的观点一致。     

氮、磷、钾营养对膜荚黄芪幼苗根系活力和游离氨基酸含量的影响

运用水培试验法研究不同营养水平对黄芪幼苗根系活力和游离氨基酸组成及含量的影响。结果表明:缺素显著降低黄芪根系活力,不同营养处理游离氨基酸含量差异显著,游离氨基酸总量的变化规律为叶片>根,各处理游离氨基酸总量为-K>-P>NPK>-N。全素处理与缺素处理相比,能提高根系活力、协调根冠比。黄芪幼苗通过提高体内游离氨基酸含量以增强对营养胁迫逆境的适应能力。     

膜荚黄芪与蒙古黄芪幼苗的光能利用及其耐光性研究

以盆栽膜荚黄芪和蒙古黄芪幼苗为试验材料,测量2种黄芪叶片的光合速率、叶绿素荧光参数、光能利用率及耐光性等指标的日变化,以探讨它们的光能利用、热耗散以及耐光性差异.结果表明:(1)随着太阳光合有效辐射的日变化进程推进,2种黄芪的初始荧光(F0)、非光化学淬灭(NPQ)、PSⅡ调节性能量耗散量子产最(YNPQ)先升高后降低...     

Inhibitory effects of astragaloside IV on diabetic peripheral neuropathy in rats

Astragaloside IV (AGS-IV), a new glycoside of cycloartane-type triterpene isolated from the root of Astragalus membranaceus (Fisch.) Bunge, has been used experimentally for its potent immune-stimulating, anti-inflammatory, and antioxidative actions. A recent study has shown AGS-IV to be an aldose-reductase inhibitor and a free-radical scavenger. This study examined the effects of AGS-IV on motor nerve conduction velocity (MNCV), tailflick threshold temperature, biochemical indexes, and the histology of the sural nerve after diabetes was induced in rats with 75 mg/kg streptozotocin (STZ). AGS-IV (3, 6, 12 mg/kg, twice a day) was administered by oral gavage for 12 weeks after diabetes was induced. Compared with control (nondiabetic) rats, obvious changes in physiological behaviors and a significant reduction in sciatic MNCV in diabetic rats were observed after 12 weeks of STZ administration. Morphological analysis showed that AGS-IV suppressed a decrease in myelinated fiber area, an increase in myelinated fiber density, and an increase in segmental demyelination in diabetic rats. The protective mechanism of AGS-IV involved a decrease in declining blood glucose concentration and HbA1C levels, and an increase in plasma insulin levels. AGS-IV increased the activity of glutathione peroxidase in nerves, depressed the activation of aldose reductase in erythrocytes, and decreased the accumulation of advanced glycation end products in both nerves and erythrocytes. Moreover, AGS-IV elevated Na+,K+-ATPase activity in both the nerves and erythrocytes of diabetic rats. These results indicate that AGS-IV exerts protective effects against the progression of peripheral neuropathy in STZ-induced diabetes in rats through several interrelated mechanisms.