丹参中脂溶性成分的亚临界水提取方法研究

通过亚临界水提取丹参药材中的丹参酮ⅡA的研究，建立了中药材中的脂溶性成分的亚临界水提取条件。分别考察了温度、压力、提取时间、提取物颗粒度等因素对提取量的影响，并与有机溶剂提取法比较。结果表明：当两者具有相同的提取效率时，亚临界水提取法的提取时间及提取溶剂的消耗大大减少，并避免了因使用有机溶剂而造成的污染。提取最佳条件为：样品颗粒度为0．18～0．15min，5MPa，180℃保持10min。并通过提取-HPLC联机分析实现了对提取物的实时监测。该技术有望成为从中药材中提取热稳定的脂溶性成分的有效方法。     

高效液相色谱法测定感冒止咳颗粒中黄芩苷的含量

采用高效液相色谱(HPLC)法,用C18色谱柱,甲醇-水-冰乙酸为(55:45:1,V/V/V)流动相,在波长276 nm处测定感冒止咳颗粒中黄芩苷的含量.黄芩苷在0.101～1.01μg范围内与峰面积有良好的线性关系(r=0.9998),平均回收率为100.26%,相对标准偏差为1.52%(n=6).该法操作简便,分析速度快,结果准确,可用于感冒止咳颗粒中黄芩苷含量的测定.     

超高效液相色谱-串联质谱法同时测定黄芩提取物中4种黄酮类成分

黄芩提取物样品中加入水,经甲醇超声提取2次,离心后,合并上清液,用水定容至50.0mL,过0.22μm微孔滤膜,采用超高效液相色谱-串联质谱法同时测定滤液中黄芩素、黄芩苷、汉黄芩苷、野黄芩苷等4种黄酮类成分的含量。以ACQUITY UPLC HSS T3色谱柱为固定相,以不同体积比的0.01%(质量分数)氨水和乙腈的混合液为流动相进行梯度洗脱,串联质谱分析中采用电喷雾离子源负离子模式(ESI-)和多反应监测模式。4种黄酮类成分的质量浓度在5.0～500.0μg·L~(-1)内与其对应的质谱响应值呈线性关系,检出限(3S/N)为0.3～1.5μg·kg~(-1),测定下限(10S/N)为1.0～5.0μg·kg~(-1)。以空白黄芩提取物样品为基体进行加标回收试验,所得回收率为91.1%～99.1%,测定值的相对标准偏差(n=6)为2.0%～4.1%。     

高效液相色谱-质谱分析指导下制备黄芩中系列黄酮成分对照品

在高效液相色谱-质谱分析指导下,针对性地分离制备了黄芩药材中系列黄酮成分对照品。首先对黄芩药材乙醇提取物进行液相色谱-质谱分析,获得各色谱峰的保留时间、紫外光谱和质谱特征。经波谱数据解析结合文献对比,鉴定了黄芩药材中的19种黄酮类成分。然后根据液相色谱-质谱分析结果和文献,设计了目标成分对照品的制备流程,采用低压制备柱色谱法依次制备了黄芩苷、汉黄芩苷、黄芩素、汉黄芩素和千层纸素A共5种黄酮类成分的对照品。结果表明这5种黄酮类成分对照品的纯度均大于98%。该方法可用于针对性地快速分离制备中药中的化学成分。     

反相高效液相色谱法测定肾复康胶囊中的野黄芩苷和芦丁

建立了肾复康胶囊中野黄芩苷和芦丁的反相高效液相色谱测定方法。以甲醇-水为提取溶剂,采用超声提取法对样品进行前处理。以0.02 mol/L磷酸二氢钾缓冲溶液(含1.0％（体积分数）冰醋酸)-甲醇（体积比为63∶37）为流动相,于330 nm波长下检测,肾复康提取液中野黄芩苷和芦丁可达基线分离,分析时间在20 min内。野黄芩苷和芦丁在10 ~300 mg/L内,其峰面积与浓度之间线性关系良好,目标物的加标回收率大于98％。该方法适用于肾复康胶囊及相关药材中野黄芩苷和芦丁黄酮类化合物的测定和质量控制。     

基于四氨基酞菁铟功能化石墨烯纳米材料的黄芩苷电化学传感器的构建及性能北大核心CSCD

本文通过非共价作用,合成四氨基酞菁铟功能化石墨烯(rGO-InTAPc)纳米材料,并用于构筑高灵敏的黄芩苷电化学传感器。由于rGO-InTAPc较大的比表面积和优异的电子传输能力,显著提高了黄芩苷的电化学响应。采用循环伏安法、计时电量法及差分脉冲伏安法详细地研究了黄芩苷在该传感器上的电化学行为。在最佳条件下,响应峰电流与黄芩苷在0.005~10μmol/L的浓度范围内呈良好的线性关系,检出限(S/N=3)低至0.5 nmol/L。将该方法应用于中药制剂银黄颗粒中黄芩苷含量的分析,与高效液相色谱结果具有高度的一致性。     

高效液相色谱-质谱联用快速筛选并鉴定黄芩甲醇提取物中抗氧化活性成分

建立了高效液相色谱-质谱联用技术快速筛选和鉴定黄芩甲醇提取物中抗氧化活性成分的方法.在黄芩甲醇提物中加入适量的二苯基三硝基苯肼( DPPH)作为实验组,避光室温反应30 min后直接经液相色谱分析,并与不加入DPPH的空白组进行比较.有抗氧化活性的成分因会与DPPH反应而使峰面积减少,而不具有抗氧化活性的成分峰面积则不变.基于色谱数据可以获得有抗氧化活性组分的相对活性强度,基于质谱数据可获得活性组分的结构信息用于结构鉴定.本方法成功地从黄芩甲醇提取物中筛选并鉴定出了黄芩苷、千层纸素A-7-O-B-D-葡萄糖醛酸苷、汉黄芩苷和千层纸素A4种较强的抗氧化活性成分.本方法利用HPLC-MS技术对复杂体系(如中药提取物)中小分子的分离和鉴定优势,可以直接筛选出黄芩甲醇提取物中的抗氧化活性成分,而不需要繁琐的前期分离和纯化,并且不需要仪器改装工作,有利于实现复杂体系中抗氧化活性成分的高通量筛选.     

化妆品中黄芩苷与白鲜碱的超高效液相色谱检测及质谱确证

建立了化妆品中黄芩苷和白鲜碱的超高效液相色谱(UPLC)检测方法和超高效液相色谱-四极杆串联飞行时间质谱仪(UPLC-Q-TOF)的质谱确证方法。不同基质类型的化妆品经甲醇-磷酸缓冲溶液(9∶1,p H 2.5)超声提取,氯化钠破乳化,以乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,利用Waters CSH C18(2.1 mm×100 mm,1.7μm)色谱柱对目标物和样品杂质进行有效分离,以314 nm为检测波长进行定量测定。黄芩苷和白鲜碱在0.05~10 mg/L范围内均呈良好线性,相关系数大于0.999,方法的回收率为92.2%~103.1%,相对标准偏差小于4%,方法检出限均为0.3 mg/kg。同时建立了对黄芩苷和白鲜碱的UPLC-QTOF质谱确证方法,通过一个母离子和子离子的精确质量数对黄芩苷和白鲜碱进行确证,分子质量精确度小于5 ppm,并结合紫外吸收光谱、精确质量数及同位素匹配对黄芩苷的降解产物进行了结构确定。     

紫外分光光度法测定黄芩中黄芩苷的含量

从黄芩中提取黄芩苷,并用紫外分光光度法对纯化后的黄芩苷进行测定。建立了一种以乙醇为溶剂、超声溶解制样、检测波长为278nm的测定黄芩苷含量的新方法。纯化后黄芩苷纯度达98．76％,黄芩苷乙醇溶液的含量在1～18μg／mL之间与吸光度呈良好的线性关系,相关系数为0．9993,平均回收率为99．49％,相对标准偏差为0．328％（n=4）。该方法适用于黄芩苷的定量测定。     

基于UHPLC-QTOFMS的黄芩汤化学成分和大鼠入血成分分析北大核心CSCD

建立了一种超高效液相色谱-四极杆飞行时间质谱(UHPLC-QTOF MS)联用鉴定黄芩汤化学成分及大鼠灌胃给药后入血成分的方法。采用ACQUITY UPLC XBridge BEH C_(18)色谱柱(2.1 mm×100 mm,2.5µm),以0.1%甲酸水和0.1%甲酸乙腈为流动相梯度洗脱;使用电喷雾离子源正负离子模式采集碎片信息。依据质谱裂解规律,结合对照品、文库比对分析,初步鉴定了黄芩汤中68种化学成分和35种入血成分,并讨论了黄芩素、黄芩苷、芍药苷、甘草苷等的治疗潜力。该方法高效、稳定、灵敏,可为黄芩汤的药效物质基础研究提供参考,也可用于其他复方的成分分析,有助于提升传统中药中小分子药物发现的效率。     

Optimization of Extraction Conditions for Flavonoid Composition and Antioxidant Activity of Radix Scutellariae

Microwave, ultrasonic, and reflux extraction were compared to provide an optimized method for flavonoids from Radix Scutellariae including the antioxidant activity of the extracts. The antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl and oxygen radical absorbance capacity assays. Baicalin, wogonoside, baicalein, wogonin, and oroxylin A were quantified using ultra-high performance liquid chromatography. For microwave extraction, with a ten minutes treatment, the extraction efficiencies of the analytes were higher than treatments by refluxing for 180 minutes and sonication for sixty minutes. In addition, the antioxidant activity of the microwave extracts was slightly higher than the extracts obtained by the other methods. Microwave extraction conditions were further optimized by a single-factor experiment and the optimum conditions were 50 percent ethanol–water (volume by volume), an extraction temperature of 100 degrees celsius, an extraction time of ten minutes, and a sample to solvent ratio of 1:50. This study combines extraction, phytochemistry, and bioactivity to screen the most efficient extraction procedure for flavonoids from Radix Scutellariae.     

Supercritical fluid extraction of flavonoids from Scutellariae Radix

An optimal condition of supercritical fluid extraction (SFE) for flavonoids of Scutellaria baicalensis was developed. In this study, various temperatures, pressures and modifiers were studied. The conventional extraction methods were conducted in parallel for comparison. The crude extracts were qualitatively compared by TLC and GC–MS, and the contents of flavonoids were determined by HPLC. The amounts of baicalin, baicalein and wogonin in the Scutellariae Radix obtained by supercritical fluid extraction and a conventional sonic shaking method were 137.6 mg/g, 8.6 mg/g and 2.2 mg/g, 113.5 mg/g, 5.7 mg/g and 2.3 mg/g, respectively. Application of SFE for extraction of the flavonoids from Scutellariae Radix was preferable. The optimal conditions of SFE was as follows: supercritical carbon dioxide–MeOH–water (20:2.1:0.9), 50°C and 200 bar.     

Simple preparation of baicalin from Scutellariae Radix

A simple, rapid and reproducible method was developed to isolate high-purity baicalin from Scutellariae Radix, the dried roots of Scutellaria baicalensis Georgi. The method involves partition/recrystallization steps without repeated column chromatography or special instruments. Isolated baicalin was characterized by comparisons of TLC, HPLC, IR, MS, and NMR data with an authentic sample. Moreover, beta-glucuronidase hydrolysis of baicalin sequentially yielded glucuronic acid and baicalein as confirmed by co-TLC with authentic samples. The purity of baicalin was more than 97% with yield ca. 8.7% (w/w). The method presented here appears suitable for commercial application.     

Determination of paeoniflorin, ferulic acid and baicalin in the traditional Chinese medicinal preparation Dang-Guei-San by high-performance liquid chromatography

A high-performance liquid chromatographic method for the determination of paeoniflorin, ferulic acid and baicalin in the traditional Chinese medicinal preparation Dang-Guei-San, which contains Paeoniae Radix, Swertiae Herba, Cnidii Rhizoma and Scutellariae Radix, was established. The samples were separated with a Cosmosil 5C₁₈-AR column by gradient elution with 0.03% (v/v) phosphoric acid- acetonitrile (0 min 96:4, 5 min 84:16, 7 min 82:18, 14–30 min 78:22) as the mobile phase at a flow-rate of 1.0 ml/min, with detection at 245 nm. Methylparaben was used as the internal standard and three equations were derived showing linear relationships between the peak- area ratios of marker components (paeoniflorin, ferulic acid and baicalin) to methylparaben and concentration. The recoveries of paeoniflorin, ferulic acid and baicalin were 27.86, 33.89 and 49.31%, respectively. The repeatability (relative standard deviation) was generally less than 5% (n = 5). The effects of various processes such as concentration by reduced-pressure evaporation, freeze-drying and spray-drying were studied and commercial concentrated herbal preparations containing Paeoniae Radix, Swertiae Herba, Cnidii Rhizoma and Scutellariae Radix were also analysed.     

Differential distribution of phytochemicals in Scutellariae Radix and Scutellariae Amoenae Radix using microscopic mass spectrometry imaging

Scutellariae Radix, the root of Scutellaria baicalensis Georgi, is widely applied in China for the treatment of fever, ulcer, bronchitis, hepatitis and inflammatory symptoms. Sctuellariae Amoenae Radix, the root of Scutellaria amoena C.H. Wright, is often prescribed as the substitute for Scutellariae Radix. Up to now, no attempt has been made to unveil and compare the localization of phytochemicals in Scutellariae Radix and its succedaneum. This investigation succeeded to look into the differential distribution of natural compounds in Scutellariae Radix and Scutellariae Amoenae Radix using microscopic mass spectrometry imaging. Compounds presenting different distribution modes in two kinds of roots were sorted out, then a quick method for the differentiation between Scutellariae Radix and Scutellariae Amoenae Radix was established. Accumulation sites of baicalein, baicalin, wogonin and wogonoside in Scutellariae Radix were also uncovered using microscopic mass spectrometry imaging. Moreover, the application of matrix assisted laser desorption ionization-quadrupole-time of flight mass spectrometry allowed the on-tissue dissociation of major flavonoids. Overall, the utilization of microscopic mass spectrometry imaging and matrix assisted laser desorption ionization-quadrupole-time of flight mass spectrometry provided a novel perspective for the discovery of natural compounds within medicinal plants.     

Evaluation of variation of acteoside and three major flavonoids in wild and cultivated Scutellaria baicalensis roots by micellar electrokinetic chromatography

Micellar electrokinetic chromatography (MEKC) conditions were developed to analyze the constituents of Scutellariae Radix (SR) and Scutellaria baicalensis roots. Using the MEKC method, the major flavonoid constituents of baicalin, baicalein and wogonin of wild and cultivated S. baicalensis roots were compared. In a preliminary comparison of electropherogram, one special peak was found in a wild sample but not in a 2-year-cultivated one. The compound corresponding to the peak was isolated and identified as a phenylethanoid glycoside, acteoside, by comparing the 1H- and 13C-NMR spectral data with that of the authentic compound. This is the first time acteoside has been isolated from the Scutellaria genus. It could only be found in SR derived from wild S. baicalensis roots and 4-year-cultivated plants, but not in plant materials cultivated for 3 years. Applying the MEKC method established in this study, rapid and simultaneous determinations of acteoside together with 3 flavonoids in samples were achieved. The method can thus be used for the quality control of SR in a shorter analysis period than HPLC.     

Microwave‐assisted extraction coupled with countercurrent chromatography for the rapid preparation of flavonoids from Scutellaria barbata D. Don

As a famous Chinese herb having good inhibitory effects on numerous human cancers both in vitro and in vivo, Scutellaria barbata D. Don attracts extensive attention worldwide. In this work, four flavonoids named scutellarin, baicalin, luteolin, and apigenin were simply and rapidly prepared from S. barbata by microwave‐assisted extraction coupled to countercurrent chromatography. Extraction conditions including irradiation time, extraction temperature, liquid/solid ratio, and microwave power were optimized using an orthogonal array design method. The extract of S. barbata was separated and purified with a two‐phase solvent system composed of hexane/ethyl acetate/methanol/acetic acid/water (1:5:1.5:1:4, v/v/v/v/v) and 4.5 mg of scutellarin, 4.6 mg of baicalin, 1.1 mg of luteolin, 2.1 mg of apigenin were obtained from 2.0 g original sample in a single run. The purities of scutellarin, baicalin, luteolin, and apigenin determined by HPLC were 93.6, 97.3, 97.6, and 98.4%, respectively. The targeted compounds were identified by LC with MS and ¹H NMR spectroscopy. The total time including extraction, separation, and purification was <300 min. Compared to traditional methods, microwave‐assisted extraction coupled to countercurrent chromatography method is more simple and rapid for the extraction, separation, and purification of flavonoid compounds from natural products.     

The overall quality control of Radix scutellariae by capillary electrophoresis fingerprint

The qualitative and quantitative analyses are developed for the overall quality control of Radix Scutellariae, a Chinese herb, by capillary electrophoresis fingerprint (CEFP). All experiments are carried out in an uncoated fused silica capillary (75 cm x 75-microm i.d., effective length 63 cm) with a 50 mmol/L sodium borate solution (containing 5% acetonitrile, pH 9.30) under 12 kV. The detection wavelength is set at 280 nm, and naproxen is selected as the referential peak. Some parameters are used to evaluate the similarities of CEFPs. Eight co-eluting peaks are selected as the fingerprint peaks of Radix Scutellariae. The similarities between each of the ten samples and the referential CEFP of Radix Scutellariae are evaluated both qualitatively and quantitatively. Determination results indicate that the baicalin contents from different locations are varied. The methods of CEFP and quantitative analysis are rapid, simple, and accurate, with good repeatability, and can be used for the quality control of Radix Scutellariae.     

Study of major flavonoids in crude Scutellariae Radix by micellar electrokinetic capillary chromatography

A method of micellar electrokinetic capillary electrophoresis for determining the six flavonoids in Scutellariae Radix (i.e., baicalin, baicalein, wogonin 7-O-glucuronide, wogonin, oroxylin A 7-O-glucuronide, and oroxylin A) has been developed. The buffer solution (pH 7.24) composed of 20 mM sodium dodecyl sulfate (SDS), 20 mM sodium dihydrogen phosphate, and 25 mM sodium borate was found to be the most suitable electrolyte for the separation. The contents of the six flavonoids in crude Scutellariae Radix could easily be determined within about 15 min. On-column UV (254 nm) monitoring allowed the quantitative determination of baicalin. The effects of pH, surfactant concentration, and applied voltage on the migration behavior of the solutes were studied.