Effect of baicalein and acetone extract of Scutellaria baicalensis on canola oil oxidation

There is an increasing interest in natural antioxidants present in traditional Chinese herbal medicines. The present study examined the antioxidant activity of heane, acetone, and methanol extracts, as well as baicalein purified from the dry roots of Scutellaria baicalensis Georgi (common name: Huangqin), in heated canola oil. Oxygen consumption and decreases in linoleic acid linolenic acid content were monitored in canola oil held at 90–93°C. Among the three extracts, the acetone extract was most effective against oxidation of canola oil, followed by the methanol extract of the dry roots. The antioxidant activity of these three extracts correlated well with their content of baicalein, which provided strong protection to canola oil from oxidation. The antioxidant activity of Huangqin acetone extract was dose-dependent. The acetone extract at 100 ppm or above was even more effective than butylated hydroxytoluene at 200 ppm in protecting canola oil from oxidation. The present results suggest that the acetone extract of these roots should be further explored as a potential source of natural antioxidants for use in the processed foods.     

SIMULTANEOUS EXTRACTION AND QUANTITATION OF OLEANOLIC ACID AND URSOLIC ACID FROM SCUTELLARIA BARBATA D. DON BY ULTRASOUND-ASSISTED EXTRACTION AND HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

A modified ultrasound-assisted extraction (MUAE) method and an HPLC technique were developed to identify and quantify simultaneously the amount of oleanolic acid (OA) and ursolic acid (UA) in Scutellaria barbata D. Don. The optimal conditions for MUAE were observed when the particle size was 0.2–0.5 mm, the duty cycle was 75%, the extraction temperature was 55°C, the ratio of solvent to raw material was 12.0:1 (mL:g), the ethanol concentration was 60%, and the extraction time was 25 min. Compared to the traditional extraction method, MUAE reduced the extraction time, extraction temperature, and solvent consumption and achieved superior yields of OA and UA. Furthermore, the combined MUAE-HPLC method was successfully applied for the first time to investigate and compare the amounts of OA and UA in samples obtained from different geographical regions.     

超声波提取黄芩药渣中的黄芩苷

为了探索黄芩植物药废渣的再利用价值,首次采用超声波萃取技术对黄芩植物药废渣中的药用有效成分-黄芩苷进行再次提取,考察溶剂浓度、超声提取时间以及溶剂量等因素对黄芩苷提取率的影响。设计正交实验对超声波提取工艺参数进行优化。结果表明超声波最佳提取工艺条件为：15倍量70％浓度的乙醇,在20℃条件下超声提取50min,黄芩苷提取率达6．0％以上。通过试验得出的结论为：黄芩植物药废渣中尚含有一定量的药用有效成分-黄芩苷,具有再资源化利用的价值。     

正交试验优选半枝莲超临界二氧化碳萃取条件及GC/MS分析

本文采用正交设计法,对半枝莲挥发油超临界CO2流体提取工艺参数进行优化,并对萃取产物的化学成分进行GC/MS分析。正交实验设计萃取压力（A）、萃取温度（B）、药材粒度（C）作为3个因素,每个因素选3个水平,以挥发油的得率来确定最优化提取条件。用GC-MS分析技术对半枝莲超临界萃取产物进行分离分析,采用MS谱库检索结合保留指数的方法对半枝莲超临界萃取成分进行结构鉴定,应用色谱峰面积归一化法确定萃取产物中各成分的峰面积百分含量。结果表明最优萃取条件：萃取压力30Mpa,萃取温度50℃,药材粒度40~60目。萃取产物GC-MS结果显示,半枝莲中除含高级脂肪酸及其酯类外,还含有大量的甾族化合物。本研究优化的萃取工艺稳定、可行;利用GC/MS分析技术,MS谱库检索结合保留指数鉴定结构的方法准确、快速。     

黄芩根提取物的制备及其在烟草香气中的作用研究

以黄芩苷为目标制备了黄芩提取物,分析其有效成分并研究了烟用效果.采用裂解气相色谱-质谱联用(PyGC-MS)法,模拟卷烟典型燃烧环境,研究了黄芩苷在不同气氛中的裂解产物,探讨其在卷烟中的致香机理.结果表明,所制备的黄芩提取物含有22.11％的黄芩苷,在卷烟中的作用为增加香气、柔和烟气、改善余味.裂解试验发现,黄芩苷在不同温度和不同环境中发生裂解,生成烃类、酮类、醛类、呋喃类及其衍生物等致香成分,含量最高的为糠醛和苯乙酮.不同温度和不同气氛条件下裂解,产物及含量均有差别.以上结果表明,黄芩提取物可作为潜在的烟用香料.     

黄芩苷体外调控乳腺癌细胞表达TIMP2的实验研究

目的: 探讨黄芩苷对Bcap-37 细胞生长及TIMP2 表达的影响。方法: 体外细胞培养、MTT 法测定不同浓度黄芩苷对Bcap-37 细胞生长曲线的影响, RT-PCR 、Western blot 方法研究不同浓度黄芩苷对Bcap-37 细胞TIMP2 的影响。结果: 黄芩苷对Bcap-37 细胞的生长抑制呈浓度依赖关系;黄芩苷对Bcap-37 细胞TIMP2 在mRNA 水平、蛋白水平呈浓度依赖关系, 小剂量上调, 高剂量下调。结论: 黄芩苷对人乳腺癌Bcap-37 细胞生长有抑制作用, 可能与肿瘤细胞TIMP2 的下调有关。     

中药黄芩研究新进展

检索国内相关文献,从黄芩的提取、含量测定、鉴别、药理作用、生物技术及制剂等方面的研究进展进行综述,以期为黄芩的深入研究提供参考。