A novel molecularly imprinted method with computational simulation for the affinity isolation and knockout of baicalein from Scutellaria baicalensis

A novel molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization with baicalein (BAI) as the template and used as solid‐phase extraction (SPE) adsorbent, aiming at the affinity isolation and selective knockout of BAI from Scutellaria baicalensis Georgi (SB). We used computational simulation to predict the optimal functional monomer, polymerization solvent and molar ratio of template to functional monomer. Characterization and performance tests revealed that MIP exhibited uniform spherical morphology, rapid binding kinetics, and higher adsorption capacity for BAI compared with nonimprinted polymer (NIP). The application of MIP in SPE coupled with high‐performance liquid chromatography to extract BAI from SB showed excellent recovery (94.3%) and purity (97.0%). Not only the single BAI compound, but also the BAI‐removed SB extract was obtained by one‐step process. This new method is useful for isolation and knockout of key bioactive compounds from herbal medicines. Copyright © 2015 John Wiley & Sons, Ltd.     

Divergent and Overlapping Roles for Selected Phytochemicals in the Regulation of Pathological Cardiac Hypertrophy

Plant-based foods, like fruits, vegetables, whole grains, legumes, nuts, seeds and other foodstuffs, have been deemed as heart healthy. The chemicals within these plant-based foods, i.e., phytochemicals, are credited with protecting the heart. However, the mechanistic actions of phytochemicals, which prevent clinical endpoints, such as pathological cardiac hypertrophy, are still being elucidated. We sought to characterize the overlapping and divergent mechanisms by which 18 selected phytochemicals prevent phenylephrine- and phorbol 12-myristate 13-acetate-mediated cardiomyocyte enlargement. Of the tested 18 compounds, six attenuated PE- and PMA-mediated enlargement of neonatal rat ventricular myocytes. Cell viability assays showed that apigenin, baicalein, berberine hydrochloride, emodin, luteolin and quercetin dihydrate did not reduce cell size through cytotoxicity. Four of the six phytochemicals, apigenin, baicalein, berberine hydrochloride and emodin, robustly inhibited stress-induced hypertrophy and were analyzed further against intracellular signaling and genome-wide changes in mRNA expression. The four phytochemicals differentially regulated mitogen-activated protein kinases and protein kinase D. RNA-sequencing further showed divergence in gene regulation, while pathway analysis demonstrated overlap in the regulation of inflammatory pathways. Combined, this study provided a comprehensive analysis of cardioprotective phytochemicals. These data highlight two defining observations: (1) that these compounds predominantly target divergent gene pathways within cardiac myocytes and (2) that regulation of overlapping signaling and gene pathways may be of particular importance for the anti-hypertrophic actions of these phytochemicals. Despite these new findings, future works investigating rodent models of heart failure are still needed to understand the roles for these compounds in the heart.     

贝加因与牛血清白蛋白相互作用的分子光谱法研究

利用荧光光谱和吸收光谱研究了贝加因与牛血清白蛋白(BSA)的相互作用,由Van't Hoff方程计算了反应的热力学参数,并根据Stern-Volmer方程计算了不同温度下的结合位点和结合常数.结果表明,贝加因可静态猝灭BSA的内源荧光;二者相互作用的焓变和熵变均大于零,说明疏水作用力是二者之间的主要作用力.与此同时,贝...     

黄芩苷元的Mannich反应

利用天然产物黄芩苷元（baicalein)在A环8－位碳上进行Mannich反应，合成 了11个新的Mannich碱化合物。反应温和，产物易纯化，收率达80％以上。同时考 察了伯胺与甲醛配比为1：2时，产物为二氢苯并E嗪类化合物和黄芩苷元A环上5－ ，6－，7－位羟基对8－位氢进行Mannich反应活性的影响。并对Mannich碱化合物 2b和2j进行盐酸成盐4b和4j，初步考察了它们的溶解度与黄芩苷元的差别。     

反相液相色谱法测定培养黄芩的有效成分

用HPLC法测定不同pH条件下培养的黄芩中黄芩甙、黄芩素的含量.结果表明:在一定的pH条件下黄芩甙、黄芩素的含量呈现有规律性的变化.在pH=5.8时最大,为组织培养黄芩提供了科学的依据.建立了测定黄芩中黄芩甙、黄芩素含量的反相液相色谱法:采用ZORBAXSB C18(150mm×4.6mm,3.5μm)色谱柱,流动相甲醇-水-磷酸(体积比60∶40∶0.2);用反相液相色谱法测定黄芩中黄芩甙和黄芩素的含量;该法的RSD分别为3.6%和5.8%(n=6),平均回收率分别为103.6%和101.8%.     

黄芩中4种黄酮类化合物的亚临界水提取研究

建立了黄芩药材中4种黄酮类化合物（黄芩苷、汉黄芩苷、黄芩素、汉黄芩素）的亚临界水提取测定方法。分别考察了温度、时间、水量对提取量的影响,并与有机溶剂甲醇提取法进行比较。结果表明,在160 ℃, 60 min时黄芩素、汉黄芩素萃取量比较高;在110 ℃, 10 min时黄芩苷、汉黄芩苷萃取量比较高。亚临界水提取法的提取时间及提取溶剂的消耗量大大减少,避免了使用有机溶剂造成的污染。该方法可以实现中药材中脂溶性成分的提取,有利于中药材的绿色产业化。     

黄芩素清除自由基作用研究

利用紫外光谱法研究了黄芩素对1,1-二苯基-2-苦肼基自由基(DPPH.)和超氧自由基的清除作用.结果表明,黄芩素能有效清除超氧阴离子自由基,在酸性条件它对DPPH.自由基具有很强的清除作用,当pH值为3时其清除率达93.05%.     

Hairy Roots of Scutellaria spp. (Lamiaceae) as Promising Producers of Antiviral Flavones

We measured and studied the growth parameters and the qualitative and quantitative composition of the flavones of hairy roots of the Scutellaria genus: S. lateriflora, S. przewalskii and S. pycnoclada. Hairy roots were obtained using wild-type Agrobacterium rhizogenes A4 by co-cultivation of explants (cotyledons) in a suspension of Agrobacterium. The presence of the rol-genes was confirmed by PCR analysis. The hairy roots of the most studied plant from the Scutellaria genus, S. baicalensis, were obtained earlier and used as a reference sample. HPLC-MS showed the predominance of four main flavones (baicalin, baicalein, wogonin and wogonoside) in the methanol extracts of the studied hairy roots. In addition to the four main flavones, the other substances which are typical to the aerial part of plants were found in all the extracts: apigenin, apigetrin, scutellarin and chrysin-7-O-β-d-glucuronide. According to the total content of flavones, the hairy roots of the studied skullcaps form the following series: S. przewalskii (33 mg/g dry weight) > S. baicalensis (17.04 mg/g dry weight) > S. pycnoclada (12.9 mg/g dry weight) > S. lateriflora (4.57 mg/g dry weight). Therefore, the most promising producer of anti-coronavirus flavones is S. przewalskii.     

黄芩素和黄芩苷抗氧化活性与结构关系的密度泛函理论研究

采用密度泛函理论方法对黄芩素和黄芩苷分子进行构象扫描,获得2个化合物的最低能量构象并对其进行了全优化.从分子的几何结构、酚羟基解离能BDE、绝热电离势IP、HOMO和LUMO能级以及其能级差ΔE(LUMO-HOMO)等方面分析了2个化合物的抗氧化活性与结构的关系.结果表明,C6位的酚羟基为黄芩素和黄芩苷的最大反应活性位点.在非极性溶剂中,化合物抗氧化活性取决于分子中酚羟基的脱氢能力,黄芩苷的抗氧化活性大于黄芩素的抗氧化活性.在极性溶剂中,抗氧化活性取决于分子中单电子的电离势,黄芩苷的抗氧化活性大于黄芩素的抗氧化活性.