Characterization of Compounds Acting on the α1A Adrenergic Receptor from Caulis spatholobi by Cell Membrane Chromatography with Possible Application for Treatment of Benign Prostatic Hyperplasia

Tamsulosin hydrochloride is a commonly used drug for treatment of benign prostatic hyperplasia which is a disease affecting elderly men. However, adverse reactions may occur when tamsulosin hydrochloride is used for long-term treatment. Caulis spatholobi is a traditional Chinese medicine with many pharmacological effects. In this study, a cell membrane chromatography column was combined with high-performance liquid chromatography–mass spectrometry to determine the active compounds acting on α1A adrenergic receptor from Caulis spatholobi. Formononetin was shown to be active on the α1A adrenergic receptor. This was investigated by a competitive binding assay that demonstrated that tamsulosin hydrochloride and formononetin employ the same binding sites. Thus, formononetin is a potential α1A adrenergic receptor antagonist for treating benign prostatic hyperplasia.     

光谱法研究刺芒柄花素与牛血清白蛋白的相互作用

在生理pH7.4条件下,应用光谱法研究药物小分子刺芒柄花素与牛血清白蛋白相互作用机理。通过荧光法和紫外吸收光谱法确定了刺芒柄花素对牛血清白蛋白的荧光猝灭机制。采用Stern-Volmer方程求出相互作用的猝灭常数,双对数方程求出结合常数Ka和结合位点数n,进而利用热力学公式判别作用力类型。结果表明:刺芒柄花素与牛血清白蛋白的相互作用的荧光猝灭属于静态方式,298 K时结合常数Ka为1.39×106L.mol-1,结合位点数为1,而主要作用力类型是静电作用。用紫外与同步荧光光谱法研究了刺芒柄花素对BSA构象的影响。     

Synthesis of haginin E, equol, daidzein, and formononetin from resorcinol via an isoflavene intermediate

New syntheses of haginin E, equol, daidzein, and formononetin are described in this Letter. Through a sequence of a Wittig reaction, O-alkylation, and another Wittig reaction, 4-benzyloxysalicylaldehyde, which was prepared from resorcinol in two steps, was converted into the desired diene in one pot. Subsequently, the prepared diene was subjected to ring-closing metathesis using Grubbs’ catalyst (II) to construct the desired isoflavene intermediate. Using the prepared isoflavene, certain isoflavonoids such as haginin E, equol, daidzein, formononetin, and other related compounds were derived smoothly and in good overall yields.     

异黄酮同分异构体的ESI-IT-TOF质谱特征及区别

采用电喷雾-离子阱-飞行时间串联质谱(ESI-IT-TOF)技术, 在正/负离子检测模式下对芒柄花素及其同分异构体7-甲氧基异黄酮的质谱裂解规律进行了系统研究. 实验结果表明, 该化合物在正、负离子模式下均得到了5级高分辨质谱. 结果显示, 二者在负离子模式下的碎片相同, 而在正离子模式下的碎片裂解不同. 根据正负离子模式的5级高分辨质谱推导了两者的可能裂解规律, 丰富了异黄酮的ESI-MSn数据, 为其它异黄酮类化合物的分析鉴定提供了有效的质谱方法.     

Hyphenated technique for the extraction and determination of isoflavones in algae: Ultrasound-assisted supercritical fluid extraction followed by fast chromatography with tandem mass spectrometry

New hyphenated technique for the extraction and determination of isoflavones in sea and freshwater algae and cyanobacteria was developed. The method consists of sonication sample pretreatment, extraction by supercritical CO₂ modified by 3% (v/v) of MeOH/H₂O mixture (9:1, v/v) at 35 MPa and 40 °C for 60 min, fast chromatography analysis by the means of Agilent 1200 Series Rapid Resolution and MS/MS determination. Agilent 1200 Series RRLC was used with Zorbax SB-CN chromatographic column (100 mm × 2.1 mm, particle size 3.5 μm), 3 μl injection volume, mobile phase consisting of 0.2% (v/v) acetic acid in water (solvent A) and acetonitrile (solvent B) and used with linear gradient (30% B at 0 min, from 0 min to 3 min up to 50% B, from 3 to 6 min up to 80% B and from 6 to 10 min down to 30% B). The flow-rate was 0.4 mL/min, column oven temperature 35 °C. MS detector Agilent Technologies 6460 Triple quadrupole LC/MS with Agilent Jet Stream was used in a negative ESI mode under following conditions: gas temperature 350 °C, gas flow 13 L/min, nebulizer gas pressure 50 psi, sheath gas temperature 400 °C, sheath gas flow 12 L/min, capillary voltage was 4 kV. Samples were analysed in the multiple reaction monitoring (MRM) mode. Eight isoflavone compounds were found for the first time in seven real samples of sea algae and in three control samples of freshwater algae and cyanobacteria. Usual optimisation study of extraction parameters was performed. Pressure and temperature optima for algae matrix are different from those obtained sooner for other matrices for most of the analytes, but the results of modifier optimisation study are in good accordance with those obtained sooner for spiked samples and red clover matrix. It seems that matrix has very small or no effect on the modifier selection. Two different approaches of sonication pretreatment were tested: sonication bath and the thorn instrument. In longer extraction time experiments, thorn sonication was more efficient and recovery of following supercritical fluid extraction was higher.     

红车轴草总异黄酮粉剂的质量标准

采用薄层色谱法建立其有效成分芒柄花素和鹰嘴豆芽素A定性方法,采用高效液相色谱法建立其有效成分芒柄花素和鹰嘴豆芽素A含量测定方法,以期建立红车轴草总异黄酮粉剂的质量标准。结果显示薄层斑点清晰、重现性好;测定芒柄花素和鹰嘴豆芽素A重现性好,平均加样回收率分别为101.10%及98.44%,RSD分别为2.19%和2.15%。本法简便、准确,可用于本品的质量控制。     

刺芒柄花素与牛血清白蛋白相互作用的研究

应用荧光猝灭法研究了刺芒柄花素(For)与牛血清白蛋白(BSA)的相互作用机理,并利用Stern-Volmer方程和Lineweaver-Burk方程,探讨了For对BSA的猝灭机制,结合常数Ka和结合位点数n,相互作用力等.为研究For的药理作用和生物学效应,及For对蛋白质构像的影响等提供了实验依据.