Total synthesis of apigenin 7,4′-di-O-β-glucopyranoside, a component of blue flower pigment of Salvia patens, and seven chiral analogues

We have succeeded in the first total synthesis of apigenin 7,4′-di-O-β-d-glucopyranoside (1a), a component of blue pigment, protodelphin, from naringenin (2). Glycosylation of 2 according to Koenigs-Knorr reaction provided a monoglucoside 4a in 80% yield, and this was followed by DDQ oxidation to give apigenin 7-O-glucoside (12a). Further glycosylation of 4′-OH of 12a with 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl fluoride (5a) was achieved using a Lewis acid-and-base promotion system (BF₃·Et₂O, 2,6-di-tert-butyl-4-methylpyridine, and 1,1,3,3-tetramethylguanidine) in 70% yield, and subsequent deprotection produced 1a. Synthesis of three other chiral isomers of 1a, with replacement of d-glucose at 7 and/or 4′-OH by l-glucose (1b-d), and four chiral isomers of apigenin 7-O-β-glucosides (6a,b) and 4′-O-β-glucosides (7a,b) also proved possible.     

高效液相色谱电化学法检测人体血浆中芹菜素和相关黄酮类化合物

建立了同时检测人体血浆中芹菜素等5种黄酮类化合物含量的反相高效液相色谱法。血浆样品经固相萃取柱提取后,用Hypersil C18色谱柱分离样品,流动相为甲醇/磷酸水溶液(V/V,2/3,pH2.25),等度洗脱,流量为1 mL/min,柱温为40℃,用电化学检测器在直接模式下,1100 mV分析检测待测物,内标法定量。对于全部待测组分r均大于0.99;槲皮素、毛地黄黄酮、山奈酚、芹菜素和异鼠李黄素线性范围分别为3~7000、3~5900、3~7000、5~7000和3~7400 nmol/L;检出限为1.4~4.8 nmol/L。方法的实际样品加标回收率为86.8%~102.9%;相对标准偏差(RSD)低于7.4%(n=3)。方法简便、快速、准确,可用于芹菜素等黄酮类化合物在人体内的生物利用度及膳食干预研究。     

Identification of Apigenin Metabolites in Rat Liver Perfusate by Column Switching High Performance Liquid Chromatography/Electrospray Ionization Mass Spectrometry

Summary.  A selective column switching high performance liquid chromatographic method has been used for the simultaneous determination of apigenin and metabolites in rat liver perfusate. This new method clearly separated apigenin and the metabolites with high resolution. The structures of metabolites were proposed based on selective ion recording and full scan analysis by electrospray ionization mass spectrometry. Corresponding author. E-mail: basly@pharma.unilim.fr Received May 15, 2002; accepted (revised) September 13, 2002     

荧光光谱法研究木犀草素、芹菜素或葛根素与牛血清白蛋白的相互作用机理

利用紫外可见光谱和荧光光谱法研究三种黄酮类药物木犀草素、芹菜素和葛根素与牛血清白蛋白(BSA)在不同温度下(292 K和311 K)的相互作用。结果表明:三种黄酮类药物与牛血清白蛋白形成复合物导致牛血清白蛋白荧光猝灭,试验数据采用Stern-Volmer拟合方程处理及双对数方程处理,进一步证明结合反应引起的荧光猝灭属于静态猝灭。采用位点结合模型公式、热力学公式和F rster非辐射能量转移理论计算了结合常数、结合位点数及作用力类型以及结合距离。     

STUDY ON THE NON-COVALENT INTERACTION OF APIGENIN MOLECULARLY IMPRINTED POLYMERS BY SPECTROMETRY

The non-covalent interaction between aPigenin （API） and different functional monomers （α-methylacrylic acid （MAA）, acrylamide （AM）, 2-vinylpyridine （2-Vpy） and combined functional monomers （AM/2-Vpy）） was determined by UV spectrometry, and a series of apigenin molecularly imprinted polymers （API-MIPs） was synthesized with different functional monomers through molecular imprinting technology. The relationship between the non-covalent interaction of template/functional monomer and absorption of MIPs also was studied. The results showed that the order of the strength of the non-covalent interaction between API and different functional monomers in tetrahydrofuran （THF） is as follows： 2-Vpy〉 AM/2-Vpy〉AM〉MAA, which is positive correlation to the absorption capability of corresponding MIPs, and 2-Vpy is the optimum functional monomer among the used monomer for preparing API- MIPs.     

Electrochemical Behavior of Apigenin at a Glassy Carbon Electrode and its Analytical Application

The electrochemical behavior of the antitumor herbal drug apigenin was studied in 0.1 mol L^?1 B‐R buffer solutions (50% ethanol, pH 3.0) by cyclic voltammetry (CV) at a glassy carbon electrode. In CV, two oxidation peaks (P₁ and P₂) with E_p1 = 1.03V and E_p2 = 1.23 V appeared at a scan rate of 0.05 V s^?1, and a new electroanalytical method for this herbal drug was established according to the oxidation peak P2. The peak currents have a linear relationship with apigenin concentration in a range from 9.0 × 10^?7 to 2.0 × 10^?5 mol L^?1. Using the established method, apigenin in a herbal drug was determined without pre‐separation with satisfactory results. Moreover, the electrode dynamics parameters were also investigated by electrochemical techniques and the possible electrode reaction mechanism was deduced.     

红外光谱法测定芹菜叶提取物中总黄酮的含量

本文建立了红外光谱测定芹菜叶提取物中总黄酮含量的新方法。以黄酮类化合物的羰基特征峰为定量峰,依据朗伯-比耳定律,采用面积定量法,测定了芹菜叶提取物中总黄酮的含量,结果与紫外分光光度法一致。芹菜叶提取物中总黄酮的含量为86.62%;方法的相对标准偏差(RSD)为3.12%(n=6),加标回收率在92.90%~104.06%范围。     

芹菜素衍生物的合成及抗肿瘤活性研究

以芹菜素为起始原料,在C-5、C-6、C-7、C-4′位置上引入甲基、苄基、乙酰基、对甲苯磺酰基、三异丙基硅烷基等多种单元结构基团,合成了16个芹菜素衍生物,采用CCK-8的方法考察了所合成化合物对人肝癌细胞(Hep3β)、人结肠癌细胞(LOVO)、人肺癌细胞(A549)的抑制作用。结果显示,经过化学修饰后的部分化合物比芹菜素有更强的抗肿瘤活性,其中化合物13对人肺癌细胞(A549)的抑制率超过了顺铂,值得进一步探讨和研究。     

光谱法研究芹菜素与牛血清白蛋白的相互作用

在模拟人体的生理条件下（pH=7.40,Tris-HCl）,采用荧光光谱研究了牛血清白蛋白与芹菜素的相互作用。研究结果表明牛血清白蛋白与较小浓度的芹菜素间的相互作用属于静态猝灭过程;随着芹菜素浓度的增加,与牛血清白蛋白间的相互作用为静态猝灭和动态猝灭共同作用,但仍以静态猝灭为主。进一步求出了在287K和310K温度条件下静态猝灭的猝灭常数,由求得的热力学参数,证明了芹菜素与牛血清白蛋白之间主要依靠静电引力结合,采用同步荧光光谱技术探讨了芹菜素对牛血清白蛋白构象的影响。     

芹菜素的电喷雾萃取电离串联质谱

采用实验室自制的电喷雾萃取电离源(EESI),结合串联质谱(MSn)技术,对芹菜素这一典型的黄酮类活性化合物的质谱行为进行了研究。实验表明,在正、负离子检测模式下,该化合物均能得到较好的EESI-MS信号,且在负离子检测模式下灵敏度更高。通过对比芹菜素的EESI-MS和电喷雾电离质谱(ESI-MS)谱图发现,芹菜素在EESI-MS和ESI-MS中的裂解规律相似,但是EESI是一种比ESI更软的电离模式。根据对芹菜素EESI-MS特征碎片离子的分析,提出了芹菜素在EESI-MS中裂解的基本规律,为EESI-MS技术用于分析、鉴定复杂基质中痕量芹菜素奠定了理论和实验基础。