Formal synthesis of semiaquilegin A

A formal synthesis of semiaquilegin A is achieved starting from readily available oridonin in 19 linear steps. The absolute configuration of the natural product has been established. A variety of useful analogues were prepared through this synthetic route.     

香茶菜属二萜的2D NMR研究(1)

本文采用一系列1D和2D NMR实验对冬凌草甲素(oridonin)和Lasiokaurinal的¹H(500 MHz)和¹³C(125 MHz)的NMR信号进行了完整的归属。     

COLOC-S脉冲序列在天然有机化合物结构分析中的应用

本文用远程异核化学位移相关谱(COLOC-S脉冲序列)和异核化学位移相关谱研究了香茶菜属二萜类化合物冬凌草甲素和香茶菜醛的化学结构,并对这两个化合物的¹³C和¹HNMR谱线进行了归属。     

Isolation and purification of oridonin from Rabdosia rubescens using upright counter-current chromatography

A preparative counter-current chromatography (CCC) method for isolation and purification of oridonin, a new cancer chemoprevention agent, from the Chinese medicinal plant Rabdosia rubescens was successfully established. The crude oridonin was obtained by elution with a light petroleum/acetone solvent mixture from ethanol extracts of R. rubescens using column chromatography on silica gel. With a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (1:2:1:2, v/v), 120 mg of oridonin at the purity of 97.8% was obtained from 200 mg of the crude sample in a single-step CCC separation. The structure of oridonin was identified by ESI-MS, 1H NMR, and 13C NMR.     

Determination of Three-Dimensional Structures of Oridonin in Solution by NOESY Spectrum and Molecular Mechanics Calculation

The phase sensitive NOESY spectrum of oridonin was treated using Full Relaxation Matrix Analysis(FRMA) approach, and the cross relaxation rates of proton pairs were obtained by diagonalizing the NOE matrix of oridonin. The inter proton distances were calculated according to 1/r6 ij ∝σij. The three-dimensional structure of oridonin in solution was calculated by the combination of WUPH, WUPH-S method with molecular mechanics minimization on the basis of NMR experiment.     

A sensitive analysis method for 7 diterpenoids in rat plasma by liquid chromatography-electrospray ionization mass spectrometry and its application to pharmacokinetic study of Isodon serra extract

A simple and sensitive LC-MS/MS method has been developed and validated for the identification and quantification of epinodosin, epinodosinol, nodosin, oridonin, lasiokariurinol, lasiokaurin and rabdoternin A in rat plasma using sulfamethoxazole as the internal standard. The plasma sample pre-treatment consisted of a liquid-liquid extraction. Chromatographic separation was achieved on a C18 column with linear gradient elution using water and methanol, which were both acidified with 0.1% formic acid, at a flow rate of 0.7 mL/min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) via an electrospray ionization (ESI) source. A novel multi-determination-periods program was executed to achieve a higher sensitivity by setting five scanning periods. The method presented here utilizes a novel determination strategy, enabling the application of positive and negative ESI-MS in a single run. The optimized mass transition ion-pairs (m/z) for quantitation were 361.2/287.1 for epinodosin, 382.3/347.3 for epinodosinol, 363.3/281.2 for nodosin, 365.3/347.3 for oridonin, 407.3/329.1 for lasiokariurinol, 405.2/59.0 for lasiokaurin, 363.2/283.1 for rabdoternin A and 254.1/156.0 for IS. The total run time was 20.50 min (including 5 min equilibration time) between injections. The specificity, linearity, accuracy, precision, recovery, matrix effect and several validation results demonstrate that this method is sensitive, specific and reliable. The proposed method was further applied to investigate the pharmacokinetics of all analytes after a single oral administration of Isodon serra extract to rats.     

冬凌草甲素分子印迹聚合物的制备及分子识别性能研究

以抗肿瘤药物分子冬凌草甲素为模板,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(ED-MA)作交联剂,采用沉淀聚合法和本体聚合法,制备对冬凌草甲素具有特定亲和选择性的分子印迹聚合物,并用激光粒度扫描和扫描电镜对聚合物的粒径和表面形貌进行了表征,采用平衡结合实验评价了两类分子印迹聚合物的吸附性能.结果表明,与使用...     

LC-MS法测定大鼠血浆中的冬凌草甲素含量

建立大鼠血浆中冬凌草甲素的LC-MS测定方法.用C18柱（150mm×2.0mm,5μm）色谱柱,乙腈-水（V/V=50∶50）为流动相,乙酸乙酯作为萃取剂,HPLC/电喷雾离子源质谱检测（HPLC/ESI-MS）.该方法测定乙酸乙酯萃取的冬凌草甲素在0.018-9.2μg·mL^-1浓度范围内线性关系良好（R2=0.9992）.定量下限为0.018μg·mL^-1,提取回收率和RSD分别为100.56％-101.74％和8.88％.采用LC-MS法检测乙酸乙酯萃取的大鼠血浆中的冬凌草甲素,可为进一步深入研究冬凌草甲素在人体内药代动力学特征提供可靠检测手段.     

COLOC—S脉冲序列在天然有机化合物结构分析中的应用

本文用远程异核化学位移相关谱(COLOC-S脉冲序列)和异核化学位移相关谱研究了香茶菜属二萜类化合物冬凌草甲素和香茶菜醛的化学结构,并对这两个化合物的~(13)C和~1HNMR谱线进行了归属。