目的本研究采用比较分子力场分析法(comparative molecular field analysis,CoMFA)和比较分子相似性指数分析法(comparative molecular similarity indices analysis,CoMSIA),系统研究了30个1,3-二氢苯并[b][1,4]二氮杂卓-2-酮类非竞争性代谢型谷氨酸受体2/3(mGluR2/3)拮抗剂的三维定量构效关系。方法通过考察网格点步长对CoMFA研究统计结果和各种分子场组合、网格点步长和衰减因子对CoMSIA研究统计结果的影响,建立了3D-QSAR模型,发现立体场、静电场、疏水场和氢键受体场的组合可得到最佳模型。结果所建立的CoMFA和CoMSIA模型的交叉相关系数q2值分别为0.729和0.713,均具有较强的预测能力。结论利用CoMFA和CoMSIA模型的三维等值线图直观地解释了化合物的构效关系,阐明了化合物结构与生物活性的关系,为进一步结构设计和优化提供了重要依据。
For quality control purpose, an approach of fingerprinting and simultaneous quantification of five major bioactive constituents of Rhizoma Coptidis was established via a high-performance liquid chromatograph coupled with a photodiode array UV detector(HPLC-DAD) and an electrospray ionization mass spectrometer(HPLC-ESI/MS). The compounds were identified on the basis of the comparison of their mass spectra with literature data and those of standard samples and quantified by the HPLC-DAD method. Baseline separation was achieved on an XTerra C 18 column(5 μm, 250 mm×4.6 mm i. d.) with linear gradient elution of formate buffer(consisting of 0.5% formic acid, adjusted to pH=4.5 with ammonia) and acetonitrile(consisting of 0.2% formic acid and 0.2% triethylamine). The me-thod was validated for linearity(r 2 >0.9995), repeatability(RSD<3.1%), intra-and inter-day precision(RSD<1.8%) with recovery(99.9%―105.1%), limits of detection(0.15―0.35 μg/mL), and limits of quantification(0.53―0.82 μg/mL). The similarities of 32 batches of Rhizoma Coptidis and their classification according to their manufacturers were based on the retention time and peak areas of the characteristic compounds. The five compounds were selected for quality assessment of Rhizoma coptidis via partial least squares analysis(PLS).
The biflavonoid isochamaejasmin is mainly distributed in the root of Stellera chamaejasme L.(Thymelaeaceae) that is used in traditional Chinese medicine(TCM) to treat tumors, tuberculosis, and psoriasis. Herein, isochamaejasmin was found to show similar bioactivity against Bcl-2 family proteins to the reference Bcl-2 ligand(–)-gossypol through 3D similarity search. It selectively bound to Bcl-xL and Mcl-1 with Ki values being 1.93 ± 0.13 μmol·L-1 and 9.98 ± 0.21 μmol·L-1, respectively. In addition, isochamaejasmin showed slight growth inhibitory activity against HL-60 with IC50 value being 50.40 ± 1.21 μmol·L-1 and moderate growth inhibitory activity against K562 cells with IC50 value being 24.51 ± 1.62 μmol·L-1. Furthermore, isochamaejasmin induced apoptosis of K562 cells by increasing the intracellular expression levels of proteins of the cleavage of caspase-9, caspase-3, and PARP which involved in the Bcl-2-induced apoptosis pathway. These results indicated that isochamaejasmin induces apoptosis in leukemia cells by inhibiting the activity of Bcl-2 family proteins, providing evidence for further studying the underlying anti-cancer mechanism of S. chamaejasme L..
