2,4,5-三苯基咪唑类化合物的合成及其双光子特性

以4,4′-二甲基苯偶酰为原料合成了3个2-(4-取代苯基)-4,5-二(4-甲基苯基)咪唑系列衍生物,对其结构进行了表征,通过测定其光物理性质,发现这类化合物不仅具有较高的荧光量子产率,而且具有较大的双光子吸收截面,是很好的双光子显微和成像以及上转换激射荧光的候选材料.     

Support vector machine applied in QSAR modelling

Support vector machine （SVM）, partial least squares （PLS）, and Back-Propagation artificial neural network （ANN） were employed to establish QSAR models of 2 dipeptide datasets. In order to validate predictive capabilities on external dataset of the resulting models, both internal and external validations were performed. The division of dataset into both training and test sets was carried out by D-optimal design. The results showed that support vector machine （SVM） behaved well in both calibration and prediction. For the dataset of 48 bitter tasting dipeptides （BTD）, the results obtained by support vector regression （SVR） were superior to that by PLS in both calibration and prediction. When compared with BP artificial neural network, SVR showed less calibration power but more predictive capability. For the dataset of angiotensin-converting enzyme （ACE） inhibitors, the results obtained by support vector machine （SVM） regression were equivalent to those by PLS and BP artificial neural network. In both datasets, SVR using linear kernel function behaved well as that using radial basis kernel function. The results showed that there is wide prospect for the application of support vector machine （SVM） into QSAR modeling.     

2-苯基吲哚衍生物的定量结构-活性关系研究

 应用半经验量子化学AM1法得到了36种2-苯基吲哚衍生物的优势构像,再利用量子化学算法和分子图形学技术获得电子结构、几何结构及连接性结构参数,并将这些参数和2-苯基吲哚衍生物在4℃时与小牛子宫雌激素受体的相对亲合力相关联.结果表明:2-苯基吲哚衍生物在4℃时与小牛子宫雌激素受体的亲合力大小和氮原子所连原子的净电荷Q;2号、3号、10号和15号原子间的二面角D;5号碳原子与其所连原子间的键长L和零阶连接性指数°G的相关性较好,成功地建立了36种2-苯基吲哚衍生物的构效关系式.     

粒子群优化算法在定量结构活性相关性研究中的应用

粒子群优化(PSO)算法是一种新兴的优化技术，该算法简单易实现，可调参数少，已广泛应用于许多研究领域，但PSO在化学中的应用还非常少．介绍了粒子群优化算法和改进的离散粒子群优化算法的基本原理，同时结合作者科研组的工作，将其在化学构效关系研究中的应用给予简述．     

基于QSAR和PCA方法的硝基芳烃综合毒性评价

化学品的风险评价与管理应该关注基于多种生物体效应的综合毒性。为了评价毒性数据稀缺化合物的综合毒性,以50种硝基芳烃为研究对象,收集了它们的多种生物毒性数据,建立了稳健的定量结构活性相关(quantitative structure-activity relationship,QSAR)模型,预测缺失毒性数据,解释了硝基芳烃的致毒机理——硝基芳烃与生物受体分子的亲电反应活性是决定其毒性的主要因素。然后应用主成分分析(principle componentan alysis,PCA)方法对基于QSAR模型计算获得的50种硝基芳烃的各种生物毒性数据进行分析,计算综合毒性因子(integrated toxicity index,ITI),对综合毒性因子进行QSAR分析,得到可直接由硝基芳烃结构参数预测综合毒性因子的单参数QSAR模型。结果表明,QSAR与PCA方法的结合可以成功地评价和预测硝基芳烃的综合毒性。     

抗爱滋病药物吡喃酮类化合物电子结构与生物活性关系

吡喃酮类化合物是抗爱滋病的一种新药，用从头计算法G98W程序对19个吡喃酮类化合物进行量子化学计算，讨论它们的电子结构特征与生物活性的关系，得到较满意的结果，可为这类抗爱滋病化合物的分子设计提供参考依据。     

六种天然抗氧化剂活性的理论评价

用DFT和AMI结合的量子化学方法计算了六种天然抗氧化剂灯盏花乙素、芦丁、葛根素、黄芩甙、灯盏花甲素、焦袂康酸的O-H键解离焓和电离势，并以此为理论指标评价了其抗氧化活性。发现在极性和非极性溶剂中，灯盏花乙素均具有较强的清除自由基活性，提示可作为治疗缺血性脑中风、冠心病、心绞痛等疾病的有效成份。     

Chemistry of odor stimuli

Summary The present state of the molecular basis of olfaction is shown. With the aid of various examples the regioselectivity of odor sensation is proven. The main part of the experimentation concerns the stereocontrolled process of odor release.     

9-Methyl-7-bromoeudistomin D,a potent inducer of calcium release from sarcoplasmic reticulum of skeletal muscle

Summary The Ca²⁺-releasing action of several derivatives of eudistomin D isolated from a marine tunicate was compared with that of caffeine. It was found that 9-methyl-7-bromoeudistomin D was approximately 1000 times more potent than caffeine in causing Ca²⁺ release from the sarcoplasmic reticulum.The authors thank Ms A. Muroyama of this institute for her technical assistance and Prof. K. L. Rinehart of University of Illinois for his encouragement.