氨基喹啉类化合物结构与抗疟原虫活性的相关分析

The extended gravitational index G Q and quantum-chemical descriptors were calculated for the relationship analysis of aminoquinolines. An evolutionary algorithm was described for variable selection and building QSAR models. And the quasi-newton neural networks were employed with better results.

Study on 3D-QSAR of Retinoids 3D-Interaction between Retinoids and their Receptor **

Fast and precise prediction of the receptor-ligand binding constant is an important aspect of structure-based drug design. Almost all de novo design methods or 3D database search methods tend to structure generation instead of structure evaluation. In this article, epididymal retinoic acid binding protein (ERABP) was used as a template to simulate the interaction between retinoids and their receptor. We deduced an equation predicting the drug-receptor binding constant. Furthermore, the conformers after docking were used in CoMFA analysis to get a pharmacophore model of this series of compounds.

Development of Cardiovascular Drugs Based on Isoquinoline Compounds from Chinese Medicinal Materials

By using active principles of Chinese medicinal materials as lead compounds soquinoline derivatives have been designed and synthesized.Their chemical structures include bisbenzylisoquinoline,benzyl-isoquinoline and protoberberine.Their cardiovascular effects were studied involving α-adrenoceptor,adenosine A_1,A_2 and DPH-calcium channel radioreceptor assays.In addition,calmodulin inhibiting,calcium antagonistic potassium channel blocking and antiplatelet aggre- gation activities were also performed.It was found that compound VI_(19) was a new potassium channe blocker with α-adrenoceptor antagonism,compound V_9,and V_(21) lowered blood pressure on various animal models with negative chronotropic action,compound VI_(13)possessed antiarrhythmic and antifi- brillation action,and it may be a candidate tot clinic evaluation.The structure-activity relationships deduced may provide a theoretical basis for further development of new agents.

A 3D-QSAR Study on C-3 Substituted 4,6-Dichloroindole-2- Carboxylic Acids with Comparative Molecular Field Analysis

Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carboxylic acids to study the relationship betweentheir structure and the affinity for the glycine site of the NMDA receptor. Result Hie coefficientsof cross-validation q^2 and non cross-validation r^2 for the model established by the study are0.744 and 0.993, respectively, the value of variance ratio F is 261.343, and standard error estimate(SE) is 0.039. Conclusion These values indicate that the CoMFA model may have a good prediction forthe activity of C-3 substituted 4, 6-dichloroin-dole-2-carboxylic acids. As a consequence, thepredicted activity values of new designed compounds supports our conclusion from the model.

Synthesis,algal inhibition activities and QSAR studies of novel gramine compounds containing ester functional groups

2,5,6-Tribromo-l-methylgramine （TBG）, isolated from bryozoan Zoobotryon pellucidum was shown to be very efficient in preventing recruitment of larval settlement. In order to improve the compatibility of TBG and its analogues with other ingredients in antifouling paints, structural modification of TBG was focused mainly on halogen substitution and N-substitution. Two halogen-substitute gramines and their derivatives which contain ester functional groups at N-position of gramines were synthesized. Algal inhibition activities of the synthesized compounds against algae Nitzschia cIosterium were evaluated and the Median Effective Concentration （EC50） range was 1.06-6.74 lag ml^-1. Compounds that had a long chain ester group exhibited extremely high antifouling activity. Quantitive Structure Activity Relationship （QSAR） studies with multiple linear regression analysis were applied to fred correlation between different calculated molecular descriptors and biological activity of the synthesized compounds. The results show that the toxicity （log （I/EC50）） is correlated well with the partition coefficient log P. Thus, these products have potential function as antifouling agents.

Structure-activity relationships of oxime compounds as flotation collectors by DFT calculations

The relationships between the structure of oxime compounds(R^(1)R^(2)C=NOH,R^(1)/R^(2)=alkyl groups) with different substituents and their corresponding flotation performances were studied. The analyses of density functional theory(DFT) calculations illustrated that the introduced phenyl group at the R^(1) position could enhance the acidity,while the heptyl group could effectively increase the hydrophobicity and benefit van der Waals interactions. Meanwhile,the introduced amino group at the R^(2) position could provide cationic sites to interact with negatively charged surfaces of minerals, while the introduced hydroxyl group could provide additional action sites to form stable chelates with metal ions. Based on the structure-activity relationships, structural optimization was carried out to obtain three efficient collectors, which possessed superior flotation separation performances, proving the effectiveness of the structural modification to oxime compounds in this work.

Docking and 3D-QSAR studies of N-benzyl isatin oximes as JNK3 inhibitors

The c-Jun N-terminal kinase （JNK） is involved in a variety of important cellular processes and aberrant JNK activity is associated with many human diseases.The ligand-based and receptor-based alignment rules were used to build 3D-QSAR models for a series of N-benzyl isatin oximes JNK inhibitors. The best models were obtained for the receptor-based alignment with CoMSIA combining steric （S）, electrostatic （E）, and hydrogen bond donor （D） and hydrogen bond acceptor （A） fields （q2 = 0.759, r2 = 0.966, r2 pred = 0.703）. Based on the contour maps of RB CoMSIA model, some key structural factors responsible for inhibitory activity were investigated. Large groups at N-substituent or R6 position are preferred to interact with hydrophobic residues Ile70, Asp150, Ala151, Asn152 and Ser193. Electron-donating or hydrogen bond donor groups on the isatin ring would form polar and hydrogen bond with the negative-charged residue Glu147. In addition, electron-withdrawing groups or hydrogen bond acceptor group near the N-substituent would enhance inhibitory activity. The results are in good accordance and complementary to each other. The developed models could provide guidance in the rational design of more potent and selective JNK inhibitors.

Prenylated flavonoids from Glycyrrhiza uralensis as promising anti-cancer agents: a preliminary structure-activity study

Prenylated flavonoids are mainly distributed in Leguminosae and Moraceae plants, and they have been reported to possess various biological activities. Previously, we have reported a prenylated isoflavonoid, isoangustone A（IAA） from licorice（Glycyrrhiza uralensis）, which induces apoptosis in colorectal cancer cells by disrupting mitochondrial functions. In the present study, we compared a group of flavonoids from licorice with IAA for their anti-proliferation activities and effects on intracellular signaling. The results indicated that the isoprenyl groups on the A and B rings, the hydroxyl groups at the ortho position of isoprenyl on A ring and the conjugated plane of C ring might contribute to the anti-cancer activity of prenylated flavonoids. Based on the above structure-activity relationship, we further identified four prenylated flavonoids with similar anti-cancer activities from licorice. Taken together, our present study established a preliminary structure-activity relationship of anti-cancer prenylated flavonoids, and our data provided important leading compounds from licorice, which deserved further research and development.

Quantitative structure-activity relationship of compounds binding to estrogen receptor β based on heuristic method

Estrogen compounds may pose a serious threat to the health of humans and wildlife. The estrogen receptor （ER） exists as two subtypes, ERα and ERβ. Compounds might have different relative affinities and binding modes for ERα and ERβ. In this study, the heuristic method was performed on 31 compounds binding to ERβ to select 5 variances most related to the activity （LogRBA） from 1524 variances, which were then employed to develop the best model with the significant correlation and the best predictive power （γ^2 = 0.829, q^2LOO = 0.742, γ^2pred = 0.772, q^2ext = 0.724, RMSEE = 0.395） using multiple linear regression （MLR）. The model derived identified critical structural features related to the activity of binding to ERβ. The applicability domain （AD） of the model was assessed by Williams plot.