Insight into the Structural Requirements of Urokinase-Type Plasminogen Activator Inhibitors Based on 3D QSAR CoMFA/CoMSIA Models

Isoquinolines: Important Cores in Many Marketed and Clinical Drugs

BACKGROUND

Isoquinoline analogs are an important, structurally diverse class of compounds that are extensively used as pharmaceuticals. Derivatives containing the isoquinoline scaffold have become a focus of therapeutic research because of their wide range of biological characteristics. Examples of these drugs, many of which are in clinical application or at the pre-clinical stage, are used to treat a broad swathe of ailments, such as tumors, respiratory diseases, infections, nervous system diseases, cardiovascular and cerebrovascular diseases, endocrine and metabolic diseases.

METHODS

Data were collected from PubMed, Web of Science, and SciFinder, through searches of drug names.

RESULTS

At least 38 isoquinoline-based therapeutic drugs are in clinical application or clinical trials, and their chemical structure and pharmacokinetics are described in detail.

CONCLUSION

The isoquinoline ring is a privileged scaffold which is often preferred as a structural basis for drug design, and plays an important role in drug discovery. This review provides a guide for pharmacologists to find effective preclinical/clinical drugs and examines recent progress in the application of the isoquinoline scaffold.

Design, synthesis and 3D-QSAR studies of new diphenylamine containing 1,2,4-triazoles as potential antitubercular agents

A new series of new diphenylamine containing 1,2,4-triazoles were synthesized from 4-arylideneamino-5-[2-(2,6-dichlorophenylamino) benzyl]-2H-1,2,4-triazole-3(4H)-thiones 3a-f. The synthesized compounds were screened for in-vitro antimycobacterial and antibacterial activities. The synthesized compounds 4a, 4e and 4d have shown potential activity against Mycobacterium tuberculosis H37Rv strain with MIC of 0.2, 1.6 and 3.125 μM respectively. To investigate the SAR of diphenylamine containing 1,2,4-triazole derivatives in more details, CoMFA (q(2)-0.432, r(2)-0.902) and CoMSIA (q(2)-0.511, r(2)-0.953) models on M. tuberculosis H37Rv were established. The generated 3D-QSAR models are externally validated and have shown significant statistical results, and these models can be used for further rational design of novel diphenylamine containing 1,2,4-triazoles as potent antitubercular agents.

Evaluation of interactions between urokinase plasminogen and inhibitors using molecular dynamic simulation and free-energy calculation

The binding modes of urokinase-type plasminogen activator (uPA) with five inhibitors (1-(7-sulfonamidoisoquinolinyl) guanidine derivatives) were predicted based on molecular dynamic simulations. MM/PBSA free-energy calculations and MM/GBSA free-energy decomposition analyses were performed on the studied complexes. The calculated binding free energies are reasonably consistent with the experimental results. The free-energy decomposition analyses elucidate the different contributions of the energy of some favorable residues in the interactions between protein and ligand of each complex. The results indicate that the inhibitors mainly interact with the S1 pocket of uPA, wherein the hydrogen bonds and the interactions between guanidines and the corresponding residues play an important role. Moreover, hydrogen bond analyses show the water-mediated hydrogen-bond network near the S1 pocket between uPA, and the ligand probably leads to excellent selectivity of these inhibitors on uPA.

Synthesis and antifungal activity of alkyland arylsulfanylpyridinylguanidines

A series of alkyl- and arylsulfanylpyridylguanidines was synthesized and their antimicrobial activity was evaluated in vitro against eight potentially pathogenic strains of fungi. Compounds with an alkylsulfanyl substitution have antifungal activity, which improves with increasing length of the aliphatic chain.