Design, Synthesis, and Anti-HIV-1 Evaluation of a Novel Series of 1,2,3,4-Tetrahydropyrimidine-5-Carboxylic Acid Derivatives.

A series of tetrahydropyrimidine derivatives (2a - 2l) were designed, synthesized, and screened for anti-HIV-1 properties based on the structures of HIV-1 gp41 binding site inhibitors, NB-2 and NB-64. A computational study was performed to predict the pharmacodynamics, pharmacokinetics, and drug-likeness features of the studied molecules. Docking studies revealed that the carboxylic acid group in the molecules forms salt bridges with either Lys574 or Arg579. Physiochemical properties (e.g., molecular weight, number of hydrogen bond donors, number of hydrogen bond acceptors, and number of rotatable bonds) of the synthesized compounds confirmed and exhibited that these compounds were within the range set by Lipinski's rule of five. Compounds 2e and 2k with 4-chlorophenyl substituent and 4-methylphenyl group at C(4) position of the tetrahydropyrimidine ring was the most potent one among the tested compounds. This suggests that these compounds may serve as leads for development of novel small-molecule HIV-1 inhibitors.

Synthesis, Biological Evaluation, and Molecular Docking Studies of Novel 4-[4-Arylpyridin-1(4H)-yl]benzoic Acid Derivatives as Anti-HIV-1 Agents.

The structural similarities between N1 substituted 1,4-dihydropyridines and the known gp41 inhibitors, NB-2 and NB-64, were considered in the current research for the design of some novel anti-HIV-1 agents. A series of novel 4-[4-arylpyridin-1(4H)-yl]benzoic acid derivatives were synthesized and after a comprehensive structural elucidation were screened for in vitro anti-HIV-1 activity. Most of the tested compounds displayed moderate to good inhibitory activity against HIV-1 growth and were evaluated for in vitro cytotoxic activity using XTT assay at the concentration of 100 µm. Among the tested compounds, 1c, 1d and 1e showed potent anti-HIV-1 activity against P24 expression at 100 µm with inhibition percentage of 84.00%, 76.42% and 80.50%, respectively. All the studied compounds possessed no significant cytotoxicity on MT-2 cell line. The binding modes of these compounds to gp41 binding site were determined through molecular docking study. Docking studies proved 1a as the most potent compound and binding maps exhibited that the activities might be attributed to the electrostatic and hydrophobic interactions and additional H-bonds with the gp41 binding site. The Lipinski's 'rule of five' and drug-likeness criteria were also calculated for the studied compounds. All derivatives obeyed the Lipinski's 'rule of five' and had drug-like features. The findings of this study suggest that novel 4-[4-arylpyridin-1(4H)-yl]benzoic acid might be a promising scaffold for the discovery and development of novel anti-HIV-1 agents.

Screening, Cloning and Expression of Active Streptokinase from an Iranian Isolate of S.equisimilis Group C in E. coli.

INTRODUCTION: Streptokinase (SK) is a fibrinolytic protein secreted by ß-hemolytic streptococci (ßHS) groups A, C and G. Due to its importance as a thrombolytic drug, national screening programs in different countries for isolation of ßHS and especially SK-producing group C (GCS) strains have been conducted. Herein, we provide data of the first screening study on ßHS isolates in Iran for the aim of recombinant SK (rSK) production from a local strain. MATERIALS AND METHODS: 252 streptococcal samples were collected and characterized using microbial/biochemical assays. The GCS strains were serologically confirmed. Activity of GCS supernatant cultures was determined by caseinolytic assay in comparison with the standard strain GCS9542. The SK gene of the highest producer strain was selected for production of rSK in E.coli system. The rSKs activities were determined using chromogenic assay. RESULTS: ßHS were detected in 75 of the collected specimens (29.4%) including groups A (25.8%), C (3.6%) and G (0.4%). Analyses by SDS-PAGE and Western blotting indicated the proper expression of 47 kDa rSK proteins in E. coli for SK genes which were cloned from both the selected (GCS-87) and standard (GCS-9542) strains with the yields of 0.53 and 0.59 mg/ml (of the purified protein), respectively. The calculated activity for rSK 87 was around 90% of rSK9542 activity (0.18x105 IU/mg v/s 0.21x105 IU/mg). CONCLUSION: RESULTS of the present study for the first time provided the possibility of producing rSK from a local and native source with comparable yields and activities similar to the standard strain.

Genetic polymorphism of chemokine receptors CCR2 and CCR5 in Swedish cervical cancer patients.

Chemokines are chemotactic cytokines that orchestrate leukocyte trafficking in tissues, thus, playing an important role in regulation of immunological processes. The aim of this study was to investigate the association of human papillomavirus (HPV) infection and cervical cancer with two DNA polymorphisms of the chemokine receptors CCR5-delta32 and CCR2-64I. The study material consisted of 50 cervical intraepithelial neoplasia (CIN) cases and 50 of age and sampling-date matched controls, 100 invasive cervix cancer cases and 100 of their corresponding matched disease-free controls. Pyrosequencing was employed to genotype the CCR2-64I polymorphism. CCR5-delta32 was genotyped using standard PCR fragment length analysis. The frequencies of CCR2 and CCR5 genotypes from 150 patients and 150 healthy controls were representative of the general population according to the Hardy-Weinberg equilibrium analysis. Risk association was computed with conditional logistic regression analysis. HPV-positive individuals with the rare CCR5deelta32/delta32 genotype have a risk of 4.58 (CI = 0.40-52.64, p-value = 0.045) compare to HPV negative group. The delta-32 mutation on the CCR locus is imperceptibly associated with increased risk of HPV infection. In total, cervical neoplasia was not associated with genetic polymorphism of CCR2 and CCR5.