ABSTRACT
Nucleocapsid protein (NCp7), which contains highly conserved retroviral zinc fingers, is essential in the early as well as the late phase of human immunodeficiency virus (HIV) life cycle and constitutes a novel target for AIDS therapy. HIV-1 NCp7 is a basic 55 amino acid protein containing two C(X)2C(X)4H(X)4C motif zinc fingers flanked by basic amino acids on each side. 2,2'-dithiobisbenzamides have previously been reported to release zinc from these NCp7 zinc fingers and also to inhibit HIV replication. Specifically, 2,2'-dithiobisbenzamides derived from simple amino acids showed good antiviral activities. The benzisothiazolone 3, the cyclic derivative of 2, was selected for clinical trials as an agent for AIDS therapy. Herein we report the syntheses and antiviral activities, including therapeutic indices, of 2,2'-dithiobisbenzamides derived from alpha-, beta- and gamma-amino acids. Electrospray ionization mass spectrometry was used to study the zinc-ejection activity of these compounds. Among the alpha-amino acid derived 2,2'-dithiobisbenzamides, analogues containing alkyl side chains were found to be antivirally active with good therapeutic indices. 2,2'-Dithiobisbenzamides, derived from beta- and gamma-amino acids, were found to possess better antiviral and therapeutic efficacies than the alpha-amino acid analogues. Thus compound 59 was found to possess an EC50 of 1.9 microM with a therapeutic index of > 50. Interestingly, 2,2'-dithiobisbenzamides derived from alpha-amino acids containing a protected acid function and polar side chains also exhibited very good antiviral activity.
Subject(s)
Amino Acids/chemistry , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Benzamides/chemistry , Capsid Proteins , Viral Proteins , Amino Acid Sequence , Anti-HIV Agents/metabolism , Capsid/chemistry , Capsid/drug effects , Gene Products, gag/chemistry , Gene Products, gag/drug effects , Humans , Mass Spectrometry/methods , Molecular Sequence Data , Sp1 Transcription Factor/metabolism , Structure-Activity Relationship , Zinc/chemistry , gag Gene Products, Human Immunodeficiency VirusABSTRACT
As part of the National Cancer Institute's Drug Screening Program, a new class of antiretrovirals active against the human immunodeficiency virus HIV-1 has been identified, and the HIV-1 nucleocapsid protein NCp7 was proposed as the target of antiviral action. The 2,2'-dithiobis-[4'-(sulfamoyl)benzanilide] (3x) and the 2,2'-dithiobis(5-acetylamino)benzamide (10) represented the prototypic lead structures. A wide variety of 2,2'-dithiobisbenzamides were prepared and tested for anti-HIV-1 activity, cytotoxicity, and their ability to extrude zinc from the zinc fingers for NCp7. The structure-activity relationships demonstrated that the ability to extrude zinc from NCp7 resided in the 2,2'-dithiobisbenzamide core structure. The 3,3' and the 4,4' isomers were inactive. While many analogs based upon the core structure retained the zinc extrusion activity, the best overall anti-HIV-1 activity was only found in a narrow set of derivatives possessing carboxylic acid, carboxamide, or phenylsulfonamide functional groups. These functional groups were more important for reducing cytotoxicity than improving antiviral potency or activity vs NCp7. All of the compounds with antiviral activity also extruded zinc from NCp7. From this study several classes of low microM anti-HIV agents with simple chemical structures were identified as possible chemotherapeutic agents for the treatment of AIDS.
Subject(s)
Anti-HIV Agents/chemical synthesis , Benzamides/chemical synthesis , Capsid Proteins , Capsid/drug effects , Gene Products, gag/drug effects , Viral Proteins , Zinc Fingers , Anti-HIV Agents/pharmacology , Benzamides/pharmacology , Humans , Structure-Activity Relationship , gag Gene Products, Human Immunodeficiency VirusABSTRACT
A series of 1-cyclopropyl-6-fluoro-8-alkoxy (8-methyoxy and 8-ethoxy)-quionoline-3-carboxylic acids and 1-cyclopropyl-5-amino-6-fluoro-8-alkoxyquinoline-3-carboxylic acids has been prepared and evaluated for antibacterial activity. In addition, they were also compared to quinolones with classic substitution at C8 (H, F, Cl) and the naphthyridine nucleus in a phototoxicity and mammalian cell cytotoxicity assay. The series of 8-methoxyquinolones had antibacterial activity against Gram-positive, Gram-negative, and anaerobic bacteria equivalent to the most active 8-substituted compounds (8-F and 8-Cl). There was also a concomitant reduction in several of the potential side effects (i.e., phototoxicity and clonogenicity) compared to the most active quinolones with classic substitution at C-8. The 8-ethoxy derivatives had an even better safety profile but were significantly less active (2-3 dilutions) in the antibacterial assay.
Subject(s)
Anti-Bacterial Agents/pharmacology , Quinolones/pharmacology , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/toxicity , Bacteria/drug effects , CHO Cells , Cricetinae , Dermatitis, Phototoxic , Drug Design , Female , Mice , Mice, Inbred Strains , Microbial Sensitivity Tests , Quinolones/chemical synthesis , Quinolones/toxicity , Structure-Activity RelationshipABSTRACT
A series of 8-(trifluoromethyl)-substituted quinolones has been prepared and evaluated for in vitro and in vivo antibacterial activity, and phototolerance in a mouse phototolerance assay. These analogues were compared to the corresponding series of 6,8-difluoro- and 6-fluoro-8H-quinolones (ciprofloxacin type). Although their in vitro antibacterial activities are less than the 6,8-difluoro analogues, the 8-(trifluoromethyl)quinolones are generally equivalent to their 8H analogues. In vivo, they are comparable to the 6,8-difluoro series and show up to 10-fold improvement in efficacy when compared to their ciprofloxacin counterparts vs Streptococcus pyogenes and Streptococcus pneumonia. In the phototolerance model, the 8-(trifluoromethyl)quinolones are comparable to the 8H-quinolones. Both of these series display much higher no effect doses (greater tolerance) than the corresponding 6,8-difluoroquinolones.
Subject(s)
Anti-Infective Agents/chemical synthesis , Anti-Infective Agents/toxicity , Photosensitivity Disorders/chemically induced , 4-Quinolones , Administration, Oral , Animals , Anti-Infective Agents/pharmacology , Bacterial Infections/drug therapy , Female , Injections, Subcutaneous , Mice , Microbial Sensitivity Tests , Structure-Activity RelationshipABSTRACT
A series of quinolone and naphthyridine antibacterial agents possessing as the C7-heterocycle bicyclic 2,5-diazabicyclo[n.2.m]alkanes, where n = 2, 3 and m = 1, 2, and a series including 4-aminopiperidine and 3-amino-8-azabicyclo[3.2.1]octanes have been prepared and evaluated in vitro and in vivo for antibacterial activity against a variety of Gram-negative and Gram-positive organisms. These compounds were also tested against the target enzyme bacterial DNA gyrase. All the examples investigated are nearly equipotent with the parent 7-piperazinyl analogues. Only endo-7-(3-amino-8-azabicyclo[3.2.1]oct-8-yl)-1-cyclopropyl-6,8-difluoro- 1,4- dihydro-4-oxo-3-quinolinecarboxylic acid displays activity that surpasses that of the piperazine parent.
