Inhibition of the synthesis of Moloney leukemia virus structural proteins by N-methylisatin-beta-4',4'-diethylthiosemicarbazone

Inhibition of Feline Immunodeficiency Virus Production and HIV Tat Activity by Thiosemicarbazone Derivatives

Two thiosemicarbazone derivatives (TSCD), N-methylisatin-β-4′:4′-diethylthiosemicarbazone (M-IBDET) and N-allylisatin-β-4′:4-diallylthiosemicarbazone (A-IBDAT), were tested for their anti-feline immunodeficiency virus (FIV) activity in FL4/FIV cells. This cell line consists of feline T-lymphocytes chronically infected with FIV. FIV production in FL4/FIV cells was inhibited by M-IBDET and A-IBDAT. Virus inhibition was proportional to drug concentrations and time of treatment. The effective antiviral drug concentrations ranged from 0.06 to 0.64 μm for M-IBDET and from 0.45 to 8.7 μm for A-IBDAT. Tests performed to determine the therapeutic index (TI) value for each drug indicated TI values of 10 and 20 for M-IBDET and A-IBDAT, respectively. Continuous treatment of the cells with low doses of the drugs, given at constant time intervals, for a whole month succeeded in suppressing the chronic infection. Experiments directed towards understanding the mode of inhibition of FIV by TSCD indicated that A-IBDAT is involved in repression of the synthesis of the p24 structural protein of FIV. Examination of the possibility that the TSCD are also involved in suppression of the activity of HIV's tat regulatory protein showed a clear dose-responsive inhibition of HIV's tat-mediated transactivation by M-IBDET and A-IBDAT.

Inhibitory Activity of 4-[(1,2-dihydro-2-oxo-3H-indol-3-ylidene)amino]-N-(4,6-dimethylpyrimidin-2-yl) Benzenesulphonamide and its Derivatives against Orthopoxvirus Replication in vitro

4-[(1,2-Dihydro-2-oxo-3H-indol-3-ylidene)amino]-N-(4,6-dimethylpyrimidin-2-yl) benzenesulphonamide and its derivatives were tested in vitro for antiviral activity against vaccinia and cowpox virus replication in human foreskin fibroblast (HFF) cells, and their activity was compared with cidofovir (CDV). Among the tested compounds, 4-[(5-methyl-1,2-dihydro-2-oxo-3-H-indol-3-ylidene)amino]- N-(4,6-dimethylpyrimidin-2-yl)benzene-sulphonamide was the most active against vaccinia virus, with a 50% effective concentration (EC50) value of 18 µM and 4-[(N-acetyl-1,2–dihydro-2-oxo-3-H-indol-3-ylidene)amino]- N-(4,6-dimethylpyrimidin-2-yl) benzenesulphonamide was the most active against cowpox virus (EC50=33 µM). Cidofovir was found to have an EC50 of 20 µM and 32 µM against vaccinia and cowpox virus, respectively. Most of the tested compounds were non-cytotoxic (>300 µM) in HFF cells as determined by a neutral red uptake assay. The substitution of a halogen atom at the 5-position of isatin abolished the antiviral activity.

Synthesis of thiocarbohydrazide and carbohydrazide derivatives as possible biologically active agents

Abstract

A series of new β-isatin aldehyde-N,N′-thiocarbohydrazone, bis-β-isatin thiocarbohydrazones, bis-β-isatin carbohydrazones was synthesized by condensation of 5-substituted isatin with thiocarbohydrazide or carbohydrazide. The chemical structures of the newly synthesized compounds were confirmed by FT-IR, ¹H NMR, and mass spectral analysis. The synthesized compounds were evaluated for in vitro antiviral activity against various strains of DNA and RNA viruses, but exhibited moderate antiviral activity compared with the reference compounds. Among all the compounds 6c exhibited the highest chemoprevention activity in a two-stage mouse-skin carcinogenesis test.

Graphical abstract

Design, Synthesis and antiHIV activity of Novel Isatine-Sulphonamides

A series of novel isatine-sulphonamide derivatives have been synthesized by combining isatin derivatives with sulphonamides. The structure of the synthesized compounds were elucidated by spectral analysis (IR, NMR and Mass). Investigation of anti-HIV activity was done against HIV-1(IIIB) in MT-4 cells and HIV integrase inhibitory activity. 4-(1-acetyl-5-methyl-2-oxoindolin-3-ylideneamino)-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide (SPIII-5ME-AC) inhibits the HIV Integrase enzymatic activity as both over all and strand transfer reaction and 4-(1-benzoyl-5-chloro-2-oxoindolin-3-ylideneamino)-N-(4,6-dimethylpyrimidin-2-yl)benzene sulfonamide (SPIII-5Cl-BZ) exhibits 36 percent maximum protection against HIV-1 at sub toxic concentration.

Anti-influenza virus activities of 4-[(1,2-dihydro-2-oxo-3H-indol-3-ylidene)amino]-N-(4,6-dimethyl-2-pyrimidin-2-yl)benzenesulphonamide and its derivatives

4-[(1,2-Dihydro-2-oxo-3H-indol-3-ylidene)amino]-N-(4,6-dimethyl-2-pyrimidinyl)-benzenesulphonamide (SPIII-5H) and related compounds were tested for antiviral activity against influenza A (H1N1, H3N2, and H5N1) and B viruses in Madin Darby canine kidney (MDCK) cell culture. Among the compounds tested, SPIII-5H and four derivatives (5-chloro [SPill-5Cl], 5-bromo [SPIII-5Br], 5-methyl [SPIII-5Me] and N-acetyl [SPIII-NA]) showed similar antiviral potencies, with only the 5-fluoro (SPIII-5F) derivative being ineffective. Fifty percent effective concentration (EC50) values were determined in cytopathic effect (CPE) inhibition assays quantified by neutral red dye uptake. By this method, the active compounds were inhibitory to the H1N1 strain of influenza A at 2.7-5.2 microg/ml, to the H3N2 strain of influenza A at 13.8-26.0 microg/ml, to the H5N1 strain of influenza A at 3.1-6.3 microg/ml and to influenza B at 7.7-11.5 microg/ml. Confirmatory virus yield reduction studies against influenza A (H1N1) virus demonstrated antiviral activity (90% inhibition) at concentrations of 2-10 microg/ml. No cytotoxic effects were evident in actively growing uninfected cells or stationary monolayers at 100 microg/ml. Potencies of the compounds were similar to those of ribavirin, but much less than those of oseltamivir carboxylate against the various viruses. Time-of-addition studies indicated the compounds inhibited an early step in the virus replication cycle, probably virus adsorption/penetration, and no virucidal activity was evident. The basic molecule is amenable to diverse chemical modifications, which may improve water solubility and antiviral potency.

Synthesis and evaluation of anti-HIV activity of isatin β-thiosemicarbazone derivatives

On the basis of pharmacophoric modelling studies of existing NNRTIs, a series of isatin beta-thiosemicarbazone derivatives was synthesized and evaluated for their anti-HIV activity in HTLV-III(B) strain in the CEM cell line. Three compounds showed significant anti-HIV activity, whereupon compound 6 was found to be the most active compound with an EC(50) value of 2.62 microM and a selectivity index of 17.41, while not being cytotoxic to the cell line at a CC(50) value of 44.90 microM. Other tested compounds exhibited marked activity below their toxicity threshold.

Synthesis and primary cytotoxicity evaluation of new 5-nitroindole-2,3-dione derivatives

A new series of 5-nitro-1H-indole-2,3-dione-3-thiosemicarbazones (3a-k) obtained by condensation of 5-nitro-1H-indole-2,3-dione (1) with N-substituted-thiosemicarbazides (2a-k) were treated with morpholine or piperidine and formaldehyde to yield 1-morpholino/piperidinomethyl-5-nitroindole-2,3-dione-3-thiosemicarbazones (4a-m). The structures of all the compounds were determined by analytical and spectral (IR, 1H-NMR, EIMS) methods. Compounds 3b, 3c, 3f, 3k, 4a, 4c, 4f and 4l chosen as prototypes were evaluated in the National Cancer Institute's 3-cell line, one dose in vitro primary cytotoxicity assay. All the compounds that passed the criteria for activity in this assay were scheduled automatically for evaluation against the full panel of 60 human tumour cell lines at a minimum of five concentrations at 10-fold dilutions. Sulphorhodamine B (SRB) protein assay was used to estimate cell stability or growth. The most active compound was found to be 1-morpholinomethyl-5-nitroindole-2,3-dione-3-N-(chlorophenyl)thiosemicarbazone (4l). This compound demonstrated the most marked effects in the National Cancer Institute's 60 human tumour cell line in vitro screen on a non-small cell lung cancer cell line (HOP-62, log(10)GI(50) value <-8.00) and on leukaemia cell lines (HL-60(TB), log(10)GI(50) value -6.30; MOLT-4, log(10)GI(50) value -6.18).

Inhibition of human immunodeficiency virus by N-methylisatin-beta 4':4'-diethylthiosemicarbazone and N-allylisatin-beta-4':4'-diallythiosemicarbazone

N-methylisatin-beta 4':4'-diethylthiosemicarbazone(M-IBDET) and N-allylisatin-beta-4':4'-diallylthiosemicarbazone(A-IBDAT ) inhibit the production of Human Immunodeficiency virus (HIV). Virus inhibition was related to the thiosemicarbazone derivative (TSCD) concentrations and time of treatment. Inhibition of HIV production was confirmed by various parameters of virus assay employing reverse transcriptase activity, plaque forming units (PFU) and levels of viral structural proteins. Effective antiviral TSCD concentrations ranged from 0.17 microM to 2.04 microM for M-IBDET, and from 1.45 microM to 17.4 microM for A-IBDAT. Treatment of the chronic HIV-infected cells for 48 h with 0.34 microM M-IBDET or 2.9 microM A-IBDAT caused about 50% inhibition in as virus yield ED50 as assayed by the PFU method. Almost 2 logs of virus infectivity (PFU) was suppressed after 48 h of treatment with 17.4 microM A-IBDAT. Therapeutic index values of 20 and 30 were found for M-IBDET and A-IBDAT, respectively. A significant selective inhibition of HIV structural protein synthesis was shown by both M-IBDET and A-IBDAT.

Selective repression of v-abl-encoded protein by N-methylisatin-beta-4',4'-diethylthiosemicarbazone and N-allylisatin-beta-4',4'-diallylthiosemicarbazone

N-Methylisatin-beta-4',4'-diethylthiosemicarbazone (M-IBDET) and N-allylisatin-beta-4',4'-diallylthiosemicarbazone (A-IBDAT) selectively inhibited v-abl protein (P120), an oncogene product associated with tyrosine kinase activity. Concentrations of M-IBDET ranging between 0.17 and 0.64 microM and concentrations of A-IBDAT from 1.45 to 2.9 microM reduced tyrosine kinase activity significantly, whereas 0.64 microM M-IBDET and 2.9 microM A-IBDAT blocked P120 production. Cellular growth rate, protein production, and synthesis of p45 actin and p53 nuclear oncogene were not affected at these conditions. M-IBDET and A-IBDAT selectively suppress the v-abl oncogene as well as Moloney murine leukemia virus production.

N-methylisatin-beta-4',4'-diethylthiosemicarbazone, an inhibitor of Moloney leukemia virus protein production: characterization and in vitro translation of viral mRNA

The mode of inhibition of N-methylisatin-beta-4',4'-diethylthiosemicarbazone (M-IBDET) on Moloney leukemia virus production was studied. Drug treatment of infected cells did not alter the amounts or sizes of the 35S and 22S subgenomic viral RNAs. The translation abilities of poly(A)+ RNA derived from M-IBDET-treated cells was also unaffected, as judged by cell-free translation analysis. Poly(A)+ RNA derived from M-IBDET-treated cells directed translation of equal amounts of viral gag precursors, gPr-80gag and Pr-65gag, as did poly(A)+ RNA prepared from untreated cells. The addition of M-IBDET to a cell-free translation system programmed with either total poly(A)+ RNA extracted from infected cells or hybrid-selected viral RNA inhibited the synthesis of viral protein precursors. An examination of the effect of M-IBDET on polysomes engaged in the translation of viral proteins revealed a fourfold accumulation of polysomal virus-specific RNA in drug-treated cells. These results suggest that the inhibition of Moloney leukemia virus by M-IBDET involves a block in the translation of viral RNA rather than interference with viral RNA transcription.