Synthesis and antitumor evaluation in mice of certain 7-deazapurine (pyrrolo[2,3-d]pyrimidine) and 3-deazapurine (imidazo[4,5-c]pyridine) nucleosides structurally related to sulfenosine, sulfinosine, and sulfonosine

7-Deaza (pyrrolo[2,3-d]pyrimidine) and 3-deaza (imidazo[4,5-c]pyridine) congeners of sulfenosine (5a and 9), sulfinosine (6a and 10), and sulfonosine (7a) have been prepared and evaluated for their antileukemic activity in mice. Amination of 2-amino-7-beta-D-ribofuranosylpyrrolo[2,3-d]pyrimidine-4(3H)-th ion e (4a) and its 2'-deoxy analogue (4c) with a chloramine solution gave the corresponding 4-sulfenamides (5a and 5c, respectively), which on selective oxidation with m-chloroperoxybenzoic acid (MCPBA) gave the respective diastereomeric 2-amino-7-beta-D-ribofuranosyl-pyrrolo[2,3-d]pyrimidine-4-sulfinamide (7-deazasulfinosine, 6a) and its 2'-deoxy derivative (6c). A similar amination of 7-(2-deoxy-beta-D-erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine-4(3H)- thione (4b) gave the corresponding 4-sulfenamide derivative (5b). Oxidation of 5b with 1 molar equiv of MCPBA furnished (R,S)-7-(2-deoxy-beta-D-erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine- 4- sulfinamide (6b), whereas use of excess of MCPBA afforded the corresponding sulfonamide derivative (7b). Treatment of 3-deaza-6-thioguanosine (8) with a chloramine solution gave 3-deazasulfenosine (6-amino-1-beta-D- ribofuranosylimidazo[4,5-c]pyridine-4-sulfenamide, 9). Controlled oxidation of 9 with MCPBA afforded 3-deazasulfinosine (10). As gauged by increases in the mean postinoculation life spans of L1210 inoculated mice, none of these nucleosides exhibited biologically significant activity (T/C greater than or equal to 125). Even so, antileukemic activity appeared to be influenced, albeit not uniformly, by structural modifications in the base and carbohydrate moieties of sulfenosine and sulfinosine. Thus, while several of the compounds were lacking in cytotoxic activity, eight others (4c, 5a, 5c, 6a, 6b, 7b, 9, and 10) were estimated to have reduced body burdens of viable L1210 cells by 16-77%.     

Synthesis and anti-DNA -virus activity of the 5'-monophosphate and the cyclic 3',5'-monophosphate of 9-(beta-D-xylofuranosyl) guanine.

9-(beta-TD-xylofuranosyl)guanine (xylo-G) was converted chemically to the 9-(beta-D-xylofuranosyl)guanine 5'-monophosphate (xylo-GMP) and 9-(beta-D-xylofuranosyl)guanine cyclic 3',5'-monophosphate (c-xylo-GMP). These compounds were tested against a variety of DNA viruses in tissue culture in parallel with 9-(beta-D-arabinofuranosyl)adenine (ara-A). This evaluation revealed that xylo-G, xylo-GMP, and c-xylo-GMP were all moderately active but less effective than ara-A. When the four compounds were administered intracerebrally as a treatment for herpes virus, type 1 induced encephalitis in mice, c-xylo-GMP exhibited superior activity to that shown by the other three. When administered intraperitoneally, c-xylo-GMP was found to have a therapeutic index of about 4, which is less than that for ara-A (approximately 30) in the same system.     

Comparative bioequivalence study of rifampicin and isoniazid combinations in healthy volunteers.

OBJECTIVE: To assess the bioavailability of rifampicin (RMP) in three brands of combination formulations of anti-tuberculosis drugs. DESIGN: A three-way double-blind, cross-over bioavailability study of RMP and isoniazid (INH), consisting of a comparison of a two-drug combination of tablets of RMP and INH each separately (reference brand R) and a tablet of RMP + INH (brand N), and a capsule of RMP + INH (brand L) was carried out in 12 healthy male volunteers. Coded plasma samples were analysed for levels of RMP as well as INH and acetylisoniazid (ACINH) by two high performance liquid chromatography (HPLC) methods. RESULTS: The mean values of RMP in brand N (Cmax 6.49+/-0.52 microg/mL, Tmax 2.33+/-0.18 h, AUC(0-24h) 39.83+/-3.44 microg/mL.h) were comparable with those obtained with brand R (Cmax 5.22+/-0.59 microg/mL, Tmax 2.50+/-0.12 h, AUC(0-24h) 33.33+/-3.47 microg/mL.h). The mean values of RMP in brand L (Cmax 3.05+/-0.52 microg/ mL, Tmax 3.79+/-0.57 h and AUC(0-24h) 21.78+/-3.67 microg/ mL.h) were significantly different from those in brand R. Nevertheless, all of the pharmacokinetic parameters obtained for INH and ACINH in all three brands were comparable. CONCLUSION: Using brand R as a comparison, brand N was bioequivalent and brand L was not bioequivalent.     

Synthesis and antiviral activity of certain 5'-monophosphates of 9-D-arabinofuranosyladenine and 9-D-arabinofuranosylhypoxanthine.

A number of 5'-phosphates of 9-D-arabinofuranosyladenine and 9-D-arabinofuranosylhypoxanthine were prepared and tested against a variety of DNA viruses in tissue culture. The syntheses of the antiviral agent 9-beta-D-arabinofuranosylhypoxanthine 5'-monophosphate (6) and a series of related nucleotides, 9-beta-D-arabinofuranosyladenine 5'-O-methylphosphate (3), 9-beta-D-arabinofuranosylhypoxanthine 5'-O-methylphosphate (7), 9-beta-D-arabinofuranosylhypaxanthine cyclic 3',5'-phosphate (13), and 9-alpha-D-arabinofuranosylhypoxanthine 5'-monophosphate (17), are described. The concepts underlying the development of these antiviral agents are discussed. Comparison of the anti-DNA viral activity is made with 9-beta-D-arabinofuranosyladenine (ara-A). Reproducible antiviral activity against three DNA viruses in vitro at nontoxic dosage levels is demonstrated by 3,6, and other related nucleotides.     

Genetic diversity of human pathogenic members of the Fusarium oxysporum complex inferred from multilocus DNA sequence data and amplified fragment length polymorphism analyses: evidence for the recent dispersion of a geographically widespread clonal lineage and nosocomial origin

Fusarium oxysporum is a phylogenetically diverse monophyletic complex of filamentous ascomycetous fungi that are responsible for localized and disseminated life-threatening opportunistic infections in immunocompetent and severely neutropenic patients, respectively. Although members of this complex were isolated from patients during a pseudoepidemic in San Antonio, Tex., and from patients and the water system in a Houston, Tex., hospital during the 1990s, little is known about their genetic relatedness and population structure. This study was conducted to investigate the global genetic diversity and population biology of a comprehensive set of clinically important members of the F. oxysporum complex, focusing on the 33 isolates from patients at the San Antonio hospital and on strains isolated in the United States from the water systems of geographically distant hospitals in Texas, Maryland, and Washington, which were suspected as reservoirs of nosocomial fusariosis. In all, 18 environmental isolates and 88 isolates from patients spanning four continents were genotyped. The major finding of this study, based on concordant results from phylogenetic analyses of multilocus DNA sequence data and amplified fragment length polymorphisms, is that a recently dispersed, geographically widespread clonal lineage is responsible for over 70% of all clinical isolates investigated, including all of those associated with the pseudoepidemic in San Antonio. Moreover, strains of the clonal lineage recovered from patients were conclusively shown to genetically match those isolated from the hospital water systems of three U.S. hospitals, providing support for the hypothesis that hospitals may serve as a reservoir for nosocomial fusarial infections.