Relationships between the chemical structure of antimycobacterial substances and their activity against atypical strains. Part 14: 3-Aryl-6,8-dihalogeno-2H-1,3-benzoxazine-2,4(3H)-diones

A set of eight derivatives of 6,8-dichloro-3-phenyl-2H-benzoxazine-2,4(3H)-dione and nine derivatives of 6,8-dibromo-3-phenyl-2H-1, 3-benzoxazine-2,4(3H)-dione, substituted on the phenyl ring, was prepared by the reaction of the corresponding salicylanilides with ethyl chloroformate. The compounds were evaluated in vitro for antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium. Their activity increases with increasing hydrophobicity and electron-withdrawing ability of the substituents on the phenyl ring.

[The technology for manufacturing antiparasitic preparations. 8. The preparation rilanid and its use for treating fascioliasis and intestinal nematodiases]

A procedure has been developed to prepare the anthelminthic Rilanide as a fine-dispersed formulation. The therapeutical dose of the agent in fascioliasis and intestinal nematodiasis is 60 mg/kg (for sheep), if given alone, and 100 mg/kg, if added to feed.

Synthesis and sigma binding properties of 1'- and 3'-halo- and 1',3'-dihalo-N-normetazocine analogues

The synthesis and sigma 1 and sigma 2 binding properties of several 1'- and 3'-halo- and 1',3'-dihalo-substituted analogues of (+)-N-benzyl- and (+)- and (-)-N-dimethylallyl-N-normetazocine are presented. Structure-activity relationship analyses of the binding data showed that halogen substitution at the 1'-position of these N-substituted N-normetazocine analogues had little effect on sigma 1 binding affinity, whereas 3'-halo substitution as well as 1',3'-dihalo substitution resulted in a reduction of affinity. sigma 2 affinity was increased by the presence of a 3'-bromo substituent in this series of (+)-N-substituted N-normetazocines.

Halogenated isoniazid derivatives as possible antimycobacterial and anti-HIV agents--III

As part of a research directed to the synthesis of novel isoniazid derivatives with potential activity on mycobacteria and HIV virus, the acetophenone-isonicotinoylhydrazones 3 and the 4-aryl-1-methoxy-1-(4-pyridyl)- 2,3-diaza-1,3-butadienes 5, obtained by reaction between isonicotinoylhydrazones and diazomethane, have been prepared and tested for such activities. Both classes of derivatives showed interesting growth inhibitory activity on non-tubercular mycobacteria, including the emerging M. avium. Such activity appears to be linked to fluorine and/or chlorine presence on benzene rings. In contrast, none of the compounds submitted to the anti-AIDS in vitro screening, displayed any protection against HIV-1 virus-induced cytopathic effect in T4-lymphocyte cell lines.

Synthesis of 5-[1-hydroxy (or methoxy)-2,2-dihaloethyl]-2'- deoxyuridines with antiviral and cytotoxic activity

The 5-[1-hydroxy (or methoxy)-2,2-dihaloethyl]-2'-deoxyuridines (3-12, Cl, Br and/or I) were synthesized by the addition of HOX or CH3OX (X = Cl, Br, I) to the vinyl substituent of the respective (E)-5-(2-halovinyl)-2'-deoxyuridines (1a-c). In vitro antiviral (HSV-1, HSV-2, HCMV, VZV, EBV) and cytotoxic (L1210) activities were determined. The 5-(1-hydroxy-2,2-dihaloethyl) series were generally more active than the 5-(1-methoxy-2,2-dihaloethyl) series against HSV-1, HSV-2, VZV and EBV. Anti-HSV-1 activity was dependent upon the steric orientation and/or hydrophobic properties of the halogen atom(s), with -CH(OH)CHBr(I) and -CH(OH)CHBr2 C-5 substituents providing the most potent activity. 5-(1-Hydroxy-2-bromo-2-iodoethyl)-2'-deoxyuridine (6), which exhibited the most potent anti-HSV-1 activity, was 12-fold less active than acyclovir. In contrast, the halogen atom(s) were not determinants of anti-VZV activity, where the approximately equipotent 5-(1-hydroxy-2,2-dihaloethyl) compounds (3, 4, 5, 6) exhibited anti-VZV activity comparable to that of acyclovir. All of the 5-(1-hydroxy (or methoxy)-2,2-dihaloethyl) analogs (3-12) were inactive against HCMV. The 5-(1-hydroxy-2-chloro-2-iodoethyl) compound (4) was an active cytotoxic agent as determined in the in vitro L1210 screen. The compounds 3-12 were non-toxic to uninfected host cells. The inhibitory effect on cell proliferation diminished upon replacement of the 5-(1-hydroxy-2,2-dihaloethyl) substituents of 3-6 with the corresponding 5-(1-methoxy-2,2-dihaloethyl) substituents (7-12).

Structure-mutagenicity and structure-cytotoxicity studies on bromine-containing cysteine S-conjugates and related compounds

Glutathione and cysteine S-conjugates of several haloalkenes are nephrotoxic and cytotoxic. Chloroalkene-derived S-(1-chloroalkenyl)-L-cysteine conjugates, but not fluoroalkene-derived S-(2,2-dihalo-1,1-difluorethyl)-L-cysteine conjugates, are mutagenic in the Ames test, although both types of S-conjugates are cytotoxic and nephrotoxic. Recent studies showed that bromine-containing S-(2,2-dihalo-1,1-difluoroethyl)-L-cysteine conjugates are mutagenic in the Ames test, thus challenging the generalization that S-(2,2-dihalo-1,1-difluoroethyl)-L-cysteine conjugates are not mutagenic. Hence a series of bromine-containing and bromine-lacking S-(2,2-dihalo-1,1-difluoroethyl)-L-cysteine conjugates was prepared, and their mutagenicity was assessed in the Ames test with Salmonella typhimurium TA2638 as the test strain. In addition, several indices of cytotoxicity, including cytotoxicity in LLC-PK1 cells, induction of Ca2+ release from pig kidney mitochondria, and DNA double-strand breaks in LLC-PK1 cells, were measured. The bromine-containing S-conjugates S-(2-bromo-2-chloro-1,1-difluoroethyl)-L- cysteine (BCD-FC), S-(2-bromo-1,1,2-trifluoroethyl)-L-cysteine (BTFC), and S-(2,2-dibromo-1,1-difluoroethyl)-L-cysteine (DBDFC) were mutagenic in the Ames test, whereas S-(2-chloro-1,1,2-trifluorethyl)-L-cysteine (CTFC), S-(2,2-dichloro-1,1-difluoroethyl)-L-cysteine (DCDFC), and S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFC), which lack bromine, were not. BCDFC, BTFC, CTFC, DBDFC, and TFC were cytotoxic in LLC-PK1 cells, and their cytotoxicity was blocked by the cysteine conjugate beta-lyase inhibitor (aminooxy)acetic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Modification of glycopeptide antibiotic eremomycin by the action of alkyl halides and study on antibacterial activity of the compounds obtained

Alkylation of glycopeptide antibiotic eremomycin by the action of different alkyl halides leads, depending on the structure of alkyl halides used, to eremomycin derivatives of six types; alkylated at the N-terminus, quaternary compounds at the N-terminus, eremomycin esters, esters of eremocycin alkylated at the N-terminus, esters of eremomycin quaternised at the N-terminus, esters of eremomycin alkylated both at the N-terminus and at the aminogroup of disaccharide branch. Five compounds demonstrated high antibacterial activity in vitro, N-allyleremomycin and methyl ester of N,N-dimethyleremomycin being at least as good as the parent eremomycin.

Empirical and rational approaches for development of inhibitors of the human immunodeficiency virus--HIV-1

The human immunodeficiency virus, HIV-1, is generally accepted to be responsible for AIDS. It is imperative that all approaches, empirical and rational, be taken for development of a drug for therapy of this disease. These approaches are discussed, with emphasis on the direction being pursued in our laboratory. Empirically, we found 3'-deoxy-2',3'-didehydrothymidine, a compound first synthesized for potential anticancer activity by J. Horwitz in the 1960s, to be a potent inhibitor of HIV-1. It is now in Phase II/III clinical trials. We have also synthesized several 2,5'-anhydro pyrimidine nucleoside analogs, which have interesting chemical and biological properties. We have evaluated a natural product, gossypol and synthesized various derivatives for anti-HIV-1 activity, but none were appreciably more inhibitory than the parent compound. More recently, we have taken the rational approach and synthesized a boron-modified tetrapeptide, Ac-Thr-Leu-Asn-boro-Phe, which corresponds to the COOH-terminal of the Phe-Pro scissle bond of the gag/pol gene polyprotein product. Potent inhibition of the HIV-1 encoded protease was observed. These approaches and findings will be discussed.

7 alpha-Methyl- and 11 beta-ethoxy-substitution of [125I]-16 alpha-iodoestradiol: effect on estrogen receptor-mediated target tissue uptake

The 7 alpha-methyl and 11 beta-ethoxy derivatives of 16 alpha-[125I]iodoestradiol were prepared via halogen exchange with 125I of the corresponding 16 beta-bromoestradiol precursors. The 16 alpha-bromo derivatives were obtained via halogenation of the analogous 17-enol acetate, epimerization to the 16 beta-isomer, and hydride reduction. Stereochemical assignments were based on high resolution 1H NMR. To evaluate the effect of the nature and stereochemistry of the 16-halo substituent on the relative binding affinity for the estrogen receptor, the analogous 16-chloro derivatives were also prepared. The highest binding affinities were observed with the 7 alpha-methyl-16 alpha-haloestradiols, particularly the bromo and chloro derivatives while the 16 alpha-iodo derivatives gave somewhat lower values. Both the 11 beta-ethoxy and 7 alpha-methyl-16 alpha-[125I]iodoestradiols localize in the uteri of immature female rats via a receptor-mediated process. Rapid blood clearance of the 125I-labeled 7 alpha-methyl derivative results in lower 125I uptake by the uterus as well as nontarget organs as compared to the 11 beta-substituted estradiol analogs. However, uterus to blood and nontarget ratios are more favorable for the 7 alpha-methyl-16 alpha-[125I]iodoestradiol as compared to the analogous 11 beta-ethoxy derivatives suggesting that this compound substituted with 123I may be useful for the in vivo imaging of estrogen receptor-rich breast tumors by single photon emission computerized tomography.

Alpha-halo [(phenylphosphinyl)methyl]phosphonates as specific inhibitors of Na(+)-gradient-dependent Na(+)-phosphate cotransport across renal brush border membrane

Certain phosphonocarboxylate analogues of phosphate are known to inhibit Na(+)-phosphate (Pi) cotransport in renal brush border membrane (BBM), but previously tested potential inhibitors incorporating structurally versatile aryl functionality were inactive. In this work, a series of novel alpha-halogenated [(phenylphosphinyl)methyl]phosphonates [PhpXYMP: X, Y = H, F (2); F, F (3); H, Cl (6); Cl, Cl (4); H, Br (7); Br, Br (5); and Cl, Br (8)] were prepared via synthesis of the corresponding triethyl esters, acid hydrolysis, and isolation as pyridine salts. The compounds were evaluated as inhibitors of Na(+)-gradient-dependent 32Pi uptake by rat renal cortex BBM vesicles (BBMV) in vitro. The PhpFMP racemate 2 had higher activity (-49% delta inhibition) than other members of the series (-22 to -39% delta inhibition). pKa values of 1.5-2.0, 2.7, and 7.1 were estimated for 2 using a 31P delta vs pH plot, indicating that in the activity assays it exists as both dianion and trianion, with the latter form predominant. PhpFMP had no significant inhibitory effect on Na(+)-gradient-dependent uptake of D-glucose or L-proline in the same BBMV, and did not inhibit BBM alkaline phosphatase. Kinetic analysis showed that PhpFMP acts as a strictly competitive inhibitor of Na(+)-Pi cotransport with Ki = 0.358 +/- 0.021 mM (n = 3). The racemate 2 was resolved as its (-)-quinine salt into enantiopure (+)-2 [Na+ salt, [alpha]25D = +6 degrees (aqueous MeOH)] and a Na+ salt of 2 enriched in (-)-2. The two compounds did not differ significantly as inhibitors of Na(+)-gradient dependent 32Pi uptake by rat renal cortex BBM vesicles (BBMV) in vitro. The results are discussed in terms of structural requirements for inhibition.

Para-substituted Phe3 deltorphin analogues: enhanced selectivity of halogenated derivatives for delta opioid receptor sites

The delta-selective opioid peptide deltorphin C(H-Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2) (DEL C) was modified by para-substitution of Phe3 with halogens (F, Cl, Br, I), amino, or nitro groups. The bioactive potencies in peripheral tissues and brain receptor selectivities of these analogues depended upon the particular substituent; peptides containing halogen substituents exhibited the least disruptive effect. In the mouse vas deferens (MVD) bioassay, [p-ClPhe3]DEL C displayed equivalent bioactivities to DEL C; in combination with the guinea pig ileum (GPI) bioassay, [p-ClPhe3]DEL C and [p-BrPhe3]DEL C exhibited marked preference for delta sites (IC50GPI/IC50MVD = 11,250 and 6,363, respectively), which are approximately 4- and 2-fold greater than DEL C. In a receptor binding assay, none of the halogenated analogues had delta affinities (Ki) exceeding that of DEL C; however, in terms of delta selectivity (Ki mu/Ki delta), [p-BrPhe3]DEL C was nearly twice as selective as DEL C, while [p-FPhe3]DEL C was equivalent, and [p-IPhe3]DEL C only 25% less selective. The only correlation evident with the halogenated derivatives occurred between IC50GPI and Ki mu (r = 0.814) rather than between delta receptor studies (MVD or Ki delta); interestingly, IC50GPI also correlated with K' (r = 0.982). The p-amino or p-nitro substituents of Phe3 in DEL C and DEL B (= [Glu4]DEL C) were deleterious for bioactivity (MVD) (losses ranged from 400- to approximately 8,000-fold) and in receptor binding assays, where delta affinities decreased 140- to 840-fold and delta selectivities by 34- to 380-fold. p-Nitro-Phe3 was the most detrimental substitution for all the parameters measured for both deltorphins: the loss in MVD activity, however, was less with DEL B than with DEL C, which was the opposite for delta receptor affinity.

Synthesis and mutagenicity of 3-halogenated and 3,3',5,5'-tetrahalogenated benzidines

3-Fluorobenzidine (FBz), 3-chlorobenzidine (ClBz), 3-bromobenzidine (BrBz), 3,3',5,5'-tetrafluorobenzidine (F4Bz), and 3,3',5,5'-tetrachlorobenzidine (Cl4Bz) were synthesized and tested for their ability to revert Salmonella typhimurium. F4Bz was the only compound to show direct-acting mutagenicity and was equally potent in strain TA98 and the acetylase-deficient strain TA98/1,8-DNP6. In the presence of hamster liver S9, all compounds except Cl4Bz were mutagenic. The relative mutagenicities in TA98 were FBz greater than ClBz greater than BrBz greater than F4Bz greater than Bz greater than Cl4Bz = 0. In TA98/1,8-DNP6 the trend was F4Bz approximately BrBz approximately ClBz greater than FBz greater than Bz greater than Cl4Bz = 0.

Synthesis and antitumor and antiviral properties of 5-halo- and 5-(trifluoromethyl)-2'-deoxyuridine 3',5'-cyclic monophosphates and neutral triesters

The title diesters (11-15; halo substituents F, Cl, Br, I) were prepared by DCC-induced cyclization of the precursor 5'-monophosphate or direct halogenation of the 2'-deoxyuridine 3',5'-cyclic monophosphate. Antitumor activities of 11-15 in cell systems (L1210 and Raji/0) were compared to those of the corresponding nucleosides and 5'-monophosphates. Thus, the 5-F- and 5-CF3-2'-deoxyuridines proved to be highly active derivatives [ID50 values (microgram/mL) for L1210, 0.002 and 0.06, respectively], with the 5'-monophosphates showing comparable potencies. The corresponding 3',5'-cyclic monophosphate diesters were 20-30 times less potent but nonetheless highly cytostatic. All derivatives including 11-15 had greatly increased ID50 values for the thymidine kinase deficient (TK-) L1210 and Raji cells. The 3',5'-cyclic diesters (11-15) evidently are not efficient prodrug sources of the nucleoside 5'-monophosphates in TK- cells. They also proved to be 100- to 2000-fold less efficient inhibitors of L1210 thymidylate synthetase than were the 5'-monophosphates. The 5-substituted 2'-deoxyuridines and their 5'-monophosphates were potent inhibitors of herpes simplex virus (MIC50 mostly 0.07-10 micrograms/mL) and vaccinia virus (MIC50 0.07-0.2 microgram/mL), with antiviral activity decreasing in the order 5-I, 5-Br greater than 5-CF3 greater than 5-Cl greater than 5-F. The 3',5'-cyclic monophosphates (11-15) were for the most part 10- to 40-fold less active than the 5'-monophosphates in the virus assay systems (e.g., MIC50 for the 5-Br and 5-I derivatives ranged 1-20 micrograms/mL). By contrast 11-15 were considerably more potent inhibitors of vaccinia virus growth (MIC50 0.4-2 micrograms/mL). As the neutral 3',5'-cyclic methyl phosphate triesters (16-18), the 5-I and 5-Br compounds were less potent in antiviral and cytostatic agents than the 3',5'-cyclic diesters, while the 5-iodo benzyl triester was in several cases as active as the 3',5'-cyclic diester. The title compounds (11-15) appear to require extracellular hydrolysis to the nucleoside before functioning as antitumor or antiviral agents.

Bioevaluation of plasma polymerized films in skeletal muscle

Plasma polymerized ethylene (PPE), styrene (PPS), and chlorotrifluoroethylene (PPCTFE) were synthesized by exposing the monomeric gases to an inductively coupled radio frequency "glow-discharge" field. The polymer films were deposited on poly(dimethyl) siloxane (medical grade Silastic), which was then surgically implanted in rat paravertebral muscle for periods up to 84 weeks. The biocompatibility of the plasma deposited films and uncoated Silastic was evaluated by qualitative (graded inflammatory cell response) and quantitative (connnective tissue capsule thickness) techniques as a function of time. The morphological features of the connective tissue capsule and the plasma polymerized films were examined by SEM after 75 weeks of implantation. Results showed that the acute inflammatory cell migration around PPS and PPCTFE was at a maximum in 2 weeks, decaying to control levels in 4 to 8 weeks. The PPE response was judged as less than the control response up to 4 weeks. After 8 weeks no qualitative difference could be detected between the plasma polymerized films and Silastic. On the other hand, a quantifiable change in fibrous capsule response as a function of time and material was noted until 24 weeks. From these data we conclude that these types of films do not elicit an untoward foreign body reaction at a skeletal muscle implant site in rats.

Oxychlordane, animal metabolite of chlordane: isolation and synthesis

Oxychlordane (C(10)H(4)Cl(8)O), a minor heretofore unidentified metabolite, was isolated from fat of pigs on diets heavily dosed with pure isomers of the insecticide, chlordane (C(10)H(6)Cl(8)). Chemical and spectroscopic evidence provides bases for proposal of structure of the metabolite as 1-exo-2-endo-4,5,6,7,8,8-octachloro-2,3-exo-epoxy-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene.

Chloroazobenzenes: studies on syntheses

Thirteen chloroazobenzenes were synthesized by reduction of chloronitrobenzenes or by oxidation of their corresponding chloroanilines. Five of the compounds have not been previously prepared or described. Reduction by LiAlH4 was the method of choice, but it proved inadequate for the syntheses of chloroazobenzenes from o-chloronitrobenzenes. This reaction eliminated chlorine if ortho to the aniline nitrogen and an additional chlorine atom; in the other cases steric hindrance of azo bond formation resulted in low yields. Chromatographic systems for the separation of pure chloroazobenzenes from the crude reaction mixtures were developed and are described.