Hybrid molecules of estrone: new compounds with potential antibacterial, antifungal, and antiproliferative activities.

New hybrid molecules of estrone were synthesized as compounds indicating promising biological activity (antibacterial, antimycobacterial, antifungal, and antiproliferative). The prepared molecules contained various heterocyclic units (pyridine, benzylsulfanyl derivatives of pyridine or derivatives of tetrazole) linked to estrone by n-heptyl bridges. The compounds with charge on molecule (the hybrid pyridinium or benzylsulfanylpyridinium salts) exhibited significant biological activity (antibacterial, antimycobacterial, antifungal, and antiproliferative). On the other hand, the compounds not in the form of salts (omega-(1-phenyl-5-tetrazolylthio)heptylethers of estrone) were inactive. The antimycobacterial activities of three different series of tetrazole derivatives (i.e., the hybrid molecules with estrone, tetrazole-5-thiols, and 5-benzylsulfanyl-1-phenyltetrazoles) with the same substituents on phenyl ring were compared. Amongst them, the 5-benzylsulfanyl-1-phenyltetrazoles were the most potent.

QSAR study of antimycobacterial activity of quaternary ammonium salts of piperidinylethyl esters of alkoxysubstituted phenylcarbamic acids.

A series of 17 halogenides of quaternary ammonium salts of the alkylpiperidinylethyl esters of 2-pentoxy (and 2-heptoxy) substituted phenylcarbamic acids were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis, M. kansasii, and M. avium. Correlation of this action with lipophilicity (log P, 1-octanol-water system) was used for the description of the structure-antimycobacterial activity relationships (QSARs). The activity increased with the increasing lipophilicity of the compounds.

1-Aryl-5-benzylsulfanyltetrazoles, a new group of antimycobacterial compounds against potentially pathogenic strains.

A set of 21 1-phenyl-5-benzylsulfanyltetrazoles substituted on the phenyl ring as well as on the benzyl moiety was evaluated for in vitro antimycobacterial activity against Mycobacterium avium and two strains of M. kansasii. We tried to use the Hansch approach, the Free-Wilson approach and their combination for structure-activity correlation but the calculations were statistically insignificant.

Synthesis and antimycobacterial activity of 2-substituted halogenobenzimidazoles.

A series of substituted 2-polyfluoroalkyl and 2-nitrobenzylsulphanyl benzimidazoles was synthesized. The compounds were evaluated for their activity against four Mycobacterium strains; the activities were expressed as the minimum inhibitory concentration (MIC). The substances tested showed appreciable antimycobacterial activity, particularly 5,6-dichloro-2-nonafluorobutylbenzimidazole (2h), and 5-halogeno- (5a-c) and 4,6-dihalogeno- (5d and 5g) 2-(3,5-dinitrobenzylsulphanyl)benzimidazoles, whose MIC values for Mycobacterium kansasii and Mycobacterium avium exceeded that of isoniazide that was used as a reference compound. Relationships between structure and biological activity of the tested benzimidazole derivatives are discussed.

A new group of potential antituberculotics: hydrochlorides of piperidinylalkyl esters of alkoxy-substituted phenylcarbamic acids.

A group of 31 of alkoxy-substituted phenylcarbamic acids with the alkoxy group in ortho, meta or para position, and methyl or ethoxymethyl attached to the ethylene moiety in position 1, including both basic ethyl esters and derivatives branched on ethylene, were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis, M. kansasii, and M. avium. To describe the structure-antimycobacterial activity relationships (QSARs), an approach based on a combination of the Free-Wilson analysis was used to express the influence of the substituents on the ethylene group as well as the position of the alkoxy groups on the phenyl ring and of the hydrophobicity of alkyls. In vitro antimycobacterial activity becomes higher with increasing hydrophobic properties of the alkoxy groups. The para- and meta-substituted derivatives were more active than the ortho-substituted ones. Substitution of ethylene in position 1 by methyl increased the activity against M. tuberculosis, a similar substitution by ethoxymethyl increased the activity against M. kansasii. The most active compounds were piperidinyl-1-(ethoxymethyl)ethylesters of heptoxyphenylcarbamic acids.

[A new group of potential antitubercular agents: antimycobacterial N-benzylsalicylamides]. / Nová skupina potenciálních antituberkulotik: antimykobakteriální N-benzylsalicylamidy.

Linking up with a previous study of antimycobacterial compounds, several groups of N-benzylsalicylamides were prepared and their antimycobacterial activities against the strains Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium were evaluated. The obtained data were analyzed by Free-Wilson method in comparison with their isosteric analogues of 3-hydroxypicolinic and 2-sulfanylbenzoic acids described in the previous communication.

Antimycobacterial activity of basic ethyl esters of alkoxy-substituted phenylcarbamic acids.

A series of 124 basic ethyl esters of alkoxy-substituted phenylcarbamic acids with the alkoxy group in position 2, 3 or 4 on the phenyl ring, and basic substituents attached to the ethyl moiety in position 2, were evaluated for in vitro antimycobacterial activity against strains of Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. In vitro antimycobacterial activity becomes higher with increasing hydrophobic properties of the alkoxy groups. The p- and m-substituted derivatives were more active than the o-substituted ones. Direct relationship between the structure of the basic substituents and the activity was not found.

[New groups of potential antitubercular agents: 3-(4-ethoxythiocarbonylphenyl)-2-H-benzoxazin-2,4(3H)-diones and 3-(4-ethoxythiocarbonylphenyl)-4-thioxy-2H-benzoxazin-2(3H)-ones]. / Nové skupiny potenciálních antituberkulotik: 3-(4-ethoxythiokarbonylfenyl)-2-H-benzoxazin-2,4(3H)-diony a 3-(4-ethoxythiokarbonylfenyl)-4-thioxy-2H-benzoxazin-2(3H)-ony.

In connection with the search for new antituberculotics, the present authors prepared a group of derivatives of 3-(4-ethoxythiocarbonylphenyl)-2H-benzoxazin-2,4(3H)-dithione and 3-(4-ethoxythiocarbonylphenyl)-4-thioxy-2H-benzoxazin-2,4(3H)-one. The modifications of substituents were carried out on the benzoxazine ring. The study was based on the present authors' previous assumption that the substitution of the oxo group for the thioxo group was connected with an increase in antimycobacterial activity. The prepared substances were evaluated by the activity against Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium. However, it was concluded that there was no assumed increase in antimycobacterial activity in the groups of 3-(4-ethoxythiocarbonylphenyl)-4-thioxy-2H-benzoxazin-2,4(3H)-one and 3-(4-ethoxythiocarbonylphenyl)-2H-benzoxazin-2,4(3H)-dithione derivatives.

Antimycobacterial 3-aryl-2H-1,3-benzoxazine-2,4(3H)-diones.

A series of 153 derivatives of 3-phenyl-2H-benzoxazine-2,4(3H)-dione substituted in position 6 or 7 on benzoxazine and on the phenyl ring was synthesized. The compounds were evaluated in vitro for antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. The activity of the compounds increases with increasing hydrophobicity and electron-withdrawing properties of the substituents on the phenyl ring, whereas the effect of the substituents on the benzoxazine ring seems to be more complex.

Antimycobacterial activity of piperidinylpropyl esters of alkoxy-substituted phenylcarbamic acids.

A series of 17 hydrochlorides of piperidinylpropyl esters of alkoxy-substituted phenylcarbamic acids with the alkoxy group in position 2, 3 or 4 on the phenyl ring, and basic substituents attached to the moiety in position 3, were evaluated for in vitro antimycobacterial activity against the strains of Mycobacterium tuberculosis, M. kansasii and M. avium. To describe the structure-antimycobacterial activity relationships (QSAR), an approach based on the Free-Wilson method was employed to express the differences between individual moieties (including propyl and ethyl). The change of ethyl to propyl moiety increases the activity to M. tuberculosis but decreases the antimycobacterial activity to all potentially pathogenic strains under study.

[Antimycobacterial effects of pyrrolidinoethylester alkoxysubstituted phenylcarbamic acids]. / Antimykobakteriální úcinky pyrrolidinoethylesteru alkoxysubstituovaných fenylkarbamových kyselin.

Pyrrolidinoethylesters of alkoxysubstituted phenylcarbamic acids, formerly investigated for local anaesthetic activity, can be considered to be potential antituberculotics. They are effective in vitro against Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium. Their effect increases with the length of the alkyl chain in the alkoxy group bound to the phenyl. The influence of the position of the alkoxyl chain on the phenyl is not too marked, but it seems to decrease in the series m-, p-, o-.

Influence of the replacement of the oxo function with the thioxo group on the antimycobacterial activity of 3-aryl-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-diones and 3-arylquinazoline-2,4(1H,3H)-diones.

Series of 3-phenyl-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-dithiones, 3-arylquinazoline-2,4(1H,3H)-diones and 3-arylquinazoline-2,4(1H,3H)-dithiones were synthesized, and the antimycobacterial activities of the derivatives evaluated in vitro. The compounds were active against Mycobacterium tuberculosis and conditionally pathogenic mycobacteria (Mycobacterium kansasii and Mycobacterium avium). The replacement of oxygen by sulfur in 3-phenyl-6,8-dichloro-2H-1,3-benzoxazine-2.4(3H)-diones and 3-arylquinazoline-2,4(1H,3H)-diones gave rise to an increase of antimycobacterial activity. The most active compound was 3-(3-chlorophenyl)-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-dithione.

[Antimicrobial salicylanilides and 3-phenyl-2H-1,3-benzoxazine-2,4(3H)-diones]. / Antimykobakteriální salicylanilidy a 3-fenyl-2H-1,3-benzoxazin-2,4(3H)-diony.

Salicylanilides and 3-phenyl-2H-1,3-benzoxazine-2,4(3H)-diones are strong antimycobacterial substances which can be considered to be potential antituberculotics. In order to be able to verify the prognostics of the relationships between the structure and antimycobacterial activity, the series of previously evaluated substances was extended to include 4'-ethoxycarbonylsalicylanilide, 4'-trifluoromethylsalicylanilide, 4'-cyanidosalicylanilide, 4'-thiocarbamoylsalicylanilide, 3-(4-ethoxycarbonylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dione, 3-(4-trifluoromethylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dione, and 3-(4-cyanidophenyl)-2H-1,3-benzoxazine-2,4-(3H)-dione. The substances were evaluated against Mycobacterium tuberculosis, M. kansasii, and M. avium. In harmony with the previous study (see ref. 1), antimycobacterial activity increased with increasing lipophilicity and electron-acceptor properties of substituents. As the values of regression coefficients were not substantially changed after the complementation of the group, the present authors consider the problem under study to be solved.

[Development of chemotherapy in tuberculosis]. / Vývoj chemoterapie tuberkulózy.

The paper belongs to the series of review papers entitled "Substances with Antituberculous Effects". In contrast to other communications of the series, it deals with the present state of tuberculosis and the development of its chemotherapy. Whereas the other review papers of the series survey the development of structures of novel potential drugs, the present paper aims to show possible treatment of tuberculosis and its problems, concentrating on the contemporary situation.

New groups of antimycobacterial agents: 6-chloro-3-phenyl-4-thioxo-2H-1,3-benzoxazine-2(3H)-ones and 6-chloro-3-phenyl-2H-1,3-benzoxazine-2,4(3H)-dithiones.

A series of 6-chloro-3-phenyl-4-thioxo-2H-1,3-benzoxazine-2(3H)-ones 3 and a series of 6-chloro-3-phenyl-2H-1,3-benzoxazine-2, 4(3H)-dithiones 4 were synthesized by melting 6-chloro-3-phenyl-2H-1, 3-benzoxazine-2,4(3H)-dione and its derivatives substituted on the phenyl ring 2 with tetraphosphorus decasulfide. Compounds 2c-e, 3 and 4 exhibited in vitro activity against Mycobacterium tuberculosis, M. kansasii (two strains) and M. avium better than or comparable to that of isoniazid. Replacement of the oxo group by a thioxo group at position 4 led to improvement in activity against M. tuberculosis and M. kansasii. The Free-Wilson method and procedure developed by the authors were used to analyse the structure-activity and structure-antimycobacterial profile relationships, respectively.

The first occurrence of a multi-drug resistant tuberculosis epidemic in the Czech Republic caused by genetically closely related Mycobacterium tuberculosis strains.

DNA fingerprinting based on the detection of the insertion sequence IS6110 in Pvull restriction fragments was applied to M. tuberculosis isolates originating in the first microepidemic of multidrug resistant tuberculosis recorded in the Czech Republic. Their disseminators were 21 individuals living in--or roaming between three distant areas. The age of 17 males ranged from 36 to 64 years (average 45 years) and of 4 females aged from 38 to 52 years. The index person was most probably a former male prisoner, aged 49 years, who disseminated multidrug resistant M. tuberculosis over a period of 28 months. In ten of the patients the following risk factors for tuberculosis were found: imprisonment, homelessness, immigration and previous stay in asylum--or in a psychiatric ward. In six cases, M. kansasii infection preceded tuberculosis. Four out of the 21 patients died. The RFLP analysis separated the patients into two distinct groups: group A comprising 14 members of which M. tuberculosis strains were isolated with six IS6110 copies, whereas the isolates of seven individuals of the group B, the RFLP profile displayed highly similar RFLP patterns compared to the isolates of group A, but with two additional IS6110 copies. In one patient, both A and B patterns were found: the first one in a M. tuberculosis strain isolated in 1993 and the second one in the isolate isolated two years later. Both the appearance of pattern B among the isolates of a part of patients and the switch from A to B pattern in one of patients can be plausibly explained by the unstability of DNA genotypes caused by transposition of IS6110 elements.

New pyridine derivatives as potential antimicrobial agents.

A set of pyridine derivatives bearing a substituted alkylthio chain or a piperidyl ring in position 2 or 4 were synthesized, and their antimycobacterial and antifugal activities were evaluated. Chemical structures were confirmed by IR and NMR data, and by elemental analysis. Minimum inhibitory concentrations (MIC) were used for the evaluation of microbiological activity in vitro. The compounds were moderately active against both Mycobacterium tuberculosis and nontuberculous mycobacteria. The most active compound was 2-cyanomethylthiopyridine-4-carbonitrile (7) with MIC against Mycobacterium kansasii in the range of 8-4 mumol/l. The antifungal activities of the compounds were relatively low.

A multidrug-resistant tuberculosis microepidemic caused by genetically closely related Mycobacterium tuberculosis strains.

IS6110 DNA fingerprinting was used to characterize an outbreak of multidrug-resistant tuberculosis in 21 individuals (17 males and 4 females) living in or roaming among four distantly separated areas in the Czech Republic. The restriction fragment length polymorphism (RFLP) analysis separated the collected Mycobacterium tuberculosis strains into group A, including 14 patients with six IS6110 copies, and group B, with 7 patients displaying highly similar RFLP patterns but with two additional IS6110 bands. A switch from pattern A to pattern B was observed in one patient, and the subsequent detection of subclone B in seven more individuals has been explained by the instability of DNA genotypes caused by transposition of IS6110 elements.

Mycobacterium bohemicum sp. nov., a new slow-growing scotochromogenic mycobacterium.

A new, slow-growing, scotochromogenic mycobacterium was isolated from sputum of a 53-year-old patient with Down's syndrome suffering from tuberculosis. Growth occurred at temperatures between 25 and 40 degrees C with an optimum at 37 degrees C. This strain had surprisingly few enzymic activities (only positive for 68 degrees C heat-stable catalase and weakly positive for urease) and was sensitive to prothionamide, cycloserine, clarithromycin, gentamicin and amikacin but showed resistance to isoniazid, streptomycin, ethambutol, rifampin and ciprofloxacin. These characteristics assign this organism to a novel mycobacterial species characterized by a unique 16S rDNA nucleotide sequence. The name Mycobacterium bohemicum sp. nov. is proposed for this new, slow-growing, scotochromogenic mycobacterium. The type strain is DSM 44277T.

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.