Seasonal Dynamics of Zygnema (Zygnematophyceae) Mats from the Austrian Alps.

Filamentous green algae of the genus Zygnema are an essential part of hydro-terrestrial ecosystems. Despite several studies on their resistance to natural stresses, little is known about the composition of their assemblages and the changes they undergo over time. Two sites at altitudes above 2200 m a.

Development of 3,5-Dinitrophenyl-Containing 1,2,4-Triazoles and Their Trifluoromethyl Analogues as Highly Efficient Antitubercular Agents Inhibiting Decaprenylphosphoryl-β-d-ribofuranose 2'-Oxidase.

We report herein the discovery of 3,5-dinitrophenyl 1,2,4-triazoles with excellent and selective antimycobacterial activities against strains, including clinically isolated multidrug-resistant strains. Thorough structure-activity relationship studies of 3,5-dinitrophenyl-containing 1,2,4-triazoles and their trifluoromethyl analogues revealed the key role of the position of the 3,5-dinitrophenyl fragment in the antitubercular efficiency. Among the prepared compounds, the highest in vitro antimycobacterial activities against HRv and against seven clinically isolated multidrug-resistant strains of were found with S-substituted 4-alkyl-5-(3,5-dinitrophenyl)-4-1,2,4-triazole-3-thiols and their 3-nitro-5-(trifluoromethyl)phenyl analogues.

Development of water-soluble 3,5-dinitrophenyl tetrazole and oxadiazole antitubercular agents.

In this work, four series of tertiary amine-containing derivatives of 3,5-dinitrophenyl tetrazole and oxadiazole antitubercular agents were prepared, and their in vitro antimycobacterial effects were evaluated. We found that the studied compounds showed lipophilicity-dependent antimycobacterial activity. The N-benzylpiperazine derivatives, which had the highest lipophilicity among all of the series, showed the highest in vitro antimycobacterial activities against Mycobacterium tuberculosis CNCTC My 331/88 (HRv), comparable to those of the first-line drugs isoniazid and rifampicin.

DNA extraction and barcode identification of development stages of forensically important flies in the Czech Republic.

Several methods of DNA extraction, coupled with 'DNA barcoding' species identification, were compared using specimens from early developmental stages of forensically important flies from the Calliphoridae and Sarcophagidae families. DNA was extracted at three immature stages - eggs, the first instar larvae, and empty pupal cases (puparia) - using four different extraction methods, namely, one simple 'homemade' extraction buffer protocol and three commercial kits. The extraction conditions, including the amount of proteinase K and incubation times, were optimized.

Structure-activity relationship studies on 3,5-dinitrophenyl tetrazoles as antitubercular agents.

In this study, we described the structure-activity relationships of substituted 3,5-dinitrophenyl tetrazoles as potent antitubercular agents. These simple and readily accessible compounds possessed high in vitro antimycobacterial activities against Mycobacterium tuberculosis, including clinically isolated multidrug (MDR) and extensively drug-resistant (XDR) strains, with submicromolar minimum inhibitory concentrations (MICs). The most promising compounds showed low in vitro cytotoxicity and negligible antibacterial and antifungal activities, highlighting their highly selective antimycobacterial effects.

S-substituted 3,5-dinitrophenyl 1,3,4-oxadiazole-2-thiols and tetrazole-5-thiols as highly efficient antitubercular agents.

Two new classes of antitubercular agents, namely 5-alkylsulfanyl-1-(3,5-dinitrophenyl)-1H-tetrazoles and 2-alkylsulfanyl-5-(3,5-dinitrophenyl)-1,3,4-oxadiazoles, and their structure-activity relationships are described. These compounds possessed excellent activity against Mycobacterium tuberculosis, including the clinically isolated multidrug (MDR) and extensively drug-resistant (XDR) strains, with no cross resistance with first or second-line anti-TB drugs. The minimum inhibitory concentration (MIC) values of the most promising compounds reached 0.

Development of 3,5-Dinitrobenzylsulfanyl-1,3,4-oxadiazoles and Thiadiazoles as Selective Antitubercular Agents Active Against Replicating and Nonreplicating Mycobacterium tuberculosis.

Herein, we report the discovery and structure-activity relationships of 5-substituted-2-[(3,5-dinitrobenzyl)sulfanyl]-1,3,4-oxadiazoles and 1,3,4-thiadiazoles as a new class of antituberculosis agents. The majority of these compounds exhibited outstanding in vitro activity against Mycobacterium tuberculosis CNCTC My 331/88 and six multidrug-resistant clinically isolated strains of M. tuberculosis, with minimum inhibitory concentration values as low as 0.

Prediction of retention characteristics of heterocyclic compounds.

The CORAL software ( http://www.insilico.eu/coral ) was used to build up quantitative structure-property relationships (QSPRs) for the retention characteristics of 93 derivatives of three groups of heterocyclic compounds: 2-phenyl-1,3-benzoxazoles, 4-benzylsulfanylpyridines, and benzoxazines.

1-Substituted-5-[(3,5-dinitrobenzyl)sulfanyl]-1H-tetrazoles and their isosteric analogs: A new class of selective antitubercular agents active against drug-susceptible and multidrug-resistant mycobacteria.

In this work, a new class of highly potent antituberculosis agents, 1-substituted-5-[(3,5-dinitrobenzyl)sulfanyl]-1H-tetrazoles and their oxa and selanyl analogs, is described. The minimal inhibitory concentration (MIC) values reached 1 μM (0.36-0.

New synthetic pyridine derivate as potential elicitor in production of isoflavonoids and flavonoids in Trifolium pratense L. suspension culture.

The production of secondary metabolites in Trifolium pratense L. suspension culture of the family of legume plants (Fabaceae) is low, and therefore there was an attempt to increase it by elicitation. New synthetic substance, 2-(2-fluoro-6-nitrobenzylsulfanyl)pyridine-4-carbothioamide, was tested as elicitor--a substance that showed the best elicitation effect after 48-hour application of 1 μmol L⁻¹ concentration.

Structure-activity relationships of 2-benzylsulfanylbenzothiazoles: synthesis and selective antimycobacterial properties.

A set of 2-benzylsulfanyl derivatives of benzothiazole was synthesized and evaluated for antimicrobial and cytotoxic activities. The biological screening on antimicrobial activity against a panel of Gram-positive and Gram-negative bacteria, yeasts and fungi identified benzylsulfanyl derivatives of benzothiazole as selective inhibitors of mycobacteria. The lead compounds in the set, dinitro derivatives exhibited significant activity against sensitive and multidrug-resistant strains of M.

Effect of substitution on the antimycobacterial activity of 2-(substituted benzyl)sulfanyl benzimidazoles, benzoxazoles, and benzothiazoles--a quantitative structure-activity relationship study.

A set of 1160 minimum inhibitory concentration (MIC) values evaluating effect of substitution on the antimycobacterial activity of the previously published 2-(substituted benzyl)sulfanyl benzimidazoles, benzoxazoles, and benzothiazoles has been analyzed by the methods of multidimensional analysis (exploratory analysis, 2D-nonlinear mapping (NLM), principal component analysis (PCA), factor analysis (FA), multiple linear regression (MLR)). The antimycobacterial activity of 2-(subst. benzyl)sulfanyl derivatives of benzimidazole (BIM), 5-methylbenzimidazole (5-Me-BIM), benzoxazole (BOZ), and benzothiazole (BTZ) increased in the order of BTZ View Article and Find Full Text PDF

A note to the biological activity of benzoxazine derivatives containing the thioxo group.

New 3-benzyl-4-thioxo-2H-1,3-benzoxazine-2(3H)-ones and 3-benzyl-2H-1,3-benzoxazine-2,4(3H)-dithiones were synthesized. The compounds were tested for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. The replacement of the carbonyl group by the thiocarbonyl group increased the antimycobacterial activity.

Preparation and in-vitro evaluation of 4-benzylsulfanylpyridine-2-carbohydrazides as potential antituberculosis agents.

A set of 4-benzylsulfanylpyridine-2-carbohydrazides was synthesized and evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis, non-tuberculous mycobacteria, and multidrug-resistant M. tuberculosis. The activities expressed as the minimum inhibitory concentration (MIC) fall into a range of 2 to 125 micromol/L, most often 4 to 32 micromol/L.

Preparation and in vitro evaluation of benzylsulfanyl benzoxazole derivatives as potential antituberculosis agents.

A set of 2-benzylsulfanyl derivatives of benzoxazole was synthesized and evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis, non-tuberculous mycobacteria and multidrug-resistant M. tuberculosis. The activities were expressed as the minimum inhibitory concentration (MIC) in mmol/L.

The oriented development of antituberculotics (Part II): halogenated 3-(4-alkylphenyl)-1,3-benzoxazine-2,4-(3H)-diones.

Based on our previous studies, 21 new halogenated 3-(4-alkylphenyl)-1,3-benzoxazine-2,4-(3H)-diones were synthesized by the reaction of salicylanilides and methyl-chloroformate. All compounds were screened in vitro against three different strains of mycobacterium, and Free-Wilson method was used to establish structure-activity relationships. 6-Bromo-3-(4-butylphenyl)-1,3-benzoxazine-2,4-(3H)-dione 3b proved to be the most active compound of the series.

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).

The oriented development of antituberculotics: salicylanilides.

On the basis of our previous results 22 salicylanilides were synthesized. The compounds were tested for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium. The Free-Wilson method was used to evaluate structure-antimycobacterial activity relationships.

Heterocyclic isosters of antimycobacterial salicylanilides.

A series of 64 derivatives of substituted heterocyclic analogues of salicylanilides was synthesized. The compounds were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium avium and two strains of Mycobacterium kansasii. For the QSAR study, the combination of Free-Wilson approach with Hansch approach was used.

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.

Synthesis and antimycobacterial activity of pyridylmethylsulfanyl and naphthylmethylsulfanyl derivatives of benzazoles, 1, 2, 4-triazole, and pyridine-2-carbothioamide/-2-carbonitrile.

A set of four types of benzazoles, 1, 2, 4-triazole, and pyridine-2-carbonitrile/-2-carbothioamide substituted with 1-naphthylmethylsulfanyl or pyridylmethylsulfanyl was prepared to modify the structure of benzylsulfanyl derivatives of the above-mentioned heterocycles. The compounds were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis, M. avium, and two strains of M.

Antimycobacterial N-pyridinylsalicylamides, isosters of salicylamides.

The series of derivatives of substituted N-pyridinylsalicylamides were synthesized. The compounds were evaluated for in vitro antimycobacterial activity against Mycobacterium avium and two strains of Mycobacterium kansasii. In the quantitative structure activity relationships analysis (QSAR), the Free-Wilson and Hansch approaches were used but the analysis was not significant.

Synthesis and antimycobacterial activity of 1,2,4-triazole 3-benzylsulfanyl derivatives.

Series of 3-benzylsulfanyl derivatives of 1,2,4-triazole and 4-methyl-1,2,4-triazole were synthesized by alkylation of starting triazole-3-thiol with appropriately substituted benzyl halide. All members of the set were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis, M. avium, and two strains of M.

3-Benzyl-2H-1,3-benzoxazine-2,4(3H)-diones, a new group of antimycobacterial compounds against potentially pathogenic strains.

A series of derivatives of 3-benzyl-2H-benzoxazine-2,4(3H)-dione substituted in positions 6, 7 or 8 on the benzoxazine, and in positions 3 or 4 on the benzyl moiety was synthesized. The compounds were evaluated for in vitro antimycobacterial activity against Mycobacterium avium and two strains of Mycobacterium kansasii. The disadvantage of the compounds is in their low solubility in water.

Antimycobacterial and antifungal isosters of salicylamides.

A set of 40 derivatives of 3-hydroxypicolinic acid and 2-sulfanylbenzoic acid, isosteric to salicylanilides was synthesized. The compounds were evaluated for in vitro activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium, Candida albicans, Candida tropicalis, Candida krusei, Candida glabrata, Trichosporon beigelii, Aspergillus fumigatus, Absidia corymbifera, Trichophyton mentagrophytes and Microsporum gypseum. Structure-activity relationships of antimycobacterial activity and antifungal activity against T.