Antitumor pyrrolobenzodiazepines (PBDs), lincosamide antibiotics, quorum sensing molecule hormaomycin, and antituberculotic griselimycin are structurally and functionally diverse groups of actinobacterial metabolites. The common feature of these compounds is the incorporation of L-tyrosine- or L-leucine-derived 4-alkyl-L-proline derivatives (APDs) in their structures. APD biosynthesis involves a set of up to six homologous proteins. According to their proposed order in the biosynthesis of 4-propyl-L-proline, a model APD of lincosamide lincomycin, the homologous proteins were named Apd1 - Apd6. Here, we report that the last reaction in the biosynthetic pathway of APDs, catalyzed by F420H2-dependent Apd6 reductases, contributes to the structural diversity of APD precursors. Specifically, the heterologous overproduction and in vitro tests of six Apd6 enzymes demonstrated that Apd6 from the biosynthesis of PBDs and hormaomycin can reduce only an endocyclic imine double bond, whereas Apd6 LmbY and partially GriH from the biosyntheses of lincomycin and griselimycin, respectively, also reduce the more inert exocyclic double bond of the same 4-substituted Δ1 -pyrroline-2-carboxylic acid substrate, making LmbY and GriH unusual, if not unique, among reductases. The two successive F420H2-dependent reduction...

Fasioloides magna is a trematode parasitizing in the liver parenchyma of ruminants. Its life cycle is associated with the humid environment and includes intermediate freshwater snail hosts from family Lymnaeidae. According to the ability of host to form a certain type of a pseudocyst during fascioloidosis, they can be,divided in three groups, specific definitive hosts (red deers, fallow deers, roe deers), nonspecific definitive hosts (cattle, wild boars and elks) and atypical hosts (sheeps and goats). Beside the natural infections also the experimental infections of other potential host species has been realized (chamois, llama and bighorn sheep and traditional laboratory animals such as mice, guinea pigs, rats and rabbits). In the context of different diseases, many changes in infected organism can occur. These can be qualitatively and quantitatively evaluated. Similarly, during fascioloidosis the changes associated with the presence of the parasite in the host's body is possible to monitor, e.g. antibody production, increase in the number of eosinophils, release of eggs in faeces, internal bleeding, or the level liver damage. The liver damage is corresponding primarily to biochemical parameters of blood, not only the liver enzymes, but also other blood components, like blood proteins, lipids,...

Cardiovascular pharmaceuticals are among the most prescribed drugs. As a result of the high consumption, these pharmaceuticals have been frequently detected in waste and surface waters. Verapamil, diltiazem and atenolol are very important representatives of cardiovascular pharmaceuticals; therefore, the present research focused on their acute and sub-chronic effects, bioconcentration, half-life time and metabolism in fish. Moreover, unified protocol for the quantitative assessment of histopathological alterations on the heart ventricle and coronary blood vessels employing heart index calculation was developed with the aim to better assess histopathological changes in fish heart which is one of the targets of cardiovascular pharmaceuticals and other chemicals. The effects caused by high concentrations of the studied substances, verapamil, diltiazem and atenolol, in fish can be considered similar to the therapeutic effects and side effects that are found in humans. The acute exposure to verapamil at the human therapeutic plasma level reduced the heart rate in common carp embryos and larvae. In addition, the acute and chronic exposure to this substance caused peripheral edema and gastrointestinal haemorrhage in carp. Similarly, the histological changes in heart and the blood vessels of the liver in diltiazem exposed rainbow trout suggested vasodilatation similar to the pharmacological effect of diltiazem in the human body. In rainbow trout sub-chronically exposed to atenolol at a human therapeutic blood plasma concentration, histopathological changes in the cardiovascular system were found. The bioconcentration of verapamil, diltiazem and atenolol in fish can be classified as low. Bioconcentration factor (BCF) of verapamil in whole body homogenates of common carp ranged between 6.6 and 16.6. The BCF of diltiazem was also relatively low (0.5-194) in analysed tissues of trout, following the order kidney liver muscle blood plasma. BCF of atenolol in rainbow trout tissues was the lowest among the tested substances (BCF = 0.002-0.27), following the order of liver > kidney > muscle. In the blood plasma, the concentration of atenolol was below the limit of quantification. Verapamil showed a longer half-life time (10.6 days) in fish compared to the human body, indicating the slow rate of biotransformation and/or elimination of verapamil in fish. Estimated half-life times of diltiazem in liver (1.5 h) and kidney (6.2 h) were in the same order of magnitudes as those determined for the human blood plasma. The half-life time of atenolol in trout was not studied, because of its very low bioconcentration. In diltiazem exposed rainbow trout, 8 groups of metabolites of diltiazem with 17 different isoforms were identified using liquid chromatography/high resolution mass spectrometry method. Diltiazem was found to undergo a biotransformation involving desmethylation, desacethylation and hydroxylation in fish. These results showed that diltiazem was metabolised in fish in a similar way like in the human body by desmethylation and desacethylation. On the other hand, hydroxylation, which was involved to a minor extent, seemed to be species specific. Verapamil had no effect on early life stages of common carp at the environmentally relevant concentration after one month lasting exposure. On the other hand, atenolol and diltiazem in environmentally realistic concentrations caused after 42-day exposure some physiological changes in rainbow trout. Namely, atenolol affected haematological and biochemical parameters of the blood in exposed rainbow trout and diltiazem caused changes in the activity of antioxidant enzymes in trout liver and gills. These data indicated that atenolol and diltiazem, when present in the aquatic environment, could be a source of sub-lethal detrimental effects in fish.

Morphological diversity of 61 Anabaena populations of 13 morphospecies was described under the field conditions of Czech fishponds and reservoirs. Polyphasic approach was then applied in classification of 45 clonal strains isolated from those populations. Detailed morphological analyses were performed and partial 16S rRNA gene sequences were obtained for 33 of the strains, and secondary metabolite production was evaluated in 20 strains. Plasticity of morphological characteristics under varied conditions of light, temperature, nitrogen and phosphorus was studied in selected strains, as well as their temperature and light growth requirements. The results were then discussed with respect to the delimitation of single Anabaena morphospecies. A new genus Sphaerospermum was defined for the morphospecies Anabaena kisseleviana, A. reniformis and Aphanizomenon aphanizomenoides, whose phenotypic and genotypic features differed considerably from all other Anabaena morphospecies. Unique information was provided on the occurrence and distribution of A. reniformis and Aph. aphanizomenoides in the Czech Republic.