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1

Charakterystyka toksyn produkowanych przez sinice

Gałczyński Ł., Ociepa A.

Proceedings of ECOpole

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2008

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Vol. 2, No. 1

177--179

PL

Coraz częstszym problemem w ekotoksykologii są toksyny naturalne. W ciągu kilku ostatnich lat szczególnie aktualnym problemem stała się obecność toksyn sinicowych w silnie zanieczyszczonych wodach jezior i zbiorników zaporowych o dużym stopniu eutrofizacji. Toksyny wytwarzane przez sinice można sklasyfikować według ich właściwości toksykologicznych. Wyróżniamy m.in. neurotoksyny (np. anatoksyna-a, anatoksyna-a(s), saksytoksyna i neosaksytoksyna); wywołujące nowotwory (np. mikrocystyny, lipopolisacharydy); dermatotoksyny (np. lyngbyatoksyna-a, aplysiatoksyna i lipopolisacharydy); hepatotoksyny (mikrocystyny, nodularyny i cylindrospermopsyna). Do gatunków produkujących toksyny zaliczmy np. Microcystis, Anabaena, Nostoc, Nodularia, Aphanizomenon. Najczęściej występującą toksyną jest zaliczana do hepatotoksyn - mikrocystyna. Obecnie znanych jest ponad 70 różnych struktur tych związków. Hepatotoksyny, do których zaliczamy mikrocystyny i nodularyny, są odpowiedzialne za zatrucie zwierząt i ludzi, mających kontakt z toksycznymi zakwitami. Są one bardzo stabilne w wodzie ze względu na swoją strukturę chemiczną. Obecnie znanych jest kilka metod oznaczania toksyn sinicowych w wodzie. Metodą najczęściej stosowaną do jakościowej i ilościowej analizy toksyn sinicowych jest wysokosprawna chromatografia cieczowa z detekcją diodową (HPLC-DAD). Toksyny sinicowe występują powszechnie na świecie. W około 60÷90% zakwitów sinicowych występujących w zbiornikach wodnych na świecie wykazano obecność mikrocystyn. Reasumując, sinice mogą być groźne dla zdrowia i życia. Nie lekceważmy więc zakazów spowodowanych ich pojawieniem się w wodzie, choćby zakazem kąpieli.

EN

Natural toxins cause in ecotoxicology more and morę problems. Compounds (PAH, dioxins, PCB, pesticides, heavy metals, etc.) introduced to the natural environment as a result of industrial and agricultural activity of the man were in a facus of interests of ecologists through the long time. The particularly current problem, since a few last years, is a presence of cyanoprokaryota toxins in polluted waters of lakes and barrage containers with high eutrophication. Toxins are produced by cyanoprokaryota may be categorized according to their toxicological properties. Thus the categories arę neurotoxins (anatoxin-a, anatoxin-a(s), saxitoxin and neosaxitoxin); the tumor promoters (microcystins, lipopolysaccharides); the deematoxins/irritant toxins(lyngbytoxin A, aplysiatoxins and lipopolysaccharides); hepatotoxins (microcystins, nodularins and cylindrospermopsin). Cyanotoxins produced by members of several cyanobacterial genera including Microcystis, Anabaena, Nostoc, Nodulana, Aphanizomenon. There are currently known more than 70 stmctural variations of microcystins (hepatotoxins). Hepatotoxins such as microcystins and nodularins have been responsible for the poisoning of both animals and humans who ingest or come into contact with toxic blooms. They are extremely stable in water due to their stable chemical structure and can tolerate radical changes in water chetnistry, including pH and salinity. There are a few methods of meaning cyanoprokaryota toxins determination in water chemistry. Cyanoprokaryota toxins analysis were carried out by high performance liquid chromatography (HPLC) with photo-diode array detection. It was demonstrated that about the 60÷90% cyanoprokaryota blooms entering into water reservoirs in world were - microcystins. Recapitulating, cyanoprokaryota, they are organisms they can be dangerous to the health and the life.

2

Toksyny wytwarzane przez sinice

Gałczyński Ł., Ociepa A.

Ecological Chemistry and Engineering. S

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2008

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Vol. 15, nr 1

69-76

PL

Coraz częstszym problemem w ekotoksykologii są toksyny naturalne. W ciągu kilku ostatnich lat szczególnie aktualnym problemem stała się obecność toksyn sinicowych w silnie zanieczyszczonych wodach jezior i zbiorników zaporowych o dużym stopniu eutrofizacji. Toksyny wytwarzane przez sinice można sklasyfikować według ich właściwości toksykologicznych. Wyróżniamy m.in. neurotoksyny (np. anatoksynaa, anatoksyna-a(s), saksytoksyna i neosaksytoksyna); wywołujące nowotwory (np. mikrocystyny, lipopolisacharydy); dermatotoksyny (np. lyngbyatoksyna-a), aplysiatoksyna i lipopolisacharydy); hepatotoksyny (mikrocystyny, nodularyny i cylindrospermopsyna). Do gatunków wytwarzających toksyny zaliczmy np. Microcystis, Anahaena, Nostoc, Nodularia, Aphanizomenon. Najczęściej występującą toksyną jest - zaliczana do hepatotoksyn - mikrocystyna. Obecnie znanych jest ponad 70 różnych struktur tych związków. Hepatotoksyny, do których zaliczamy mikrocystyny i nodularyny, są odpowiedzialne za zatrucie zwierząt i ludzi, mających kontakt z toksycznymi zakwitami. Są one bardzo trwałe w wodzie ze względu na swoją strukturę chemiczną. Obecnie znanych jest kilka metod oznaczania toksyn sinicowych w wodzie. Metodą najczęściej stosowaną do jakościowej i ilościowej analizy toksyn sinicowych jest wysokosprawna chromatografia cieczowa z detekcją diodową (HPLC-DAD). Toksyny sinicowe występują powszechnie na świecie. W około 60-90% zakwitów sinicowych występujących w zbiornikach wodnych na świecie wykazano obecność mikrocystyn. Sinice, mimo ze są organizmami o mikroskopijnych rozmiarach, mogą być groźne dla zdrowia i życia.

EN

Natural toxins cause in ecotoxicology more and more problems. Compounds (PAH, dioxins, PCB, pesticides, heavy metals, etc.) introduced to the natural environment as a result of industrial and agricultural activity of the man were in a facus of interests of ecologists through the long time. The particularly current problem, since a few last years, is a presence of cyanoprokaryota toxins in polluted waters of lakes and barrage containers with high eutrophication. Toxins are produced by cyanoprokaryota may be categorized according to their toxicological properties. Thus the categories are neurotoxins (anatoxin-a, anatoxin-a(s), saxitoxin and neosaxitoxin); the tumor promoters (microcystins, lipopolysacchańdes); the dermatoxins/irritant toxins(lyngbyatoxin-a, aplysiatoxins and lipopolysaccharides); hepatotoxins (microcystins, nodularins and cylindrospermopsin). Cyanotoxins produced by members of several cynnopr-oka~yota genera including Microcystis, Anabaena, Nostoc, Nodularia, Aphanizomenon. There are currently known more than 70 structural variations of microcystins (hepatoxins). Hepatotoxins such as microcystins and nodularins have been responsible for the poisoning of both animals and humans who ingest or come into contact with toxic blooms. They arc extremely stable in water due to their stable chemical structure and can tolerate radical changes in water chemistry, including pH and salinity. There arc a few methods of cyanoprokaryota toxin determination in the water. Cyanoprokaryota toxins analyses were carried out by high performance liquid chromatography (HPLC) with photo-diode array detection. It was demonstrated that about the 60-90% cyanoprokaryota blooms entering into water reservoirs in world were - microcystins. Recapitulating, cyanoprokaryota, they are microrganisms they can be dangerous to the health and the life.

3

Nodularyny i inne toksyny produkowane przez cyjanobakterie (sinice)

Mazur-Marzec H., Toruńska A.

Wiadomości Chemiczne

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2007

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[Z] 61, 3-4

247-277

EN

Cyanobacteria are photosynthetic prokaryotes that produce a wide range of secondary metabolites. Part of them is toxic or shows bioactivity in other organisms, including mammals . The main classes of cyanobacterial toxins comprise of hepatotoxins, neurotoxins, cytotoxins, dermatotoxins and lipopolysaccharides. Hepatotoxins, microcystins and nodularins are the most common cyanotoxins. Microcystins, the cyclic heptapeptides are produced by freshwater cyanobacteria of the genera Microcystis, Anabaena, Planktothrix (Oscillatoria), Nostoc, Hapalosiphon and Anabaenopsis. Nodularin (NOD-R) the cyclic pentapeptide hepatotoxin is produced by brackish water cyanobacterium Nodularia spumigena. Microcystins and nodularins are extremely toxic due to their action on type 1 and 2A protein phosphatase enzymes that play a key role in the control of cellular meta-bolism. The main groups of neurotoxins produced by cyanobacteria include anatoxin-a, anatoxin-a(s), saxitoxins and the recently identified B-N-methylamino--L-alanine (BMAA). The latter has been reported to biomagnify within the Guam ecosystem and was suggested to be a possible cause of the amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC). In the Baltic Sea N. spumigena is the main toxic and bloom-forming cyanobacterial species [7]. Nodularin concentration can temporarily reach over 20 mg dm-3. The toxin accumulates in different elements of the Baltic ecosystem, including sediments, mussels and fish. Apart from NOD-R, minor amounts of other NOD analogues have been characterized in N. spumigena cells: geometrical isomers, linear forms, three demethylated analogues and three analogues with additional methyl group. Nodularin is characterized by high stability. The loss of the toxin in water is mainly due to degradation by the naturally occurring bacterial community. However, the UV radiation as well as sorption on sediments and sus-pended particles has also some impact on nodularin concentration. In organisms microcystins are detoxified by conjugation with activated glutathione, however, the pathway of nodularin biotransformation has not been revealed yet.

4

Peptydowe toksyny cyjanobakterii

Łukomska J., Kasprzykowski F., Łankiewicz L., Grzonka Z.

Wiadomości Chemiczne

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2002

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[Z] 56, 1-2

57--82

EN

This review presents chemical and biological aspects of secondary metabolites produced by cyanobacteria. The main goal of the work was to present studies related to microcystins and nodularins. Cyanobacteria (blue-green algae) growing both in freshwater and marine environment release to the medium numerous secondary metabolites. Some of cyanobacteria produce lethal toxins (cytotoxins and biotoxins). Therefore, cyanobacteria can be harmful for mammals, birds and fish, and also cause effects on human health. The secondary metabolites are the mostly derivatives of amino acids and peptides or depsipeptides. The best described among cyanobacteria toxins are the hepatotoxins: microcystins and nodularins. These toxins cause severe intrahepatic haemorrhage and hypovolaemic shock, and act as tumor promoters. Microcystins and nodularins are potent inhibitors of PP1 and PP2A protein phosphatases. Microcystins and nodularins, which are cyclic hepta- or penta-peptides, respectively, consists of various uncoded amino acid residues. The most characteristic and unique amino acid residue is Adda [(2S,3S,8S,9S,4E,6E)-3-amino-9-metoxy-2,6,8-trimethyl-10-phenyl-deca-4,6-dienoic acid]. Typical isolation of these toxins is realized by extraction combined with reversed-phase chromatography. Structure-activity relationship studies of microcystins and nodularins have revealed indispensability of Adda moiety, and two carboxyl groups of aspartic and glutamic acids, for the activity towards phosphatases. The total synthesis of both toxins represents quite a big challenge because of the necessity of preparation of Adda, as well as many other uncoded amino acids (D-erythro-b-methyl-aspartic acid, Masp; dehydroalanine, Dha, or dehydrobutyrine, Dhb, and their N-methyl derivatives etc.) prior to a final cyclization. Syntheses of Adda, the compound with four chiral centers and two specific configurations at the double bonds, were carried out mostly by the condensation of the previously obtained C1-C4 and C5-C10 fragments. Microcystins and nodularins are quite stable compounds in aqueous solution. They can be destroyed and removed by chlorination, or by treatment with ozone (Scheme 9) combined with ultrafiltration. On the other hand, microcystins and nodularins could be modified for example by esterification (Asp and/or Glu residues), transformation of guanidine moiety of arginine, Michael type addition to dehydroamino acids (Dha, Dhb). These modifications provide less toxic compounds, with interesting biological activities.