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Aspidospermine is an indole alkaloid with biological properties associated with combating parasites included in the genera Plasmodium, Leishmania and Trypanossoma. The present study evaluated the cytotoxicity (resazurin test), genotoxicity (comet assay) and mechanism of action (gene expression analysis via qRT-PCR) of this alkaloid in human HepG2 cells. The results demonstrated that treatment with aspidospermine was both cytotoxic (starting at 75 μM) and genotoxic (starting at 50 μM). There was no significant modulation of the expression of the following genes: GSTP1 and GPX1 (xenobiotic metabolism); CAT (oxidative stress); TP53 and CCNA2 (cell cycle); HSPA5, ERN1, EIF2AK3 and TRAF2 (endoplasmic reticulum stress); CASP8, CASP9, CASP3, CASP7, BCL-2, BCL-XL BAX and BAX (apoptosis); and PCBP4, ERCC4, OGG1, RAD21 and MLH1 (DNA repair). At a concentration of 50 μM (non-cytotoxic, but genotoxic), there was a significant increase in the expression of CYP1A1 (xenobiotic metabolism) and APC (cell cycle), and at a concentration of 100 μM, a significant increase in the expression of CYP1A1 (xenobiotic metabolism), GADD153 (endoplasmic reticulum stress) and SOD (oxidative stress) was detected, with repression of the expression of GR (xenobiotic metabolism and oxidative stress). The results of treatment with aspidospermine at a 100 μM concentration (the dose indicated in the literature to achieve 89 % reduction of the growth of L. amazonensis) suggest that increased oxidative stress and an unfolded protein response (UPR) occurred in HepG2 cells. For the therapeutic use of aspidospermine (antiparasitic), chemical alteration of the molecule to achieve a lower cytotoxicity/genotoxicity in host cells is recommended.

Four virulent strain isolates of the fungus, Bipolaris euphorbiae (previously identified as a Helminthosporium sp.), isolated from host plants in four states within Brazil were screened for the production of phytotoxins that promoted wilting and defoliation of the Brazilian weed, Euphorbia heterophylla, commonly found growing among soyabean crops. Only one isolate, B. euphorbiae Strain I (EUPH petropar from Mato Grosso state), produced phytotoxin in-vitro when grown in stationary culture for 7 d at 28 ° C on minimum salts medium supplemented with 1.5 % glucose as the sole carbon source. Phytotoxin was also produced when the fungal strain was grown on fructose, galactose, mannose, xylose and sucrose. The addition of nitrogen source (yeast extract, peptone or malt extract) to the culture medium did not influence phytotoxin production. The phytotoxin produced by Strain I was most active at pH 6.0, stable between pH 3-9, and was highly thermostable, remaining fully active when heated at 90 ° C for 1 h.

A 3′,3′-di-(γ,γ-dimethylallyl)-2′, 4′-di-oxo-enolchalcone (tunicatachalcone) and five known C-prenylflavonoids were isolated and/or identified from the roots of Tephrosia tunicata. Their structures were established by spectral methods and chemical transformation.

Two new eudesmanolide lactones (1 and 2) were isolated from the flowers of Wedelia paludosa. The structures of these sesquiterpenoids were elucidated from spectral data.

Phytochemical investigation of the flowers of Wedelia paludosa afforded two diterpenes, ent-kaur-16-en-19-oic acid and ent-kaur-9(11),16-dien-19-oic acid, three acylated triterpenes, 3beta-O-hexa-decanoylolean-12-en-28-oic acid, 3beta-O-pentadecanoylolean-12-en-28-oic acid and 3beta-O-tetradecanoylolean-12-en-28-oic acid, and three steroids, stigmasterol, 3beta-O-beta-D-glycopyranosyl sitosterol and 3beta-O-beta-D-glycopyrano-sylstigmasterol. The substances were identified by their spectral data.

Coccoloba mollis (Family Polygonaceae) is a medicinal plant popularly used in cases of memory loss, stress, insomnia, anemia, impaired vision, and sexual impotence, but the scientific literature, to date, lacks studies on the biological effects of this species, particularly with regard to cytotoxicity and induction of DNA damage. The aim of the present study was to assess in vitro (in hepatic HTC cells) ethanolic extracts of the roots and leaves of C. mollis for cytotoxicity, genotoxicity, and induction of apoptosis. For these evaluations the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, comet assay, micronucleus test with cytokinesis block, and an in situ test for detection of apoptotic cells with acridine orange staining were used. The results showed that the extract obtained from the roots of C. mollis is more cytotoxic than that obtained from the leaves and that the reduction in cell viability observed in the MTT assay was a result, at least in part, from the induction of apoptosis. Both extracts induced DNA damage at a concentration of 20 microg/mL in the comet assay, but no genotoxicity was detected with any of the treatments carried out in the micronucleus test.

The flowers of Stiffitia chrysantha Mikam(Asteraceae) contain eriodictiol, quercetin, luteolin and b-D-glycopyranosil-sitosterol. These compounds and its derivatives were identified by their 1H and 13C NMR, infra-red and mass spectra data. The heteronuclear 2D NMR were used to confirm the assignments of the proton and carbon chemical shifts, it was used to eliminate definitively the ambiguous correlation reported in the literature for C-5 and C-9 of quercetin and C-23 and C-25 of b-D-glycopyranosil-sitosterol.

Asperphenamate is a natural phenylalanine derivative. This compound was produced through a new, two-step synthetic route. It was also evaluated by the antimicrobial activity of the pure substance against Escherichia coli, Staphylococcus aureus and Cladosporium herbarum.

Numerical taxonomy characterization of Baccharis genus species was performed using ultraviolet-visible spectrophotometry. The aim was to present a more convenient, more practical, more economic and faster method based on chemometric methods and UV-vis absorbance to give the most information about species identity and discrimination, especially when their classification has been doubtful. Three Baccharis species: B. genistelloides Persoon var. trimera (Less.) DC, B. milleflora (Less.) DC, and B. articulata (Lam.) Persoon were included in the study. With the help of principal component analysis (PCA) and cluster analysis (CA), we could characterize the three species. Application of soft independent modeling of class analogy (SIMCA) and K-nearest neighbor (KNN) methods on a training set of 65 extracts resulted in models that correctly classified all samples of an independent validation set, eight samples of B. genistelloides Persoon var. trimera (Less.) DC and one sample donated by Prof. Alarich Schultz Herbarium, Porto Alegre-RS, Brazil.

The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa.

Phytochemical investigation of the aerial parts of three Baccharis species (Asteraceae family) was performed using HPLC and chemometric methods, with the objective of distinguishing between three morphologically very similar species: Baccharis genistelloides Persoon var. trimera (Less.) DC, B. milleflora (Less.) DC and B. articulata (Lam.) Persoon. With the help of Principal Component Analysis (PCA) and variance weights, it was possible to characterize the chromatographic profiles of the alcoholic extracts of the three species. Application of Soft Independent Modeling of Class Analogy (SIMCA) and K-Nearest Neighbor (KNN) methods on a training set of 74 extracts resulted in models that correctly classified all eight samples in an independent test set.

A 3′,3′-di-(γ,γ-dimethylallyl)-2′, 4′-di-oxo-enolchalcone (tunicatachalcone) and five known C-prenylflavonoids were isolated and/or identified from the roots of Tephrosia tunicata. Their structures were established by spectral methods and chemical transformation.

The roots of Aspidosperma polyneuron, family Apocynaceae, were subjected to chemical and biological investigations. From an ethanolic extract of the roots, the new alkaloid 2,7-dihydroxyquebrachamine (1) was isolated. The structure was established mainly from 1D and 2D NMR spectroscopic and mass spectrometric data. The 1D and 2D NMR spectra were also used to assign all the 1H and 13C chemical shifts of this alkaloid. Artemia salina was used for a preliminary investigation of biological activity.

OBJECTIVE : To evaluate the free radical scavenging and cytotoxic activities of the butanolic (BuOH) extract, methanolic (MeOH) extract and 20-hydroxyecdysone extracted from the roots of Pfaffia glomerata . MATERIALS AND METHODS : Pfaffia glomerata roots were collected, powdered and extracted with methanol by maceration at room temperature. The extract was concentrated under vacuum, yielding a residue, followed by a butanol extraction. The 20-hydroxyecdysone (EC) was obtained by chromatographic separation of the BuOH fraction. An amount of 10 mg of each dry extract and EC was dissolved in 0.1% dimethyl sulphoxide-phosphate-buffered-saline solution (DMSO-PBS) and screened for their capabilities on scavenging thiobarbiturate reactive substances (TBARS). The antioxidant activity of each extract was determined in vitro by measuring malonyldialdehyde (MDA) and 4-hydroxynonenal (4-HNE) in erythrocyte ghosts treated with ferric-ascorbate. The investigation has also included the cytotoxicity measurement by Trypan blue exclusion test and tetrazolium reduction assay in mice peritoneal macrophages. RESULTS : The free radical scavenging activity of EC was higher than that present in the BuOH fraction. The MeOH extract showed a remarkable pro-oxidant activity. The EC-free radical reaction-inhibition was almost twice of that of the control a-Tocopherol (aT). The Trypan blue exclusion assay confirmed toxicity of the MeOH extract, whose lethality surpassed 80% of the treated macrophages after 1 h of 0.01 mg exposure per 106 cells. CONCLUSIONS : The present study shows the antioxidant effect of the Brazilian Ginseng. The scavenging effect was evidenced for EC as well the BuOH fraction. The MeOH extract showed cytotoxicity on mice peritoneal macrophages. Such toxicity is probably due to ginsenosides present in this latter fraction and warrants further toxicological evaluation of the Brazilian Ginseng roots.

Isomeric 6- and 9-hydroxy-naphtho-z.sfnc;2,3-bz.sfnc;pyran-5,10-quinones were synthesised by alkylation-cyclisation of 2- and 3-hydroxyjuglone in a single step and can be distinguished by UV-visible spectra in the presence of additives and 1 HNMR.

Coccoloba mollis (Polygonaceae) é uma planta medicinal amplamente utilizada em Londrina- PR como energético e modulador da memória. Este trabalho apresenta a avaliação química dos extratos etanólicos das raízes e folhas de C. mollis e testes biológicos. Os extratos foram submetidos a processos cromatográficos usuais de fracionamento e purificação em Química de Produtos Naturais conduzindo ao isolamento dos seguintes constituintes: Nas folhas e raízes foram identificadas misturas de hidrocarbonetos alifáticos de cadeias longas (C-28 a C- 34 excetuando C-30 e 31 e C-16 a C-31 exceto o C-17 respectivamente) e ésteres etílicos de ácidos graxos (C- 18, 22, 24, 25 e 27 e C - 12, 15, 18, 22, 25, 26, 27 respectivamente), nas raízes foram identificadas duas antraquinonas: a emodina (1,6,8-trihidroxi-3- metilantraquinona) e a fisciona (1,8-dihidroxi-3-metil-6-metoxi-antraquinona) e nas folhas um triterpeno, a taraxerona (13 - metil - 27-norolean-14-en-3-ona (D-Friedoolean-14-en-3-ona)) e o malato de dietila. A quimioprospecção realizada com as raízes e as folhas utilizando-se de métodos farmacognósticos revelou a presença de flavonóides e taninos, em ambas, e antraquinonas apenas nas raízes. Os extratos das raízes e das folhas foram submetidos a testes biológicos: avaliação da atividade antioxidante (DPPH), da atividade antimicrobiana, alelopatia, letalidade de Artemia salina e toxicidade materna em camundongos. O poder antioxidante (CMI50 μg/mL) resultante das folhas (10,11 ± 0,12) e das raízes (15,96 ± 0,55) apresentaram valores semelhantes aos do BHT (butil hidroxi tolueno). Nos testes antimicrobianos as raízes apresentam a melhor atividade antibacteriana e as folhas melhor atividade antifúngica. As raízes apresentaram maior toxicidade em relaçao à Artemia salina, e ambos os extratos não revelaram toxicidade materna nas concentrações testadas. As antraquinonas isoladas das raízes revelaram atividade antifúngica. Coccoloba mollis (Polygonaceae) is a plant that is being used as medicine in Londrina (memory herb), this specie has been praised as efficient in the treatment of stress, and as memory modulator. This work presents the chemical evaluation of the root and leaf ethanolic extracts of C. mollis and biological tests. The extracts were submitted to usual chromatographic methods of separation and purification in Natural Products Chemistry. Leading to the isolation of the following constituents: In the leaves and roots were identified aliphatic hydrocarbons (C-16 to C-31 except -17 and C-28 to C-34 except C-30 and 31 respectively) and fatty acids ethyl esters ( C – 18, 22, 24, 25 and 27 and C – 12, 15, 18, 22, 25, 26, and 27 respectively) . In the roots they were identified two anthraquinones emodin (1,6,8-trihydroxy-3- methyl-anthraquinone) and fission (1,8-dihydroxy-3-methyl-6-metoxianthraquinone). In the leaves one triterpen taraxerone (13 - methyl - 27-norolean-14-en-3- one (d-friedoolean-14-en-3-one)) and diethyl malate. Phytochemical screening have been characterized using pharmacognostic methods to determine the major chemical groups present in roots and leafs of this species. Flavonois and tannins in both and anthraquinones in roots. The extracts of roots and leaves were sunjected to biological tests: Evaluation of antioxidant activity (DPPH), antimicrobial activity, allelopathy, lethality of Artemia salina and maternal toxicity in mice. The antioxidant activity (CMI50 μg/mL) das folhas (10.11 ± 0.12) e raizes (15.96 ± 0.55) are similar of BHT (butylateg hydroxytoluene). Antimicrobial tests roots showed the best results as antibacterial and the leaves as antifungal. Roots presented toxicity larger against Artemia salina than leaves. and both extracts don’t’ show maternal toxicity at the concentrations assayed. The isolated anthraquinones showed antifungal activity.

Este trabalho descreve a anatomia de folhas e caules e o estudo químico das folhas de Pimenta pseudocaryophyllus (Gomes) L.R. Landrum, uma arvore cujas folhas são usadas pela população para fazer chá para estados gripais e na culinária. Foram coletados segmentos do primeiro, segundo e quarto entrenós e folhas de 10 indivíduos em São Jerônimo da Serra - PR (23º43’34,5”S; 50º43’58,7”W). Os segmentos de caules e folhas foram fixados em álcool 70% e submetidos às técnicas usuais de microscopia e histoquímica. O caule apresenta epiderme unisseriada recoberta por cutícula espessa e córtex parenquimatoso com cavidades secretoras próximo a epiderme. O tecido vascular forma um anel continuo ao redor da medula com xilema envolto externa e internamente por floema. O quarto entrenó apresenta estrutura semelhante a do primeiro e segundo entrenós, mas com crescimento secundário evidente no tecido vascular. O pecíolo apresenta epiderme unisseriada coberta por cutícula espessa, córtex parenquimatoso com cavidades secretoras próximas a epiderme e um feixe anficrival envolto por periciclo esclerenquimático. A folha e hipostomática e possui epiderme unisseriada revestida por cutícula evidente. Sua face adaxial e glabra, mas tem muitos tricomas na face abaxial. O limbo apresenta hipoderme múltipla na face adaxial, parênquima palicadico formado por duas ou três camadas e parênquima lacunoso. Cavidades secretoras estão presentes, especialmente no parênquima palicadico. A nervura central e formada por epiderme unisseriada coberta por cutícula espessa, córtex parenquimatoso com cavidades secretoras próximas a epiderme e um feixe anficrival envolto por periciclo esclerenquimatico. Dentre os testes histoquímicos foram obtidos resultados positivos para lipídios, compostos fenólicos, amido e oxalato de cálcio. A espécie apresenta características anatômicas típicas da família e as cavidades secretoras presentes nas folhas e caules estão relacionados aos metabólitos secundários detectados. Os dados apresentados contribuem para o estabelecimento de um padrão anatômico e químico para a espécie. Foi feito o estudo químico do extrato das folhas de Pimenta pseudocaryophyllus em acetato de etila e de seu óleo essencial, e a atividade antimicrobiana do óleo essencial. O óleo essencial foi obtido por hidrodestilação utilizando o aparelho de Clevenger. Seus componentes foram identificados por CG-EM, CG-DIC e pelo Índice de Kowats e o eugenol foi identificado como constituinte majoritário. O extrato em acetato de etila (35 g) foi cromatografado em coluna de sílica gel, do qual foram obtidas as frações hexanica, hexano/diclorometano 50 %, diclorometanica e etanolica. As frações hexanica, hexano/diclorometano 50 % e diclorometanica foram submetidas a técnicas de purificação usuais. Os constituintes isolados foram identificados através de métodos espectométricos (RMN, 1H/13C, CG-EM, IV). Foram isolados misturas de hidrocarbonetos de cadeias longas, acido ursolico, ƒÀ-amirina e uma mistura oleosa contendo vitamina E e eugenol como constituintes principais. Nos testes de atividade antimicrobiana, o óleo essencial apresentou uma boa atividade contra os microrganismos testados. A espécie apresenta potencial para o uso no desenvolvimento de fármacos e de defensivos agrícolas menos agressivos ao ambiente, uma vez que contem constituintes químicos de reconhecidas atividades biológicas (eugenol, acido ursolico e ƒÀ-amirina) e seu óleo apresentou atividade contra microrganismos prejudiciais à saúde humana e a espécies vegetais de interesse agronômico. This paper describes the leaf and stem anatomy of Pimenta pseudocaryopyllus (Gomes) L.R. Landrum, a tree which leaves are used by the population in the production of tea for cold and at culinary. There were collected segments of the first, second and fourth internodes and leaves of 10 individuals in São Jerônimo da Serra (23º43’34,5”S; 50º43’58,7”W), Parana State. The stem and leaf segments were fixed in 70% alcohol and submitted to the usual microtechniques. The stem presents uniseriate epidermis covered by a thick cuticle. The cortex is parenchymatous and has secretory cavities near the epidermis. The vascular tissues form a continuous ring around the pith with the xylem surrounded by phloem in his internal and external face. The fourth internode shows similar structure to the first and second internodes, but with evident secondary growth in the vascular tissue. The petiole shows uniseriate epidermis covered by a thick cuticle, parenchymatous cortex with secretory cavities near the epidermis and an amphicrival bundle surrounded by a sclerenchymatic pericycle. The leaf is hypostomatic and is characterized by a uniseriate epidermis covered by evident cuticle. Its adaxial face is glabrous but has abundant trichomes on the abaxial face. The leaf presents a multiple hypodermis at the upper face, a palisade parenchyma formed by two or three layers and a spongy parenchyma with many intercellular spaces. Several secretory cavities are present at the leaf, especially in the palisade parenchyma. The midrib is formed by a uniseriate epidermis covered by a thick cuticle, parenchymatous cortex with some collenchyma group cells and secretory cavities near the epidermis and an amphicrival bundle surrounded by a sclerenchymatic pericycle. Among the histochemical tests positive results were obtained for lipids, phenolic compounds, starch and calcium oxalate. The species has anatomical features typical of the family and the secretory cavities present in the leaves and stems are related to secondary metabolites detected. Chemical and anatomical studies are needed in order to establish a pattern for the species and identify the substances in their secondary metabolites, and their activities. There was made the chemical study of the extract of Pimenta pseudocaryophyllus leaves in ethyl acetate and its essential oil, and the essential oil antimicrobial activity. The essential oil was obtained by hidrodestilation using the Clevenger apparatus. Its components were identified by CG-MS, GC-FID and by the Kowats Index and the eugenol was identified as majoritary constituent. The extract in ethyl acetate (35g) was chromatographed on silica gel column, which were obtained the fractions hexanic, hexane / ichloromethane 50 %, dichloromethanic and ethanolic. The fractions hexanic, hexane / dichloromethane 50 % and ichloromethanic were submitted to usual purification techniques. The isolated constituents were identified through spectroscopy methods (NMR, 1H/13C, GC-MS, IV). There were isolated mixture of long chairs hydrocarbons, ursolic acid, β-amyrin and an oily mixture containing vitamin E and eugenol as the main constituent. In the antimicrobial activities tests the essential oil showed a good activity against the tested microorganisms. The specie presents potential to use in the development of drugs and of agricultural chemicals less agrasive to environment, since it contains components of known biological activity in its essential oil (eugenol) and in the extract of its leaves (ursolic acid and β-amyrin), and its essential oil presented activity against microorganism harmful to the human health and to plants of agronomic interest.

A freqüente ocorrência de floração de cianobactéria toxigênica e a ineficiência do tratamento de água convencional para remoção de microcistina (MC) tornaram relevante o desenvolvimento de alternativa para prevenir ou diminuir o risco de contaminação. Rações utilizadas na piscicultura são compostas por grão susceptível à contaminação com aflatoxina B1 (AFB1) e seu manejo inadequado favorece a eutrofização da água. A interação de Microcystis aeruginosa e AFB1 foi avaliada em tilápia (Oreochromis niloticus). Os ensaios de genotoxicidade cometa e micronúcleo (MN) e a imunoistoquímica (IHQ) para detecção de MC em peixe foram aplicados, visando métodos adequados para o monitoramento destes contaminates. Amostras de água foram coletadas na Estação de Tratamento de Esgoto (ETE São Lourenço, Londrina-PR) com objetivo de isolar antagonistas contra cianobactéria. O mecanismo de biodegradação de MCLR pela cepa B9 foi investigado através do método avançado de Marfey e ESI-LCMS (Electrospray Ionization - Liquid Chromatography Mass Spectrometry) para detecção dos produtos da biodegradação. O ensaio com tilápias (N=96) foi realizado através de exposição intraperitoneal (ip) de AFB1 (10mg/Kg) e extrato celular de M. aeruginosa cepa CCBUSP262 nas dose de 2x105, 4x105 e 1x106 céls/Kg (0,602, 1,204 e 3,011 mg/Kg de 7D-MCLR) e exposição por imersão em 1x104 e 1x105 céls/mL e em doses cumulativas de 1x104, 2x104 e 5x104 céls/mL (30,1, 60,2, 150,5 e 301 mg/L de 7D-MCLR). Para seleção de microrganismos com atividade anti-cianobactéria, as cepas Microcystis aeruginosa NIES 298, M. viridis NIES 102, Anabaena mendotae NIES 808, Phormidium tenue NIES 611 foram inoculadas com cada isolado e após 0, 24, 48, 72 e 96 h a absorbância do extrato da biomassa foi medida em 405 e 665 nm. Uma colônia de cada isolado foi adicionada em 10 mg/mL de MCLR e após 0, 24, 48 e 72h foi analisado por CLAE. O método avançado de Marfey, utilizando derivatização com L-FDLA (L-1-flúor-2,4-dinitrofenil-5-alaninamida) foi padronizado e aplicado para análise dos produtos de biodegradação de MCLR (1mg/mL) pela cepa B9. A freqüência de MN e escore de cometa mostraram efeito mutagênico e genotoxicidade sinérgica do extrato celular de M. aeruginosa com AFB1 (ip). A IIQ detectou MC em todos os fígado de peixe ip inoculados e imersos a 1x105cells/mL (301mg/L de 7D-MCLR). Embora MC não tenha sido detectada no músculo (comestível) a resistência dos peixes às doses mostrou possibilidade de contaminação e risco na cadeia alimentar. Entre os 35 isolados, apenas 7 microrganismos mostraram atividade antagônica contra M. aeruginosa NIES 298 e nenhum foi capaz de degradar MCLR. Os resultados indicaram potencial para isolamento de microrganismos antagonistas em pontos de ocorrência de florações. Peptídeos e aminoácidos derivatizados com L-FDLA foram detectados por ESI-LCMS. A biodegradação de MCLR pela cepa B9, inicia-se pela linearização de MCLR que é clivada formando Adda-Glu-Mdha-Ala e Arg-bMeAsp-Leu. O tetrapeptídeo é preferencialmente degradado em Adda e Glu-Mdha-Ala, sendo este degradado em Glu-Mdha e Mdha-Ala. A ligação bMeAsp-Leu é clivada cujo principal produto é Arg-bMeAsp. Entre os resíduos de aminoácido Arg, Adda e Mdha foram detectados como produtos finais da biodegradação. A identificação destes compostos é uma ferramenta importante para entender a atividade enzimática hidrolítica da cepa B9 nos processos de detoxificação de microcistina. The frequently toxic cyanobacteria bloom and inadequate remotion of microcystin (MC) by conventional water treatment, the development of alternative to prevent and reduce contamination risk become a topic in concerning. Fish feed is composed by grains susceptible to aflatoxin B1 (AFB1) contamination and inadequate feeding management enhances water eutrophication. The interaction between Microcystis aeruginosa and AFB1 was evaluated in tilapia (Oreochromis niloticus). Comet and micronucleous (MN) assay to evaluate effect of genotoxicity and immunohistochemistry (IHC) for MC detection in fish were applied to have in view suitable and profitable monitoring method. Water were sampled from Sewage treatment of Londrina (ETE São Lourenço, Londrina-PR) aiming to select antagonistis against cyanobacteria. The MCLR biodegradation pathway by B9 strain was investigated using the advanced Marfey's method and ESI-LCMS (Electrospray Ionization- Liquid Chromatography Mass Spectrometry) for biodegradation products detection. The bioassay with tilapia (N=96) was carried out with intraperitoneal (ip) exposure of AFB1 (10 mg/Kg ) and M. aeruginosa BCCUSP262 cellular extract at 2x105, 4x105 e 1x106 cells/Kg (0.602, 1.204 and 3.011 mg/Kg of 7D-MCLR) and immersion exposure 1x104 e 1x105 cells/mL and cumulative doses at 1x104, 2x104 e 5x104 cells/mL (30.1, 60.2, 150.5 and 301 mg/L of 7D-MCLR). To select microorganisms with anti-cyanobacteria activity the strains Microcystis aeruginosa NIES 298, M. viridis NIES 102, Anabaena mendotae NIES 808, Phormidium tenue NIES 611 were inoculated with each isolated and after 0, 24, 48, 72 and 96 h the absorbance of biomass extract was mensured at 405 and 665 nm. One colony of each isolated was added to 10 mg/mL of MCLR and after 0, 24, 48 e 72 h was analyzed by HPLC. The advanced Marfey method with L-FDLA (L-1-fluor-2,4-dinitrophenyl-5-alaninamide) derivatization was standardized and applied for detection of biodegradation products of MCLR (1 mg/mL) by B9 strain. The MN frequency and comet score showed synergic mutagenic and genotoxic effects of M. aeruginosa cellular extract interaction with AFB1 (ip). The IHC detected MC in all ip inoculated fish liver and immersed at 1x105 cells/mL (301 mg/L de 7D-MCLR). Although MC has not been detected in edible muscle, fish doses resistence showed the possibility of contamination and risk in the food chain. Among 35 microorganisms isolated, only 7 microorganisms showed antagonic activity against M. aeruginosa NIES 298 and none was able to degrade MCLR. The results indicated the potencial of antagonist isolation at bloom ocorrence point. L-FDLA derivatization detected aminoacid residues and peptides. The biodegradation of MCLR by B9 strain begins by MCLR linearization that is degraded to Adda-Glu-Mdha-Ala and Arg-bMeAsp-Leu. The tetrapeptide is mainly degraded in Adda and Glu-Mdha-Ala, which is cleaved as Glu-Mdha and Mdha-Ala. The linkage between bMeAsp-Leu is cleaved, forming mainly dipeptide Arg-bMeAsp. Among amino acid residues we detected Arg, Adda and Mdha, as MCLR biodegradation final products. The identification of these compounds is an important tool to understand tha hydrolitic enzimatic activity of B9 strain in the microcystin detoxification process.