ABSTRACT
Endophytic fungi represent ubiquitous microbial organisms able to live in the tissues of different plants around the world and represent a prolific source of bioactive metabolites. In the present study, the endophytic fungus Aspergillus calidoustus was isolated from the medicinal plant Acanthospermum australe (Asteraceae), and identified using molecular, physiological and morphological methods. A methylene chloride crude extract of A. calidoustus has been produced and subjected to antifungal bioassay-directed fractionation which resulted in the isolation of the two bioactive compounds: ophiobolin K and 6-epi-ophiobolin K. These pure compounds displayed antifungal activity against fungal plant pathogens, protozoal activity against Trypanosoma cruzi, and cytotoxic activity against human tumoral cell lines. The results show that A. calidoustus was able to produce the antifungal and cytotoxic metabolites ophiobolin K and 6-epi-ophiobolin K, which may help the fungus to colonise and occupy the substratum as well as survive in natural environments.
Subject(s)
Antifungal Agents/chemistry , Antimalarials/chemistry , Antineoplastic Agents/chemistry , Aspergillus/chemistry , Sesterterpenes/chemistry , Antifungal Agents/isolation & purification , Antimalarials/isolation & purification , Antineoplastic Agents/isolation & purification , Asteraceae/microbiology , Cell Line, Tumor , HumansABSTRACT
One hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive Brazilian plant species Ageratum myriadenia, Palicourea tetraphylla, Piptadenia adiantoides, and Trixis vauthieri. All fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. The crude extracts were tested in bioassay panels using Leishmania amazonensis, Trypanosoma cruzi, the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and three human cancer cell lines. Thirty-three extracts (27.2 percent) exhibited at least one biological activity. Seventeen extracts (14 percent) were cytotoxic against one or more human cancer cell line with the IC50 values ranged of >0.2 to 25 µg/mL. Twenty-four extracts (19.8 percent) inhibited the activity of TryR, and three showed ability to inhibit the growth of T. cruzi above 60 percent and their IC50 values ranged among 1 to 10 µg/mL. Eleven extracts (9 percent) were able to inhibit the growth of L. amazonensis and showed with IC50 values ranged among 4.6 to 24.4 µg/mL. The endophytic fungi were identified as belonging to the genera Alternaria, Arthrinium, Cochliobolus, Colletotrichum, Penicillium, Fusarium, and Gibberella. An interesting result was obtained for the bioactive isolates UFMGCB 508, 537, 899 and 903, which were related to fungi associated with medicinal plants native to Asia, Australia, Africa, and Polynesia. These results indicate that bioactive plants living in Brazilian ecosystems are a potential host of endophytic fungi able to produce bioactive prototype molecules for drug development against neglected tropical diseases.
Subject(s)
Humans , Fungi/isolation & purification , Leishmania , Metabolism , Plant Extracts , Trypanosoma , Tumor Cells, Cultured , Biological Assay , Methods , Plants , MethodsABSTRACT
One hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive Brazilian plant species Ageratum myriadenia , Palicourea tetraphylla , Piptadenia adiantoides, and Trixis vauthieri. All fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. The crude extracts were tested in bioassay panels using Leishmania amazonensis , Trypanosoma cruzi, the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and three human cancer cell lines. Thirty-three extracts (27.2%) exhibited at least one biological activity. Seventeen extracts (14%) were cytotoxic against one or more human cancer cell line with the IC50 values ranged of >0.2 to 25 µg/mL. Twenty-four extracts (19.8%) inhibited the activity of TryR, and three showed ability to inhibit the growth of T. cruzi above 60% and their IC50 values ranged among 1 to 10 µg/mL. Eleven extracts (9%) were able to inhibit the growth of L. amazonensis and showed with IC50 values ranged among 4.6 to 24.4 µg/mL. The endophytic fungi were identified as belonging to the genera Alternaria , Arthrinium , Cochliobolus , Colletotrichum , Penicillium , Fusarium, and Gibberella. An interesting result was obtained for the bioactive isolates UFMGCB 508, 537, 899 and 903, which were related to fungi associated with medicinal plants native to Asia, Australia, Africa, and Polynesia. These results indicate that bioactive plants living in Brazilian ecosystems are a potential host of endophytic fungi able to produce bioactive prototype molecules for drug development against neglected tropical diseases.
ABSTRACT
The CH(2)Cl(2) extract of the stem bark of Kielmeyera albopunctata was subjected to a bioassay-linked LC-MS dereplication procedure using the KB cell line to afford the new coumarins 4-(1-methylpropyl)-5,7-dihydroxy-8-(4-hydroxy-3-methylbutyryl)-6-(3-methylbut-2-enyl)chromen-2-one (1), 9-(1-methylpropyl)-4-hydroxy-5-(4-hydroxy-3-methylbutyryl)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofuro[2,3-f]chromen-7-one (2), and 5,7-dihydroxy-8-(4-hydroxy-3-methylbutyryl)-6-(3-methylbut-2-enyl)-4-phenylchromen-2-one (3). Coumarins 1 and 3 showed moderate cytotoxicity, while 2 was inactive at 20 microg/mL. Compound 1was active in vitro against the trypomastigote form of the parasite Trypanosoma cruzi, killing 80% of the parasites after 24 h contact at 4 degrees C when added at 125 microg/mL to infected murine blood.
Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Clusiaceae/chemistry , Coumarins/isolation & purification , Plants, Medicinal/chemistry , Trypanocidal Agents/isolation & purification , Animals , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Brazil , Chagas Disease/blood , Chagas Disease/drug therapy , Coumarins/chemistry , Coumarins/pharmacology , Humans , KB Cells/drug effects , Lung Neoplasms , Male , Mice , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Bark/chemistry , Plant Stems/chemistry , Prostatic Neoplasms , Trypanocidal Agents/chemistry , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Tumor Cells, Cultured/drug effectsABSTRACT
Fourteen compounds were evaluated for their activity against Trypanosoma cruzi blood stream forms at the concentration of 500 g/ml. Six compounds were active and re-tested at lower concentrations.
Subject(s)
Nitro Compounds/pharmacology , Trypanosoma cruzi/drug effects , Animals , Drug Evaluation, Preclinical , Inhibitory Concentration 50 , Mice , Nitro Compounds/chemistryABSTRACT
Fourteen compounds were evaluated for their activity against Trypanosoma cruzi blood stream forms at the concentration of 500 æg/ml. Six compounds were active and re-tested at lower concentrations