Bioactive endophytic fungi isolated from Caesalpinia echinata Lam. (Brazilwood) and identification of beauvericin as a trypanocidal metabolite from Fusarium sp.
Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 μg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 μg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 μg/mL), Candida albicans and Candida tropicalis (MIC 64-128 μg/mL). Fourteen extracts at a concentration of 20 μg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 μg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 μg/mL (2.43 μM) in a T. cruzi cellular culture assay.
Departamento de Ciências Biológicas e da Saúde, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, Brasil.
Fernanda Fraga
FF
Campos
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Policarpo A
PA
Sales Junior
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Alvaro José
AJ
Romanha
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Márcio S S
MS
Araújo
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Ezequias P
EP
Siqueira
Departamento de Química, Instituto de Ciências Exatas.
Jarbas M
JM
Resende
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Tânia M A
TM
Alves
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Olindo A
OA
Martins-Filho
Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
Vera Lúcia dos
VL
Santos
Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
Carlos A
CA
Rosa
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Carlos L
CL
Zani
Centro de Pesquisas René Rachou-Fiocruz, Belo Horizonte, MG, Brasil.
Betania Barros
BB
Cota
D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology; D029911:Caesalpinia / Q000382:microbiology*; D002176:Candida albicans / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects; D005591:Chemical Fractionation; D045424:Complex Mixtures; D017931:DNA Primers; D047630:Depsipeptides / Q000302:isolation & purification / Q000494:pharmacology*; D060026:Endophytes / Q000145:classification / Q000302:isolation & purification*; D004755:Enterobacteriaceae / Q000187:drug effects; D005670:Fusarium / Q000302:isolation & purification* / Q000378:metabolism; D016937:Gram-Positive Endospore-Forming Rods / Q000187:drug effects; D006801:Humans; D007891:Leishmania / Q000187:drug effects; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D014344:Trypanocidal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects*
D000890:Anti-Infective Agents; D045424:Complex Mixtures; D017931:DNA Primers; D047630:Depsipeptides; D014344:Trypanocidal Agents; C004456:beauvericin