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Abstracts - Vitor B. Lourenzon

CHEMICAL AND BIOLOGICAL STUDY OF ACTINOBACTERIA ASSOCIATED WITH THE STINGLESS BEE Melipona scutellaris

Vitor B. Lourenzon1*, Carla Menegatti1, Weilan G. P. Melo1, Fábio S. do Nascimento2, Adriano D. Andricopulo3, Jon Clardy4 and Mônica T. Pupo1

1 Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Brazil; vitor.lourenzon@usp.br

2 Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP, Brazil;

3 Instituto de Física de São Carlos, USP, Brazil

4 Harvard Medical School, USA

* Correspondence: mtpupo@fcfrp.usp.br

Throughout evolution, insects have established symbiotic relationships with microorganisms that are able to produce bioactive secondary metabolites. These compounds can protect the host against pathogens, playing an important role in chemical ecology. As a result of their functional role, these natural products can also perform several pharmacological activities being an important and understudied source of new chemical entities for hit discovery. Based on these evidences, this work aims to study bioactive compounds produced by actinobacteria associated with the stingless bee Melipona scutellaris, as part of an ongoing International Cooperative Biodiversity Group (ICBG) project between Brazil and the US. Five actinobacteria (coded as ICBG1307, ICBG1314, ICBG1316, ICBG1318 and ICBG1325) isolated from nurse and foraging bees were selected based on the antiprotozoal activities of their ethyl acetate extracts against the protozoan parasites Leishmania donovani and Trypanosoma cruzi. The strains were also screened against three entomopathogens: Metarhizium anisopliae, Beauveria bassiana and Paenibacillus larvae. Strains were identified by 16S rRNA gene sequencing as Streptomyces kunmingensis ICBG1307, S. drozdowiczii ICBG1314, S. drozdowiczii ICBG1316, S. albiaxialis ICBG1318 and S. rhizosphaerihabitans ICBG1325. S. albiaxialis is described as a thermotolerant and halotolerant actinobacteria with poorly explored secondary metabolism, and has not been previously reported as a bee symbiont.

S. albiaxialis ICBG1318 was selected for further studies since it showed a good inhibition against the bacterium P. larvae, which causes American Foulbrood disease in beehives, and its ethyl acetate extract displayed 99% of inhibition against the parasite L. donovani.

S. albiaxialis ICBG1318 was cultivated in ISP-2 agar and the bioguided fractionation of ethyl acetate extract by SPE and HPLC led to the isolation of two compounds (VL-1 and VL-2). Analyses of 1D and 2D NMR data indicate that they are analogous compounds. HR-ESI-MS analyses are being performed to complete structural elucidation.