A new cyclodipeptide from Tetragonisca angustula honey active against Neospora caninum and in silico study.

A new cyclic natural compound formed by succinic acid and two alanine amino acid units was isolated from the Tetragonisca angustula honey extract. The chemical structure of 1 was established based on spectroscopic data analysis, including one- (1H and 13C NMR) and two-dimensional NMR techniques (1H-1H-COSY, HSQC and HMBC). A primary culture model previously infected with Neospora caninum was used to evaluate 1 for two time intervals (24 and 72 h), showing a reduction (40-56%) of the number of tachyzoites in the first 24 h and until 72 h, a dose-dependent reduction in parasite proliferation (25-50%). Glial cells treated with 1 did not demonstrate toxicity at concentrations up to 25 ug/mL. Treated and infected cultures showed an increase in NO when compared to control cells in 24 h and 72 h. In silico studies suggest that the new compound may affect DNA synthesis and impair -protein production.