Daniel Fabio Kawano*, Marcelo Rodrigues de Carvalho, Mauricio Ferreira Marcondes Machado, Adriana Karaoglanovic Carmona, Gilberto Ubida Leite Braga and Ivone Carvalho Pages 1899 - 1904 ( 6 )
Background: Fungal secondary metabolites are important sources for the discovery of new pharmaceuticals, as exemplified by penicillin, lovastatin and cyclosporine. Searching for secondary metabolites of the fungi Metarhizium spp., we previously identified tyrosine betaine as a major constituent.
Methods: Because of the structural similarity with other inhibitors of neprilysin (NEP), an enzyme explored for the treatment of heart failure, we devised the synthesis of tyrosine betaine and three analogues to be subjected to in vitro NEP inhibition assays and to molecular modeling studies.
Results: In spite of the similar binding modes with other NEP inhibitors, these compounds only displayed moderate inhibitory activities (IC50 ranging from 170.0 to 52.9 µM). However, they enclose structural features required to hinder passive blood brain barrier permeation (BBB).
Conclusions: Tyrosine betaine remains as a starting point for the development of NEP inhibitors because of the low probability of BBB permeation and, consequently, of NEP inhibition at the Central Nervous System, which is associated to an increment in the Aβ levels and, accordingly, with a higher risk for the onset of Alzheimer's disease.
Neprilysin, heart failure, tyrosine betaine, fungal metabolites, Metarhizium spp, blood brain barrier.
Faculty of Pharmaceutical Sciences, University of Campinas - UNICAMP, Rua Candido Portinari 200, 13083-871 Campinas-SP, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Av. do Cafe s/n, 14040-903 Ribeirao Preto-SP, Department of Biophysics, Federal University of Sao Paulo, Rua Pedro de Toledo n° 699 7° andar, 04039-032 Sao Paulo-SP, Department of Biophysics, Federal University of Sao Paulo, Rua Pedro de Toledo n° 699 7° andar, 04039-032 Sao Paulo-SP, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Av. do Cafe s/n, 14040-903 Ribeirao Preto-SP, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Av. do Cafe s/n, 14040-903 Ribeirao Preto-SP