Antimicrobial Activity of 3,4- seco -Diterpenes Isolated from Croton blanchetianus against Streptococcus mutans and Streptococcus parasanguinis

Abstract

In this study, acid and neutral fractions and three diterpenes were isolated from the hexane extracts from roots of three individual specimens of Croton blanchetianus Baill., collected from the same geographical site. Moreover, the antimicrobial activity of the extracts, fractions and diterpenes isolated was evaluated against Streptococcus mutans and Streptococcus parasanguinis , bacteria related with dental caries. The structures of the diterpenes were elucidated mainly by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, and high-resolution mass spectrometry, such as methyl 12-hydroxy-3,4- seco -cleistanta-8,11,13,15,4(18)-pentaene-3-oate; ent -3,4- seco atisa- 4(18),16-dien-3-oic acid and a novel diterpene 3,4- seco -beieren-3-oic acid. Regarding to the antimicrobial activity, in general, all extracts, the neutral and acid fractions of the hexane extracts roots of all three specimens, showed antimicrobial activity in concentrations ranging from 500 to 7.8 μg mL -1 . In addition, the three diterpenes isolated showed bactericidal and bacteriostatic activity against S. mutans and S. parasanguinis , suggesting them as alternative agents with the potential to prevent oral diseases.