[Antimicrobial substances of superior plants. 44. Isolation of diterpene acid from Croton aff. argyrophylloides Muell arg. (Euphorbiaceae)].

In this paper the authors present the first report concerning the biological effects of a diterpene isolated from Croton aff. argyrophylloides Muell. Arg (Euphorbiaceae). Some biological and physiochemical properties of the antibiotic, named argyrophillic acid, were appreciated in comparison with those presented by cunabic acid, an antibiotic isolated from Icthyothere cunabi. The authors still show the microbial action of the abietic acid and confront it with that of the argyrophilic acid, the new antibiotic here reported.