A set of biogenetically interesting polyhalogenated acetogenins from Ptilonia magellanica

Ptilonines A−F, pyranosylmagellanicus D−E and magellenediol are previously undescribed acetogenins isolated from the red alga Ptilonia magellanica. Their structures were determined from spectroscopic evidence. The absolute configuration of the known pyranosylmagellanicus A, was established by derivatization with (R)− and (S)−α−methoxy −α−phenylacetic acids (MPA). Ptilonines exhibit an unusual halogenation pattern, that may confer evolutionary advantages to Ptilonia magellanica, for which a biogenetic origin is proposed. The antimicrobial effect of some of these compounds was evaluated.This work was supported by the Ministerio de Ciencia e Innovación (SAF2009-0839 and RTA 2015-00010-C03-02). ARDM acknowledges funding from IMBRAIN project (FP7-REGPOT-2012-CT2012-31637-IMBRAIN). A.B.G. would like to thank Convenio Universidad de Magallanes (Chile) and CSIC, project 2009CL0031 and Programa PR-F2-03-CRN16 for financial support.Peer Reviewe