title: Bioactive principles in the bark of Pilidiostigma tropicum.
abstract: The crude dichloromethane bark extract of Pilidiostigma tropicum (Myrtaceae) from north Queensland, Australia, shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of rhodomyrtoxin B and ursolic acid-3-p-coumarate as the biologically active materials. The structures of these compounds were elucidated on the basis of spectral analysis. The intercalation interaction of rhodomyrtoxin B with DNA was investigated using molecular mechanics and ab initio molecular-orbital techniques. A favorable pi-pi interaction between rhodomyrtoxin B and the cytosine-guanine base pair is predicted, but the orientation of the interaction cannot be predicted based on frontier molecular orbitals.
authors.affiliation: Department of Chemistry, University of Alabama in Huntsville, Huntsville, AL 35899, USA. wsetzer@chemistry.uah.edu
authors.forename: William N
authors.initials: WN
authors.lastname: Setzer
authors.forename: Glenn F
authors.initials: GF
authors.lastname: Rozmus
authors.forename: Mary C
authors.initials: MC
authors.lastname: Setzer
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Schmidt
authors.forename: Bernhard
authors.initials: B
authors.lastname: Vogler
authors.forename: Sabine
authors.initials: S
authors.lastname: Reeb
authors.forename: Betsy R
authors.initials: BR
authors.lastname: Jackes
authors.forename: Anthony K
authors.initials: AK
authors.lastname: Irvine
mesh_terms: D000677:Amsacrine / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001409:Bacillus cereus / Q000187:drug effects; D020029:Base Pairing; D001572:Benzofurans / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003596:Cytosine / Q000737:chemistry; D004317:Doxorubicin / Q000737:chemistry; D006147:Guanine / Q000737:chemistry; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D027822:Myrtaceae / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001572:Benzofurans; D010936:Plant Extracts; C515961:rhodomyrtoxin B; D000677:Amsacrine; D006147:Guanine; D004317:Doxorubicin; D003596:Cytosine