Isolation and frontier molecular orbital investigation of bioactive quinone-methide triterpenoids from the bark of Salacia petenensis
- Publication Type
- Journal contribution
- Authors
- Setzer, W.N.; Holland, M.T.; Bozeman, C.A., Rozmus, G.F.; Setzer, M.C.; Moriarity, D.M.; Reeb, S.; Vogler, B.; Bates, R.B.; Haber, W.A.
- Year of publication
- 2001
- Published in
- Planta Medica
- Band/Volume
- 67/01
- ISBN / ISSN / eISSN
- 0032-0943
- Page (from - to)
- 65-69
The crude dichloromethane bark extract of Salacia petenensis (Hippocrateaceae) from Monteverde, Costa Rica, shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of tingenone and netzahualcoyonol as the biologically active materials. Also isolated from the extract were 3-methoxyfriedel-2-en-1-one (a new natural product) and 29-hydroxyfriedelan-3-one. The structures of these compounds were elucidated on the basis of NMR spectral analysis. Molecular orbital calculations have been carried out using the semi-empirical PM3 and Hartee-Fock 3-21G ab initio techniques on the quinone-methide nortriterpenoids tingenone and netzahualcoyonol, as well as on the nucleotide bases adenine, guanine, cytosine, and thymine. The molecular orbital calculations suggest that a possible mode of cytotoxic action of quinone-methide triterpenoids involves quasi-intercalative interaction of the compounds with DNA followed by nucleophilic addition of the DNA base to carbon-6 of the triterpenoid.