Chemical constituents of Talauma arcabucoana (Magnoliaceae): their brine shrimp lethality and antimicrobial activity

Abstract

A new aporphine alkaloid, (–)-arcabucoine [(6aR)-N-formyl-1,2-methylenedioxy-9,10-dimethoxy-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline] 1 was isolated from the leaves of Talauma arcabucoana (Magnoliaceae), along with the known compounds (–)-erythro-saccharinic acid lactone 2 and (–)-shikimic acid 3. Furthermore, the known aporphine alkaloids (–)-dicentrine 4, (–)-nordicentrine 5 and dicentrinone 6 were isolated from the stem bark. The alkaloids 4 and 5 were found to be the most active compounds in a brine shrimp lethality assay. In addition, alkaloids 1, 4 and 5 showed moderate growth inhibition against Staphylococcus aureus and Candida albicans.

Keywords:

• Talauma arcabucoana
• Magnoliaceae
• aporphine alkaloids
• brine shrimp lethality assay
• antimicrobial activity

Acknowledgements

The authors thank the Department of Chemistry at Universidad Nacional de Colombia for the financial support, the NMR Laboratory of Universidad Nacional de Colombia for the NMR spectra, the LC-MS Laboratory at Universidad Nacional de Colombia for the HR-ESI-MS spectra, the Macromolecules Laboratory at Universidad Nacional de Colombia for analytical support, the Department of Chemistry at Pontificia Universidad Javeriana for the optical rotation measurements, Fundación Instituto de Inmunología de Colombia (FIDIC) for the CD curves, Professor Milton Crosby for donating the microbial strains and Diana Castellanos at the Instituto de Estudios Ambientales (IDEA) for her assistance in the antimicrobial assay.