Antiplasmodial Chromanes and Chromenes from the Monotypic Plant Species Koeberlinia spinosa
- J Nat Prod. 2018 Mar 23;81(3):475-483. doi: 10.1021/acs.jnatprod.7b00579.
- 1. Department of Biochemistry and Molecular Biology, and Center for Tropical and Emerging Global Diseases (CTEGD) , University of Georgia , Athens , Georgia 30602 , United States.
- 2. Natural Products Discovery Institute , 3805 Old Easton Road , Doylestown , Pennsylvania 18902 , United States.
Nine new compounds containing either a chromane or chromene ring moiety were isolated from the monotypic plant Koeberlinia spinosa. Compounds 1-4 are chromanes with all possible E and Z isomers of the isoprenoid side chain, with compound 5 a methylated derivative of 1. Compounds 6 and 7 were assigned as diastereomeric cyclized derivatives of 2 and were probably artifacts formed during the extraction or the isolation processes. Compounds 8 and 9 were characterized as new chromenes. Structure elucidation of 1-9 was conducted via 1D and 2D NMR spectroscopic data interpretation, and absolute configurations were determined by ECD spectroscopic analysis. Compounds 2, 5, 6, and 7 had weak antiplasmodial activity, while none of the compounds exhibited antiproliferative activity. The isolation, structure elucidation, and biological evaluation of these compounds are presented.