Chromones and flavanones from Artemisia campestris subsp. maritima

From the acetone extract of Artemisia campestris subsp. maritima six flavanones, two chromones and the coumarin scopoletin were isolated. 5-Hydroxy-7-methoxychromone and 5,7-dimethoxychromone are new compounds, while the flavanone eriodictyol-7,3'-dimethyl ether is reported for the first time in this species. The structures were elucidated by 1D and 2D NMR techniques. The unequivocal assignments of carbon resonances, mainly made by using 1D selective INEPT and 2D HETCOR experiments, allowed us to correct some H-1 and C-13 resonances of the isolated flavanones and also to differentiate between the flavanone isomers sakuranetin/isosakuranetin and eriodictyol-7,3'-dimethyl ether/eriodictyol-7,4'-dimethyl ether. (C) 1998 Elsevier Science Ltd. All rights reserved.