Sesquiterpenes and Flavonoids of Anthemis odontostephana var. odontostephana

Abstract

Phytochemical investigation of the flowers of Anthemis odontostephana Boiss. var. odontostephana (Asteraceae) resulted in the isolation of a natural cyclohexenone sesquiterpenoid with a bisabolene skeleton, 1-hydroxydelobanone (1), for the first time as a natural product, and a previously reported cyclohexenone derivative, antheminone A (2), along with two known flavonoids, pectolinaringenin (3), and salvigenin (4). The stereochemistry at positions C-4 and C-5 of the cyclohexenone ring of compound 2 was established based on H-1-H-1 spin-spin coupling constants and ROESY spectra. Compounds 2 and 3 were reported previously as antileishmanial and cytotoxic agents by other authors. The structures of the compounds were elucidated using NMR spectroscopic methods including H-1 NMR, C-13 NMR, APT, COSY, HSQC, and HMBC, and mass spectrometry.