The essential oils of fresh leaves of Eucalyptus globulus L. (Myrtaceae), and leaves and stems of Smyrnium olusatrum L. (Apiaceae), obtained by hydrodistillation in a Clevenger-type apparatus, were analyzed by GC/MS. Twenty compounds were characterized, representing 98.3% of the essential oil of E. globulus, with 1,8-cineole (48.6%), globulol (10.9%), trans-pinocarveol (10.7%), and α-terpineol (6.6%) as main components, while thirty-three compounds were characterized, representing 94.3% of the essential oil of S. olusatrum, with sabinene (27.1%), curzerene (13.7%), methyl-1-benzyl-2oxocyclooctane carboxylate (12.3%), α-pinene (7.2%), cryptone (7.1%) and β-pinene (5.7%) as the major components. The essential oils of E. globulus and S. olusatrum were tested against a wide range of fungal and bacterial strains. Both oils showed significant antimicrobial activity.

One new flavonol glycoside, patuletin-7-O-[6-O-caffeoyl-2-O-[(S)-3-hydroxyisobutanoyl]glucopyranoside] (astermaritimoside) (1) and four known flavonoids, patuletin-7-O-β-[-6-O-[(S)-3-hydroxyisobutanoyl]glucopyranoside] (2), patuletin-7-O-[6-O-caffeoylglucopyranoside] (3), patuletin-7-O-β-Dglucopyranoside (4) and quercetin-3-O-β-rutinoside (5) have been isolated from Asteriscus maritimus (L.) Less. Chemical structures were elucidated by mass spectrometric, and 1 H NMR, 13 C NMR, COSY, HMQC and HMBC spectroscopic techniques. The antioxidative effect was evaluated using an electronic spin resonance (ESR) method in order to visualize the inhibition of the DPPH radical. The n-butanol fraction was found to possess a remarkable antioxidant activity that was correlated with the total amount of phenolics. The isolated compounds exhibited good antioxidant activity.