Volatile components of Centaurea bracteata and C. pannonica subsp. pannonica growing wild in Croatia

This paper reports on the volatile components of oils from the aerial parts (CBA) and roots (CBR) of Centaurea bracteata Scop. and aerial parts of C. pannonica (Heuffel) Simonkai subsp. pannonica (CPA), two Asteraceae growing wild in Croatia. The volatile components, obtained by hydrodistillation, were determined by GC-MS analysis. The yields (w/w) of the dried oils were 0.10% (CBA), 0.22% (CBR) and 0.09% (CPA), respectively. A total of 91 compounds were identified accounting for 91.1%, 93.3% and 87.9% of the total oil for CBA, CBR and CPA, respectively. All the samples were characterized mainly by hydrocarbons (7.1-34.1%), fatty acids (9.7-45.9%), and oxygenated sesquiterpenes (15.2-16.6%). The major components of the samples were hexadecanoic acid (8.1-31.1%), nonacosane (0.6-13.4%) and caryophyllene oxide (4.5-11.9%). Monoterpenes, both hydrocarbons and oxygenated, were either absent or present in low amounts in all the oils. The similarity in the oil contents is consistent with the two species being placed in the same section, Jacea.     

Natural and hemisynthetic neoclerodane diterpenoids from scutellaria and their antifeedant activity

The genus Scutellaria (Labiatae) is a very rich source of neoclerodane diterpenoids, with interesting structural features. These secondary metabolites show several biological properties, the most important being the antifeedant activity against pest insects. The present review reports on natural and hemisynthetic diterpenoids and their antifeedant activity.     

Chemical composition of volatile and fixed oils from of Salvia argentea L. (Lamiaceae) growing wild in Sicily

The chemical compositions of the essential oil and of the non-polar extracts (petroleum ether, dichloromethane) of the aerial parts (flowers, leaves and stems) of Salvia argentea L. were determined by GC-FID and gas chromatography–mass spectrometry analysis. 14-Hydroxy-α-humulene (40.1%) was recognised as the main constituents of the essential oil of S. argentea, together with 1,3,8-p-menthatriene (12.1%), globulol (7.4%) and β-sesquiphellandrene (5.8%). Tritriacontane (9.9% and 14.1%), heptacosane (8.4% and 10.5%), hentriacontane (8.3% and 10.9%), tetradecanal (8.4% and 10.2%) and methyldotriacontane (7.9% and 7.6%) were recognised as the main constituents of the extracts in petroleum ether and dichloromethane, respectively, whereas methyl linolenate (36.6% and 13.5%) and methyl myristoleate (10.5% and 18.5%) were recognised as the main constituents of the methylated extracts.     

Chemical composition and biological activity of Salvia verbenaca essential oil

Salvia verbenaca L. (syn. S. minore) is a perennial herb known in the traditional medicine of Sicily as "spaccapetri" and is used to resolve cases of kidney stones, chewing the fresh leaves or in decoction. The chemical composition of the essential oil obtained from aerial parts of S. verbenaca collected in Piano Battaglia (Sicily) on July 2009, was analyzed by GC and GC-MS. The oil was strongly characterized by fatty acids (39.5%) and carbonylic compounds (21.2%), with hexadecanoic acid (23.1%), (Z)-9-octadecenoic acid (11.1%) and benzaldehyde (7.3%) as the main constituents. The in vitro activity of the essential oil against some microorganisms in comparison with chloramphenicol by the broth dilution method was determined. The oil exhibited a good activity as inhibitor of growth of Gram + bacteria.     

Artalbic acid, a sesquiterpene with an unusual skeleton from Artemisia alba (Asteraceae) from Sicily

From the aerial parts of Artemisia alba (Asteraceae) artalbic acid (1), a sesquiterpene with an unusual skeleton, was isolated. Its structure was elucidated on the basis of extensive proton, ¹³C and two-dimensional NMR experiments, as well as by transformation in its methyl ester derivative.     

Chemical Composition of Essential Oil from Italian Populations of <em>Artemisia alba</em> Turra (Asteraceae)

The use of essential oils as chemotaxonomic markers could be useful for the classification of Artemisia species and to caracterize biodiversity in the different populations. An analysis of the chemical composition of four essential oils from Italian populations of Artemisia alba Turra (collected in Sicily, Marche and Abruzzo) was investigated. In this paper an in depth study of the significant differences observed in the composition of these oils is reported.