The Diterpenoids of the Genus Marrubium (Lamiaceae)

The occurrence and chemical structures of labdane diterpenoids from the genus Marrubium are reviewed and the published 13C NMR spectroscopic data for these compounds is presented. The pharmacological activities and biogenesis of these diterpenoids are also reported

GC and GC-–MS Analysis of Volatile Compounds From Ballota nigra subsp. uncinata Collected in Aeolian Islands, Sicily (Southern Italy)

In the present study, the chemical composition of the essential oils from aerial parts of Ballota nigra subsp. uncinata (Beg.) Patzak collected in Sicily was evaluated by gas chromatography (GC) and GC-mass spectrometry. The main components of the oil were (E)-phytol (20.0%), alpha-pinene (9.0%), hexahydrofarnesyl acetone (5.7%), and alpha-selinene (5.1%). Cluster analysis of the essential oil compositions of all the taxa belonging to B. nigra s.l. group was performed

A novel approach to prevent graphene oxide re-aggregation during the melt compounding with polymers

The technology for the preparation of polymer-GO nanocomposites was investigated by studying the structure-properties relationships of two different systems, based on PA6 and EVA, fabricated by using different preparation methods, i.e. melt mixing, wet phase inversion, and the combination of the two. The morphology of nanocomposites resulted dramatically influenced by the technique adopted and showed to be the critical variable affecting the physical properties of the materials. Finally, the mechanical and dynamic-mechanical of the nanocomposites were improved by using the hybrid technique combining the two procedures

The Essential Oil Compositions of Three Teucrium Taxa Growing Wild in Sicily: HCA and PCA Analyses

The chemical composition and the qualitative and quantitative variability of the essential oils of three taxa belonging to the Teucrium genus were studied. The investigated taxa, that grow wild in Sicily, were Teucrium flavum L. (section Chamaedrys (Mill.) Scheb.), Teucrium montanum and Teucrium capitatum L. of section Polium (Mill.) Scheb. Essential oils were extracted by hydrodistillation and analyzed by GC-MS. In total, 74 compounds were identified. Sesquiterpene hydrocarbons were found to be the main group for T. flavum (48.3%). T. capitatum consisted essentially of monoterpene hydrocarbons (72.7%), with α-pinene (19.9%), β-pinene (27.6%) and sylvestrene (16.6%) as the most abundant compounds whereas ledene oxide (12.1%), epiglobulol (13.5%) and longifolenaldehyde (14.5%) were identified as the main constituents among the oxygenated sesquiterpenes (63.5%) of T. montanum. Furthermore, a complete literature review on the composition of the essential oils of all the other accessions of these Teucrium taxa, studied so far, was performed. Hierarchical Cluster Analysis (HCA) and Principal Component Analyses (PCA) were used in order to demonstrate geographical variations in the composition of the essential oils

Metabolites from the aerial parts of the Sicilian population of Artemisia alba.

Phytochemical investigation of the CH2Cl2 extract of the aerial parts of Artemisia alba Turra afforded one new irregular sesquiterpenoid, artemiric acid, and five known metabolites: hydroxydavanone, the coumarins isofraxidin and scopoletin, (6 S*,7 S*,10 R*)–6,10-dimethyl-7,10-epoxyocta-11-enoic acid and artalbic acid. From the MeOH extract three flavonoids were identified: chrysoeriol, quercetin and isorhamnetin. The possible biogenetic pathways of artemiric and artalbic acids are discussed

Cytotoxic effect of eudesmanolides isolated from flowers of Tanacetum vulgare ssp. siculum

A phytochemical analysis of the dichloromethane extract from the flowers of a subspecies of Tanacetum vulgare growing in Sicily was carried out. Five known sesquiterpene lactones with the eudesmane skeleton have been isolated and the cytotoxic activity of these compounds was tested in vitro on A549 (human lung carcinoma epithelial-like) and V79379A (Chinese hamster lung fibroblast-like) cells using the tetrazolium salt reduction (MTT) assay. All of tested compounds induced high time- and concentration-dependent cytotoxic effects

Guaianolides from the aerial parts of Centaurea hololeuca

Seven guaianolides were isolated from the acetone extract of the aerial parts of Centaurea hololeuca Boiss. The antifeedant activity of the natural compounds (1–7) and of four chloro derivatives (8–11), synthesized from repin (1) and janerin (3) were tested against larvae of Spodoptera littoralis. Cebellin J (6) and chlorojanerin (11) showed significant antifeedant activity at 100 ppm, whereas at this concentration cebellin G (4) and 15-deschloro-15-hydroxychlorojanerin (7) stimulated feeding. Cebellin G (4) stimulated larvae of S. littoralis to feed at low concentration, but deterred feeding at high concentrations. The addition of chlorine to repin (1) resulted in an increase in antifeedant activity

Chemical Composition of the Essential Oil from Aerial Parts of Stachys palustris L. (Lamiaceae) Growing Wild in Southern Italy

The paper reports the composition of the essential oil from aerial parts of Stachys palustris L. (Lamiaceae) from Southern Italy. The essential oil was extracted by hydrodistillation from selected plants and its chemical composition was determined by the GC-MS system on two fused- silica capillary columns of different polarity. The mass fraction of oil was 0.21 % on a dry weight basis. Altogether, 92 compounds were identified accounting for 93.6 % of the total oil, which was characterized mainly by carbonylic compounds (25.4 %), fatty acids and their esters (24.2 %), along with sesquiterpenoidic compounds (16.0 %) and phenols (11.2 %). The major components of the sample were caryophyllene oxide (7.8 %), hexahydrofarnesyl acetone (7.4 %), hexadecanoic acid (6.8 %), (Z,Z,Z)-9,12,15-octadecatrienoic acid (6.7 %), (Z)-phytol (6.4 %), thymol (5.8 %), p-methoxyacetophenone (5.1 %), 4-vinylguiacole (3. %), tetradecanoic acid (3.8 %), (E)-caryophyllene (3.6 %), b-ionone (3.3 %) and b-damascenone (3.0 %)

Volatile components from aerial parts of Centaurea spinosociliata Seenus ssp. cristata (Bartl.) Dostál and Centaurea spinosociliata Seenus ssp. spinosociliata growing wild in Croatia

The paper reports on the volatile components oil from aerial parts of two Asteraceae growing wild in Croatia: Centaurea spinosociliata ssp. cristata (syn. Centaurea cristata Bartl. subsp. rabenhorstiana (Sch.Bip.) Nyman) (CSC) and C. spinosociliata ssp. spinosociliata (CSS). The volatile components were obtained by hydrodistillation from selected plants and were determined by the GC-MS system on two fused-silica capillary columns of different polarity. The oil content was 0.08 % (CSC) and 0.07 % (CSS) on a dry weight basis. Altogether 73 compounds were identified accounting for 90.8 % (CSC) and 92.8 % (CSS) of the total oil, that were characterized mainly by hydrocarbons (37.9 %; 30.4 %), sesquiterpene hydrocarbons (14.1 %; 29.1 %), oxygenated sesquiterpenes (22.2 %; 13.1 %). The major components of the samples were heptacosane (11.2 %; 12.6 %), cyclosativene (2.1 %; 6.4 %), caryophyllene oxide (10.2 %; 4.7 %). Monoterpenes, fatty acids and phenolic compounds were absent or present in low amount in both oils. The chemotaxonomy of the subgenus Acrolophus is briefly discussed