Synthetic Derivatives of Natural ent-Kaurane Atractyligenin Disclose Anticancer Properties in Colon Cancer Cells, Triggering Apoptotic Cell Demise.

The antitumor activity of different ent-kaurane diterpenes has been extensively studied. Several investigations have demonstrated the excellent antitumor activity of synthetic derivatives of the diterpene atractyligenin. In this research, a series of new synthetic amides and their 15,19-di-oxo analogues obtained from atractyligenin by modifying the C-2, C-15, and C-19 positions were designed in order to dispose of a set of derivatives with different substitutions at the amidic nitrogen. Using different concentrations of the obtained compounds (10-300 µM) a reduction in cell viability of HCT116 colon cancer cells was observed at 48 h of treatment. All the di-oxidized compounds were more effective than their alcoholic precursors. The di-oxidized compounds had already reduced the viability of two colon cancer cells (HCT116 and Caco-2) at 24 h when used at low doses (2.5-15 µM), while they turned out to be poorly effective in differentiated Caco-2 cells, a model of polarized enterocytes. The data reported here provide evidence that di-oxidized compounds induced apoptotic cell death, as demonstrated by the appearance of condensed and fragmented DNA in treated cells, as well as the activation of caspase-3 and fragmentation of its target PARP-1.

Seseli tortuosum L. subsp. tortuosum Essential Oils and Their Principal Constituents as Anticancer Agents.

Seseli tortuosum L. subsp. tortuosum, belonging to the Apiaceae family, is a species that grows in Europe, mainly in the Mediterranean regions. The history of its application in traditional medicine highlights its various biological properties. Trying to explore the phytochemistry and pharmacological aspects of this species, the essential oils (EOs) extracted from flowers, stems, and roots of a locally wild accession, never previously investigated, growing in Sicily, Italy, were investigated. The chemical composition of all EOs, obtained by the hydrodistillation method, was evaluated by GC-MS. The most abundant class of all investigated samples was that of monoterpene hydrocarbons (79.98-91.21%) with p-cymene, α-pinene, ß-pinene, and ß-ocimene as major compounds. These EOs, and their main components, were tested for their possible anticancer activity. Obtained data provided evidence that among the different EOs tested, at the dose of 100 µg/mL, those extracted from stems and roots were particularly effective, already at 24 h of treatment, in reducing the cell viability of 42% and 95%, respectively, in HCT116 colon cancer cell line. These EOs also exerted a remarkable cytotoxic effect that was accompanied by morphological changes represented by cell shrinkage as well as a reduction in residual cell population. Differently, modest effects were found when EOs extracted from flowers were tested in the same experimental conditions. The evaluation of the phytocompounds mainly represented in the EOs extracted from different parts of the plant and tested in a range of concentrations between 20 and 200 µg/mL, revealed that α-pinene, ß-pinene, and p-cymene exerted only modest effects on cell viability. Differently, a remarkable effect was found when ß-ocimene, the most abundant phytocomponent in EOs from roots, was tested on colon cancer cells. This phytocompound, among those identified in EOs from Seseli tortuosum L. subsp. tortuosum, was found to be the most effective in reducing colon cancer cell viability with IC50 = 64.52 µg/mL at 24 h of treatment. All together, these data suggest that ß-ocimene could be responsible for the effects observed in colon cancer cells.

Phytochemical investigation and antitumor activity of coumarins from Sicilian accession of Ferulago nodosa (L.) Boiss. roots.

Ferulago nodosa (L.) Boiss. (Apiaceae) is a species occurring in the Balkan-Tyrrhenian area being present in Crete, Greece, Albania, and probably in Macedonia. From the roots of this accession of species, not previously investigated, four coumarins, grandivittin, aegelinol benzoate, felamidin and aegelinol, and two terpenoids, (2E)-3-methyl-4-[(3-methyl-1-oxo-2-buten-1yl)oxy]-2-butenoic acid and pressafonin-A, were isolated and spectroscopically characterized. The last one was never detected in Ferulago species. The evaluation of the anti-tumor effects of F. nodosa coumarins on colon cancer HCT116 cells showed only a modest effect on reduction of tumor cell viability. For aegelinol, the reduction of colon cancer cell viability already appears with 25 µΜ, while using 50 e 100 µM doses of marmesin the residual viability amounted to 70% and 54%, respectively. This effect resulted more evident at higher doses of compounds (at 200 µM from 80% to 0%). The most effective compounds resulted coumarins lacking ester group.

Cytotoxic Effect Induced by Sicilian Oregano Essential Oil in Human Breast Cancer Cells.

Origanum vulgare L. is an aromatic plant that exerts antibacterial, antioxidant, anti-inflammatory, and antitumor activities, mainly due to its essential oil (EO) content. In this study, we investigated the possible mechanism underlying the in vitro antitumor activity of EO extracted by hydrodistillation of dried flowers and leaves of Origanum vulgare L. grown in Sicily (Italy) in MDA-MB-231 and MCF-7 breast cancer cell lines. Gas chromatography-mass spectrometry analysis of Oregano essential oil (OEO) composition highlighted the presence of twenty-six major phytocompounds, such as p-cymene, γ-terpinene, and thymoquinone p-acetanisole. OEO possesses strong antioxidant capacity, as demonstrated by the DPPH test. Our studies provided evidence that OEO reduces the viability of both MCF-7 and MDA-MB-231 cells. The cytotoxic effect of OEO on breast cancer cells was partially counteracted by the addition of z-VAD-fmk, a general caspase inhibitor. Caspases and mitochondrial dysfunction appeared to be involved in the OEO-induced death mechanism. Western blotting analysis showed that OEO-induced activation of pro-caspases-9 and -3 and fragmentation of PARP decreased the levels of Bcl-2 and Bcl-xL while increasing those of Bax and VDAC. In addition, fluorescence microscopy and cytofluorimetric analysis showed that OEO induces a loss of mitochondrial membrane potential in both cell lines. Furthermore, we tested the effects of p-cymene, γ-terpinene, thymoquinone, and p-acetanisole, which are the main components of OEO. Our findings highlighted that the effect of OEO on MDA-MB-231 and MCF-7 cells appears to be mainly due to the combination of different constituents of OEO, providing evidence of the potential use of OEO for breast cancer treatment.

Seseli bocconei Guss. and S. tortuosum subsp. maritimum Guss. essential oils inhibit colon cancer cell viability.

In this study, the chemical compositions of two essential oils (EOs) obtained from different parts (flowers, leaves, stems, and roots) of Seseli bocconei Guss. and of Seseli tortuosum subsp. maritimum Guss., wild endemic species of Sicily, were investigated. The main classes of metabolites for the essential oils of S. bocconei were, respectively, monoterpenes hydrocarbons for flowers, sesquiterpenes hydrocarbons for leaves, and a breakdown between the two previously mentioned classes for stems. In the case of S. tortuosum subsp. maritimum, on the other hand, the main metabolite class for all the vegetative parts analyzed (flowers, stems, and roots) was monoterpene hydrocarbons, with a slight percentage in other non-terpenoid compounds. Furthermore, the EOs' antitumor effects against HCT116, human colon cancer cells were evaluated. Cell viability assays evidenced that stems' EOs of both plants exhibit strong cytotoxic effects at low concentrations, while the EOs from other vegetative parts do not show a relevant effect. In fact, EO of stems of S. tortuosum subsp. maritimum reduced the cell viability of 82% at the concentration of 125 µg/mL, while at the concentration of 250 µg/mL of stems EO of S. bocconei the 97% of cells resulted dead. The analysis of the effects exerted by the main phytocostituents (S-(-)-limonene, R-(+)-limonene, sabinene, (1S)-(-)-α-pinene, (1R)-(+)-α-pinene, and (-)-ß-pinene, and germacrene D) of these EOs on colon cancer cells revealed germacrene D as a new promising molecule with anticancer properties that deserve to be explored in future directions.

Reuse of almond by-products: Functionalization of traditional semolina sourdough bread with almond skin.

Almond production generates large amounts of by-products rich in polyphenols. In this study, almond skin was explored as a valuable food ingredient in bread making. To this purpose, almond skin was used to produce functional products modifying a traditional sourdough bread recipe. The doughs were prepared replacing semolina with powdered almond skin (PAS) at 5 and 10 % (w/w). Sourdough inoculum was started with a mix of lactic acid bacteria (LAB) and propagated in semolina until reaching pH 3.7. The pH of PAS added breads was higher than that of control (CTR) breads before and after fermentation. Plate counts showed a similar evolution of LAB and total mesophilic microorganisms, but members of Enterobacteriaceae and coliform were detectable in PAS doughs. Illumina data clearly showed a dominance of lactobacilli in all trials, but PAS doughs displayed the presence of Bacillus. The final bread characteristics were influenced by PAS and its addition percentage; in particular, crust and crumb colour resulted darker, the alveolation decreased and, regarding sensory attributes, odour intensity increased, while bread odour diminished. In presence of PAS, bread emissions were characterized by lower percentages of alcohols and aromatic hydrocarbons and higher percentages of the other volatile compound classes, especially terpenoids like ß-pinene, ß-myrcene and limonene than CTR trial. After in vitro simulated digestion, the final release of phytochemicals from 10 % PAS bread was almost 100 %. Thus, PAS determined an increase of the antioxidant capacity of the breads. Phytochemicals released from digested PAS-fortified bread can provide antioxidant protection in a complex biological environment such as human intestinal-like cells. Besides the positive functional properties of PAS, this work also evidenced the hygienic issues of almond skin and, in order to avoid potential risks for the human health, highlighted the need to preserve its microbiological characteristics during storage for their reuse in bread production.

The chemical composition of the aerial parts essential oil of Ferulago nodosa (L.) Boiss. (Apiaceae) growing wild in Crete (Greece).

Ferulago nodosa (L.) Boiss. (Apiaceae) is a species occurring in the Balkan-Tyrrhenian area being present in Crete, Greece, Albania, and probably in Macedonia. Although the western disjointed population of Sicily has been classified as an endemic sub-species, F. nodosa subsp. geniculata (Guss.) Troia & Raimondo, its official acceptance is quite controversial. In order to verify the existence of two different sub-species, we investigated the chemical composition of the essential oil of F. nodosa, collected in Crete (Greece), not previously reported, and we compared it with the previously oil compositions reported in literature. Main constituents of the Cretan accessions of F. nodosa were trimethyl benzaldehyde derivatives (29.5%) and monoterpene hydrocarbons (56.14%).

Cytotoxic activity of several ent-kaurane derivatives of atractyligenin. Synthesis of unreported diterpenic skeleton by chemical rearrangement.

Atractyloside, carboxyatractyloside, their aglycon atractyligenin, and several synthetic derivatives were tested and found to be active against a panel of human tumor cell lines. Atractyligenin was subjected to oxidation, bromination, and elimination reactions, obtaining several compounds. A singular skeleton was synthesized by chemical rearrangement starting from 3ß-bromo-2,15-diketoatractyligenin methyl ester. The synthesized compounds resulted active against all cell lines tested. In particular, 15-ketoatractyligenin methyl ester and 3ß-bromo-2,15-diketoatractyligenin methyl ester resulted the most active with IC50 values of 0.427 and 0.723 µM against A375 melanoma cell line. Excellent results were also obtained against the colon cancer cell line CaCo2, with slightly lower antiproliferative activity. An interesting extension of the study should be to analyze the atractyligenin derivatives also as target for human melanoma and human colon cancer cells.

Essential oil of Foeniculum vulgare subsp. piperitum fruits exerts an anti­tumor effect in triple­negative breast cancer cells.

At present, the growing spread of tumor cases worldwide renders the research of new promising and selective anticancer drugs urgent. The biological action of extracts of medicinal plants or their essential oils (EOs) is an emerging field of interest, since they could comprise a rich source of phytochemicals that can prove promising. In the present study, the biological activity and mechanism of action of the EO of Foeniculum vulgare subsp. piperitum fruits (FVPEO) were investigated using MTT assays, morphological analyses and western blotting in MDA­MB231 cells, a triple­negative breast cancer cell line. The findings revealed that FVPEO could exert strong anticancer effects, causing a dose­dependent inhibition of breast cancer MDA­MB231 cell growth, accompanied with DNA condensation and fragmentation. The cytotoxic effect of FVPEO was counteracted by the addition of the antioxidant N­acetylcysteine and was associated with a marked increase in reactive oxygen species and stress­related proteins; such as manganese superoxide dismutase, c­Jun, phospho­c­Jun N­terminal kinase and nuclear factor E2­related factor 2, and the latter's transcriptional targets, Heme oxygenase­1 and NAD(P)H quinone oxidoreductase 1 (NQO1). As evidenced by the activation of caspase­3 and fragmentation of poly(ADP­ribose) polymerase­1, which are typical apoptosis markers, FVPEO promoted apoptotic cell death accompanied with an increase in phosphorylated H2A histone family member X and the activation of the NQO1/p53 axis. In combination, the present experiments provided evidence that FVPEO could represent a reservoir of biologically active compounds suitable for both cancer prevention and treatment.

Bio-Waste Products of Mangifera indica L. Reduce Adipogenesis and Exert Antioxidant Effects on 3T3-L1 Cells.

Several studies highlighted the beneficial value of natural compounds in the prevention and treatment of obesity. Here, we investigated the anti-obesity effects of extracts of peel and seed of mango (Mangifera indica L.) cultivated in Sicily (Italy) in 3T3-L1 cells. Mango Peel (MPE) and Mango Seed (MSE) extracts at a 100 µg/mL concentration significantly reduced lipid accumulation and triacylglycerol contents during 3T3-L1 adipocyte differentiation without toxicity. HPLC-ESI-MS analysis showed that both the extracts contain some polyphenolic compounds that can account for the observed biological effects. The anti-adipogenic effect of MPE and MSE was the result of down-regulation of the key adipogenic transcription factor PPARγ and its downstream targets FABP4/aP2, GLUT4 and Adipsin, as well SREBP-1c, a transcription factor which promotes lipogenesis. In addition, both MPE and MSE significantly activated AMPK with the consequent inhibition of Acetyl-CoA-carboxylase (ACC) and up-regulated PPARα. The addition of compound C, a specific AMPK inhibitor, reduced the effects of MPE and MSE on AMPK and ACC phosphorylation, suggesting a role of AMPK in mediating MPE and MSE anti-lipogenic effects. Notably, MPE and MSE possess an elevated radical scavenging activity, as demonstrated by DPPH radical scavenging assay, and reduced ROS content produced during adipocyte differentiation. This last effect could be a consequence of the increase in the antioxidant factors Nrf2, MnSOD and HO-1. In conclusion, MPE and MSE possesses both anti-adipogenic and antioxidant potential, thus suggesting that the bio-waste products of mango are promising anti-obesity natural compounds.

Effects of different yeast strains, nutrients and glutathione-rich inactivated yeast addition on the aroma characteristics of Catarratto wines.

Catarratto is one of the most common non-aromatic white grape varieties cultivated in Sicily (Southern Italy). In order to improve the aromatic expression of Catarratto wines a trial was undertaken to investigate the effect of yeast strain, nutrition and reduced glutathione. Variables included two Saccharomyces cerevisiae strains, an oenological strain (GR1) and one isolated from honey by-products (SPF52), three different nutrition regimes (Stimula Sauvignon Blanc™ (SS), Stimula Chardonnay™ (SC) and classic nutrition practice), and a specific inactivated yeast rich in reduced glutathione to prevent oxidative processes [Glutastar™ (GIY)] ensuing in ten treatments (T1-T10). Microbiological and chemical parameters demonstrated the aptitude of strain SPF52 to successfully conduct alcoholic fermentation. During fermentation, the Saccharomyces yeast populations ranged from 7 to 8 logarithmic CFU/mL. All wines had a final ethanol content ranging between 12.91 and 13.85% (v/v). The dominance of the two starter strains over native yeast populations was higher than 97% as estimated by interdelta analysis. The addition of nutrients SS or SC increased the aromatic complexity of the wines as reflected by volatile organic compounds (VOCs) composition and sensory profiles. In particular, 32 VOCs were identified; alcohols (62.46-81.1%), thiols (0.27-0.87%), ethers (0.09-0.16%), aldehydes (0-1.21%), ketones (0-2.28%), carboxylic acids (4.21-12.32%), esters (0-10.85%), lactones (0.9-1.49%) and other compounds (0.77-6.9%). Sensory analysis demonstrated a significant impact on wine aroma in relation to yeast starter strain used, the type of nutrition (SS, SC or classic nutrition) and the presence/absence of GIY. The wines produced with GR1 yeast strain and SS (T2), SPF52 with SC (T9) both in presence of GIY showed higher overall quality. Trials T2 and T9 showed the highest scores for 13 and 18 attributes, respectively. The different nutrition, addition of GIY and the yeast starter strains diversified and enhanced sensory expression of Catarratto wines.

The Anti-Cancer Effect of Mangifera indica L. Peel Extract is Associated to γH2AX-mediated Apoptosis in Colon Cancer Cells.

Ethanolic extracts from Mangifera indica L. have been proved to possess anti-tumor properties in many cancer systems. However, although most effects have been demonstrated with fruit pulp extract, the underlying molecular mechanisms of mango peel are still unclear. This study was designed to explore the effects of mango peel extract (MPE) on colon cancer cell lines. MPE affected cell viability and inhibited the colony formation trend of tumor cells, while no effects were observed in human dermal fibroblasts used as a non-cancerous cell line model. These events were a consequence of the induction of apoptosis associated to reactive oxygen species (ROS) production, activation of players of the oxidative response such as JNK and ERK1/2, and the increase in Nrf2 and manganese superoxide dismutase (MnSOD). Significantly, mango peel-activated stress triggered a DNA damage response evidenced by the precocious phosphorylation of histone 2AX (γH2AX), as well as phosphorylated Ataxia telangiectasia-mutated (ATM) kinase and p53 upregulation. Mango peel extract was also characterized, and HPLC/MS (High Performance Liquid Chromatography/Mass Spectrometry) analysis unveiled the presence of some phenolic compounds that could be responsible for the anti-cancer effects. Collectively, these findings point out the importance of the genotoxic stress signaling pathway mediated by γH2AX in targeting colon tumor cells to apoptosis.

Composition of essential oil of lemon thyme (Thymus × citriodorus) at different hydrodistillation times.

Distillation time can both to optimise the production and to engineer the composition of essential oil in essential oil bearing plants. Purpose of this study was to evaluate the effect of duration of hydrodistillation on composition of essential oil of Thymus × citriodorus, the natural source of commercially important geraniol and citral, a component with valuable biological properties. Essential oils were isolated by hydrodistillation at different distillation times and analysed by GC/MS analytical methods. Increase in percentage of essential oil during all hydrodistillation time gradient was uneven. Elongation of hydrodistillation time decreased percentages of monoterpenes but increased percentages of sesquiterpenes in essential oil. Results showed that the hydrodistillation of essential oil from lemon thyme longer than 60 min is useless.

Sicilian Litchi Fruit Extracts Induce Autophagy versus Apoptosis Switch in Human Colon Cancer Cells.

Litchi chinensis Sonnerat is a tropical tree whose fruits contain significant amounts of bioactive polyphenols. Litchi cultivation has recently spread in Sicily where the climate conditions are particularly favorable for this crop. Recent findings have shown that Litchi extracts display anti-tumor and pro-apoptotic effects in vitro, but the precise underlying mechanisms have not been fully elucidated. In this study, we report for the first time the effects of Sicilian litchi fruit extracts on colon cancer cells. The results indicated that litchi exocarp, mesocarp and endocarp fractions reduce the viability and clonogenic growth of HT29 cells. These effects were due to cell cycle arrest in the G2/M phase followed by caspase-dependent cell death. Interestingly, litchi exocarp and endocarp triggered a precocious autophagic response (16⁻24 h), which was accompanied by an increase in the level of autophagy related 1/autophagy activating kinase 1 (ATG1/ULK1), beclin-1, microtubule associated protein 1 light chain 3 (LC3)-II and p62 proteins. Autophagy inhibition by bafilomycin A1 or beclin-1 silencing increased cell death, thus suggesting that autophagy was initially triggered as a pro-survival response. Significant effects of Litchi extracts were also observed in other colon cancer cells, including HCT116 and Caco-2 cells. On the other hand, differentiated Caco-2 cells, a model of human enterocytes, appeared to be insensitive to the extracts at the same treatment conditions. High-Performance Liquid Chromatography⁻Electrospray Ionization-Quadrupole-Time-Of-Flight HPLC/ESI/Q-TOF evidenced the presence of some polyphenolic compounds, specifically in exocarp and endocarp extracts, that can account for the observed biological effects. The results obtained suggest a potential therapeutic efficacy of polyphenolic compounds purified from Sicilian Litchi fractions for the treatment of colon cancer. Moreover, our findings indicate that modulation of autophagy can represent a tool to improve the effectiveness of these agents and potentiate the anti-tumor response of colon cancer cells.

Chemical composition, in vitro antitumor and pro-oxidant activities of Glandora rosmarinifolia (Boraginaceae) essential oil.

The biological properties of essential oils have been demonstrated in the treatment of several diseases and to enhance the bioavailability of other drugs. In natural habitats the essential oils compounds may play important roles in the protection of the plants as antibacterials, antivirals, antifungals, insecticides and also against herbivores by reducing their appetite for such plants or by repelling undesirable others. We analyzed by gas-chromatography mass spectrometry the chemical composition of the essential oil of aerial parts of Glandora rosmarinifolia (Ten.) D.C. Thomas obtained by hydrodistillation and verified some biological activities on a panel of hepatocellular carcinoma cell lines (HA22T/VGH, HepG2, Hep3B) and triple negative breast cancer cell lines (SUM 149, MDA-MB-231). In the essential oil we detected 35 compounds. The results of the biological assays indicate that essential oil of G. rosmarinifolia induces cell growth inhibition at concentration-dependent way in all cell line models. This oil does not seem to possess antioxidant activity, while the cytotoxicity of G. rosmarinifolia essential oil appeared to involve, at least in part, a pro-oxidant mechanism. Our results show for the first time the antitumoral and pro-oxidant activities of G. rosmarinifolia essential oil and suggest that it may represent a resource of pharmacologically active compounds.

Metabolite and mineral profiling of "Violetto di Niscemi" and "Spinoso di Menfi" globe artichokes by 1H-NMR and ICP-MS.

Globe artichoke has been long considered a nutraceutical food for its valuable content of bioactive compounds. However, beside a well-known polyphenol profile, poor information is available about its metabolite and mineral composition. The aim of this study was to investigate edible parts of Sicilian artichokes, 'Spinoso di Menfi' and 'Violetto di Niscemi', by 1H NMR and ICP-MS for elucidating these compositional aspects. Although bracts and hearts of both artichokes shared a very similar metabolite pattern, 'Spinoso di Menfi' showed a higher number of metabolites, such as amino acids and polyphenols, than 'Violetto di Niscemi'. 'Spinoso di Menfi' was also marked by higher levels of macro- and microelements when compared to 'Violetto di Niscemi'. Also, artichoke heart demonstrated to accumulate higher mineral levels than bracts. 1H NMR and ICP-MS successfully profiled metabolites and metals in such plant food, partially covering the lack of literature data about 'Spinoso di Menfi' and 'Violetto di Niscemi' artichokes.

Chemodiversity of the Essential Oil from Leaves of Abies nebrodensis (Lojac.) Mattei.

Abies nebrodensis (Lojac.) Mattei (Pinaceae) is a species occurring in a very small population only in a restricted area of Sicily. Its taxonomic classification as different species has been object of discussion. In this work the chemical composition of the essential oil from the leaves is presented for the first time and compared to the essential oils from other euroasiatic species reported in literature. Peculiar characteristics of the essential oil of A. nebrodensis are highlighted.

Essential-Oil Variability in a Collection of Ocimum basilicum L. (Basil) Cultivars.

Ocimum basilicum L. (Lamiaceae) is an aromatic plant of great tradition in the Mediterranean area. Its economic importance is growing up determining an expansion of cultivation. This paper evaluated the morphological traits, the chemical profiles, and antibacterial activity of 21 cultivars of basil belonging to 'Genovese', 'Napoletano', and 'Purple basil' types. The cultivars were characterized by different growth rate and morphological traits. The chemical composition of the oils analyzed by GC and GC/MS analysis, supported by the PCA analysis, underlined the strong influence of chemotype. It is noteworthy that estragole, never present in Genovese and purple basil types, occurred in Napoletano type. The high presence of eugenol, methyl eugenol, and linalool in the majority of cultivars, belonging both to Genovese and to Napoletano types was registered. Of great interest resulted the composition of the purple basil 'Opal'. All the samples tested exhibited similar antibiotic profiles with moderate antibacterial activity. The results enhanced the importance of determination of essential-oil profile in the selection of cultivars characterized by diverse morphological traits and are useful for different purposes.

Contribution to a Taxonomic Revision of the Sicilian Helichrysum Taxa by PCA Analysis of Their Essential-Oil Compositions.

The chemical profile of the essential oils in ten populations of the genus Helichrysum Mill. (Asteraceae), collected in the loci classici of the nomenclatural types of the taxa endemic to Sicily, were analyzed. Our results confirm that the analysis of secondary metabolites can be used to fingerprint wild populations of Helichrysum, the chemical profiles being coherent with the systematic arrangement of the investigated populations in three main clusters, referring to the aggregates of H. stoechas, H. rupestre, and H. italicum, all belonging to the section Stoechadina. The correct nomenclatural designation of the investigated populations is discussed and the following two new combinations are proposed: Helichrysum preslianum subsp. compactum (Guss.) Maggio, Bruno, Guarino, Senatore & Ilardi and Helichrysum panormitanum subsp. latifolium Maggio, Bruno, Guarino, Senatore & Ilardi.

Chemical composition of the essential oil of Jacobaea maritima (L.) Pelser & Meijden and Jacobaea maritima subsp. bicolor (Willd.) B. Nord. & Greuter (Asteraceae) collected wild in Croatia and Sicily, respectively.

In this study, the chemical compositions of the essential oils from aerial parts (JmA) and radices (JmR) of Jacobaea maritima (L.) Pelser & Meijden, collected in Croatia, and of Jacobaea maritima subsp. bicolor (Willd.) B. Nord. & Greuter, collected in Sicily, were evaluated by using gas chromatography and gas chromatography-mass spectrometry. The main components of the essential oil from J. maritima, both in JmA and JmR, were pentacosane (15.7%), heptacosane (13.1%) and nonacosane (8.1%) whereas the essential oil from J. maritima subsp. bicolor was characterised by the presence of hexadecanoic acid (14.6%), caryophyllene oxide (9.3%) and hexahydrofarnesylacetone (6.5%). The comparison of the essential oil with other studied oils of the genus Jacobaea is discussed.