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The present study reports about the phytochemical analysis of a sample of Daphne oleoides Schreb. subsp. oleoides (family Thymelaeaceae) collected from the Majella National Park. Twenty components, belonging to different classes of natural products, have been identified by means of spectroscopic and spectrometric techniques: [monomeric (4), bis- (5, 7–10, 20) and trimeric coumarins (11), including aglycones and glycosides, coumarinolignoid (6); flavonoids (16–19); glycosidic furolignans (14, 15), glucosidic phenylpropanoids (12, 13), cyclic tetrapyrrole derivatives (2, 3), unsaturated triglyceride (1)]. Besides the chemosystematic markers of the genus (4–10, 12, 14–18, 20) several other components were identified for the first time in the species (17, 20) and/or in the Daphne genus (1–3, 13, 19). The observed composition was discussed from the chemotaxonomic standpoint and compared with those recognized from a Sardinian accession. It was observed a pronounced difference in the two metabolites patterns, most probably attributable to geographic isolation of the studied populations and, in some extent, also by the different environmental conditions, evidencing a possible tendency of D. oleoides to the infraspecific chemovariability. Considering the wide traditional uses of Daphne spp. in ethnomedicine of several countries, also the pharmacologic potential of the identified secondary metabolites is discussed.

We propose the cell culture approach to investigate oleuropein (1) biogenesis in Olea europaea L. We suggest employing olive callus cultures to identify the iridoidic precursor of oleuropein. In fact, we confirmed that callus cells from olive shoot explants are able to produce key secoiridoid as 1. To enable this approach, we synthesised and characterised deuterium-labelled iridoidic precursors belonging both to the loganin and the 8-epiloganin series. These iridoids are [7,8-(2)H2]-7-deoxy-8-epi-loganin (2(D)), [8,10-(2)H2]-8-epi-loganin (4(D)) and [7,8-(2)H2]-7-deoxy-loganin (3(D)).

In this study, we evaluated, in the mouse, the effects of 20 mg/kg i. p. daily administration for 15 consecutive days of a blend of polyphenols, containing mostly oleuropein, extracted from the olive leaves (Olea europaea) on brain nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and on the expression of their receptors, TrkA, TrkB and p75. Polyphenols decreased the levels of reduced glutathione (GSH) and increased the levels of NGF and BDNF in the serum. In the brain, we found decreased levels of NGF and BDNF in the hippocampus and striatum but elevated levels of NGF in the olfactory lobes and hypothalamus and again BDNF potentiation in the olfactory lobes. No changes in TrkA, TrkB and p75 expression were observed. In conclusion, olive polyphenols may not only elicit an activation of the rodent olfactory system by increasing the levels of NGF and BDNF but also be stressing for the animal by reducing both the levels of hippocampal NGF/BDNF and serum GSH and increasing serum levels of NGF and BDNF.

Nocellara del Belice, a cultivated variety (cultivar) of olive tree (Olea europaea L.), was examined with respect to the medium-polar compounds present in the wastewaters of olive oil extraction at the end of 2007. Charcoal-polyamide chromatography of obtained wastewaters showed the presence of the chemotaxonomical markers of Olea europaea. In addition a new compound was isolated which resulted to be a lactone related to oleuropein aglycone. We propose the name of nocellaralactone (NOC). This compound is also present in the leaves and it appears to be structurally, probably biogenetically, related to jasminanhydride, a monoterpenoid previously isolated from Jasminum grandiflorum. NOC showed a significant in vitro anti-inflammatory activity.

The phytochemical study of the polar fraction of Bellardia trixago (L.) All. led to the isolation of eight iridoid glucosides. Five of these glucosides (aucubin (1), bartsioside (2), melampyroside (3), mussaenoside (4) and gardoside methyl ester (5)) were confirmed as they were previously isolated from this plant, and the remaining three known compounds (mussaenosidic acid (6), geniposidic acid (7) and 8-epiloganin (8)) were isolated here for the first time. Of particular interest were the presence of 7 and 8 due to two reasons: the first one because it is not accompanied with geniposide, the corresponding methyl ester, as in the case of 4 and 6, and the second one because it is the parent compound of iridoids characteristic of Orobanchaceae family. Also an alditol, D-mannitol (9), was recognised for the first time from this species.

This work presents the first reported phytochemical study on the hydro-distilled essential oil from Achillea tenorii (Grande), collected in the protected area of Majella National Park (Italy). The composition of the essential oil was very different from those reported for the other species of Achillea nobilis group, being constituted mainly by oxygenated monoterpenes, among which ketones, alcohols and acetates compounds were the most representative. The marker compounds of A. nobilis group were not detected while the most abundant phytoconstituents were α-thujone (29.7%), trans-sabinol (18.6%) and trans-sabinyl acetate (15.7%), revealing a composition quite similar to that of Artemisia absinthium.

Chemistry of natural organic products regards studies of molecular structural characters devoted to the identification of new molecular architectures and searching new compounds present in natural matrices characterized by biological useful activity. More recently, particular attention has been directed to phytochemical studies of plants, the so-called endemic species, growing in particular areas, characterized by narrow limits. The hypothesis is that a wide variety of climates, environmental, geological, geographical, and biological conditions has led to the diversification of species. Endemism is the condition of being restricted to a particular area with a prescribed extent and describes species that are native to a particular geographic territory, and usually occurs in areas that are in some way isolated. The term “endemism” derives from the medical language and it was used for the first time, referred to plants, in 1820 by De Candolle. It is possible to distinguish several categories of endemisms. In 1926 Herzog sets the differences between neoendemics and paleoendemics species. Favarger & Contandriopoulos in 1961 and Favarger in 1964 proposed a new classification based on the mode of genesis of the species: schizoendemism, apoendemism, patroendemism, and paleoendemism. Paleoendemism and patroendemism represent the conservative component of the flora of a territory while schizoendemism and apoendemism represent the innovating component of it. Like other Mediterranean-type ecosystems, the Mediterranean Basin has high levels of plant diversity and endemism. The floral diversity of the Mediterranean Basin is dramatic. Its 25,000 vascular plants species (13,000 endemic species) are more than four times the number found in all the rest of Europe. The Mediterranean region constitutes both a refuge area and one that encourages floral exchange and active plant speciation. Many of the endemic species are concentrated on islands, peninsulas, cliffs, and peaks. In this review, studies on the molecular pattern of endemic plants of restricted areals (Sardinia Island and Central Italy with Monti Sibillini National Park and Majella National Park) are reported, with particular attention toward plants containing active compounds and plants with an ethnopharmacologic history and tradition. These two areas were selected as representative sites of insular and peninsular areas of Italy.

In this study, we report the isolation and identification of several compounds from Plantago sempervirens Crantz, collected in the protected area of Majella National Park. We examined the polar fraction, in particular the iridoidic one. Aucubin, caryoptoside, plantarenaloside and gardoside were isolated and identified. For the first time, in this species, 8-epiloganic acid was recognised. Also, verbascoside, a phenylethanoid glycoside, was recognised in this plant.

The phenyl propanoid fraction of Teucrium subspinosum Pourrette ex Willd. (Lamiaceae) from Baleari Island, was examined together with the same fraction of T. subspinosum from Sardinia. In T. subspinosum, besides verbascoside as main component, a new phenyl-propanoid-glycoside was isolated and identified by (1)H- and (13)C-NMR spectra analysis. Comparison with molecular composition of T. marum confirmed the differences between these species and evidenced their endemic character.

Dihydroasparagusic acid (DHAA) is the reduced form of asparagusic acid, a sulfur-containing flavor component produced by Asparagus plants. In this work, DHAA was synthetically produced by modifying some published protocols, and the synthesized molecule was tested in several in vitro assays (DPPH, ABTS, FRAP-ferrozine, BCB, deoxyribose assays) to evaluate its radical scavenging activity. Results show that DHAA is endowed with a significant in vitro antioxidant activity, comparable to that of Trolox. DHAA was also evaluated for its inhibitory activity toward tyrosinase, an enzyme involved, among others, in melanogenesis and in browning processes of plant-derived foods. DHAA was shown to exert an inhibitory effect on tyrosinase activity, and the inhibitor kinetics, analyzed by a Lineweaver-Burk plot, exhibited a competitive mechanism. Taken together, these results suggest that DHAA may be considered as a potentially active molecule for use in various fields of application, such as pharmaceutical, cosmetics, agronomic and food.

This article deals with the monoterpenic and phenolic micro-components present in olives and the manner in which these compounds are transferred into the olive oil. Of particular interest is the molecular structure of the isolated compounds and the transformations of oleuropein during the technological process of olive oil preparation. The existing relationship between the quality/taste of the olive oil and these micro-components are also discussed.

The monoterpenoid composition of Verbascum conocarpum and Scrophularia trifoliata, both endemic plants of Sardinia, was examined. The main chemotaxonomic markers of Scrophulariaceae, the iridoids aucubin, verbascoside and catalpol, were isolated.

In this study, we examined the composition regarding secondary metabolites of P. mugo Turra ssp. mugo growing in the protected area of Majella National Park, which is the southernmost station of the habitat of this species. Both the nonpolar and polar fractions were considered. In particular, the essential-oil composition showed a high variety of compounds, and 109 compounds were detected, and 101 were identified, among which abietane-type compounds have a taxonomic relevance. Abietanes were also isolated from the polar fraction, together with an acylated flavonol and a remarkably high amount of shikimic acid.

Dihydroasparagusic acid is the first naturally occurring dimercaptanic compound that was isolated in 1948 from Asparagus concentrate. Although several synthetic procedures were proposed in the past decades for this natural substance, most of its chemical properties remain unstudied. In this work the capacity of the acid to act as an antidote against mercury(II) toxicity was evaluated in a simple biological model system, Saccharomyces cerevisiae, and is explained by the formation of a precipitate between mercury(II) and dihydroasparagusic acid. The precipitate was analyzed and studied. The solubility was determined by measuring in equilibrated solutions either the concentration of the total mercury(II) present in solution or the free concentration of hydrogen ions. The protonation constants were determined at 25 °C and in 1.00 M NaCl, as constant ionic medium, by means of potential difference measurements of a galvanic cell with a glass electrode. The experimental data are explained by proposing the chemical composition of the precipitate and the value of its solubility product. As the solubility of the precipitate increases by increasing the concentration of dihydroasparagusic acid, the further formation of a complex between mercury(II) and dihydroasparagusic acid is assumed.

Among HIV-1 reverse transcriptase (RT)-associated functions, DNA polymerase and Ribonuclease H (RNase H) are both essential for HIV replication and excellent targets for drug development. While all RT inhibitors approved for therapy target the DNA polymerase activity, there is the pressing need for new RT inhibitors possibly targeting the RNase H function. In the last 20 years, many natural substances have shown antiviral activity against HIV-1, but only a few against the RNase H function. In this study, we have tested the ethanolic extracts obtained by the Hypericum hircinum L. (Hypericaceae) growing in Sardinia (Italy) on the HIV-1 RT-associated RNase H function and found that they have inhibitory effects. Active extracts were fractionated up to obtain the main components that have been isolated, tested, and identified to be betulinic acid, shikimic acid, chlorogenic acid, quercetin, 5,7,3',5'-tetrahydroxyflavanone, and 5,7,3',5'-tetrahydroxyflavanone 7-O-glucoside. Betulinic acid and 5,7,3',5'-tetrahydroxyflavanone 7-O-glucoside were active on both RT-associated activities, and betulinic acid was also active on HIV-1 mutant RTs resistant to efavirenz. Overall, our results suggest that some of these compounds inhibit the HIV-1 RT binding to an allosteric site previously described for other natural compounds and are potential leads for further drug development of a single molecules having dual inhibitory activity.

Leaves of Olea europaea, cultivar Nocellara del Belice, were examined with respect to the medium-polar fraction, obtained by an ethyl acetate extraction of the whole extract. In the medium polar fraction, we isolated the two hydroxy-phenyl-ethyl alcohols (hydroxyl-tyrosol and tyrosol) that are the main component of olives. In addition, we isolated a flavonoidic compound, aromadendrine, a dihydroflavonol yet known but quite rare in nature. It is the first time that aromadendrine is isolated in O. europaea and we studied the aromadendrine biological activity. In particular, the ability of aromadendrine to reduce the inflammation induced in normal keratinocytes using an in vitro cell model was evaluated. The results of the present research indicate aromadendrine as a novel component in O. europaea with effective activity against skin inflammation.

In this study, we report the isolation and identification of several compounds present in the polar fraction of Stachys germanica L. subsp. salviifolia (Ten.) Gams, collected in the protected area of Majella National Park. In particular, we have isolated and identified harpagide, 7 -β-hydroxy-harpagide, ajugol, 5-allosyloxy-aucubin, verbascoside and, for the first time in this genus, arbutin.

The analysis of the polar fraction of Galeopsis angustifolia Ehrh. ex Hoffm. indicates that the main components are iridoids and flavonoids. Six compounds were identified: a new flavonoid, 3′-hydroxy-isoscutellarein 7-O-[6′″acetyl-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranoside]; three iridoid glucosides: harpagide, acetyl harpagide and for the first time in this species, 8-epi-loganin; two known acetylated flavonoid glycosides: 3′-hydroxy-4′-O-methylisoscutellarein 7-O-[6′″acetyl-β-D-allopyranosyl-(1 → 2)-6″-acetyl-β-D-glucopyranoside], 3′-hydroxy-4′-O-methylisoscutellarein 7-O-[6′″acetyl-β-D-allopyranosyl-(1 → 2)-β-D-glucopyranoside]. Both flavonoids and iridoids are present in high amount; respectively, 16.7% and 4.5% of the crude extract.

A series of bay-substituted perylene derivatives is reported as a new class of G-quadruplex ligands. The synthesized compounds have differing N-cyclic substituents on the bay area and differing side chains on the perylene major axis. ESI-MS and FRET measurements highlighted the strongest quadruplex binders in this series and those showing the highest quadruplex/duplex selectivity. Several biological assays were performed on these compounds, which showed that compound 5 (PPL3C) triggered a DNA damage response in transformed cells with the formation of telomeric foci containing phosphorylated γ-H2AX and 53BP1. This effect mainly occurred in replicating cells and was consistent with Pot1 dissociation. Compound 5 does not induce telomere damage in normal cells, which are unaffected by treatment with the compound, suggesting that this agent preferentially kills cancer cells. These results reinforce the notion that G-quadruplex binding compounds can act as broad inhibitors of telomere-related processes and have potential as selective antineoplastic drugs.

The flavonoid fraction of the aerial parts of Genista cadasonensis Valsecchi (Leguminosae), an endemic plant from Sardinia, was examined and compared with the flavonoid pattern already known in the Genista genus. This comparison evidenced the endemic nature of this species, showing the presence of a rare flavonoid, the 6-hydroxy-genistein. The antioxidant activity of dichloromethanic, ethanolic and acetonic total extracts of aerial parts was evaluated.

Secondary metabolite isolation and analysis of Plumbago europaea L. (Plumbaginaceae) is the aim of this work, which is included in a project of our groups on spontaneous and endemic Sardinian species. Plumbago europaea is the only specie of the genera that grows wild in Italy. Metabolites from leaves and roots of this specie were compared. Moreover, at present, literature on the phytochemical characterisation of P. europaea is poor. Plumbagin was isolated in both of the samples analysed, confirming its nature in the Plumbaginaceae family as chemotaxonomic marker of the Plumbaginae tribe. In this work, hydroplumbagin-4-O-glucoside and myricetin-3-O-rhamnoside are isolated for the first time in the genus.

The monoterpenoid fractions of three endemic Galium ssp. (Rubiaceae) from Sardinia Island were examined and compared with the iridoidic pattern yet known in Galium species. This comparison evidenced theirs endemic characters. In particular, in G.corsicum and in G. glaucophyllum loganic acid was isolated and identified for the first time in Galium genus. In G. schmidii a rare iridoid is present, 10-hydroxy-loganin, whose presence in this genus was evidenced only in G. mollugo and loganin isolated for the first time.

Teucrium marum and T. subspinosum have been extracted with different polarity solvents, each crude extract was analysed with (1)H-NMR to compare the overall metabolic component. The polar extracts showed antioxidant activity in vitro. Verbascoside and arabinosyl-verbascoside were isolated and identified. Their concentrations were in connection to the antioxidant activity.

Two flavonoid glycosides containing acetylated allose, and two iridoid glucosides were obtained from a EtOH extract of Stachys corsica, an endemic plant of Sardinia and Corsica. All the compounds have previously been isolated from other species of Stachys.

In this work the iridoidic fraction of Teucrium marum from Sardinia, was examined. A new clerodane, teumarin B, was isolated and identified by 1H- and 13C-NMR spectra analysis. The endemic character of this plant was further confirmed. Teumarin B showed cytotoxic properties.