Giffonins A–I, Antioxidant Cyclized Diarylheptanoids from the Leaves of the Hazelnut Tree (<i>Corylus avellana</i>), Source of the Italian PGI Product “Nocciola di Giffoni”

Eight new diaryl ether heptanoids, giffonins A–H (<b>1</b>–<b>8</b>), and one diaryl heptanoid, giffonin I (<b>9</b>), were isolated from the methanol extract of the leaves of <i>Corylus avellana</i>. Its hazelnut is the PGI product of the Campania region (Italy) known as “Nocciola di Giffoni”. The MeOH extract of <i>C. avellana</i> leaves and giffonins A–I (<b>1</b>–<b>9</b>) were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H₂O₂ and H₂O₂/Fe²⁺, by measuring the concentration of TBARS (thiobarbituric acid reactive substances). Compounds <b>4</b> and <b>8</b> at 10 μM reduced both H₂O₂- and H₂O₂/Fe²⁺-induced lipid peroxidation by more than 60% and 50%, respectively, indicating higher activity than curcumin used as reference compound

Chemical constituents of <i>Silene montbretiana</i>

<p>A new steroidal glycoside, 3-<i>O</i>-β-d-glucopyranosyl-3β,25-dihydroxy-5β-cholest-7-en-6-one 25-<i>O</i>-β-d-glucopyranoside (<b>1</b>), together with six known steroidal derivatives (<b>2</b>-<b>7</b>), one cerebroside (<b>8</b>) and one flavonoid (<b>9</b>) were isolated from <i>Silene montbretiana</i> Boiss (Caryophyllaceae), a perennial herb growing mainly in the Middle and East Anatolia, Azerbaijan, Iran, and Turkey. Their structures were established by the extensive use of 1D and 2D NMR experiments along with ESI-MS analyses. The cytotoxicity against the cancer A549 (human alveolar basal carcinoma) and Hela (human epitheloid cervix carcinoma) cell lines has been evaluated. None of the tested compounds, in a range of concentrations between 12.5 and 100 μM, caused a significant reduction of the cell number.</p

Three new triterpene saponins from roots of <i>Eryngium planum</i>

<div><p>Saponin composition of the roots of <i>Eryngium planum</i> L. was investigated. Triterpene saponins found in <i>E. planum</i> and also present in <i>Eryngium maritimum</i> were different from those described previously in <i>Eryngium campestre</i> L. Three primary saponins were isolated and their tentative identifications, based on the electrospray MS/MS fragmentation patterns, were subsequently confirmed by 1D and 2D NMR analyses. Their structures were established as 3-<i>O</i>-β-d-glucopyranosyl-(1 → 2)-β-d-glucuronopyranosyl-21-<i>O</i>-acetyl-22-<i>O</i>-angeloyl-R1-barrigenol (<b>1</b>) and 3-<i>O</i>-β-d-glucopyranosyl-(1 → 2)-β-d-glucuronopyranosyl-22-<i>O</i>-angeloyl-A1-barrigenol (<b>2</b>) and 3-<i>O</i>-β-d-glucopyranosyl-(1 → 2)-β-d-glucuronopyranosyl-22-<i>O</i>-angeloyl-R1-barrigenol (<b>3</b>). Concentrations of the newly identified compounds in aerial parts and roots of both species were estimated using the liquid chromatography–mass spectrometry method.</p></div

Determination of volatile organic compounds in the dried leaves of <i>Salvia</i> species by solid-phase microextraction coupled to gas chromatography mass spectrometry

<p><i>Salvia</i> spp. are used throughout the world both for food and pharmaceutical purposes. In this study, a method involving headspace solid-phase microextraction combined with gas chromatography–mass spectrometry was developed, to establish the volatiles profile of dried leaves of four Iranian <i>Salvia</i> spp.: <i>Salvia officinalis</i> L., <i>Salvia leriifolia</i> Benth, <i>Salvia macrosiphon</i> Boiss. and two ecotypes of <i>Salvia reuterana</i> Boiss. A total of 95 volatiles were identified from the dried leaves of the five selected samples. Specifically, α-thujone was the main component of <i>S. officinalis</i> L. and <i>S</i>. <i>macrosiphon</i> Boiss. (34.40 and 17.84%, respectively) dried leaves, <i>S</i>. <i>leriifolia</i> Benth was dominated by β-pinene (27.03%), whereas α-terpinene was the major constituent of the two ecotypes of <i>S</i>. <i>reuterana</i> Boiss. (21.67 and 13.84%, respectively). These results suggested that the proposed method can be considered as a reliable technique for isolating volatiles from aromatic plants, and for plant differentiation based on the volatile metabolomic profile.</p

Sesquiterpene lactones from <i>Centaurea rhizantha</i> C.A. Meyer

<p>Two new sesquiterpene lactones, rhizantholide A (<b>1</b>) and rhizantholide B (<b>2</b>), together with five known compounds (<b>3-7</b>) have been isolated from the aerial parts of <i>Centaurea rhizantha</i> (Asteraceae). Sesquiterpene lactones belong to guaianolide class, and rhizantholide B is a rare guaianolide characterized by a free primary alcoholic function at C-10 along with a 3β,10β-epoxy function. Their structures have been established on the basis of 1D and 2D NMR experiments, as well as HR-ESIMS. The antimicrobial activity of compounds <b>1-7</b> has been evaluated against Gram-positive and Gram-negative strains. Only deacylcynaropicrin 8-<i>O</i>-[3′-hydroxy-2′-methylpropionate] (<b>5</b>) showed moderate antibacterial activity against <i>Staphylococcus aureus</i> with a MIC/MBC value of 500 μg/mL. All isolated compounds have been also evaluated for their cytotoxic activities against cancer cells. Among them, compound <b>5</b> showed the highest cytotoxic activity with IC₅₀ values in the range 5.02–16.76 μg/mL.</p

Isolation, Chemical and Free Radical Scavenging Characterization of Phenolics from Trifolium scabrum L. Aerial Parts

For the first time Trifolium scabrum L. was researched for its phenolic profile. Sixteen phenolics (isoflavones and flavonoids) were isolated and identified in the aerial parts of <i>T. scabrum</i> L. Their structures were established by electrospray ionization–mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) techniques. Quantitative analysis of individual phenolics performed by means of ultraperformance liquid chromatography–mass spectrometry (UPLC-MS) was based on calibration curves obtained for previously isolated standard compounds. Additionally, the free radical scavenging potential of these substances was assessed by means of a simple benchtop thin-layer chromatography–2,2-diphenyl-1-picrylhydrazyl radical (TLC-DPPH^•) bioassay. Thus, <i>T. scabrum</i> L. can be regarded as a potential source of estrogenic and antioxidant compounds, both of significance in the pharmaceutical as well as the food industry. The results show that <i>T. scabrum</i> L. can be considered as a natural and very good commercial source of phenolic compounds (mainly isoflavones)

Phenolics from <i>Castanea sativa</i> leaves and their effects on UVB-induced damage

<p>The phytochemical investigation of the methanol extract of the leaves of <i>Castanea sativa</i> Mill.<i>,</i> source of the Italian PGI (Protected Geographical Indication) product ‘Marrone di Roccadaspide’ (Campania region) afforded as main compounds crenatin (<b>1</b>), chestanin (<b>2</b>), gallic acid (<b>3</b>), cretanin (<b>4</b>), 5-<i>O</i>-<i>p</i>-coumaroylquinic acid (<b>5</b>), <i>p</i>-methylgallic acid (<b>6</b>) and quercetin-3-<i>O</i>-glucoside (<b>7</b>). To quantify the isolated compounds a LC-ESI(QqQ)MS method working with a very sensitive and selective mass tandem experiment called Multiple Reaction Monitoring (MRM) has been developed. Moreover the antioxidant capacity by TEAC assay and the ability of compounds <b>1</b>–<b>7</b> to protect HaCaT human keratinocytes from UVB-induced damage has been investigated.</p

Unusual Fernane and Gammacerane Glycosides from the Aerial Parts of <i>Spergula fallax</i>

The aerial parts of <i>Spergula fallax</i> afforded four glycosides (<b>1</b>–<b>4</b>) based on two new triterpene aglycones (<b>1a</b> and <b>2a</b>), along with the known hopane glycoside succulentoside A. Compound <b>1</b> was identified as belonging to the fernane class, unusual migrated hopane triterpenoids, mainly isolated from ferns and only rarely from higher plants. Compounds <b>2</b>–<b>4</b> were assigned as gammacerane glycosides, having as aglycone a hydroxylated derivative of tetrahymanol. The structures of the isolated compounds <b>1</b>–<b>4</b> and their aglycones <b>1a</b> and <b>2a</b> obtained by acid hydrolysis were elucidated by spectroscopic data interpretation. The growth inhibitory activity of the isolated compounds and their aglycones was evaluated against the HeLa and DLD-1 cancer cell lines

Cyclic Diarylheptanoids from <i>Corylus avellana</i> Green Leafy Covers: Determination of Their Absolute Configurations and Evaluation of Their Antioxidant and Antimicrobial Activities

The methanol extract of the leafy covers of <i>Corylus avellana</i>, source of the Italian PGI (protected geographical indication) product “Nocciola di Giffoni”, afforded two new cyclic diarylheptanoids, giffonins T and U (<b>2</b> and <b>3</b>), along with two known cyclic diarylheptanoids, a quinic acid, flavonoid-, and citric acid derivatives. The structures of giffonins T and U were determined as highly hydroxylated cyclic diarylheptanoids by 1D and 2D NMR experiments. Their relative configurations were assigned by a combined quantum mechanical/NMR approach, comparing the experimental ¹³C/¹H NMR chemical shift data and the related predicted values. The absolute configurations of carpinontriol B (<b>1</b>) and giffonins T and U (<b>2</b> and <b>3</b>) were assigned by comparison of their experimental electronic circular dichroism curves with the TDDFT-predicted curves. The ability of the compounds to inhibit the lipid peroxidation induced by H₂O₂ and H₂O₂/Fe²⁺ was determined by measuring the concentration of thiobarbituric acid reactive substances. Furthermore, the antimicrobial activity of the methanol extract of leafy covers of <i>C. avellana</i> and of the isolated compounds against the Gram-positive strains <i>Bacillus cereus</i> and <i>Staphylococcus aureus</i> and the Gram-negative strains <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i> was evaluated. Carpinontriol B (<b>1</b>) and giffonin U (<b>3</b>) at 40 μg/disk caused the formation of zones of inhibition

HPLC-ESIMS^<i>n</i> Profiling, Isolation, Structural Elucidation, and Evaluation of the Antioxidant Potential of Phenolics from <i>Paepalanthus geniculatus</i>

The methanol extract of the flowers of <i>Paepalanthus geniculatus</i> Kunth. showed radical-scavenging activity in the TEAC assay. An analytical approach based on HPLC-ESIMS^<i>n</i> was applied to obtain the metabolite profile of this extract and led to the rapid identification of 19 polyphenolic compounds comprising flavonoids and naphthopyranones. The new naphthopyranone (<b>10</b>, <b>16</b>), quercetagetin (<b>1</b>, <b>5</b>, <b>7</b>, <b>13</b>), and galetine derivatives (<b>9</b>, <b>11</b>, <b>17</b>, <b>19</b>), and a flavonol glucoside cyclodimer in the truxillate form (<b>12</b>), were identified. Compounds <b>2</b>, <b>6</b>, and <b>7</b> showed the highest antioxidant capacity and ability to affect the levels of intracellular ROS in human prostate cancer cells (PC3)