Identification of onosma visianii roots extract and purified shikonin derivatives as potential acaricidal agents against tetranychus urticae

There is an increasing need for the discovery of reliable and eco-friendly pesticides and natural plant-derived products may play a crucial role as source of new active compounds. In this research, a lipophilic extract of Onosma visianii roots extract containing 12% of shikonin derivatives demonstrated significant toxicity and inhibition of oviposition against Tetranychus urticae mites. Extensive chromatographic separation allowed the isolation of 11 naphthoquinone derivatives that were identified by spectral techniques and were tested against Tetranychus urticae. All the isolated compounds presented effects against the considered mite and isobutylshikonin (1) and isovalerylshikonin (2) were the most active, being valuable model compounds for the study of new anti-mite agents

Studies on the Biosynthesis of Psoralen and Bergapten in the Leaves of Ficus carica

With the aim of studying the biosynthesis of psoralen and bergapten, two furocoumarins present in the leaves of "Ficus carica" (Moraceae), the Authors, continuing preceding researchs on this topic, have fed the leaves with the following labelled precursors: 4′,5′-dihydropsoralen, 4′,5′-dihydrobergapten, 7-hydroxycoumarin, 5,7-dihydroxycoumarin and 5-methoxy-7-hydroxycoumarin. The results obtained indicate that all these substances are certain biogenetic precursors for psoralen and bergapten. On the basis of the results obtained the biosynthetic pathway of furocoumarins seems to involve first of all the formation of a coumarinic derivative 7-hydroxylated, then an isoprenylation reaction which leads to the formation of the hydrogenated furan ring, finally dehydrogenation of the 4′,5′-dihydrofurocoumarins to psoralen and bergapten

Chemical Composition and Antioxidant Activity of Essential Oil from the Aerial Parts of Teucrium luteum (Mill.) Degen subsp. flavovirens (Batt.) Greuter & Burdet Growing Wild in Tunisia

Essential oils (EOs), the odorous and volatile products of a plant's secondary metabolism, have wide applications in folk medicine, in food flavoring and preservation, and in fragrance industries. The aim of this study was to analyze the chemical composition of the EO from the aerial parts (including the inflorescences) of wild Teucrium luteum subsp. flavovirens from Tunisia. The EO obtained by the hydrodistillation of air-dried plant material in a Clevenger-type apparatus was analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Fifty-three components representing 83.9% of the total constituents were identified. The EO of T. luteum subsp. flavovirens is characterized by the presence of beta-elemol (7.2%), (+)-alpha-pinene (6%), beta-eudesmol (5.5%), guaiol (4.2%), alpha-bisabolol (4.2%), and beta-caryophyllene (4.1%) as principal chemical components. In vitro (DPPH and beta-carotene bleaching assays), it showed significantly higher radical scavenging and antioxidant properties than the reference compound, BHT. To the best of our knowledge, this is the first report describing the composition and antioxidant properties of the EO from Tunisian T. luteum subsp. flavovirens. Our preliminary data will help to valorize this potentially useful plant species from Tunisia and represent a starting point for further studies on its volatile fraction

Variations of polyphenols, sugars, carotenoids, and volatile constituents in pumpkin (Cucurbita moschata) during high pressure processing: A kinetic study

High pressure processing (HPP) is an attractive technology for the preservation of vegetables with health promoting properties such as pumpkins. In this study pumpkin cubes were treated at six different pressures (100 to 600 MPa) at 20 °C for 3 min. Polyphenols (extracted both with solvent and by squeezing the residual material), carotenoids, sugars, and volatiles were evaluated. HPP at medium pressures (200–400 MPa) resulted in higher number of extractable polyphenols. Total sugars in HPP-treated samples were overall declining with increasing pressure. The total amount of carotenoids was higher in samples treated at lower pressures (100–300 MPa) and in the one at 600 MPa compared to untreated ones. Regarding volatile compounds, significant changes were observed for some aldehydes that increase after HPP application. This study revealed that treatment with intermediate pressure could ensure a higher amount of “availability” of polyphenols, carotenoids, volatiles, and total sugars in pumpkin samples

Studies on the Biosynthesis of Some Furocoumarins Present in Ruta graveolens

The biosynthesis of some furocoumarins present in Ruta graveolens has been studied administering labeled psoralen, xanthotoxin, rutaretin, marmesin and 7-hydroxycoumarin-derivatives. The results obtained indicate that the biosynthetic pathway involves not only psoralen, but also xanthotoxin and bergapten, by means of methoxylation or demethoxylation reactions. Moreover results achieved from administering rutaretin demonstrate that this substance is a new very effective natural precursor for xanthotoxin; in a parallel way marmesin is incorporated into psoralen. The reported results indicate that also at the stage of natural 4′,5′-dihydrofurocoumarins intermediates an interconversion can occur. Finally the essential role of umbelliferone in the biosynthesis of furocoumarins has been confirmed

Supercritical Carbon Dioxide Extraction of Lyophilized Aristotelia chilensis (Mol.) Stuntz Berries as Pre-treatment for Enhanced Anthocyanin Recovery

The supercritical carbon dioxide extraction of lyophilized berries of Aristotelia chilensis (Mol.) Stuntz was studied as possible pre-treatment for enhanced anthocyanin recovery. Effect of pressure, temperature, and process time on the extracted oil yields and on the anthocyanins recovery in the pre-treated fractions were considered. The operating parameters were optimized using the central composite design, and extractions were run in the pressure, temperature, and time ranges of 99.6 to 200.4 bar, 36.6 to 53.4 degrees C, and 0.7-2.3 h. The successive multiple regression analysis indicated pressure and time as major influencing parameters on the extraction yield. Those parameters induced no clear changes in the fatty acid composition of almost all the extracted oils, obtaining an aver-age linoleic acid amount between 35-44 % weight in the lipophilic fractions. Standard-ized methanol extractions demonstrated the influence of the different conditions in the SCO2 pre-treatment processes, resulting in extracted anthocyanin increments ranging from 9 to 26 %

New diterpenoid glucoside and flavonoids from Plectranthus scutellarioides (L.) R. Br.

Abstract Three new compounds, diterpenoid glucoside (13S,15S)-6β,7α,12α-trihydroxy-13β,16-cyclo-8-abietene-11,14-dione 7-O-β-D-glucoside 1, flavonoids apigenin 7-O-(3′′-O-acetyl)-β-D-glucuronide 2 and apigenin 5-O-(3′′-O-acetyl)-β-D-glucuronide 3, together with known compounds caffeic acid 4, luteolin 5-O-β-D-glucoside 5 and rosmarinic acid 6 were isolated from the aerial parts of Plectranthus scutellarioides (L.) R. Br. The structures of the new compounds were elucidated by spectroscopic and mass-spectrometric analyses, including 1D- and 2D-NMR. Compound 1 inhibited hyaluronidase by 25% at the concentration of 200 μM, compounds 2 and 3 showed inhibitory activity on butyrylcholinesterase better than standard galanthamine at the concentration of 100 μM, and compound 6 is a potent antioxidant with an ORAC value of 2.15 ± 0.12

Selenium biofortification differentially affects sulfur metabolism and accumulation of phytochemicals in two rocket species (Eruca sativa mill. and diplotaxis tenuifolia) grown in hydroponics

Biofortification can be exploited to enrich plants in selenium (Se), an essential micronutrient for humans. Selenium as selenate was supplied to two rocket species, Eruca sativa Mill. (salad rocket) and Diplotaxis tenuifolia (wild rocket), at 0-40 \u3bcM in hydroponics and its effects on the content and profile of sulphur (S)-compounds and other phytochemicals was evaluated. D. tenuifolia accumulated more total Se and selenocysteine than E. sativa, concentrating up to ~300 mg Se kg 121 dry weight from 10-40 \u3bcM Se. To ensure a safe and adequate Se intake, 30 and 4 g fresh leaf material from E. sativa grown with 5 and 10-20 \u3bcM Se, respectively or 4 g from D. tenuifolia supplied with 5 \u3bcM Se was estimated to be optimal for consumption. Selenium supplementation at or above 10 \u3bcM differentially affected S metabolism in the two species in terms of the transcription of genes involved in S assimilation and S-compound accumulation. Also, amino acid content decreased with Se inE. sativa but increased in D. tenuifolia and the amount of phenolics was more reduced in D. tenuifolia. In conclusion, selenate application in hydroponics allowed Se enrichment of rocket. Furthermore, Se at low concentration (5 \u3bcM) did not significantly affect accumulation of phytochemicals and plant defence S-metabolites

Hairy garlic (Allium subhirsutum) from Sicily (Italy): LC-DAD-MSn analysis of secondary metabolites and in vitro biological properties

Allium subhirsutum, known as hairy garlic, is a bulbous plant widespread in the Mediterranean area and locally used as a food and spice. In the present study, the chemical profile of the ethanolic extracts from bulbs (BE) and aerial parts (APE) were analyzed by HPLC-ESI-MSn, and antioxidant properties were evaluated by DPPH, ABTS and TEAC assays. The traditional use in the diet, and the well documented biological activity of Allium species suggest a potential as a new nutraceutical. For this reason, the potential usefulness of this food can be considered in the treatment and prevention of degenerative Alzheimer disease. For this reason, acetylcholinesterase inhibitory property was investigated. Furthermore, due to the observed presence of sulfur-containing and phenolic constituents, the cytotoxicity on tumor cells line was investigated. Results revealed significant AChE inhibitory activity for BE and APE. Both extracts exhibited also moderate antioxidant properties in the in vitro assays. Finally, limited cytotoxic activity was observed towards Human colon carcinoma and adenocarcinoma cell line, with differences between the individual parts tested. HPLC-ESI-MSn analysis showed that hairy garlic is a good source of sulphur compounds, flavonoids and phenylpropanoids derivatives, thus being a valid alternative to the common garlic (A. sativum). This work opens new opportunities for the application of A. subhirsutum as a health-promoting food