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Biomedical subjects

Antonio Fiorentino

Publications and source records attributed to Antonio Fiorentino.

At least 19 recordsLinked to original sources
PubMed2006

Spectroscopic identification and antioxidant activity of glucosylated carotenoid metabolites from Cydonia vulgaris fruits.

Carotenoid metabolites are common plant constituents with significant importance for the flavor and aroma of fruits. Three new carotenoid derivatives, (2E,4E)-8-hydroxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid 1-O-beta-D-glucopyranosyl ester (1), (2Z,4E)-8-beta-D-glucopyranosyloxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid (3), and 3,9-dihydroxymegastigmast-5-ene-3-O-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (5), as well as three known compounds, have been isolated from the ethanolic extract of peels of Cydonia vulgaris, the fruit of a shrub belonging to the same family as the apple. All the compounds were identified by spectroscopic techniques, especially 1D and 2D NMR. Antioxidant activities of all the isolated metabolites were assessed by measuring their ability to scavenge DPPH radical and superoxide radical (O2*-) and to induce the reduction of Mo(VI).

Antioxidants↗
PubMed2006

Natural dibenzoxazepinones from leaves of Carex distachya: Structural elucidation and radical scavenging activity.

Two new dibenzoxazepinones have been isolated from the leaves of Carex distachya, an herbaceous plant growing in the Mediterranean area. The structures have been elucidated on the basis of their spectroscopic properties. Bidimensional NMR (DQ-COSY, TOCSY, NOESY, ROESY, HSQC, and HMBC) furnished important data useful for the characterization of the molecules. The compounds have been assayed, for the antioxidant activity, by measuring its capacity to scavenge the DPPH, the superoxide anion, and nitric oxide radicals.

Biphenyl Compounds↗
PubMed2006

Distachyasin: A new antioxidant metabolite from the leaves of Carex distachya.

A novel antioxidant prenylated stilbenoid, distachyasin, has been isolated from the leaves of Carex distachya. Its structure has been elucidated on the basis of the spectroscopic characteristics. Bidimensional NMR, and crystallographic data and computational calculations have furnished important data useful for the characterization and the stereochemistry of the molecule. The compound has a tetracyclic skeleton derived from carexane. The compound has been assayed, for the antioxidant activity, by measuring its capacity to scavenge the H(2)O(2), nitric oxide, superoxide radical and to inhibit formation of TBARS (thiobarbituric acid reactive species).

Antioxidants↗
PubMed2006

Chemical constituents of the aquatic plant Schoenoplectus lacustris: evaluation of phytotoxic effects on the green alga Selenastrum capricornutum.

Forty-nine secondary metabolites were isolated from aqueous and alcoholic extracts of the aquatic plant Shoenoplectus lacustris. All compounds were characterized based on spectroscopic data. Eleven free and glycosylated low-molecular polyphenols, 17 cinnamic acid and dihydrocinnamic acid derivatives, 11 flavonoids, and 10 C13 nor-isoprenoids were identified. The structure of the new compound, 1-benzoyl-glycerol-2-alpha-L-arabinopyranoside, was elucidated by 2D NMR experiments (COSY, HSQC, HMBC, NOESY). To evaluate potential phytotoxic effects, all compounds were tested on the green alga Selenastrum capricornutum, a unicellular organism commonly used in tests of toxicity as a bioindicator of eutrophic sites. The most active compound was (-)-catechin, showing an inhibition similar to that of the algaecide CuSO4.

Chlorophyta↗
PubMed2006

Free-radical-scavenging and antioxidant activities of secondary metabolites from reddened cv. Annurca apple fruits.

Forty-three secondary metabolites were isolated and characterized from cv. Annurca apple fruit, an apple variety cultivated in the south of Italy. This apple cultivar undergoes a typical reddening treatment after collection. All of the compounds were characterized on the basis of their spectroscopic data. The compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge DPPH* (2,2'-diphenyl-1-picrylhydrazyl radical), H2O2, and NO (nitric oxide) and to inhibit the formation of methyl linoleate conjugated diene hydroperoxides or TBARS (thiobarbituric acid reactive species).

Antioxidants↗
PubMed2006

Terpenoids and phenol derivatives from Malva silvestris.

A sesquiterpene and a tetrahydroxylated acyclic diterpene as well as two known monoterpenes, 6 C(13)nor-terpenes and 11 aromatic compounds were isolated from the water extract of Malva silvestris. The structures of the compounds were determined by spectroscopic NMR and MS analysis. Effects of these compounds on germination and growth of dicotyledon Lactuca sativa L. (lettuce) were studied in the 10(-4)-10(-7)M concentration range.

Lactuca↗
PubMed2006

Structures of bioactive carexanes from the roots of Carex distachya Desf.

Four metabolites, named carexanes I-L, have been isolated from the roots of Carex distachya Desf, an herbaceous plant living in the Mediterranean maquis, together with three known compounds, already isolated from the aerial part of the plant. All the compounds have been characterized on the basis of their spectroscopic properties. Carexane I derived from the lose of a proton from the C-18 carbon of an intermediate isopropyl cation. Its stereostructure has been elucidated by Mosher's method, NOESY/ROESY experiments and computational calculations. The bioactivity on seed germination and root/shoot growth of Lactuca sativa L. of all the isolated compounds is also reported.

Carex Plant↗
PubMed2005

Structural characterization of phytotoxic terpenoids from Cestrum parqui.

Isolation, chemical characterization and phytotoxicity of nine polyhydroxylated terpenes (five C13nor-isoprenoids, two sesquiterpenes, a spirostane and a pseudosapogenin) from Cestrum parqui L'Herr are reported. In this work we completed the phytochemical investigation of the terpenic fraction of the plant and described the structural elucidation of polar isoprenoids using NMR methods. All the configurations of the compounds have been assigned by NOESY experiments. Four new structures have been identified as (3S,5R,6R,7E,9R)-5,6,9-trihydroxy-3-isopropyloxy-7-megastigmene, 5alpha-spirostan-3beta,12beta,15alpha-triol, and 26-O-(3'-isopentanoyl)-beta-d-glucopyranosyl-5alpha-furost-20(22)-ene-3beta,26-diol, and as an unusual tricyclic sesquiterpene. The compounds have been assayed for their phytotoxicity on lettuce at the concentrations ranging between 10(-4) and 10(-7)M. The activities of some compounds were similar to that of the herbicide pendimethalin.

Cestrum↗
PubMed2005

Isolation, characterization, and antioxidant activity of E- and Z-p-coumaryl fatty acid esters from cv. Annurca apple fruits.

A total of 12 fatty acid esters of Z- and E-p-coumaryl alcohol were isolated from cv. Annurca apple fruit and characterized. This apple variety is widely cultivated in the south of Italy, and the fruits typically undergoe a reddening treatment after harvest. Structures of the p-coumaryl esters were elucidated by GC-MS and (1)H and (13)C NMR after purification of individual compounds by HPLC. It was found that the esters are localized in the fruit peel. During reddening of the fruit, there was a substantial increase in the amount of esters and particularly in molecular species with unsaturated fatty acids. The individual compounds were tested for antioxidant activity, and over half were shown to be at least as effective as alpha-tocopherol.

Antioxidants↗
PubMed2005

Structure elucidation and phytotoxicity of ecdysteroids from Chenopodium album.

The leaves of Chenopodium album were infused in H2O/MeOH. The extract treated with cold acetone gave heavy precipitation, which was removed by centrifugation. Solid material was fractionated into acidic and neutral fractions. The acidic material was subjected to different silica-gel column chromatographies, and then it was purified by reversed-phase HPLC to afford four known ecdysteroids and the new 3beta,14alpha-dihydroxy-5beta-pregn-7-ene-2,6,20-trione that were characterized by extensive spectroscopic investigation, especially by 1D- and 2D-NMR. Their effects on germination and growth of Lactuca sativa L. have been studied. The results are reported as percentage differences of germination, root elongation and shoot elongation, from the control at concentrations ranging from 10(-4) to 10(-7) M.

Chenopodium album↗
PubMed2005

Radical-scavenging activities of new hydroxylated ursane triterpenes from cv. Annurca apples.

Two new ursolic acid triterpene derivatives, compounds 2 and 3, have been isolated from cv. Annurca apple fruit, a high-quality apple variety widely cultivated in southern Italy, together with the known 2-oxopomolic acid (1). The new compounds were identified by means of different spectroscopic techniques as 3-epi-2-oxopomolic acid (= (3alpha)-3,19-dihydroxy-2-oxours-12-en-28-oic acid; 2) and (1alpha)-1-hydroxy-3-oxours-12-en-28-oic acid (3). Compounds 1-3 were tested for their radical-scavenging activities with the aid of a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (Fig. 2). All three constituents showed activities similar to that of the reference antioxidant alpha-tocopherol (vitamin E).

Free Radical Scavengers↗
PubMed2004

Olive oil mill wastewater treatment using a chemical and biological approach.

Olive oil mill wastewaters (OMW) are recalcitrant to biodegradation for their toxicity due to high values of chemical oxygen demand (COD), biological oxygen demand (BOD), and phenolic compounds. In the present study OMW, collected in southern Italy, were subjected first to a chemical oxidative procedure with FeCl3 and then to a biological treatment. The latter was performed in a pilot plant where mixed commercial selected bacteria, suitable for polyphenols and lipid degradation, were inoculated. The effect of treatments was assessed through COD removal, reduction of total phenols, and decrease of toxicity using primary consumers of the aquatic food chain (the rotifer Brachionus calyciflorus and the crustacean Daphnia magna). The results showed that the chemical oxidation was efficacious in reducing all parameters analyzed. A further decrease was found by combining chemical and biological treatments.

Bacteria↗
PubMed2004

Low molecular weight phenols from the bioactive aqueous fraction of Cestrum parqui.

The aqueous fraction of fresh leaves of Cestrum parqui and its organic fractions have been assayed for their phytotoxicity on Lactuca sativa, Lycopersicon esculentum, and Allium cepa. The tests showed that the bioactivity was retained in the organic fractions. Chromatographic processes led to isolation and characterization of the N-(p-carboxymethylphenyl)-p-hydroxybenzamide together with 17 low molecular weight phenols and 2 flavones. The phytotoxicity tests showed a good activity of these compounds on the target species. Comparison of some metabolites with commercial herbicides revealed a major activity of the natural compounds at lower concentrations.

Cestrum↗
PubMed2004

Toxicity of prednisolone, dexamethasone and their photochemical derivatives on aquatic organisms.

Light exposure of aqueous suspensions of prednisolone and dexamethasone causes their partial phototransformation. The photoproducts, isolated by chromatographic techniques, have been identified by spectroscopic means. Prednisolone, dexamethasone and their photoproducts have been tested to evaluate their acute and chronic toxic effects on some freshwater chain organisms. The rotifer Brachionus calyciflorus and the crustaceans Thamnocephalus platyurus and Daphnia magna were chosen to perform acute toxicity tests, while the alga Pseudokircheneriella subcapitata (formerly known as Selenastrum capricornutum) and the crustacean Ceriodaphnia dubia to perform chronic tests. The photochemical derivatives are more toxic than the parent compounds. Generally low acute toxicity was found. Chronic exposure to this class of pharmaceuticals caused inhibition of growth population on the freshwater crustacean C. dubia while the alga P. subcapitata seems to be less affected by the presence of these drugs.

Animals↗
PubMed2004

Structure elucidation and phytotoxicity of C13 nor-isoprenoids from Cestrum parqui.

Twelve C(13) nor-isoprenoids have been isolated from the leaves of Cestrum parqui (Solanaceae). The structure (2R,6R,9R)-2,9-dihydroxy-4-megastigmen-3-one has been assigned to the new compound. All the structures have been determined by spectroscopic means and chemical correlations. The compounds showed phytotoxic effect on the germination and growth of Lactuca sativa L.

Cestrum↗
PubMed2003

Lignans and neolignans from Brassica fruticulosa: effects on seed germination and plant growth.

Five lignans, five neolignans, two sesquilignans, and a dilignan were identified from a phytotoxic extract of Brassica fruticulosa L. Compounds 8, 9, 12, and 13 have been isolated for the first time. Structures were determined on the basis of their spectroscopic features. Their effects on the germination and growth of two dicotyledons, Lactuca sativa (lettuce) and Lycopersicon esculentum (tomato), and a monocotyledon, Allium cepa (onion), as standard target species have been studied.

Brassica↗
PubMed2003

Environmental effects caused by olive mill wastewaters: toxicity comparison of low-molecular-weight phenol components.

Olive oil mill wastewaters (OMWs) show significant polluting properties due to their content of organic substances, and because of their high toxicity toward several biological systems. Wastewaters' toxicity has been attributed to their phenolic constituents. A chemical study of wastewaters from a Ligurian oil mill characterized phenolic products such as 1,2-dihydroxybenzene (catechol), derivatives of benzoic acid, phenylacetic acid, phenylethanol, and cinnamic acid. The OMWs were fractioned by ultrafiltration and reverse osmosis techniques and tested for toxicity on aquatic organisms from different trophic levels: the alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum); the rotifer Brachionus calyciflorus; and two crustaceans, the cladoceran Daphnia magna and the anostracan Thamnocephalus platyurus. The fraction most toxic to the test organisms was that from reverse osmosis containing compounds of low molecular weight (<350 Da), and this was especially due to the presence of catechol and hydroxytyrosol, the most abundant components of the fraction.

Animals↗