86,701 research outputs found
Green Method Comparison and Optimization of Anthocyanin Recovery from “Sangiovese” Grape Pomace: A Critical Evaluation of the Design of Experiments Approach
No full textGrape pomace is the main by-product obtained from wine production that is still enriched in bioactive compounds. Within a framework of waste/by-product reuse through a sustainable approach, various green methods were utilized in this work to recover anthocyanins from the pomace resulting from “Sangiovese” grape vinification. Ultrasound- and Microwave-Assisted Extractions (UAE and MAE) were coupled with the use of green solvents, such as acidified water, an ethanol/water mixture, and Natural Deep Eutectic Solvents (NaDES), and their efficacy was compared with that of a conventional method based on a methanol/acidified water mixture. The Total Anthocyanin Index ranged from 36.9 to 75.2 mg/g DW for UAE, and from 54.4 to 99.6 mg/g DW for MAE, while resulting in 47.1 mg/g DW for conventional extraction. A Design of Experiments (DoE) approach was applied to MAE, the most efficient technique. Temperature, time, and the solid-to-liquid ratio were set as X variables, while malvidin-3-O-glucoside content and antioxidant activity were used as response variables, measured by High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The correlation between temperature and time and the antioxidant activity of the extract was positive, while it was found to be negative when considering malvidin-3-O-glucoside concentration as a response variable. Thus, the optimal conditions in temperature, time and solid-to-liquid ratio were different depending on the chosen variable. The results underline the importance of selecting an accurate response when using the response surface methodology approach
Bis(guanylhydrazones) negatively affect in vitro germination of kiwifruit pollen and alter the endogenous polyamine pool
No full textPolyamine binding to plasma membrane vesicles isolated from zucchini hypocotyls
No full textThe general features of [14C]spermidine binding to plasmalemma vesicles isolated from zucchini (Cucurbita pepo L.) etiolated hypocotyls are reported in the present paper. The specific interaction of the polyamine with the plasma membranes was reversible and thermolabile, since it decreased by about 50% in the assay performed at 4O°C compared to that carried out on ice. On the contrary, nonspecific binding was unaffected by temperature. Specific spermidine binding showed a pH dependence with a maximum at pH 8.0 and it reached saturation between 0.75 and 1 mM external spermidine concentration. The value of the dissociation constant calculated from Scatchard analysis was 4.4 × 10-5 M. Specific spermidine interaction appeared to be sensitive to detergents and was markedly reduced by the presence of divalent cations, such as Mg2+ and Ca2+, whereas it was stimulated by monovalent cations. Polyamine binding sites were highly sensitive to pronase treatment. Competition experiments, performed using a series of compounds structurally related to spermidine, may provide some indication of the characteristics of spermidine binding sites. The results presented here suggest that specific spermidine binding occurs mainly with the protein component of the plasma membrane
Over-accumulation of putrescine induced by cyclohexylamine interferes with chromium accumulation and partially restores pollen tube growth in Actinidia deliciosa.
No full textBoth trivalent and hexavalent chromium, i.e., Cr(III) and Cr(VI), respectively, were previously demonstrated
to affect in vitro germination and ultrastructure of kiwifruit (Actinidia deliciosa) pollen. In the
present work, the response to chromium in germinating pollen was evaluated in terms of changes in the
polyamine profile. Slight, though significant, increases in free spermidine and spermine occurred after
exposure to Cr(III), while the levels remained almost unchanged after Cr(VI) treatment. The spermidine
synthase inhibitor cyclohexylamine (CHA) caused a dramatic increase in free putrescine in both
chromium-treated and untreated samples, while spermidine content was not affected. Interestingly, CHA
positively affected the performance of chromium-treated pollen by partially, though significantly,
restoring pollen tube growth. The major growth recovery was registered with 1 mM CHA in the presence
of Cr(VI), concomitant with a considerable reduction in uptake of the metal. Conversely, endogenous
calcium levels were more heavily affected in Cr(III)-treated pollen. The effect of CHA on production of
reactive oxygen species also varied depending on the chromium species. The response of pollen to the
CHA-induced putrescine excess was compared with that exerted by an exogenous supply of the same
diamine. Results show that in Cr(III)-treated pollen, putrescine over-accumulation induced by CHA
exerted similar effects as exogenous putrescine, while this was not true in the Cr(VI) treatment. It appears
that the diamine was able to improve pollen tolerance to metal stress through different mechanisms,
mostly depending upon the chromium species, namely via reduced metal uptake or by
substituting for calcium
Andamento di trigliceridi e colesterolo nel siero di sangue e lipidi totali nel siero di latte di pecore infettate sperimentalmente.
No full textAnti‐candida activity of essential oils from lamiaceae plants from the mediterranean area and the middle east
No full textExtensive documentation is available on plant essential oils as a potential source of antimicrobials, including natural drugs against Candida spp. Yeasts of the genus Candida are responsible for various clinical manifestations, from mucocutaneous overgrowth to bloodstream infections, whose incidence and mortality rates are increasing because of the expanding population of immunocompromised patients. In the last decade, although C. albicans is still regarded as the most common species, epidemiological data reveal that the global distribution of Candida spp. has changed, and non‐albicans species of Candida are being increasingly isolated worldwide. The present study aimed to review the anti‐Candida activity of essential oils collected from 100 species of the Lamiaceae family growing in the Mediterranean area and the Middle East. An overview is given on the most promising essential oils and constituents inhibiting Candida spp. growth, with a particular focus for those natural products able to reduce the expression of virulence factors, such as yeast‐hyphal transition and biofilm formation. Based on current knowledge on members of the Lamiaceae family, future recommendations to strengthen the value of these essential oils as antimicrobial agents include pathogen selection, with an extension towards the new emerging Candida spp. and toxicological screening, as it cannot be taken for granted that plant‐derived products are void of potential toxic and/or carcinogenic properties
Triterpenoids isolated from Jatropha macrantha (Müll. Arg.) inhibit the NF-κB and HIF-1α pathways in tumour cells
No full textActivity-guided fractionations of Jatropha macrantha Müll. Arg. led to the isolation of pomolic acid (1) and euscaphic acid (2). The potential for inhibition against NF-κB and HIF-1α production of these two compounds was tested in different tumour cell lines. Compounds 1 and 2 showed an inhibitory activity of HIF-1α in the SK-MEL-28 (IC50=3.01 ± 0.02 μM and 3.78 ± 0.02 μM), A549 (IC50=9.97 ± 0.01 μM and 10.25 ± 0.01 μM) and U-373 MG (IC50=6.34 ± 0.02 μM and 8.85 ± 0.02 μM) cell lines. In addition, compounds 1 and 2 showed an inhibitory activity on NF-κB in SK-MEL-28 (IC50=1.05 ± 0.02 μM and 2.71 ± 0.01 μM), A549 (IC50=3.63 ± 0.01 μM and 3.73 ± 0.02 μM) and U-373 MG (IC50=2.55 ± 0.02 μM and 3.39 ± 0.01 μM) cell lines. This is the first report that isolates these compounds from J. macrantha and tests their antitumor potential
Application of an early monitoring tool to assess the effects on soil microbial biomass of organic fertilizers and soil conditioners in different soils
No full textThe dosimetric impact of the bladder volume variations on the dose to organs at risk (OAR) during HDR brachytherapy endometrial cancer
No full textMedium composition and methyl jasmonate influence the amount and spectrum of secondary metabolites in callus cultures of Zanthoxylum stenophyllum Hemsl.
No full textIn the present study callus cultures of Zanthoxylum stenophyllum were initiated in vitro and the effect of different growth regulators and elicitors was tested both upon callus growth and secondary metabolite production. On a medium containing naphthalenacetic acid (NAA), kinetin and 2,4 dichlorophenoxyacetic acid (2,4D), a yellowish and friable callus was obtained from 90% of cotyledon explants, while no callus appeared from other portions of the seedlings. The time course of callus growth and secondary metabolite accumulation was followed after subculturing the established callus culture on different media containing various hormonal combinations. Results indicate that medium containing NAA and a higher concentration of 2,4-D compared to maintenance medium gave the highest stimulation of callus growth, suggesting that this auxin has a critical role in influencing growth. Addition of an organic nitrogen source such as casein hydrolysate also had a positive effect on growth. HPLC analysis of methanol extractable secondary metabolites from Z. stenophyllum calli grown on different media showed that phytohormones and nutrients were able to modify the chromatographic pattern of compounds. Calli grown on the medium giving the highest stimulation of growth show a reduced accumulation of some secondary products. Under the same hormonal conditions, the presence or absence of casein also altered the metabolites produced, both qualitatively and quantitatively. In response to elicitation by methyl jasmonate (MJ), metabolite production was different for the different classes of compounds, and hormonal composition of the culture medium turned out to be very important in determining the response to MJ. Thus, results confirm the importance of the reciprocal interactions between hormones, nutrients and elicitors when attemps are made to enhance secondary metabolite accumulation in in vitro cultures
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