Arbutin-2'-sulphonyl from the infusion of Ilex theezans leaves

A sulphate arbutin derivative was isolated from the leaves of Ilex theezans, an adulterant of mate (Ilex paraguariensis). The structure was determined by spectral analysis.     

Radical scavenging activities of peels and pulps from cv. Golden Delicious apples as related to their phenolic composition

The relationship between phenolic composition and radical scavenging activity of apple peel and pulp was investigated in fruit produced according to both organic and integrated agricultural methods. Apple tissue extracts were subjected to high-performance liquid chromatography separation, which showed that as compared with pulps, peels are richer in almost all of the quantified phenolics. Flavonols, flavanols, procyanidins, dihydrochalcones, and hydroxycinnamates were the identified phenolic classes in peel tissue, and the most abundant compounds were epicatechin, procyanidin B2, and phloridzin. Pulps were poorer in phytochemicals. Their major phenolics were procyanidins and hydroxycinnamates. Flavonols in amounts <20 mg kg(-1) fresh weight (fw) were also found. In both peels and pulps, integrated production samples were richer in polyphenols. Among the 14 compounds identified, only phloridzin had a tendency to appear higher in organic peels. The total antioxidant capacities (TAC) of extracts were evaluated using the 1,1-diphenyl-2-picrylhydrazyl radical assay and were expressed as Trolox equivalents. Integrated peels gave the highest TAC (18.56 mM kg(-1) fw), followed by organic peels (TAC = 14.96), integrated pulps (TAC = 7.12), and organic pulps (TAC = 6.28). In peels, the top contributors to the antioxidant activity were found to be flavonols, flavanols, and procyanidins, which accounted for about 90% of the total calculated activity whereas in pulps, the TAC was primarily derived from flavanols (monomers and polymers) together with hydroxycinnamates. A good correlation between the sum of polyphenols and the radical scavenging activities was found. Among the single classes of compounds, procyanidins (in peels and pulps) and flavonols (in peels) were statistically correlated to the TAC.     

Influence of ethylene inhibition by 1-methylcyclopropene on apricot quality,volatile production,and glycosidase activity of low- and high-aroma varieties of apricots

Apricots of two varieties, Ceccona with strong aroma and San Castrese with low aroma but good firmness, were treated with 1 microL L(-)(1) 1-methylcyclopropene (1-MCP) for 12 h at 20 degrees C and then kept for shelf life at 20 degrees C and 85% relative humidity. 1-MCP treatment strongly inhibited ethylene production in apricots of both varieties, and softening was delayed. Fruit softening started before the rise of ethylene in air-treated apricots, which softened even when the rise of ethylene production was inhibited by 1-MCP. The softening reduction was more significant in Ceccona apricots than in San Castrese. Pectinmethylesterase (PME) activity declined in Ceccona fruit regardless of the treatment; in San Castrese, PME of air-treated fruit slightly increased, whereas in 1-MCP-treated apricots the activity declined. alpha-d-Galactosidase (alpha-gal) and beta-d-galactosidase (beta-gal) activities in Ceccona apricot were significantly reduced by 1-MCP treatment, whereas in San Castrese apricot no difference in activities was observed between air- and 1-MCP-treated fruit. The pattern of beta-d-xylosidase (xyl) activity in San Castrese apricot was similar to that of beta-gal, showing a peak on day 4 without difference between treatments. alpha-d-Mannosidase (alpha-man) activity of air-treated apricots of both varieties rose slightly, and 1-MCP treatment decreased the enzyme activity in both varieties. alpha-d-Glucosidase (alpha-glu) decreased in air-treated apricots in both varieties, and 1-MCP maintained higher activity in Ceccona fruit but not in San Castrese. Acidity decreased during postharvest ripening regardless of the treatment, whereas soluble solids content (SSC) increased in Ceccona apricot and slightly diminished in San Castrese ones without any effect by 1-MCP treatment. 1-MCP did not show any effect on apricot color; in contrast, it affected the volatiles profile, especially in Ceccona apricot, reducing the synthesis of lactones and promoting the rise of terpenols.     

Cytotoxicity of withanolides isolated from Acnistus arborescens

A new withanolide identified by spectroscopic analysis as 12β-acetoxy-4-deoxy-5,6-deoxy-Δ⁵–withanolide D and Withanolide D, were isolated from the leaves of Acnistus arborescens. Cytotoxic activity of these two compounds against human tumor cell lines HT-29, MCF-7, MKN-45, HEp-2, HeLa, U-937 and two human normal fibroblast cultures, Fib04 and Fib05, were assessed. Withanolide D presented in vitro cytotoxic activity against tumor cell lines at the low micromolar range (LC₅₀:1.0 to 1.69 µM) and showed a slightly lower activity against Fib04, suggesting moderated selectivity among tumoral and normal cells. No cytotoxic effect was observed for 12β-acetoxy-4-deoxy-5,6-deoxy-Δ⁵–withanolide D.     

Technological parameters of water curing affect postharvest physiology and storage of marrons (Castanea sativa Mill., Marrone fiorentino)

Little is known about the biochemistry of the marron (Castanea sativa cv Marrone fiorentino) when it is soaked in water for the curing process; the immersion treatment time is still empirical and based on traditional knowledge. A study was carried out by keeping marrons in water for 7 d at 14 °C. Tap water and acid water (pH 3) were used in the following water/marron ratios 1:1, 1:2, and 3:2. After curing, the marrons were moved to air storage at room temperature (20 °C and 90% RH) for 1 week (shelf-life), and at 0 °C and 90% RH for 60 d. A large accumulation of carbon dioxide in the head space of the glass jar where the marrons were kept, was observed during water soaking, above all in samples in acid water with a water/marron ratio 1:2. In the first 5 d of water curing, a significant increase in acetaldehyde concentration and phenol content was measured in the marron pulp and subsequently, both compounds declined. Ethanol decreased slightly or remained constant. During the following week of shelf-life, the lowest respiration rate was measured in 1:1 and 1:2 samples while the highest rate was measured in acid water samples. SSC (solid soluble contents) increased in marrons soaked in acid water but remained constant under shelf-life conditions. SSC, ethanol, acetaldehyde and polyphenols did not change following storage at 0 °C for 2 months, but acid water samples showed a higher percentage of decayed marrons. Finally, it is possible to define some technological parameters. The immersion time of marrons in water must be at least 5 and no longer than 7 d, in order to avoid cell destruction. A water/marron ratio of 1:1 is advised. Using acid water, the samples with the ratios of 1:2 and 1:1 showed higher polyphenol and sugar contents. However, the metabolic response of these marrons was assumed to be a “stress response” to acid water.     

Pro-oxidant activity of oleuropein determined in vitro by electron spin resonance spin-trapping methodology

In this work, the pro-oxidant behavior of oleuropein (OLP, 1) is characterized in a Fenton-like experiment by means of ESR spectroscopy using the spin trap system DMSO and 4-(pyridyl-1-oxide)-N-tert-butyl nitrone (POBN) in phosphate buffer (PB) solution. Ferrous ions in the absence of hydrogen peroxide cause the formation of the stable nitroxide species 4 and 5 through the intermediate perferryl species. OLP displays its antioxidant activity in vitro blocking the oxidation path that leads to methoxyl radicals hence to the formation of the stable radical species 5. The role of the catechol moiety was proved when the perferryl experiments were repeated in the presence of the dimethylated oleuropein homologue (OLP-Met2, 2). The dual behavior of oleuropein, similar to that ascertained for other catechol and non-catechol natural active species, should provide warnings for its use as nutraceutical or as drug with manifold healing effects.     

Monitoring the effects of storage in caviar from farmed Acipenser transmontanus using chemical, SEM, and NMR methods

The effects of storage at 4 degrees C on the quantity and quality of chemical components in the caviar from farmed Acipenser transmontanus have been analyzed by SEM, chemical methods, and NMR and MRI techniques. Particular attention has been focused on the lipid components, the distribution and mobility of which were strongly affected by the storage time. MRI and relaxation data indicated that lipids are endowed with two different mobility regimes, one slow (short T1) and one fast (long T1), both lengthening with the storage time. Chemical analysis assessed a total fat content that remained practically unchanged and a constant fatty acid composition during the total storage time. The combination of the two methods allowed one (a) to suppose that a mechanism of lipid hydrolysis (faster in unsalted than in salted eggs) is still occurring during storage of caviar at 4 degrees C for up to approximately 4 months and (b) to exclude that an intensive oxidative process is active in the same storage period.     

Soil porous system changes quantified by analyzing soil water retention curve modifications

Soil water retention curves (SWRCs) relate soil water pressure head (h) to soil water content (θ) and can also be used to find information regarding soil pore distribution. To analyze SWRCs in relation to pore size distribution (PSD), changes due to wetting and drying (W–D) cycles were studied in three different tropical soils (Geric Ferralsol, GF; Eutric Nitosol, EN; Rhodic Ferralsol, RF), using three different treatments: T₀, the control with samples not submitted to W–D cycles; T₃, samples submitted to three consecutive W–D cycles; T₉, samples submitted to nine consecutive W–D cycles. Log-normal PSD equations for each treatment were obtained using the S-theory. For the GF soil, the pressure heads separating structural and matrix domains (h_s) were 17.7, 12.2 and 14.7 kPa for T₀, T₃, and T₉, respectively. These values are equivalent to pore radia of 8.4 μm (T₀), 12 μm (T₃), and 10 μm (T₉). For the RF soil, h_s values were 8.5 kPa (T₀), 20.5 kPa (T₃), and 15.1 kPa (T₉), equivalent to radia of 18 μm (T₀), 7.3 μm (T₃), and 9.9 μm (T₉); and finally, for the EN soil, h_s were 18.1 kPa (T₀), 9.1 kPa (T₃), and 13.5 kPa (T₉), equivalent to radia of 8.2 μm (T₀), 16 μm (T₃), and 11 μm (T₉). It was found that the soil structure presented important changes in PSD due to W–D cycles for all the investigated soils. It was also observed that the W–D cycles increased the S_inf (slope of SWRC) value for the GF soil for all treatments; S_inf did not substantially change in all treatments for the EN soil; S_inf decreased between T₀ and T₃, and T₀ and T₉ for the RF soil. According to the S-theory, it is possible to infer that W–D cycles improved the soil structure of GF, made the RF soil structure worse and did not substantially change the EN soil structure.