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151.
González-Sarrías A Gromek S Niesen D Seeram NP Henry GE 《Journal of agricultural and food chemistry》2011,59(16):8632-8638
Research has shown that members of the Carex genus produce biologically active stilbenoids including resveratrol oligomers. This is of great interest to the nutraceutical industry given that resveratrol, a constituent of grape and red wine, has attracted immense research attention due to its potential human health benefits. In the current study, five resveratrol oligomers (isolated from Carex folliculata and Carex gynandra ), along with resveratrol, were evaluated for antiproliferative effects against human colon cancer (HCT-116, HT-29, Caco-2) and normal human colon (CCD-18Co) cells. The resveratrol oligomers included one dimer, two trimers, and two tetramers: pallidol (1); α-viniferin (2) and trans-miyabenol C (3); and kobophenols A (4) and B (5), respectively. Although not cytotoxic, the resveratrol oligomers (1-5), as well as resveratrol, inhibited growth of the human colon cancer cells. Among the six stilbenoids, α-viniferin (2) was most active against the colon cancer cells with IC(50) values of 6-32 μM (>2-fold compared to normal colon cells). Moreover, α-viniferin (at 20 μM) did not induce apoptosis but arrested cell cycle (in the S-phase) for the colon cancer but not the normal colon cells. This study adds to the growing body of knowledge supporting the anticancer effects of resveratrol and its oligomers. Furthermore, Carex species should be investigated for their nutraceutical potential given that they produce biologically active stilbenoids such as α-viniferin. 相似文献
152.
Suely Ruiz Giolo Enrico Antonio Colosimo Clarice Garcia Borges Demétrio 《Journal of Agricultural, Biological & Environmental Statistics》2009,14(2):154-169
Interval-censored survival data, in which the event of interest is not observed exactly but is only known to occur within
some time interval, occur very frequently. In some situations, event times might be censored into different, possibly overlapping
intervals of variable widths; however, in other situations, information is available for all units at the same observed visit
time. In the latter cases, interval-censored data are termed grouped survival data. Here we present alternative approaches
for analyzing intervalcensored data. We illustrate these techniques using a survival data set involving mango tree lifetimes.
This study is an example of grouped survival data. 相似文献
153.
154.
Siani AC Tappin MR Ramos MF Mazzei JL Ramos MC De Aquino Neto FR Frighetto N 《Journal of agricultural and food chemistry》2002,50(12):3518-3521
A new chemotype of the aromatic Verbenaceae species Lippia alba Mill. N. E. Br. from southeastern Brazil has recently been shown to have a high content of linalool in the leaf essential oil. Vegetative propagation of this chemotype was conducted at six different locations in Brazil, and the variation of the content and the optical purity of linalool in the oils were verified. Yields (0.6-0.9%, hydrodistillation), chemical composition, linalool content, and optical purity of the oils from all the plants were compared, using GC-FID, GC-MS, chiral chromatography, and retention index calculation. No plant exceeded the matrix in linalool content (46.5 to 90.7%), and the chemical profile of the oils was the same for all the samples. Purification of linalool to a content close to 100% was effected by vacuum distillation of the crude oil. Chiral analysis showed exclusively the presence of S-linalool in all the crude oils and in the distilled samples. 相似文献
155.
Soil chemical and biochemical properties of a salt-marsh alluvial Spanish area after long-term reclamation 总被引:2,自引:0,他引:2
Vito Armando Laudicina Maria Dolores Hurtado Luigi Badalucco Antonio Delgado Eristanna Palazzolo Michele Panno 《Biology and Fertility of Soils》2009,45(7):691-700
Marisma, one of the largest salt-marsh alluvial areas in SW Spain, has been reclaimed since 1970 by artificial drainage and
amendment with phosphogypsum (PG) so as to reduce Na+ saturation. Within the reclaimed area, two 250- × 20-m plots were treated as follows: (1) amendment with 25 Mg/ha of PG every
2 to 3 years between 1979 and 2003 (plot PY); (2) like PY but PG treatment stopped after 1997 (plot DR). A contiguous virgin
Marisma salt-marsh plot (MV), neither drained nor amended, was the control. In MV, soil microbial biomass C, most enzyme activities
and total organic C content were much greater than in PY and DR soils, despite the salinity stress. The decrease in soil organic
matter content in PY and DR soils was likely due to cotton-cropping practices, which favoured the organic C mineralisation
and nutrients removal by crops. Microbial activity of MV soil, probably stimulated by the rhizodepositions of the natural
vegetation, did not suffer from the osmotic effect due to the raising of soil solution ionic strength. Microbial quotient
could be ranked as MV > PY > DR, whereas the metabolic quotient had an opposite trend. Thus, both quotients suggested that
the interruption of PG amendment was not favouring microbial activity. Principal component analysis clearly identified the
chemical and biochemical soil properties mostly affected by the reclamation and also indicated the longer PG amendment in
PY plot. Stepwise discriminant analysis identified two physiologically different types of soil microflora, one less active
present in the MV virgin soil and another more active present in the reclaimed PY and DR soils. 相似文献
156.
Remo Bucci Andrea D Magrí Antonio L Magrí Domenico Marini Federico Marini 《Journal of agricultural and food chemistry》2002,50(3):413-418
This work has focused on discriminating extra virgin olive oils from Sabina (Lazio, Italy) by olive fruit variety (cultivar). A set of oils from five of the most widespread cultivars (Carboncella, Frantoio, Leccino, Moraiolo, and Pendolino) in this geographical area was analyzed for chemical composition using only the Official Analytical Methods, recognized for the quality control and commercial classification of this product. The obtained data set was converted into a computer-compatible format, and principal component analysis (PCA) and a method based on the Fisher F ratio were used to reduce the number of variables without a significant loss of chemical information. Then, to differentiate these samples, two supervised chemometric procedures were applied to process the experimental data: linear discriminant analysis (LDA) and artificial neural network (ANN) using the back-propagation algorithm. It was found that both of these techniques were able to generalize and correctly predict all of the samples in the test set. However, these results were obtained using 10 variables for LDA and 6 (the major fatty acid percentages, determined by a single gas chromatogram) for ANN, which, in this case, appears to provide a better prediction ability and a simpler chemical analysis. Finally, it is pointed out that, to achieve the correct authentication of all samples, the selected training set must be representative of the whole data set. 相似文献
157.
da Silva Ferreira AC Barbe JC Bertrand A 《Journal of agricultural and food chemistry》2002,50(9):2560-2564
In Port wine, isomers of glycerol and acetaldehyde acetals have been found at total contents ranging from 9.4 to 175.3 mg/L. During oxidative aging, the concentrations of the 5-hydroxy-2-methyl-1,3-dioxane and 4-hydroxymethyl-2-methyl-1,3-dioxolane isomers increased with time showing a linear correlation (r > 0.95). The flavor threshold for the mixture of the four isomers was evaluated in wine at 100 mg/L. Thus, it is expected that they contribute to "old Port wine" aroma in wines older than 30 years. Experiments with model solutions and wine clearly demonstrated that SO(2) combines with acetaldehyde and blocks the acetalization reaction. 相似文献
158.
Romero C Brenes M García P Garrido A 《Journal of agricultural and food chemistry》2002,50(13):3835-3839
There is increasing interest in olive polyphenols because of their biological properties as well as their contribution to the color, taste, and shelf life of olive products. However, some of these compounds remain unidentified. It has been shown that hydroxytyrosol 4-beta-D-glucoside (4-beta-D-glucosyl-3-hydroxyphenylethanol) coeluted with hydroxytyrosol [(3,4-dihydroxyphenyl)ethanol] under reversed phase conditions in the phenolic chromatograms of olive pulp, vegetation water, and pomace of olive oil processing. A method to separate this compound from hydroxytyrosol by HPLC has been developed. The concentration of this glucoside increased in olive pulp with maturation and could be the main phenolic compound in mature olives. In contrast, the presence of this compound was not detected in olive oil by using HPLC-MS. The compound must be considered both in table olives and olive oil processing because of its glucose and hydroxytyrosol contribution to these products. 相似文献
159.
Capasso R De Martino A Cristinzio G 《Journal of agricultural and food chemistry》2002,50(14):4018-4024
The dark polymeric organic fraction rich in potassium recovered from olive oil mill waste waters (OMWW) and named polymerin and the potassium salified deglycosylated polymerin derivative (K-SDpolymerin) were easily transformed into their metal derivatives by saturation with various metals, including Na, Cu, Zn, Mn, Fe, and Al. Saturated metal polymerins were characterized by diffuse reflectance infrared Fourier transform spectroscopy and atomic absorption spectrometry. Tests on tomato plants of the various polymerins showed that only the soluble polymerin, K-SDpolymerin, and the insoluble Mn-SDpolymerin were significantly toxic. The toxic effects of OMWW on tomato at the original concentration and diluted 1:10 were much stronger than those of any polymerin. The possible exploitation of polymerins as bioamendments and/or metal biointegrators as a functon of their phytotoxic effects, their humic acid-like nature, and their richness in macro- and micronutrient metals is also discussed. 相似文献
160.
Paulo Sergio Pavinato Alexandre Merlin Ciro Antonio Rosolem 《Soil & Tillage Research》2009,105(1):149-155
No-tillage systems lead to physical, chemical and biological changes in soil. Soil fertility is responsive to changes in tillage as it depends on nutrient status, soil water content and biological characteristics. This work aimed to determine long term changes in phosphorus forms and availability in the profile of two tropical soils under conventional and no-till systems, and to discuss the significance of these changes on plant growth and demand for P fertilizers. Undisturbed soil cores with 20 cm in diameter were collected to a depth of 40 cm, accommodated in PVC tubes and taken to a greenhouse, where the experiment was conducted. Two soils were collected in Central Brazil, in areas under Cerrado. Both soils had been cropped for at least 10 years under conventional tillage and no-till. In the greenhouse, pots received phosphorus fertilization or not at 43.7 kg ha−1, and soybean was grown for 60 days, when soil P fractions were determined. Labile P fractions in the soil profile were not affected by management systems, and there was no accumulation of available P under no-till. A large amount of P added as fertilizer was adsorbed in soil and remained in moderately labile fractions, mainly on uppermost soil layers. Therefore, the phosphate fertilizer has promoted P accumulation on less available fractions in soil, remaining P on the soil after crop harvest. Eventually this phosphorus could migrate to more labile fractions and be available for crops grown in succession. 相似文献