Phytotoxic polyketides produced by <Emphasis Type="Italic">Phomopsis foeniculi</Emphasis>, a strain isolated from diseased Bulgarian fennel

Recently, a new fungal disease caused by Diaporthe angelicae (anamorph Phomopsis foeniculi) has been found with increasingly frequency on fennel (Foeniculum vulgare) in Bulgaria. Using a bioassay-guided isolation and purification procedure, different metabolites were isolated from the fungal culture filtrates. They were identified by spectroscopic methods as nectriapyrone, a pentaketide monoterpenoid, and altersolanols A and J and macrosporin, three octaketides anthracenones. Leaf puncture bioassay was applied on detached tomato leaves to prove the phytotoxic activity of the fractions and of pure compounds. Nectriapyrone and altersolanols A and J showed a modulated phytotoxicity, while macrosporin was not toxic. Altersolanol A was the most active compound.     

Activity of octylthiotrifluoropropan-2-one,a potent esterase inhibitor,on growth,development, and intraspecific communication in Spodoptera littoralis and Sesamia nonagrioides

A series of experiments were conducted to examine the effect of 3-octylthio-1,1,1-trifluoro-2-propanone (OTFP) on growth, development, and behavior of the cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae), and the corn stalk borer, Sesamia nonagrioides (Lepidoptera: Noctuidae). The chemical behaved as an oviposition deterrent and, when added to the diet of the second-instar larvae of both insects, reduced diet consumption and growth, pupation, and adult emergence. Treatment of 100-5000 ng of the compound on fourth-instar larvae for 3-24 h, however, did not produce significant differences in the amount of diet ingested. Our results suggest that the effect of OTFP is long-lasting and that the inhibitor is not fully detoxified by the detoxification enzymes of the digestive tract of the insects. In behavioral assays, adult males which had been treated with the chemical at the larval stage were less attracted to the pheromone source than regular untreated males. When Sp. littoralis untreated females were used as the attractant source, treated males also displayed significantly fewer contacts with the cage-containing females than untreated or solvent-treated males. In the presence of treated females, only 27% of treated males successfully completed the flight in comparison to animals responding to solvent-treated females (54.5%). By contrast, when Se. nonagrioides females, whether they had been subjected or not to the treatment, were used as the attractant source, males were similarly attracted to them regardless of whether they had been treated or not at the larval stage. Analyses of gland extracts of Sp. littoralis treated females showed no difference from control insects in the qualitative or quantitative composition of the pheromone blend. The results obtained, in combination with other results previously reported by us (Riba, M.; Sans, A.; Bau, P.; Grolleau, G.; Renou, M.; Guerrero, A. J. Chem. Ecol. 2001, 27, 1879-1897), provide new and relevant information about the possible utility of these chemicals in future studies directed to the development of new approaches for pest control.     

Multiresidue analysis of pesticides in soil by gas chromatography with nitrogen-phosphorus detection and gas chromatography mass spectrometry

A rapid multiresidue method for the simultaneous determination of 25 fungicides and insecticides in soil was developed. Soil samples are extracted by sonication with a water-acetonitrile mixture, and the pesticides are partitioned into dichloromethane. Final determination was made by gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Confirmation analysis of pesticides was carried out by GC-MS in the selected ion monitoring (SIM) mode. The identification of compounds was based on retention time and on comparison of the primary and secondary ions. The average recovery by the GC-NPD method obtained for these compounds varied from 68.5% to 112.1% with a relative standard deviation between 1.8% and 6.2%. The GC-NPD method presents good linearity over the range assayed 50-2000 microg/L, and the detection limit for the pesticides studied varied from 0.1 to 10.4 microg/kg. The proposed method was used to determine pesticide levels in soil samples from experimental greenhouse pepper cultivation.     

Lead dietary intake in a Spanish population (Canary Islands)

For most people diet is the main route of exposure to trace metals, so information about dietary intake is also important to assess risks to human health for these elements. The purpose of this study was to determine the levels of Pb in the foods and drinks of highest consumption in the authors' our community to estimate daily intakes of Pb for each of the seven Canary Islands. Four hundred and twenty samples were analyzed using GFAAS. The total Pb intake of the Canarian population is 72.8 microg/day, 29.12% (for a person of 70 kg body weight) of the provisional tolerable weekly intake limit of 25 microg/kg fixed by the FAO/WHO. The island that presents the highest lead intake is La Gomera, followed by Lanzarote, Tenerife, and Gran Canaria islands. These four islands present a lead dietary intake over the mean Pb intake for the whole archipelago. The islands with lower Pb intakes are La Palma and Fuerteventura, with intakes under 70 microg/day. These results have also been compared with the values found for other national and international communities.     

Preparation and promotion of fruit growth in kiwifruit of fluorinated N-phenyl-N'-1,2,3-thiadiazol-5-yl ureas

Seventeen phenyl-fluorinated analogues of thidiazuron [N-phenyl-N'-(1,2,3-thiadiazol-5-yl)urea, TDZ] have been prepared and characterized. The effects of each fluorinated urea on growth and quality of kiwifruits (Actinidia deliciosa) were evaluated by comparison with untreated (control) and TDZ-treated fruits. The results obtained showed a clear dependence of the growth-promoting activity of these fluorinated ureas on the pattern and degree of fluorine substitution in the phenyl ring. The most effective for promoting fruit growth was N-(2,3,5,6-tetrafluorophenyl)-N'-(1',2',3'-thiadiazol-5'-yl)urea at 25 ppm (at harvest, treated fruits were 58% heavier than untreated ones) followed by N-(3,5-difluorophenyl)-N'-(1',2',3'-thiadiazol-5'-yl)urea at 10 ppm (50%). Comparatively, TDZ-treated fruits were 31% (10 ppm) and 38% (25 ppm) heavier than untreated ones. The results also indicate that the effects of the more active phenyl-fluorinated ureas on some standard quality parameters of fruits, for example, percent of fruit dry matter content, soluble solids contents, total titratable acids, shape, and internal structure, are similar to those of TDZ. Quantitative structure-activity relationships have been derived for the fruit growth promoting activity of the phenyl-fluorinated analogues of TDZ.     

Quantitation of short-chain glycerol-bound compounds in thermoxidized and used frying oils. A monitoring study during thermoxidation of olive and sunflower oils

Major short-chain glycerol-bound compounds were investigated in olive oil (OO) and conventional sunflower oil (SO) during thermoxidation at 180 degrees C for 5, 10, and 15 h. These compounds included methyl heptanoate (C7:0), methyl octanoate (C8:0), methyl 8-oxo-octanoate (8-oxo-C8:0), methyl 9-oxononanoate (9-oxo-C9:0), dimethyl octanodiate (C8:0 diester), and dimethyl nonanodiate (C9:0 diester), which were analyzed by GC after derivatization of triacylglycerols to fatty acid methyl esters. An acceptable linear correlation (r = 0.967) was found between the total content of these compounds and the total content of polar compounds, suggesting that quantitation of the major short-chain glycerol-bound compounds provides a good indication of the total alteration level of oils heated at frying temperature. Samples with levels of polar compounds around 25% on oil showed total contents within 2-3 mg/g of oil. To determine the content of these compounds in used frying oils, 10 samples from restaurants and fried-food outlets in Spain were analyzed. Results showed total levels between 2.13 and 7.56 mg/g of oil in samples with contents of polar compounds ranging from 18.8 to 55.5% on oil. Samples with levels of polar compounds of approximately 25% showed total contents of the short-chain compounds similar to those found in the thermoxidized oils, that is, within 2-3 mg/g of oil.     

Adsorption of pesticides from water by functionalized organobentonites

Replacement of natural inorganic cations of clay minerals with organic cations has been proposed as a strategy to improve the adsorptive capacity of clay minerals for organic compounds, including pesticides. The organic cations most commonly used for this purpose have been quaternary ammonium ions containing alkyl or aryl chains without specific functional groups. In this work, we evaluated the ability of two bentonites (SWy-2 and SAz-1) exchanged with four natural organic cations containing diverse functional groups (L-carnitine, L-cysteine ethyl ester, L-cystine dimethyl ester, and thiamine) as adsorbents of pesticides varying in their chemical structures (simazine, hexazinone, triadimefon, alachlor, carbaryl, and imazethapyr). For comparison purposes, the adsorptive properties of two "classical" organobentonites, hexadecyltrimethylammonium- and phenyltrimethylammonium-exchanged bentonites, were also determined. Most organobentonites displayed higher affinity for the pesticides than the untreated bentonites, but the improvement in adsorption capacity varied depending on the characteristics of the pesticide and the interlayer organic cation. Triadimefon, carbaryl, and imazethapyr displayed the highest affinity for carnitine (K(f) = 229-2377)-, thiamine (K(f) = 83-354)-, and cystine (K(f) = 96-100)-treated bentonites, respectively, whereas alachlor was adsorbed similarly by all organobentonites. In general, pesticide adsorption-desorption hysteresis was greater for adsorbents with the highest adsorption capacities. The results demonstrate that selective modification of smectitic clay minerals with natural organic cations containing appropriate functional groups can be a useful strategy to improve their performance for the removal of specific pesticides from the environment.     

Extending applicability of the oxygen radical absorbance capacity (ORAC-fluorescein) assay

The ORAC-fluorescein (ORAC-FL) method recently validated using automatic liquid handling systems has now been adapted to manual handling and using a conventional fluorescence microplate reader. As calculated for Trolox, the precision of the method was <3.0, expressed as percent coefficient of variation. The accuracy of the method was <2.3, expressed as percent variation of the mean. The detection and quantification limits were those corresponding to 0.5- and 1-microM Trolox standard solutions, respectively. The method has been applied to 10 pure compounds (benzoic and cinnamic acids and aldehydes, flavonoids, and butylated hydroxyanisole), to 30 white, rose, and bottled- and oak-aged red wines, and to 7 commercial dietary antioxidant supplements. All samples exhibited a good linear response with concentration. As seen by other methodologies, the chemical structure of a compound determines its antioxidant activity (ORAC-FL value). Of particular interest were the results with oak-aged red wines from different vintages (1989-2002) that confirm influence of vintage, but not origin of the oak, in the antioxidant activity of wines from the same variety. Dietary antioxidant supplements presented a great variability (170-fold difference) in their antioxidant potency. This work proves applicability of the ORAC-FL assay in evaluating the antioxidant activity of diverse food samples.     

Food, youth and the Mediterranean diet in Spain. Development of KIDMED, Mediterranean Diet Quality Index in children and adolescents

OBJECTIVE: To evaluate dietary habits in Spanish children and adolescents based on a Mediterranean Diet Quality Index tool, which considers certain principles sustaining and challenging traditional healthy Mediterranean dietary patterns. DESIGN: Observational population-based cross-sectional study. A 16-item Mediterranean Diet Quality Index was included in data gathered for the EnKid study (in which two 24-hour recalls, a quantitative 169-item food-frequency questionnaire and a general questionnaire about socio-economic, demographic and lifestyle items were administered). SETTING: Spain. SUBJECTS: In total, 3850 children and youths aged 2-24 years residing in Spain. RESULTS: Of the sample, 4.2% showed very low KIDMED index results, 49.4% had intermediate values and 46.4% had high index results. Important geographical differences were seen, with subjects from the Northeast showing the most favourable outcomes (52% with elevated scores vs. 37.5% of those from the North). Lower percentages of high diet quality were observed in low socio-economic groups, compared with middle and upper income cohorts (42.8%, 47.6% and 54.9%, respectively). Large cities had more positive results and only slight variations were seen for gender and age. CONCLUSIONS: The KIDMED index, the first to evaluate the adequacy of Mediterranean dietary patterns in children and youth, confirms that this collective is undergoing important changes, which makes them a priority target for nutrition interventions. Results challenge certain commonly perceived notions tied to income level, population size and diet quality.