Giovanni Dinelli

Selective extraction, separation, and identification of anthocyanins from Hibiscus sabdariffa L. using solid phase extraction-capillary electrophoresis-mass spectrometry (time-of-flight /ion trap).

A method for selective extraction using SPE, electrophoretic separation at basic condition and the identification by using exact masses and fragmentation patterns has been developed in order to know the anthocyanins in dried calyces of Hibiscus sabdariffa L. A detailed and comparative study of several extraction procedures has been carried out to obtain the maximum number of anthocyanidins from the calyces and then a CE‐TOF‐MS method in positive mode using ESI has been developed for the separation and rapid identification of anthocyanins in H. sabdariffa L. Delphinidin‐3‐sambubioside, cyanidin‐3‐sambubioside have been detected as main components and cyanidin‐3‐O‐rutinoside, delphinidin‐3‐O‐glucoside and cyanidin‐3,5‐diglucoside, and chlorogenic acid as minor constituents. The confirmation of the anthocyanidins and chlorogenic acid was carried out using fragmentation ions with the IT‐mass spectrometer (IT‐MS).

Glyphosate-Resistant Hairy Fleabane (Conyza bonariensis) in Spain

Forty-three Spanish populations of hairy fleabane, sampled from perennial crop locations, were studied under controlled and field conditions to confirm and characterize glyphosate resistance. In the initial screening, under controlled conditions, significant differences in glyphosate response between locations and among plant progenies within location were observed. From the initial screening, six populations (five potentially resistant [R] and one susceptible [S]) were selected, and a dose–response experiment was conducted to determine the resistance factor. The resistance factor was close to 10× for the most resistant population. In addition, the glyphosate response of R and S populations was dependant on phenological stages: the glyphosate rate required for control increased as a function of plant age. Finally, the resistance was confirmed with field trials conducted in five locations (one S and four R previously studied under controlled conditions). The field trials were also used to find alternative solutions for Spanish farmers to control resistant hairy fleabane populations. Nomenclature: Flazasulfuron; fluroxypyr; glyphosate; glufosinate; hairy fleabane, Conyza bonariensis (L.) Cronq. ERIBO.

Evaluation of Bt-toxin uptake by the non-target herbivore, Myzus persicae (Hemiptera: Aphididae), feeding on transgenic oilseed rape.

As consequence of the concern about the biosafety of genetically modified plants, biological and ecological studies are considered crucial for environmental risk assessment. Laboratory experiments were carried out in order to evaluate the transfer of the Cry1Ac Bt-toxin from a transgenic Bt-oilseed rape to a non-target pest, Myzus persicae Sulzer. Cry1Ac protein levels in plants and aphids were determined using a double sandwich enzyme-linked immunosorbent assay. Phloem sap from (Bt+) and (Bt-) oilseed rape plants was collected from leaves using a standard method of extraction in an EDTA buffer. Bt-toxin was present in phloem sap, with a mean concentration of 2.7 +/- 1.46 ppb, corresponding to a 24-fold lower level than in oilseed rape leaves. Toxin was also detected in aphid samples, with a mean concentration in the positive samples of 2.0 +/- 0.8 ppb. The evidence that Bt-toxin remains in herbivores, in this case an aphid, could be useful to clarify functional aspects linked to possible consequences of Bt-crops on food chains involving herbivore-natural enemy trophic systems. Further studies are needed in order to improve the knowledge on the functional aspects linked to the transfer of the Cry1Ac Bt-toxin from GM-oilseed rape to aphids and their possible consequence.

Urinary excretion of kaempferol from common beans (Phaseolus vulgaris L.) in humans.

The aim of this study was to assess kaempferol bioavailability in healthy humans, after bean (Phaseolus vulgaris L.) consumption through the monitoring of the excretion in relation to intake. In seven healthy subjects receiving kaempferol from cooked bean, maximum excretion of hydrolysed flavonol was obtained after 2–8 h. Intersexual variations in urinary excretion were found to be 6.10±5.50% and 5.40±5.40% of the kaempferol dose for male and female subjects, respectively. Although a 6.72-fold inter-individual variation between the highest and lowest excretion concentrations was found, all individuals exhibited similar excretion profiles. Moreover, a direct correlation between the percentage of kaempferol excreted and the body mass index of volunteers was observed with a correlation index equal to 0.80. All except two individuals exhibited a first peak of kaempferol excretion 2 h after ingestion. The study reveals information about inter-individual excretion capacity after kaempferol intake and that kaempferol can be used as a biomarker for flavonol consumption.