1,721,662 research outputs found
Acaricides of natural origin. Part 2. Review of the literature (2002-2006)
No full textAcari are responsible for millions of dollars worth of damage each year as a result of infestations of animals, plants and man. They directly affect our health and prosperity as animal and plant parasites, vectors of disease, and producers of allergens. The indiscriminate use of pesticides has quickly induced resistance in many parasites. At present, the control of acarid parasitic diseases in agriculture, human and veterinary medicine is mainly based on the use of drugs; and for this reason the lack of effective drugs often prevents the control of some parasitic diseases, making them more serious and important. The use of commercial drugs involves many problems, besides the drug-resistance shown by the most important parasites. Environmental damage and the toxicity of many synthetic drugs, represent the main problems that strongly limit drug use. In addition, drug residues in plant and animal food products are important reasons for further economic losses for farmers and must be regarded as potentially hazardous to man and the environment. Plant-derived compounds are generally more easily degradable and could show a smaller negative environmental impact with respect to synthetic drugs. For these reasons, the evaluation of the antiacarid activity of plant extracts is increasingly being investigated in order to obtain new leads, as demonstrated by recent studies that have evaluated and confirmed the effectiveness of many plant compounds on bacteria, fungi, protozoa, helminths and arthropods. This review will be limited to the class Arachnida, sub-class Acaridi, particularly to their control in agriculture, veterinary and human medicine using natural method
Pollination strategies: the point of view of plants-Personal experiences and review of the literature
No full textPollinators provide an essential service to both natural and agricultural ecosystems. More than 80% of crop production, that is the majority of fruit, vegetable, oil plant, protein plant, nut and spices depend on insect pollination. It is known that the color of a flower is the first and foremost cue for pollinator's attraction, but the scent of a flower also plays a major role in attracting pollinating insects. Other plants, such as some orchids, use deceptive pollination methods producing hormonal-like substances.
Studies of floral scents and of their patterns within a single flower are important to better understand the chemical bases of plant-animal relationships and pollination ecology. Furthermore, they may reveal new scented molecules that could be of value to both the food industry and perfumery.
Besides volatiles, also nutrients may be used by plants as a reward for pollination services. Sugars, amino acids and secondary metabolites are contained in nectar, a liquid secretion produced by dedicated structures within the flower and highly appreciated by insects and other pollinators
Flavonoids and Other Compounds from the Aerial Parts of Viola etrusca
No full textThe non-volatile constituents of the rare species Viola etrusca Erben (Violaceae), collected at Mount Amiata, Italy, were phytochemically investigated for the first time. Two new flavonoid glycosides, 4'-methoxyrhamnetin (1) and violetruscoside (2), an isorhamnetin derivative, were isolated from the flowering aerial parts, together with eleven known substances, including eight flavonoids, a phenolic acid, glycerin, and a coumarin derivative. The NMR data of violanthin (10) and isoviolanthin (11) are reported for the first tim
Headspace analyses in valuable and functional foods: application of SPME in the quality control and characterization of olive oils
No full textVirgin olive oil, obtained from Olea europaea L. (Oleaceae) fruits, is an important ingredient in the Mediterranean diet. There is now overwhelming scientific evidence that it has health benefits; that include reduction of risk factors for coronary heart disease and the prevention of several pathologies, including some types of cancer. Olive oil appears to be an example of a functional food with a high content of volatiles that contribute to its palatability. However, because of its high added value, it is often adulterated with less valuable oils. Many analytical techniques have been developed to validate the authenticity of the oil. Among them, SPME seems to be one of the more promising approaches, as demonstrated by the many published studies. Being a solvent-free sample preparation technique, its implementation is fast and simple and couples well with GC-MS and HPLC systems. These validation techniques are very important considering the strict regulations imposed by the USA and the EU. Finally, it can be helpful in geographical certification, giving consumers the assurance that the goods come from an area where a given quality, reputation, or other characteristics of the goods is essentially attributable to their geographical origi
Iris lutescens on serpentine soil: volatile emission profiles in different organs of its two colour morphs
Full text linkIris lutescens is a rhizomatous species of the Iridaceae family, generally found in the dry areas of the Mediterranean basin. It is characterised by large flowers, exhibiting a colour polymorphism in two varieties (yellow and purple). Even though it can grow on calcareous soils, it is reported as a serpentine-preferential taxon. In this work, the volatile emission in the headspaces of flowers, leaves and rhizomes of specimens of both the colour morphs growing on an ultramafic garigue have been analysed. The flower and rhizome headspaces had greater overall similarities compared to the leaves; flowers were the organs for which the volatile emission differed the most between the two colour morphs. Moreover, a comparison with a published headspace composition ofI. lutescens yellow and purple flowers growing on calcareous soil evidenced quali-quantitative differences, as well as a greater differentiation of the volatile organic compounds emitted by the two colour morphs growing in a serpentine environment. To the best of our knowledge, this is the first report on the volatile emission of different organs of I. lutescens specimens growing on serpentine soil
Wild Harenna coffee: flavor profiling from the cherry to the cup
No full textCoffee is one of the world’s most popular beverages, representing a major source of
income for many producing countries. The typical aroma is certainly the reason of its
success: it depends on the coffee variety, with its specific set of chemical precursors, as well
as on the processing and consumption phases [1]. In the Harenna Forest, in the Bale National
Park of Ethiopia, at an altitude of around 1800 meters, an Arabica wild coffee grows
spontaneously: the Harenna Forest Wild Coffee Presidium recognizes the value of this
unique and high quality product, which has been bestowed the Slow Food Presidium in
2012. It is naturally dried in loco and its exports volumes are limited, as its availability is
greatly variable.
The aroma of coffee is a complex bouquet of odorants of different origin: the
evaluation of its composition could be used as a tool for the coffee industry to control
desirable flavor outcomes of coffee through processing or other farm management technique.
In this perspective, the Head-Space analysis could represent a simple, fast and accurate
technique to evaluate the development of flavor-active compounds in all the phases of the
coffee production.
In the present study, the volatile aroma profile of Harenna wild coffee has been
analysed by means of HS-SPME-GC/MS from the coffee cherry to the coffee cup, all
throughout the processing phases which lead to the final product. The dried green cherries,
rich in monoterpenes (especially dihydro myrcenol and limonene), esters (mainly cis-2-tertbutyl-
cyclohexanol acetate), alkanes, and phenylpropanoids, also contain the precursors for
the aroma compounds formation through the Maillard reaction, which takes place during the
roasting phase. Pyrazines (mainly 2,6-dimethylpyrazine, 2-ethyl-6-methylpyrazine, and
2,3,5-trimethyl pyrazine) begin to be detected at 100 °C, to become the most abundant
chemical class on the later roasting phases, when the temperature reaches 160, 180, and 204
°C, the final roasting temperature.
Pyridines (mostly pyridine) are also developed during the roasting phase: they are only
detected in the samples roasted over the temperature of 160 °C. Furans (mostly 2-furan
methanol, 5-methyl furfural and furfuryl acetate) are also developed through thermal
treatment, while monoterpenes decrement as they are volatilized very soon in the roasting
process. This is also confirmed by their detection in the coffee silverskins, for which the
volatiles emission profile is similar to the green cherries one: they retain the early-released
volatiles as they are soon separated from the cherries in the roaster
Natural Herbicides as a Safer and More Environmentally Friendly Approach to Weed Control: A Review of the Literature Since 2000
No full textNon presente nel capitol
Cap. 7 ""Screening Fitochimico"; Cap. 8 "Isolamento dei costituenti degli estratti"; Cap. 9 "Identificazione dei costituenti secondari"
No full textAcaricides of natural origin, personal experiences and review of literature (1990-2001)
No full textAcari are responsible for millions of dollars worth of damages each year as a result of infestations in animals, plants and man. They affect our health directly and prosperity as animal and plant parasites, vectors of disease, and producers of allergens. The indiscriminate use of pesticides has destroyed many of their natural enemies of hitherto harmless species and quickly induced resistance in many parasites. At present, the control of acarid parasitic diseases in agriculture, human and veterinary medicine is mainly based on the use of drugs; for this reason the lack of effective drugs often prevents the control of some parasitic diseases, making them more serious and important. The use of commercial drugs involves many problems; besides the drug-resistance shown by the most important parasites, the environmental damage and the toxicity of many synthetic drugs, represent the main problems that strongly limit their use. In addition, drug residues in plant and animal food products are important reasons for further economic losses for farmers and must be regarded as potentially hazardous to man and environment. Plant-derived compounds are generally more easily degradable and could show a smaller negative environmental impact with respect to synthetic drugs. For these reasons, the evaluation of the antiacarid activity of plant extracts is increasingly being investigated in order to obtain new leads, as demonstrated by recent studies that have evaluated and confirmed the effectiveness of many plant compounds on bacteria, fungi, protozoa, helmints and arthropods. This review will be limited to the class Arachnida, sub-class Acaridi, particularly to their control in agriculture, veterinary and human medicine with natural method
Seasonal variation of the chemical consituents of the essential oil of Santolina etrusca from Italy
No full textThe seasonal variation of the essential oil, in terms of both yield and composition, of a population of Santolina etrusca (Asteraceae) is reported in detail for different aerial parts, including sterile branches, fertile branches, and capitula. The yields generally increased from November to June, and then decreased in August and September. The main constituents of the sterile branches were 1,8-cineole and viridiflorol. The oil from fertile branches was characterized by myrcene as principal compound, whereas the essential oil obtained from the capitula contained germacrene D as the main constituent. Several compounds, identified by GC and GC/MS, were found to prevail during the cold seaso
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