Search results for "leave"
showing 10 items of 372 documents
An Au(iii)–amino alcohol complex for degradation of organophosphorus pesticides
2015
An Au(III)–amino alcohol complex has been used to cleave organophosphorous pesticides of the dithiophosphate family. P–S bond breaking was readily demonstrated by 1H NMR, 31P NMR and MS. Thiol fragment release was also demonstrated using 2,4-dinitrobenzenesulfonyl fluorescein ethyl ester as a fluorescent sensor.
Green extraction approach for the recovery of polyphenols from Croatian olive leaves (Olea europea)
2017
Abstract Pressurized liquid extraction (PLE) is shown as an innovative green technology for the effective extraction of the various phytochemicals from food by-products, therefore the aims of this study were to evaluate the application of PLE to engineer green extracts of Croatian olive leaves ( Olea europaea , cv. Oblica) for potential industrial production (functional foods/pharmaceuticals). PLE was conducted under various cycle numbers (1, 2), temperature (60, 80, 100 °C) and static times (5, 10, 15 min). Obtained extracts were characterized in terms of: (i) total polyphenols (TP); (ii) total flavonoids (TF); hydroxycinnamic acids (HCA); and (iv) flavonols (FLA). Response surface methodo…
Application of pressurized fluid extraction to determine cadmium and zinc in plants
2006
Abstract A procedure for the determination of Cd and Zn in plants is proposed. The metals are extracted by pressurized fluid extraction (PFE). Operational conditions are: pressure 1500 psi, temperature 75 °C, static time 5 min, flush volume 35%, purge time 60 s, cycles 1 and 1,2-diaminocyclohexane- N , N , N ′, N ′-tetraacetic acid (CDTA) 0.01 M at pH 4.5 as extracting solution. Determination of Zn is carried out by flame atomic absorption spectroscopy and depending on the concentration level, Cd content is determined by flame or electrothermal atomic absorption spectroscopy. Certified samples of Virginia tobacco leaves, tea leaves, spinach leaves, poplar leaves, a commercial spinach sample…
Chlorophyll content in senescent Pelargonium graveolens leaves
2019
Pelargonium graveolens należy do rodziny Geraniaceae. Roślina ta jest aromatycznym, owłosionym krzewem, sięgającym 1,2 metra wysokości i osiągającym 1 m szerokości. Jej liście są mocno powcinane, miękkie w dotyku i wydzielają intensywny zapach, natomiast kwiaty są małe, zwykle różowe, zebrane w baldachy. Ojczyzną P. graveolens jest Afryka Południowa, ale uprawia się ją obecnie w wielu krajach świata, np. wyspie Reunion, Egipcie, Rosji, Chinach czy Maroko, głównie z przeznaczeniem na produkcję olejku eterycznego. Wykorzystywany jest on w wielu gałęziach przemysłu, m.in. perfumiarstwie, kosmetyce, przemyśle spożywczym czy medycynie. Dane literaturowe pokazują, że o kondycji całej rośliny świa…
Combined dynamics of the 500–600 nm leaf absorption and chlorophyll fluorescence changes in vivo: Evidence for the multifunctional energy quenching r…
2021
Carotenoids (Cars) regulate the energy flow towards the reaction centres in a versatile way whereby the switch between energy harvesting and dissipation is strongly modulated by the operation of the xanthophyll cycles. However, the cascade of molecular mechanisms during the change from light harvesting to energy dissipation remains spectrally poorly understood. By characterizing the in vivo absorbance changes (Delta A) of leaves from four species in the 500-600 nm range through a Gaussian decomposition, while measuring passively simultaneous Chla fluorescence (F) changes, we present a direct observation of the quick antenna adjustments during a 3-min dark-to-high-light induction. Underlying…
Heritable Epichloë symbiosis shapes fungal but not bacterial communities of plant leaves
2019
Keystone microbial species have driven eco-evolutionary processes since the origin of life. However, due to our inability to detect the majority of microbiota, members of diverse microbial communities of fungi, bacteria and viruses have largely been ignored as keystone species in past literature. Here we tested whether heritable Epichloë species of pooidae grasses modulate microbiota of their shared host plant. peerReviewed
Classification of olive leaves and pulp extracts by comprehensive two-dimensional liquid chromatography of polyphenolic fingerprints.
2019
Abstract The development of a new comprehensive two-dimensional liquid chromatographic method is described, to obtain the profiles of polyphenolic compounds present in olive (Olea europaea L.) leaves and pulps from different genetic origin. Optimisation of the stationary phase nature, particle size, column length and internal diameter, as well as other separation conditions, was performed. Along the study, three stationary phases (C18, PFP and phenyl) in the first dimension (1D), and five (C18, amide, cyano, phenyl and PFP) in the second dimension (2D) were combined to obtain the maximal number of resolved peaks. The optimised method successfully characterised the presence of 26 and 29 comm…
Phenol Profiling and Nutraceutical Potential of
2019
In recent years, agricultural and industrial residues have attracted a lot of interest in the recovery of phytochemicals used in the food, pharmaceutical, and cosmetic industries. In this paper, a study on the recovery of phenol compounds from Lycium spp. leaves is presented. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been used with alcoholic and hydroalcoholic solvents. Methanolic UAE was the most successful technique for extracting phenols from Lycium leaves, and we used on leaves from L. barbarum and L. chinense cultivated in Italy. The extracts were then characterized as regards to the antioxidant properties by in vitro assays and the phenol profil…
Characterisation of Pythium paroecandrum and its antagonism towards Botrytis cinerea, the causative agent of grey mould disease of grape.
2004
Pythium paroecandrum (B-30), an oomycete, was isolated from soil samples taken from a wheat field in Genlis in the Burgundy region of France and was found to check the growth and development of Botrytis cinerea, a serious grapevine pathogen. The oomycete is a fast-growing organism, living on vegetable debris, and can be recognised by its catenulate hyphal swellings, catenulate oogonia, and monoclinous antheridia. When grown together with B. cinerea, the causal agent of the grey mould disease of the grapevine, P. paroecandrum shows a pronounced antagonism and suppresses its growth and its aptitude to provoke the grey mould symptoms. Morphological features of this oomycete, its antagonism to …
Chemical variability in the essential oil of Cinnamomum tamala L. leaves from India.
2011
The chemical composition of the essential oils obtained from the fresh leaves of Cinnamomum tamala Nees et Eberm. was determined by GC and GC–MS. The yield of the oil on a dry weight basis ranged from 1.2% to 3.9% (w/w). Phenyl propanoids constitute the major portion (88.9–95.0%) of the oils. Fifty-four compounds were identified from the oils. Eugenol (91.4–41.8%) was the main compound, followed by eugenyl acetate (0.0–47.1%) and α-phellandrene (0.6–2.5%) in the analysed oils.