Search results for "Organo"

Room-Temperature Phosphorescence and Efficient Singlet Oxygen Production by Cyclometalated Pt(II) Complexes with Aromatic Alkynyl Ligands

2020

The synthesis of five novel cyclometalated platinum(II) compounds containing five different alkynyl-chromophores was achieved by the reaction of the previously synthesized Pt–Cl cyclometalated compound (1) with the corresponding RC≡CH by a Sonogashira reaction. It was observed that the spectral and photophysical characteristics of the cyclometalated platinum(II) complexes (Pt–Ar) are essentially associated with the platinum-cyclometalated unit. Room-temperature emission of the Pt–Ar complexes was attributed to phosphorescence in agreement with DFT calculations. Broad nanosecond (ns)-transient absorption spectra were observed with decays approximately identical to those obtained from the emi…

Thiourea-Catalyzed Domino Michael–Mannich [3+2] Cycloadditions: A Strategy for the Asymmetric Synthesis of 3,3′-Pyrrolidinyl-dispirooxindoles

2017

The asymmetric synthesis of trifluoromethylated 3,3′-pyrrolidinyl-dispirooxindole derivatives with four contiguous stereogenic centers, including two vicinal spiro-stereocenters, is described. Employing a bifunctional thiourea catalyst, a domino Michael–Mannich [3+2] cycloaddition occurs readily between isatin ketimines and isatin-derived enoates with good yields and very high stereoselectivities, providing a direct entry to the title compounds of potential medical value.

Organocatalytic Asymmetric Synthesis of 2,3′-Connected Bis-Indolinones by Mannich Reactions of N-Acetylindolin-3-ones with Isatin N-Boc Ketimines

2017

A highly diastereo- and enantioselective Mannich reaction of N-acetylindolin-3-ones with isatin N-Boc ketimines to form 2,3′-connected bis-indolinones is developed employing a low loading of a readily available bifunctional thiourea catalyst. The asymmetric synthesis connects two indolinones via a vic-diamine unit and generates two neighboring stereocenters.

Rigid Closed‐Cell PUR Foams Containing Polyols Derived from Renewable Resources: The Effect of Polymer Composition, Foam Density, and Organoclay Fill…

2017

Determination and Toxicology Studies of Quaternary Ammonium Salts in Solution after Organoclay Processing

2018

Organoclays have potential to be used as additives in various facade paints and other finishing materials. Such new innovative materials must be rigorously tested for them to have no impact on environment. Focus of this study was to develop HPLC – TOF/MS method for determining quaternary ammonium salts in various material washing solutions and to determine organoclay toxicity by performing acute toxicity test on Daphnia magna. From the obtained results, it was possible to conclude that organoclays can be safely used as additives in various materials with low or no impact on environment. We determined that organoclays are significantly less toxic then some quaternary ammonium salts on its ow…

Phosphinotripeptidic Inhibitors of Leucylaminopeptidases

2021

Phosphinate pseudopeptide are analogs of peptides containing phosphinate moiety in a place of the amide bond. Due to this, the organophosphorus fragment resembles the tetrahedral transition state of the amide bond hydrolysis. Additionally, it is also capable of coordinating metal ions, for example, zinc or magnesium ions. These two properties of phosphinate pseudopeptides make them an ideal candidate for metal-related protease inhibitors. This research investigates the influence of additional residue in the P2 position on the inhibitory properties of phosphinopeptides. The synthetic strategy is proposed, based on retrosynthetic analysis. The N-C-P bond formation in the desired compounds is …

The effects of meta-Topolin and benzyladenine on in vitro organogenesis from epicotyl cuttings of Troyer citrange (Citrus sinensis[L.] Osbeck ×Poncir…

2017

Citrus tristeza virus (CTV), worldwide considered as one of the worst disease affecting Citrus plants, produced great changes in citriculture, mainly because it made mandatory the turnover of the sensitive sour orange rootstock with virus resistant ones. Among them, Troyer citrange has become one of the most employed rootstocks, due to its CTV tolerance and to the positive characteristics induced to the scion fruit production. Unfortunately, in Italy, there is a scarcity of seed mother plants. Micropropagation can be a solution for this problem. Among the in vitro techniques allowing the production of good quality true-to-type plants, the regeneration from seedling epicotyl cuttings general…

Extending the Shelf Life of White Peach Fruit with 1-Methylcyclopropene and Aloe arborescens Edible Coating

2020

The maintenance of high-quality standards for prolonging the shelf life of fruit and preserving sensory and nutritional quality is a priority for horticultural products. The aim of this work is to test the effectiveness of a single treatment of edible coating based on Aloe arborescens (EC) and a combined treatment of 1-methylcycyclopropene (1-MCP) and edible coating to prolong the shelf life of &ldquo

Horticultural performance of 23 Sicilian olive genotypes in hedgerow systems: Vegetative growth, productive potential and oil quality

2017

Abstract The super high density (SHD) model is a new olive growing system characterized by earlier and higher yields, fully mechanized harvesting and reduced orchard management costs. Until recently all commercial SHD orchards were planted primarily with three varieties: ‘Arbequina’, ‘Arbosana’ and ‘Koroneiki’. To increase variety diversity, broaden available olive oil chemical and organoleptic profiles, and olive oils for marketing, minor local varieties should be evaluated for adaptability to the SHD system. This study compares multiple Sicilian native genotypes to the three current cultivars ‘Arbequina’, ‘Arbosana’ and ‘Koroneiki’. The cumulative fruit and oil production, trunk-cross sec…

2021

Although insect herbivores are known to evolve resistance to insecticides through multiple genetic mechanisms, resistance in individual species has been assumed to follow the same mechanism. While both mutations in the target site insensitivity and increased amplification are known to contribute to insecticide resistance, little is known about the degree to which geographic populations of the same species differ at the target site in a response to insecticides. We tested structural (e.g., mutation profiles) and regulatory (e.g., the gene expression of Ldace1 and Ldace2, AChE activity) differences between two populations (Vermont, USA and Belchow, Poland) of the Colorado potato beetle, Lepti…