Search results for "amina"

Pd-catalyzed amination in the synthesis of cyclen-based macrotricycles

2012

Abstract Three approaches to three types of cyclen-based macrotricycles have been elaborated starting from trans-bis(3-bromobenzyl)cyclen. The macrotricycles were synthesized via Pd-catalyzed amination. The first approach employed consecutive macrocyclization and benzylation steps giving a cage-like tricycle. In the second, cyclen amino groups were Boc-protected prior to formation of the second and the third rings. In the third method, macrotricycles were synthesized according to a one-step procedure using diazacrown ethers.

ChemInform Abstract: Gold-Catalyzed Intramolecular Hydroamination of o-Alkynylbenzyl Carbamates: A Route to Chiral Fluorinated Isoindoline and Isoqui…

2013

Title compounds are prepared in enantiomerically pure form by the diastereoselective addition of fluorinated nucleophiles to N-(tert-butanesulfinyl)imines (I) followed by a sequence of Sonogashira cross-coupling/gold(I)-catalyzed cycloisomerization of the corresponding carbamate.

Effect of pulsed electric field on Maillard reaction and hydroxymethylfurfural production

2020

Abstract As an emerging nonthermal processing technology, the application of pulsed electric field (PEF) has received increasing attention not only for its capability to inactivate enzymes and microorganisms or to enhance mass transfer during the extraction process but also for its potential to inhibit the formation of chemical contaminants during processing, such as the formation of hydroxymethylfurfural (HMF). HMF is a potential carcinogen to humans that can be produced via the Maillard reaction (MR). Compared with thermal treatment, PEF can minimize the extent of MR, reducing the contents of HMF. However, in some cases, MR and HMR may be promoted, closely associated with PEF conditions a…

Efficient and stereodivergent electrochemical synthesis of optically pure menthylamines.

2011

Zur Frage des Verhaltens der Glutamins�ure-Brenztraubens�ure-Transaminase im Blut-und Hautblasenserum bei Ekzem und bull�sen Dermatosen

1959

Vergleichende Untersuchungen der Glutaminsaure-Brenztraubensaure-Transaminase im Blutserum und dem Serum von Spontan-und Cantharidinblasen zeigten Aktivitatsunterschiede, die keinen Zusammenhang mit dem jeweiligen Hautprozes erkennen lassen. Die in Blut und Hautblasenflussigkeits oftmals nur wenig differenten Enzymaktivitaten dieser Aminopherase sprechen eher gegen als fur die Annahme ihrer Entstehung in menschlicher Epidermis.

Editorial: Mechanism of mycotoxins.

2018

Fungal Contaminants and Mycotoxins in Nuts

2021

Contamination by fungi and mycotoxins in nuts has achieved much attention in recent years. In fact, the fungal metabolites produced by the species of Aspergillus, Penicillium (aflatoxins and ochratoxins), Fusarium (trichothecenes, zearalenones and fumonisins) and Alternaria (alternariotoxins) with toxic and/or carcinogenic effects are considered a threat to human and animal health. In this chapter we will discuss the main fungal taxa and related mycotoxins most frequently associated with these materials. In this regard, the first results on the level of contamination by fungi and mycotoxins in samples of almonds and pistachios of different origins will be reported. The main strategies to re…

Intake, decontamination and legislation of fumonisins in foods

2004

Fumonisins (FB) are mycotoxins synthesized mainly by different species of the genus Fusarium with different toxicological effects in humans and animals and associated to esophageal cancer in different countries. This review gives an overview about the intake of fumosins from foods with a careful attention for people with gluten intolerance, celiac or Duhring's disease, infants and alcohol consumers. Furthermore, a section on decontamination is focused on physical, chemical and biological methods. Finally, the legislation of fumonisins in foods in different countries is reviewed.

Effect of Cd-containing wood ash on the microflora of coniferous forest humus

2000

The use of wood ash in forestry has been questioned because the cadmium (Cd) concentration of ash, which varies between 1 and 20 mg kg(-1) ash, exceeds the level allowed for fertilizers (3 mg kg(-1)) used in agriculture. To investigate the combined and separated effects of Cd and ash on the forest humus microflora, pumice or wood ash, spiked with a water-soluble (CdCl(2)) or -insoluble (CdO) form of Cd at three levels (0, 400 and 1000 mg kg(-1)), were applied at a fertilization level of 5000 kg ha(-1) in a laboratory microcosm study. The trial consisted of 60 microcosms (five replications per treatment), which were incubated in darkness at +20 degrees C and a constant relative air humidity …

Platinum in indoor settled dust matter (homes and cars)

2015

Abstract This paper presents a method for Pt analysis in indoor (homes and cars) settled dust, used as passive samplers, and the results relative to samples collected in the Sicilian area are used to evaluate the magnitude and distribution of concentrations inside common environments and the possible origins of the considered contaminant. The concentrations of platinum in settled indoor dust were measured by differential pulsed voltammetry (DPV). Concentrations of Pt in homes are in the range from 30 to 1460 μg kg − 1 d.w. while, in the vehicles from 30 to 1750 μg kg − 1 d.w. Considering the geoaccumulation index (I geo ), 42% of the settled dust sampled in homes could be classified as extr…