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1.
Chem Commun (Camb) ; 60(11): 1416-1419, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38204402

RESUMO

An unprecedented palladium-catalysed fragmentary esterification-induced allylic alkylation (FEAA) of cyclic vinylogous anhydrides (CVAs) and allyl carbonates has been disclosed. The protocol features broad sp3-rich scaffold tolerance, rendering highly functionalized 1,6 and 1,7-dicarbonyls in up to high yields and diastereoselectivities. Three-component FEAA is also well tolerant to generate 1,6-dicarbonyls through the addition of extra O/N-nucleophiles. Furthermore, cyclic allyl carbonate-involved FEAA provides an efficient approach for the synthesis of structurally complex medium-sized rings.

2.
J Appl Toxicol ; 43(11): 1576-1593, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36806101

RESUMO

Microplastics (MPs) are plastic particles of a diameter of less than 5 mm and a major carrier of pollution. In accordance with its diameter range, MPs can be divided into microplastics (100-5 mm) and nanoplastics (<100 nm). In recent years, in addition to the impact of MPs on the environment, the ways in which MPs affect the body has also attracted continuous attention. However, relevant studies on the cytotoxicity of MPs are not comprehensive. Based on the current research, this paper summarizes four main cytotoxic mechanisms of MPs, inducing oxidative stress, damaging cell membrane organelles, inducing immune response, and genotoxicity. Generally, MPs cause cytotoxicity such as oxidative stress, damage to cell membranes and organelles, activation of immune responses, and genotoxicity through mechanical damage or induction of cells to produce reactive oxygen species. Understanding these toxic mechanisms is helpful for the evaluation and prevention of human toxicity of MPs. This paper also analyzes the limitations of current research and prospects for future research into cellular MPs, with the aim of providing a scientific basis and reference for further research into the toxic mechanism of MPs.

3.
Plant Physiol Biochem ; 149: 153-158, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32070908

RESUMO

This study investigated the tolerance of plants to vanadium (Ⅴ). The hydroponic method was employed to evaluate the absorption, transport, content, and subcellular distribution of vanadium in the polysaccharide fraction of corn seedlings cell wall under different concentrations of vanadium stress. Results showed that: (a) vanadium was mainly concentrated in the roots of the corn seedlings, and only trace amounts were transported to the leaves; (b) in terms of its subcellular distribution, vanadium was mainly enriched in cell wall regions followed by soluble fraction; (c) the content of vanadium in polysaccharide fraction was highest in alkali-soluble pectin, followed by chelated pectin (P < 0.05).


Assuntos
Parede Celular , Plântula , Vanádio , Zea mays , Parede Celular/química , Folhas de Planta , Raízes de Plantas , Polissacarídeos/química , Plântula/química , Plântula/metabolismo , Distribuição Tecidual , Vanádio/metabolismo , Zea mays/química , Zea mays/metabolismo
4.
Bull Environ Contam Toxicol ; 102(3): 425-431, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30683955

RESUMO

The heavy metal pollution in ecosystems is of increasing global concern. This study investigated firstly the responses of phytochelatins (PCs), glutathione (GSH) and other nonprotein thiols (NPT) in maize seedlings under vanadium (V), mercury (Hg) or their combined stress. With V or V-Hg combined stress, the contents of PCs, GSH and NPT in shoots and roots both increased with increasing the V stress level, and reached the maximum when the V stress level was 5 mg/L. Accumulation of V in all organs of maize seedlings was in sequence as follows: roots ≫ shoots, while Hg inhibited the accumulation of V. Results show that the root of plant has stronger tolerance to V, and the low V stress level can promote the synthesis of thiol groups to reduce the toxicity of Hg for plants.


Assuntos
Mercúrio/toxicidade , Poluentes do Solo/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Compostos de Sulfidrila/metabolismo , Vanádio/toxicidade , Zea mays/efeitos dos fármacos , Glutationa/metabolismo , Fitoquelatinas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo , Zea mays/metabolismo
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