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1.
Small ; : e2402696, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39152533

RESUMEN

Fluoride in drinking water has beneficial or harmful health effects depending on its concentration. This highlights the need for new low-cost and portable sensors capable of in situ monitoring of F- ions. Unfortunately, achieving high levels of water compatibility and fluoride specificity remains a challenge. Here, four new urea-based discrete sensors are prepared and characterized. The sensors containing anthracenyl- (5) and 9H-fluorenyl- (7) signaling units exhibit intense luminescent emissions in dimethyl sulfoxide, the former being particularly sensitive and selective to fluoride. In water, 5 displays a superior sensitivity (871 M-1) and a detection limit (8 µm) below international guidelines, albeit with cross-sensitivity to H2PO4‾. To enhance the performance, 5 and 7 are embedded into a fluoride-imprinted polymeric matrix to give solid-state sensors (5P and 7P, respectively). 5P shows good sensitivity (360 M-1) and specificity in water. Besides, it has a low detection limit (35 µm) and a response linear range (118-6300 µm) encompassing the limit established by the Environmental Protection Agency (211 µm). Furthermore, 5P also displays good reusability and adequate recovery values in real-sample testing (102 ± 2%), constituting the first example of a low-cost anion-imprinted polymeric probe tailored for the selective sensing of fluoride in aqueous samples.

2.
Org Lett ; 15(8): 1982-5, 2013 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-23597127

RESUMEN

Two types of trans-THF cores, present in acetogenins, have been synthesized by an intramolecular iodoetherification reaction. The starting alkenol was obtained in a few steps from a chiral cis-diol resulting from microbial oxidation of bromobenzene. The cyclization gave complete stereoselectivity for trans-THF cores with either (S,S) or (R,R) configurations at the THF chiral carbons.


Asunto(s)
Acetogeninas/síntesis química , Bromobencenos/química , Furanos/síntesis química , Acetogeninas/química , Alcoholes/química , Annonaceae/química , Ciclización , Furanos/química , Estructura Molecular , Oxidación-Reducción , Estereoisomerismo , Relación Estructura-Actividad
3.
Nat Prod Commun ; 7(9): 1215-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23074912

RESUMEN

The interactions were studied by FTIR and DSC of the terminal lactone of annonaceous acetogenins (ACGs) and synthetic analogues, such as THF, with POPC bilayers, as well as the toxic effect produced by these compounds on Spodoptera frugiperda larvae. The aim of this work was to find a relationship between ACG insecticidal properties and the specific sites of interaction with lipid membranes. ACGs interact to different extents with the phosphate of lipid membranes and differences in the antisymmetric stretching of the phosphate groups were found in the presence of water that indicate water loss and further hydrogen bonding.The ACG tested produced more than 70% larval mortality. Rolliniastatin-1 (3) proved to have the most toxic effects (100%) on early larval instars when incorporated in the larval diet at a dose of 100 microg per g of diet. Additionally, it produced a significant decrease in growth rate (GR) and consumption index (CI), and reduced the efficiency with which larvae converted ingested food into biomass (ECI). The destabilization that occurs in the membrane due to dehydration around the phosphate groups caused by interaction with ACGs and their synthetic analogues would account for ACGs' insecticidal action.


Asunto(s)
Acetogeninas/farmacología , Insecticidas/farmacología , Lípidos de la Membrana/química , Acetogeninas/química , Animales , Rastreo Diferencial de Calorimetría , Insecticidas/química , Espectroscopía Infrarroja por Transformada de Fourier , Spodoptera
5.
J Org Chem ; 73(15): 5776-85, 2008 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-18582114

RESUMEN

The 3-oxygenated-cis-dialkyl-2,5-substituted tetrahydrofuran system, present in several natural products, was prepared with good selectivity by acidic cyclization of 5-alkene-1,2,4-triol derivatives. The starting alkenol was obtained in few steps from a chiral cis-diol resulting from microbial oxidation of bromobenzene. The study of the cyclization allowed the rationalization of all experimental results by assuming a complete ionization at the allylic position and a model close to the one proposed by Labelle for homoallylic induction in five-membered ring closures.


Asunto(s)
Ciclohexenos/química , Furanos/síntesis química , Oxígeno/química , Ácidos/química , Alquenos/química , Alquilación , Ciclización , Furanos/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Estereoisomerismo
6.
Carbohydr Res ; 339(10): 1773-8, 2004 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-15220087

RESUMEN

epi-Inositol was synthesized in six steps in 40% overall yield from a bacterial bromobenzene metabolite. The chemoenzymatic route involved toluene dioxygenase oxidation, substrate-directed catalytic osmylation, m-CPBA epoxidation, radical debromination, and Amberlite-catalized hydrolysis. The route described is amenable to scaleup and could allow access to cis-inositol, and deoxy derivatives of epi-inositol.


Asunto(s)
Bromobencenos/química , Inositol/química , Oxigenasas/química , Catálisis , Cloroformo , Compuestos Epoxi/química , Hidrólisis , Inositol/síntesis química , Modelos Químicos , Oxígeno/metabolismo , Estereoisomerismo , Especificidad por Sustrato
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