RESUMEN
Adipose tissue is essential for whole-body glucose homeostasis, with a primary role in lipid storage. It has been previously observed that lactate production is also an important metabolic feature of adipocytes, but its relationship to adipose and whole-body glucose disposal remains unclear. Therefore, using a combination of metabolic labeling techniques, here we closely examined lactate production of cultured and primary mammalian adipocytes. Insulin treatment increased glucose uptake and conversion to lactate, with the latter responding more to insulin than did other metabolic fates of glucose. However, lactate production did not just serve as a mechanism to dispose of excess glucose, because we also observed that lactate production in adipocytes did not solely depend on glucose availability and even occurred independently of glucose metabolism. This suggests that lactate production is prioritized in adipocytes. Furthermore, knocking down lactate dehydrogenase specifically in the fat body of Drosophila flies lowered circulating lactate and improved whole-body glucose disposal. These results emphasize that lactate production is an additional metabolic role of adipose tissue beyond lipid storage and release.
Asunto(s)
Adipocitos/metabolismo , Homeostasis , Ácido Láctico/biosíntesis , Células 3T3 , Animales , Células Cultivadas , Drosophila , Cuerpo Adiposo/metabolismo , Glucosa/metabolismo , Insulina/metabolismo , Ácido Láctico/metabolismo , Masculino , Ratones , Ratas , Ratas Sprague-DawleyRESUMEN
Allylic sulfones were synthesized with excellent selectivity and good yield via Pd-catalyzed cross-coupling of vinyl iodide with N-tosylhydrazone. This process involves palladium carbene migratory insertion/trapping with sulfinic acid salts. For the previous Pd-catalyzed N-tosylhydrazone cross-coupling, sulfinic acid salt is generated as a byproduct. In this transformation, the diazo compound and the sulfinic acid salt, which are all generated from N-tosylhydrazone, were used as cross-coupling partner.
RESUMEN
An iodine-promoted one-pot radical cyclization reaction of 1,6-enynes with sulfonyl hydrazides to provide five-membered and hexatomic ring sulfonylated products under the same conditions is established. This reaction proceeded smoothly in water and gave the corresponding products by using I2/TBHP instead of expensive and toxic catalysts with C-S and C-I bond formed in one step. This method also allowed easy access to significant functional sulfones for potential applications in medicinal and organic chemistry.
RESUMEN
A straightforward method for the synthesis of highly functionalized vinylarenes through palladium-catalyzed, norbornene-mediated C-H activation/carbene migratory insertion is described. Extension to a one-pot procedure is also developed. Furthermore, this method can also be used to generate polysubstituted bicyclic molecules. The reaction proceeds under mild conditions to give the products in satisfactory yields using readily available starting materials. This is a Catellani-Lautens reaction that incorporates different types of coupling partners. Additionally, this reaction is the first to demonstrate the possibility of combining Pd-catalyzed insertion of diazo compounds and Pd-catalyzed C-H activation.
RESUMEN
A convenient zinc-promoted [4+3] cycloaddition of a carbonyl ene-yne with simple dienes was first achieved. This reaction provided an efficient strategy to prepare various cyclohepta[b]furan rings by cascade cycloadditions. Additionally, a multicomponent reaction of dione, alkynal, and diene was also reported, which exhibited a novel strategy for selective creations of C-O bonds and C-C bonds.
Asunto(s)
Furanos/síntesis química , Compuestos Heterocíclicos/síntesis química , Zinc/química , Catálisis , Reacción de Cicloadición , Furanos/química , Compuestos Heterocíclicos/químicaRESUMEN
Without extra addition of sulfinate salt, allylic sulfones were synthesized by palladium-catalyzed cross-coupling of aryl iodide with N-tosylhydrazone. In this transformation, not only the diazo compound but also the sulfinate salt, which were both generated in situ from base-mediated decomposition of the N-tosylhydrazone, was used as nucleophilic partner.
Asunto(s)
Compuestos Alílicos/síntesis química , Hidrazonas/química , Paladio/química , Sulfonas/síntesis química , Compuestos de Tosilo/química , Compuestos Alílicos/química , Catálisis , Sulfonas/químicaRESUMEN
ortho-Aminated vinylarene derivatives were obtained via a reaction of aryl iodides, N-benzoyloxyamines, and N-tosylhydrazones. This approach involves a palladium-catalyzed, norbornene-mediated ortho-amination/N-tosylhydrazone insertion reaction. In this transformation, one C-N bond and one C-C bond are formed and an amine group is introduced at the ortho position successfully.
RESUMEN
A palladium-catalyzed C-H allylation of electron-deficient polyfluoroarenes with gem-difluorinated cyclopropanes is reported. It provides a useful and facile approach to 2-fluoroallylic polyfluoroarenes in moderate to excellent yields with high Z-selectivity. In addition, this new approach has good functional group compatibility and broad substrate scope.
RESUMEN
PURPOSE: To evaluate the features of parotid neoplasms on real-time elastosonography. METHODS: The elastograms of parotid lesions in 43 patients with 48 neoplasms were analyzed and classified into 5 grades, with pathologic diagnosis as the gold standard for comparision. The data was statistically analyzed with SPSS13.0 software package. RESULTS: The elastographic grades of most benign neoplasms were I-II, while those of malignancies were III-IV. The elastographic grades of benign and malignant lesions were of significant difference (P<0.05). CONCLUSIONS: Some typical features of different parotid lesions on elastosonography are found, which are useful for differential diagnosis of parotid lesions.
Asunto(s)
Diagnóstico por Imagen de Elasticidad , Neoplasias de la Parótida/patología , Diagnóstico Diferencial , Humanos , Glándula Parótida , Neoplasias de la Parótida/diagnósticoRESUMEN
A facile access to 4-((trifluoromethyl)thio)-2,3-dihydrofurans from unprotected homopropargylic alcohols in high regioselectivity is reported. This method is the first example of using a free hydroxy group as a nucleophile to complete a trifluoromethylthiolation/cyclization protocol with an alkyne in moderate to excellent yields.
Asunto(s)
Alquinos/química , Amidas/química , Compuestos de Anilina/química , Furanos/química , Propanoles/química , Sulfuros/química , Catálisis , EstereoisomerismoRESUMEN
A novel method of a palladium-catalyzed/norbornene-mediated intramolecular C-H activation/N-tosylhydrazones insertion reaction is developed. In this process, various bicyclic or tricyclic substituted vinylarenes are obtained with high efficiency under mild conditions.
RESUMEN
A silver-promoted oxidative cyclization of 1,6-enynes with disubstituted phosphine oxides is developed for the synthesis of fluorene derivatives. The reaction proceeds with high regioselectivity by constructing one C-P bond and two C-C bonds in one step. Moreover, reduction of the pentavalent phosphine enlarges the application scope of the product.
Asunto(s)
Alquinos/química , Fluorenos/síntesis química , Fosfinas/química , Plata/química , Catálisis , Ciclización , Fluorenos/química , Estructura Molecular , Oxidación-Reducción , EstereoisomerismoRESUMEN
A new and efficient metal-free cascade cyclization of 1,6-enynes with aldehydes is developed for the synthesis of tricyclic fluorene derivatives. The reaction involves a radical process and one C(sp(2))-C(sp(2)) and two C(sp(2))-C(sp(3)) bonds are formed simultaneously in one pot by using PivOH and TBHP.
Asunto(s)
Aldehídos/química , Alquenos/química , Alquinos/química , Fluorenos/síntesis química , Ciclización , Fluorenos/química , Radicales Libres/químicaRESUMEN
A Pd-catalyzed three-component cross-coupling reaction of vinyl iodide, N-tosylhydrazone, and carbon nucleophiles is reported, and a one-pot procedure is also developed. The cross-coupling is proposed to proceed through a palladium-carbene migratory insertion, carbopalladation other than classic palladium-carbene migratory insertion, and ß-H elimination. Moreover, the reaction proceeds under mild conditions and with high stereoselectivity.
RESUMEN
Isoindolines are synthesized by palladium-catalyzed coupling reaction of N-(2-iodobenzyl) anilines with α,ß-unsaturated N-tosylhydrazones. The reaction has several potential advantages: (1) toleration of a wide range of functional groups, (2) easy to handle and with mild conditions, (3) enriches the isoindoline family, (4) two new bonds form in one step.
Asunto(s)
Hidrazonas/química , Indoles/química , Paladio/química , Aldehídos/química , Compuestos de Anilina/química , Catálisis , Indoles/síntesis químicaRESUMEN
Palladium-catalyzed carbene migratory insertion-cyclization reactions were reported, delivering dihydronaphthalene and indene derivatives in moderate to good yields. A three-component cross-coupling was also developed. The reactions are easy to handle, under mild conditions and various functional groups are tolerated.
Asunto(s)
Carbono/química , Hidrazonas/química , Paladio/química , Compuestos de Tosilo/química , Catálisis , Indenos/química , Estructura Molecular , Naftalenos/químicaRESUMEN
Two different cyclic amino esters are synthesized by palladium-catalyzed cross-coupling reaction of diazoesters with N-substituted-2-iodoanilines. Aryldiazoacetates lead to cyclic α-amino esters with an α-quaternary carbon centre in the presence of CO. Additionally, arylvinyldiazoacetates afford cyclic α,ß-unsaturated γ-amino esters.