Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Forensic Sci Int ; 303: 109932, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31473560

RESUMO

With the increasing prevalence of obesity, the use of counterfeit drugs for weight loss is widespread owing to their easy and rapid availability. Since counterfeit weight-loss drugs are not prepared under the rigorous standard of Good Manufacturing Practice (GMP), they pose a risk to public health and cause significant side effects. To counteract the risk posed by counterfeit drugs, we investigated counterfeit weight-loss drugs seized by the Incheon Customs Services using UHPLC-PDA. Five of 23 confiscated samples with distinctive pink-coloured coating contained levothyroxine, sennoside A and B, and phenolphthalein in amounts ranging from 0.03-132.40 mg/g. In addition, three unknown compounds in one of the adulterated samples containing phenolphthalein were structurally elucidated by several analytical techniques. Their accurate masses corresponded to molecular formula of C34H22O7, C34H20O6, and C20H12O3, respectively. These compounds were identified as impurities, possibly produced during the synthesis of phenolphthalein or by improper removal during purification. These impurities were detected for the first time in counterfeit drugs.


Assuntos
Fármacos Antiobesidade/química , Medicamentos Falsificados/química , Cromatografia Líquida de Alta Pressão , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular
2.
Org Lett ; 21(10): 3774-3779, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31062986

RESUMO

A convenient visible-light photoredox catalysis has been developed for the synthesis of thioesters from two readily available starting materials: acid chlorides and sodium sulfinates. The facile generation of acyl radical species under the visible light photoredox conditions allows the formation of thiyl radical species from sodium sulfinates via multiple single electron transfer reactions, where the final acyl radical-thiyl radical coupling has been accomplished. The direct radical-radical coupling strategy offers a mild and controlled photochemical approach to important synthetic building blocks such as thioesters.

3.
Org Lett ; 20(20): 6398-6402, 2018 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-30295489

RESUMO

A stereoselective protection-free asymmetric total synthesis of (+)-chamuvarinin (1), a potent anticancer and antitrypanosomal agent, has been accomplished. The adjacently linked [bis(tetrahydrofuran)]tetrahydropyran (THF-THF-THP) core of this natural product with seven stereogenic centers was constructed in a completely substrate-controlled fashion. The inter-ring stereochemistry ( threo,threo,threo) of the oxatricyclic core was established in a stereoselective fashion by a chelation-controlled Keck allylation, whereas the intraring cis or trans relative stereochemistry was controlled by a stereoselective internal alkylation.

4.
Org Lett ; 20(9): 2711-2715, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29672060

RESUMO

A direct acyl radical addition to 2 H-indazoles has been achieved for the first time, where the less-aromatic quinonoid 2 H-indazoles readily accepted radical species to the C-3 position. Motivated by the lack of direct acylation strategy for 2 H-indazoles, the current method utilizes the radical acceptability of 2 H-indazoles, discovering an ambient temperature reaction to provide facile access to a diverse array of 3-acyl-2 H-indazoles with three points of structural diversification in 25%-83% yields.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...