RESUMO
A catalyst-free, additive-free, and eco-friendly method for synthesizing 1,2,4-triazolo[1,5-a]pyridines under microwave conditions has been established. This tandem reaction involves the use of enaminonitriles and benzohydrazides, a transamidation mechanism followed by nucleophilic addition with nitrile, and subsequent condensation to yield the target compound in a short reaction time. The methodology demonstrates a broad substrate scope and good functional group tolerance, resulting in the formation of products in good-to-excellent yields. Furthermore, the scale-up reaction and late-stage functionalization of triazolo pyridine further demonstrate its synthetic utility. A plausible reaction pathway, based on our findings, has been proposed.
RESUMO
The secondary metabolites from Hericium erinaceus are well-known to have neurotrophic and neuroprotective effects. Isohericerinol A (1), isolated by our colleagues from its fruiting parts has a strong ability to increase the nerve growth factor secretion in C6 glioma cells. The current work describes the total synthesis of 1 and its regioisomer 5 in a few steps. We present two different approaches to 1 and a regiodivergent approach for both 1 and 5 by utilizing easily accessible feedstocks. Interestingly, the natural product 1, regioisomer 5, and their intermediates exhibited potent neurotrophic activity in in vitro experimental systems. Thus, these synthetic strategies provide access to a systematic structure-activity relationship study of natural product 1.
Assuntos
Produtos Biológicos , Glioma , Fármacos Neuroprotetores , Produtos Biológicos/farmacologia , Humanos , Fármacos Neuroprotetores/farmacologiaRESUMO
Biologically important quinazolinones have been synthesized from 2-aminobenzamides and DMSO. The key feature of the reaction is the utilization of DMSO as a methine source for intramolecular oxidative annulation. The CNS depressant drug methaqualone has also been synthesized by our methodology. The present method involves the synthesis of quinazolinones with a broad substrate scope and a good yield.
RESUMO
A series of catechol and dioxolane analogs containing thiazole CGA derivatives have been synthesized and evaluated for their inhibitory activity against α-MSH. The inhibitory activity was improved by replacing an α,ß-unsaturated carbonyl of previously reported caffeamides with thiazole motif. Surprisingly, compound 7d, one of the derivatives of dioxolane analogs, displayed the most potent inhibitory activity with an IC50 of 0.90µM. Further studies on metabolic stability and bioactivation potential were also accomplished.
Assuntos
Ácido Clorogênico/química , Melaninas/metabolismo , Tiazóis/química , alfa-MSH/metabolismo , Animais , Catecóis/síntese química , Catecóis/química , Catecóis/metabolismo , Linhagem Celular Tumoral , Ácido Clorogênico/síntese química , Ácido Clorogênico/metabolismo , Humanos , Concentração Inibidora 50 , Fígado/metabolismo , Melaninas/antagonistas & inibidores , Camundongos , Microssomos Hepáticos/metabolismo , Relação Estrutura-Atividade , alfa-MSH/antagonistas & inibidoresRESUMO
We have disclosed our effort to develop caffeic acid derivatives as potent and non-toxic inhibitors of α-MSH-stimulated melanogenesis to treat pigmentation disorders and skin medication including a cosmetic skin-whitening agent. The SAR studies revealed that cyclohexyl ester and secondary amide derivatives of caffeic acid showed significant inhibitory activities.
Assuntos
Ácidos Cafeicos/farmacologia , Preparações Clareadoras de Pele/farmacologia , Pigmentação da Pele/efeitos dos fármacos , alfa-MSH/antagonistas & inibidores , Animais , Ácidos Cafeicos/síntese química , Ácidos Cafeicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Camundongos , Estrutura Molecular , Preparações Clareadoras de Pele/síntese química , Preparações Clareadoras de Pele/química , Relação Estrutura-Atividade , alfa-MSH/metabolismoRESUMO
In continuation of studies for α-MSH stimulated melanogenesis inhibitors, we have evaluated the design, synthesis, and activity of a new series of chlorogenic acid (CGA) analogues comprising pyridine, pyrimidine, and diacyl derivatives. Among nineteen synthesized compounds, most of them (fifteen) exhibited better inhibitions of melanin formation in B16 melanoma cells. The results illustrated that a pyridine analogue 6f and a diacyl derivative 13a of CGA showed superior inhibition profiles (IC50: 2.5 ± 0.7 µM and 1.1 ± 0.1 µM, respectively) of α-MSH activities than positive controls, kojic acid and arbutin (IC50: 54 ± 1.5 µM and 380 ± 9.5 µM, respectively). The SAR studies showed that both -CF3 and -Cl groups exhibited better inhibition at the meta position on benzylamine than their ortho and para positions. In addition, the stability of diacyl analogues of CGA in methanol monitored by HPLC for 28 days indicated the steric bulkiness of acyl substituents as a key factor in their stability.
RESUMO
A metal-free and efficient procedure for the synthesis of pyrrolo[1,2-a]quinoxalines, quinazolinones, and indolo[1,2-a]quinoxaline has been developed. The key features of our method include the in situ generation of aldehyde from α-hydroxy acid in the presence of TBHP (tert-butyl hydrogen peroxide), and further condensation with various amines, followed by intramolecular cyclization and subsequent oxidation to afford the corresponding quinoxalines, quinazolinones derivatives in moderate to high yields.