RESUMO
Two eudesmane sesquiterpene lactones, wedetrilides B (1) and C (2), along with five known analogues (3 - 8), an ent-kaurane diterpenoid (9), a steroid (10), as well as cinnamic acid derivatives (11 - 13), were isolated from the flowers of Wedelia trilobata. Their structures were elucidated on the basis of extensive spectroscopic analyses and by comparison of their NMR data with those of related compounds. Furthermore, the structures of 1 and 3 - 5 were confirmed by X-ray single-crystal diffraction analyses. Compounds 4 and 5 exhibited weak cytotoxic activities against the MCF-7, HeLa, and A549 cell lines. Compounds 3 - 5 were also evaluated for their inhibitory effects against HIV lytic replication.
Assuntos
Fármacos Anti-HIV/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Flores/química , HIV/efeitos dos fármacos , Sesquiterpenos/farmacologia , Wedelia/química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacosRESUMO
A pair of epimers of flavonoid alkaloids, with a pyrrolidone moiety, 2S,5''R-eupodoratin A (1), 2S,5''S-eupodoratin A (2), together with two known analogues, drahebephin A (3), drahebephin B (4), were isolated from the flowers of Chromolaena odorata (L.) R.M.King & H.Rob. Their structures were elucidated on the basis of HR-ESI-MS, 1D/2D NMR spectral analyses. The absolute configuration of compounds (1) and (2) was determined by its experimental and calculated electronic circular dichroism (ECD) spectra. All compounds were isolated from the Asteraceae family for the first time. The ABTS·+ scavenging activity of compound (4) reached 93.56% at a concentration of 0.5 mM, while the scavenging capacity of positive control Trolox was 55.94%. In addition, all compounds show moderate antimicrobial activity against Escherichia coli (ATCC, 337304), Staphylococcus aureus (ATCC, 337371) and Candida albicans (ATCC, 186382) with a MIC value of more than 50 µg/mL.
RESUMO
Chemical investigations of the flowers of Praxelis clematidea resulted in the isolation of 12 known compounds (1-12). Their structures were elucidated by extensive spectroscopic studies and chemical evidence. The structure and absolute configuration of 1 was precisely determined by a combination of 2 D NMR and quantum chemical calculations of ECD spectra analysis. Compounds 1, 4, 11 were isolated from the genus Praxelis for the first time, while 1-6, 8-12 were isolated from P. clematidea for the first time. The antibacterial activity of compounds 1, 2, 7, 9 were evaluated.