RESUMO
Three new triterpenoid alkaloids, namely buxmicrophyllines P-R (1-3), were isolated from the twigs and leaves of Buxus microphylla. Their structures were elucidated on the basis of NMR and MS spectroscopic analyses. Structurally, compounds 1-3 belong to the 9,10-cycloartane type alkaloids. In addition, compound 3 exhibited moderate cytotoxic activities in vitro against HL-60, SMMC-7221, A-549, MCF-7, and SW480 cell lines (with IC50 values ranging from 4.51 to 15.58 µM).
Assuntos
Alcaloides , Antineoplásicos Fitogênicos , Buxus/química , Citotoxinas , Triterpenos , Células A549 , Alcaloides/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Citotoxinas/química , Citotoxinas/isolamento & purificação , Citotoxinas/farmacologia , Células HL-60 , Humanos , Células MCF-7 , Triterpenos/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologiaRESUMO
Seven undescribed 3,4-secolanostane triterpenoids, daldiconoids A-G (1-7), were isolated from the fruiting bodies of Daldinia concentrica. Daldiconoid A (1) was a highly modified 4,6,28,29-tetranorlanostane triterpenoid alkaloid featuring an unusual δ-lactam fused with a flanking cyclopentenone architecture. Their structures were determined by spectroscopic data, NMR calculations coupled with the DP4+ analysis, X-ray single-crystal diffraction, and chemical transformation. The plausible biosynthetic pathway for 1 was proposed. Compounds 1, 2, and 4-6 inhibited the expressions of IL-1ß, IL-6, and TNF-α in lipopolysaccharide stimulated RAW264.7 cells at a concentration of 10 µM. Mechanistically, Compounds 1 and 2 blocked the JAK2/STAT3 signaling pathway induced by lipopolysaccharide.