Abstract
Three new flavanols, (2R,3S)-7-methoxy-flavan-3-ol (1),
(2R,3S)-7-hydroxy-flavan-3-ol (2), and
(2R,3S)-2′-hydroxy-7-methoxy-flavan-3-ol (3), together
with two known flavans (4 and 5), were isolated from the
chloroform extract of Crinum asiaticum. Their structures were elucidated
by various spectroscopic methods, including 1D and 2D NMR, HR-ESI-MS, and CD
data. The isolated compounds 1 and 3−5 showed inhibitory
activity toward LPS-induced nitric oxide (NO) production. Further investigation
of the NF-κB pathway mechanisms indicated that 1 and
3−5 inhibited the LPS-induced IL-6 production and p65 subunit
phosphorylation of NF-κB in RAW264.7 cells, with an effective dose of
10 µM.
Key words
Crinum asiaticum
- flavans - flavanols - NO inhibition - NF-
κB pathway