Flavanols and Flavanes from Crinum asiaticum and Their Effects on LPS Signaling Pathway Through the Inhibition of NF-κB Activation.

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.