A new biflavonol glycoside, quercetin-3-
O-β-D-glucopyranoside-(3¢→
O-3¢¢¢)- quercetin-3-
O-β-D-galactopyranoside (
9), together with eight known compounds was isolated for the first time from the leaves of
Machilus zuihoensis Hayata (Lauraceae). The structure of compound
9 was elucidated by various
[...] Read more.
A new biflavonol glycoside, quercetin-3-
O-β-D-glucopyranoside-(3¢→
O-3¢¢¢)- quercetin-3-
O-β-D-galactopyranoside (
9), together with eight known compounds was isolated for the first time from the leaves of
Machilus zuihoensis Hayata (Lauraceae). The structure of compound
9 was elucidated by various types of spectroscopic data analysis. Analysis of the biological activity assay found that compound
9 showed significant superoxide anion scavenging activity (IC
50 is 30.4 μM) and markedly suppressed LPS-induced high mobility group box 1 (HMGB-1) protein secretion in RAW264.7 cells. In addition, the HMGB-1 protein secretion was also inhibited by quercitrin (
3), ethyl caffeate (
6), and ethyl 3-
O-caffeoylquinate (
7) treatment. In the LPS-stimulated inducible nitric oxide synthase (
iNOS) activation analysis, two known compounds, quercetin (
1) and ethyl caffeate (
6), were found to markedly suppress nitric oxide (NO) production (IC
50 value, 27.6 and 42.9 μM, respectively) in RAW264.7 cells. Additionally, it was determined that ethyl caffeate (
6) down-regulated mRNA expressions of
iNOS, IL-1β, and IL-10 in the LPS-treatment of RAW264.7 cells via a suppressed NF-kB pathway. These results suggested for the first time that the new compound
9 and other constituents isolated from
M. zuihoensis have potential anti-inflammatory and superoxide anion scavenging effects. These constituents may be useful for treating various inflammatory diseases.
Full article