2-methyl-L-erythritol glycosides from Gardenia jasminoides.

Two new glycosides, 2-methyl-L-erythritol-4-O-(6-O-trans-sinapoyl)-β-D-glucopyranoside (1) and 2-methyl-L-erythritol-1-O-(6-O-trans-sinapoyl)-β-D-glucopyranoside (2), along with two known triterpenoids (3-4), four quinic acid derivatives (5-8) and one flavonoid (9) were isolated from the fruit of Gardenia jasminoides. Their structures were elucidated through MS and 2D NMR experiments (HMQC and HMBC). Inhibitory effects of the isolated compounds on nitric oxide production in lipopolysaccharide-activated macrophages were evaluated. Though 2-methyl-D-erythritol and its glycosides have been reported in a few references, this is the first report about 2-methyl-L-erythritol glycosides. Based on this finding, we propose that 2-methyl-L-erythritol might be a new intermediate in the non-mevalonate biosynthesis of terpenoids.