Phytochemical Study of Eryngium cymosum F. Delaroche and the Inhibitory Capacity of Its Main Compounds on Two Glucose-Producing Pathway Enzymes.

One undescribed acylated flavonol glucoside and five known compounds were isolated from the aerial parts of Eryngium cymosum F. Delaroche, a plant that is used in traditional Mexican medicine to treat type 2 diabetes. The chemical structures of the isolated compounds were elucidated using a variety of spectroscopic techniques, including 1D and 2D nuclear magnetic resonance (NMR) and mass spectrometry (MS). Chlorogenic acid ( 1 ), rosmarinic acid ( 2 ), caffeic acid ( 3 ), protocatechuic acid ( 4 ), kaempferol-3- O -(2,6- di - O - trans - ρ -coumaryl)- β -d-glucopyranoside ( 5 ), and the new acylated flavonol glucoside quercetin-3- O -(2,6- di - O - trans - ρ -coumaryl)- β -d-glucopyranoside ( 6 ) were isolated. This is the first report on the natural occurrence of quercetin-3- O -(2,6- di - O - trans - ρ -coumaryl)- β -D-glucopyranoside ( 6 ). In addition, according to the HPLC profile obtained for the water extract (WE), chlorogenic acid ( 1 ) and rosmarinic acid ( 2 ) were identified as the main compounds, while kaempferol-3- O -(2,6- di - O - trans - ρ -coumaryl)- β -d-glucopyranoside ( 5 ) were the main compound in the butanolic extract. We demonstrate the important role of compound 5 over the inhibition of G6Pase and FBPase. The isolated compounds may play an important role in the hypoglycemic effect of the extract and may act in a synergic way, but more experiments are needed to corroborate these findings.