New tannin-related compounds from Tagetes erecta

A mixture of two new anomers: 3,4-di-O-[syringate]-alpha-D-glucopyranose (1) and 3,4-di-O-[syringate]-beta-D-glucopyranose (2), together with syringic acid (3), were isolated from the alcohol extract of Tagetes erecta. The structures of these compounds were elucidated by various spectroscopic methods, including intensive 1D, 2D NMR and HR-ESI-MS studies. The structural assignment was further supported by HPLC-ESI-MS with compound 1 at t(R) = 3.22 min (m/z 538.9 [M-H](-)) and compound 2 at 3.25 min (m/z 538.9 [M-H](-)) in the mixture.