Acyl quinic acid derivatives from the stems of Erycibe obtusifolia

Eleven new acyl quinic acid derivatives, 4-O-caffeoyl-3-O-syringoylquinic acid methyl ester (1), 4-O-caffeoyl-3-O-vanilloylquinic acid (2), 4-O-caffeoyl-3-O-vanilloylquinic acid methyl ester (3), 5-O-caffeoyl-3-O-vanilloylquinic acid (4), 5-O-caffeoyl-3-O-vanilloylquinic acid methyl ester (5), 5-O-caffeoyl-3-O-sinapoylquinic acid (6), 5-O-caffeoyl-4-O-vanilloylquinic acid (7), 4-O-(7‴S, 8‴R)-glycosmisoyl-5-O-caffeoylquinic acid methyl ester (8), 4-O-(7‴S, 8‴R)-glycosmisoyl-5-O-caffeoylquinic acid (9), 3-O-(7‴S, 8‴R)-glycosmisoyl-4-O-caffeoylquinic acid (10), and 3-O-(7‴S, 8‴R)-glycosmisoyl-4-O-caffeoylquinic acid methyl ester (11), have been isolated from the stems of Erycibe obtusifolia together with eight known compounds (12–19). Their structures were elucidated on the basis of spectroscopic data analysis (UV, IR, HRESIMS, CD, and 1D and 2D NMR) and chemical evidence. In in vitro assay, compounds 7 and 16–18 exhibited significant neuroprotective effects against rotenone induced PC12 cell damage at 10 μM.

Graphical abstractAcyl quinic acid derivatives from the stems of Erycibe obtusifolia.Figure optionsDownload full-size imageDownload high-quality image (144 K)Download as PowerPoint slide