Iridoid and phenylethanoid glycosides from the aerial part of Barleria lupulina

Abstract

Abstract A new iridoid glycoside, barlupulin C methyl ester (1), together with two known phenylethanoid glycosides (2 and 3) and three known simple phenolic glycosides (4-6) were isolated from the aerial parts of Barleria lupulina Lindl., Acanthaceae. The structure of the new compound (1) was elucidated through 1D and 2D NMR spectroscopic data, and HR-ESIMS. Interestingly, compound (1) has a formate group attached to the C-6 hydroxy group of the glucose unit. Compounds 2-6 were identified as poliumoside (2), decaffeoylacteoside (3), protocatechuic acid 4-O-β-glucoside (4), vanillic acid 4-O-β-glucoside (5), and leonuriside A (6) on the basis of NMR spectroscopic data analyses and comparison with those reported in the literature. Compounds 3-6 were isolated from B. lupulina for the first time.