A new β-naphthalenecarboxylic acid biglycoside from Chirita longgangensis var. hongyao

To investigate the chemical constituents in the stems of Chirita longgangensis var. hongyao, methanol extract of the stems was subjected to column chromatography with various chromatographic techniques.  One new β-naphthalenecarboxylic acid biglycoside, 1, 4-dihydroxy-2-naphthalenecarboxylic acid methyl ester- 4-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (1) was isolated, along with two known compounds: isotaxiresinol 4-O-methyl ether (2) and (R)-7-hydroxy-α-dunnione (3).  Compound 2 was first obtained from Chirita genus and compound 3 was isolated from this plant for the first time.  All structures were elucidated on the basis of spectral and chemical evidence, and the NMR spectroscopic data of compound 2 was published for the first time.