Neolignan and monoterpene glycoside from the seeds of Pharbitis nil

Phytochemical investigation of an EtOH extract of Pharbitis nil seeds (Convolvulaceae) resulted in the isolation and identification of a new neolignan, 7R,8S-threo-dihydroxydehydrodiconiferyl alcohol (1), and a new monoterpene glycoside, (3Z,7S)-7-hydroxy-3,7-dimethyl-3,8-octadienyl-β-D-glucopyranoside (2), together with a known compound, ethyl α-L-arabinofuranoside (3). The chemical structures of these compounds were unambiguously determined using physical data, HR-ESI–MS and spectroscopic evidence, including 1D and 2D NMR experiments. The anti-inflammatory activities of the isolates were evaluated by estimating the inhibition of nitric oxide (NO) production. Compounds 1 and 2 reduced NO levels in lipopolysaccharide (LPS)-stimulated murine microglial BV-2 cells. In addition, compound 2 showed weak cytotoxicity against the HCT-15 cell line with an IC₅₀ value of 28.6 μM.