Hepatoprotective Lignan Glycosides from the Leaves and Stems of Symplocos cochinchinensis (Lour.) S. Moore.

Abstract

This study investigates Symplocos cochinchinensis (Lour.) S. Moore leaves and stems, commonly known as Symplocos, a plant indigenous to Asia renowned for its traditional use in holistic medicine. A comprehensive phytochemical analysis of S. cochinchinensis led to the isolation of two new lignans, namely symplolignans A and B (1 and 2) along with eleven known lignan glucosides: nortrachelogenin 4-O-β-D-glucopyranoside (3), nortracheloside (4), matairesinol 4-O-β-D-glucopyranoside (5), lariciresinol 4'-O-β-D-glucopyranoside (6), balanophonin 4-O-β-D-glucopyranoside (7), dehydrodiconiferyl alcohol 4-O-β-D-glucopyranoside (8), dehydrodiconiferyl alcohol γ'-O-β-D-glucopyranoside (9), 3-(β-D-glucopyranosyloxymethyl)-2-(4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-(2R,3S)-dihydrobenzofura (10), and pinoresinol 4'-O-β-D-glucopyranoside (11). Their chemical structures were elucidated using 1D- and 2D-NMR, mass spectrometry, and their spectroscopic data were compared with those reported in literatures. Furthermore, all compounds were evaluated for their hepatoprotective effects using the Resazurin reduction assay in HepG2 hepatocellular carcinoma cells. Compounds 1, 5, 7, and 8 exhibited notable hepatoprotective efficacy, with cell viability ranging from 105.0±2.6 to 109.2±3.3 at a concentration of 10 μM. This research highlights the therapeutic potential of these compounds and enhanced to the understanding of lignans and neolignans in liver cell proliferation.