Neurotrophic neolignans of Pinus koraiensis twigs.

Four undescribed neolignan analogs, together with eight known compounds, were isolated from the twigs of Pinus koraiensis (Korean pine). The chemical structure of the isolated compounds was determined through extensive spectroscopic analysis and chemical method. Their relative and absolute configurations were assigned through a well-established empirical rule and electronic circular dichroism (ECD) analysis, respectively. Four compounds (3 and 9 – 11) at 20 μM concentration showed significant neurotrophic effect by inducing nerve growth factor (NGF) secretion in C6 cells with the stimulation levels a range of 140.82 ± 4.62% to 160.04 ± 11.04%. Additionally, the result indicated that the glycosylation of neolignan led to an improvement in neurotrophic activity compared to their aglycone form. A compound (7) inhibited nitric oxide production with an IC 50 value of 31.74 μM in LPS-activated BV2 cells. Twelve neolignans, including four undescribed compounds, were isolated from the twigs of Pinus koraiensis and their neurotrophic and anti-inflammatory activities were assessed. [Display omitted] • Four undescribed neolignans were isolated from the twigs of Pinus koraiensis. • The chemical structures established by spectroscopic analysis. • The stereochemistry was elucidated through an empirical rule and ECD analysis. • Some isolates showed neurotrophic activity by inducing NGF secretion in C6 cells. [ABSTRACT FROM AUTHOR]