Rigenolides D–H, norsecoiridoid and secoiridoids from Gentiana rigescens Franch

Five new compounds, rigenolides D–H (1–5), were isolated from the aerial parts of Gentiana rigescens Franch. Their structures were assigned by detailed spectroscopic analyses and chemical conversions. Rigenolides D (1) and E (2) were elucidated to be a secoiridoid and a norsecoiridoid, respectively, possessing a dienone moiety in common. Rigenolides F–H (3–5) were assigned as acylated secoiridoid glucosides.