Notolutesins A–J, Dolabrane-Type Diterpenoids from the Chinese Liverwort <i>Notoscyphus lutescens</i>

Abstract

Ten new dolabrane-type diterpenoids, notolutesins A–J (<b>1</b>–<b>10</b>), were isolated from the Chinese liverwort <i>Notoscyphus lutescens</i>, along with four known compounds. The structures of the new compounds were established on the basis of extensive spectroscopic data, and that of <b>1</b> was confirmed by single-crystal X-ray crystallography. The absolute configuration of <b>1</b> was determined by comparing its experimental and calculated electronic circular dichroism spectra. All of the isolates were evaluated for their cytotoxicity against a small panel of human cancer cell lines, and compound <b>1</b> exhibited an IC₅₀ value of 6.2 μM against the PC3 human prostate cancer cell line