Studies on the Constituents of Orchidaceous Plants. V. : Isolation, Structure, and C-13 Signal Assignments of Novel Methylsterols from Nervilia purpurea SCHLECHTER

Abstract

Four new methylsterols, cyclonervilasterol, 24-epicyclonervilasterol, dihydrocyclonervilasterol, and 24-epihihydrocyclonervilasterol, were isolated from the methylsterol fraction of Nervilia purpurea SCHLECHTER by reversed-phase high-performance liquid chromatography. The structures 2a, 3a, 5a, and 6a were proposed for these compounds, respectively, based on chemical evidence and two-dimensional nuclear magnetic resonance spectroscopy including INADEQUATE (Incredible Natural Abandance Double Quantum Transfer Experiment).