Selaginellin C, a new natural pigment from Selaginella pulvinata Maxim (Hook et Grev.)

A novel compound, selaginellin C (1), was isolated from Selaginella pulvinata Maxim (Hook et Grev.) as (R,S)-4-((1,2-dihydroxyethyl)-2',4'-dihydroxy-3-((4-hydroxyphenyl)ethynyl)biphenyl-2-yl)((4-hydroxyphenyl)methylene)cyclohexa-2,5-dienone, along with two known compounds, selaginellin (2) and selaginellin A (3). The structure of the new compound was elucidated on the basis of 1D and 2D NMR as well as HR-ESI-MS spectroscopic analysis.