A new unusual natural pigment from Selaginella sinensis and its noticeable physicochemical properties.
A new unusual pigment with a novel carbon framework named selaginellin (1) was isolated from the acetone extract of Selaginella sinensis, and its methoxy derivative (1a) was synthesized. Both selaginellin 1 and 1a are racemic compounds. The structure of selaginellin 1 was established as (R,S)-4-[(4'-hydroxy-4-(hydroxymethyl)-3-((4-hydroxyphenyl)ethynyl)biphenyl-2-yl)(4-hydroxyphenyl)methylene]-2,5-cyclohexadien-1-one and 1a as (R,S)-4-[(4'-methoxy-4-(methoxymethyl)-3-((4-methoxyphenyl)ethynyl)biphenyl-2-yl)(4-methoxyphenyl)methylene]-2,5-cyclohexadien-1-one by the analysis of one- and two-dimensional NMR data, HR-ESIMS, EI-MS, IR, UV, CD, and single-crystal X-ray experiments, and the mechanism of their color change according to different pH values and fluorescent properties was studied.
Zhang
Li-Ping
LP
State Key Laboratory of Applied Organic Chemistry (SKLAOC), Lanzhou University, Lanzhou 730000, People's Republic of China.
Liang
Yong-Min
YM
Wei
Xiu-Cheng
XC
Cheng
Dong-Liang
DL
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D010860:Pigments, Biological / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D032503:Selaginellaceae / Q000737:chemistry*
D010860:Pigments, Biological; D011084:Polycyclic Aromatic Hydrocarbons