Studying of chemical structure of lignins of Rhodiola rosea L. and Serratula coronata L. by 2D NMR-spectroscopy

Lignins of plants Rhodiola rosea L. and Serratula coronata L. are extracted for the first time. By the method of two-dimensional NMR-spectroscopy the general regularities of chemical structure are defined, it is shown that studied lignins are built of quaiacic, syringic and p-coumaric fragments connected, mainly, by ƒ- О-4 binding. Structural distinctions of lignins are established, in particular, it is shown that acetated groups and coumaric fragments in lignin of Rhodiola rosea L. are present only at ƒ-position of phenyl-propane units. It is established that coumarates and acetates of coniferyl and sinapic spirits can be predecessors of lignin of Rhodiola rosea L.