THE ISOLATION AND STRUCTURE OF THE ARGUTONEA NEW BACTERIOSTATIC CONSTITUENT OF INCARVILLEA ARGUTA

Argutone——a new constituent having bacteriostatic and sedative activities was isolated from the foliage of the Incarvillea arguta (Royle) Royle. Its structure was evidenced by UV IR ¹H-NMR ¹³C-NMR MS and X-ray diffraction etc as 2-ethoxymethylene-3,5-dihydroxy-γ-pyrone. Both of pyrane ring and two side chain hydroxy groups (C₃-OH, C₅-OH) form a plane structure, and side chain -CH₂OCH₂CH₃ with folding form extends toward a vertical position from this plane. It has weak intra-molecular hydrogen bond and the molecules are held together by Van Der Waals force in the solid state.