Chartspiroton, a Tetracyclic Spiro-naphthoquinone Derivative from a Medicinal Plant Endophytic Streptomyces.A novel 6/6/5/6 tetracyclic polyketide named chartspiroton (1) was isolated from a medicinal plant endophytic Streptomyces in Dendrobium officinale.  Chartspiroton features an unprecedented naphthoquinone derivative spiro-fused with a benzofuran lactone moiety. 
Chartspiroton
Chartspiroton, a Tetracyclic Spiro-naphthoquinone Derivative from a Medicinal Plant Endophytic Streptomyces.A novel 6/6/5/6 tetracyclic polyketide named chartspiroton (1) was isolated from a medicinal plant endophytic Streptomyces in Dendrobium officinale. 
Tetracyclic Spiro-naphthoquinone Derivative
Chartspiroton, a Tetracyclic Spiro-naphthoquinone Derivative from a Medicinal Plant Endophytic Streptomyces.A novel 6/6/5/6 tetracyclic polyketide named chartspiroton (1) was isolated from a medicinal plant endophytic Streptomyces in Dendrobium officinale. 
Streptomyces
Chartspiroton, a Tetracyclic Spiro-naphthoquinone Derivative from a Medicinal Plant Endophytic Streptomyces.A novel 6/6/5/6 tetracyclic polyketide named chartspiroton (1) was isolated from a medicinal plant endophytic Streptomyces in Dendrobium officinale. 
Dendrobium officinale
The complete structure assignment with absolute stereochemistry was elucidated through spectroscopic data, computational calculations, and single-crystal X-ray diffraction. 
spectroscopic data
The complete structure assignment with absolute stereochemistry was elucidated through spectroscopic data, computational calculations, and single-crystal X-ray diffraction. 
computational calculations
The complete structure assignment with absolute stereochemistry was elucidated through spectroscopic data, computational calculations, and single-crystal X-ray diffraction. 
single-crystal X-ray diffraction