Three Naphthoquinones from Streptomyces sp. XZYN-4

Two new naphthoquinones, named 12-hydroxy-naphthgeranine A (1) and isonaphthgeranine C (2) together with naphthgeranine A (3), were isolated from the cultures of Stereospermum’s rhizosphere strain Streptomyces sp. XZYN-4. Their structure were established on the basis of 1D, 2D-NMR experiments and HR QTOF MS. The absolute configurations of C-12 (12R ) in both (1) and (2) are different from those reported in naphthgeranine family. C ompounds 1 and 3 showed moderate activity against Aspergillus niger ACCC30005 by disk diffusion test at a dose of 20 m g/disk.