(±)-Spiro-oxanthromicin A
(±)-Spiro-oxanthromicin A (Compound 4), a polyketide, is a K-Ras inhibitor with an IC50 of 26.7 μM. (±)-Spiro-oxanthromicin A can be isolated from soil-derived Streptomyces sp. (±)-Spiro-oxanthromicin A can mislocalize oncogenic mutant K-Ras from the plasma membrane of intact MDCK cells. (±)-Spiro-oxanthromicin A can be used for cancers research.