Fig. 3. (a) Racemic 1, Λ-1 and Δ-1 (5 μM) disrupt the interaction of H-Ras-Myc and Raf-1-Flag in A498 cells as revealed by a pull-down assay. Protein complexes were immunoprecipitated by the Flag antibody and analyzed with the Myc antibody. (b) Effects of racemic 1, Λ-1 and Δ-1 (5 μM) on inhibiting the H-Ras-Flag and Raf-1-RBD-his PPI in A498 cells as determined by a pull-down assay. (c) Effects of racemic 1, Λ-1 and Δ-1 on inhibiting the H-Ras-Flag or Raf-1-CRD-HA PPIs in A498 cells as determined by the pull-down assay. Significantly different from control at *p < 0.05, **p < 0.005, and ***p < 0.001.