Ascochlorin, an isoprenoid antibiotic, induces G1 arrest via downregulation of c-Myc in a p53-independent manner

► Ascochlorin, an isoprenoid antibiotic, induces G1 arrest in human cancer cells. ► Activation of p21WAF1/CIP1 by ascochlorin, a non-toxic anti-cancer agent, is dependent on c-Myc, and not p53. ► Ascochlorin inhibits the phosphorylation of pRB and represses E2F1 transcriptional activity.