β-Glucuronide-NB-bis[N (Me) -methyl ester]-MMAE

β-Glucuronide-NB-bis[N (Me) -methyl ester]-MMAE (compound 20), an auristatins-glucuronide conjugate, exhibits in vitro antiproliferative effects on cancer cells, both β-glucuronidase pretreated and untreated, with an IC50 range of 5.7 nM to 9.7 nM. Demonstrating powerful antitumor efficacy in an HCT-116 xenograft mouse model, this compound does not induce side effects [1].