| abstract |
In one aspect, the present disclosure provides tubulysin analogs of the formula (I) wherein R 1 , R 2 , R 3 , R 4 , X 1 , X 2 , X 3 , and A 1 are as defined herein. In another aspect, the present disclosure also provides methods of preparing the compounds disclosed herein. In another aspect, the present disclosure also provides pharmaceutical compositions and methods of use of the compounds disclosed herein. |