The present invention provides synthesis, pharmaceutically acceptable formulations and uses of compounds in accordance with Formula I or Formula II, or a stereoisomer, tautomer or pharmaceutically acceptable salt thereof. For Formula I compounds X1, X2, X3, X4, X5, Y1, Y2, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12 and R13 are as defined in the specification. The inventive Formula I and Formula II compounds are inhibitors of Mnk and find utility in any number of therapeutic applications, including but not limited to treatment of inflammation and various cancers.