Compounds of Formula (A′), (B′), (C′), (D′), (E′), (A″), (B″), (C″), (D″), (E″), (G1), and (G2) are useful as therapeutics for treating a wide variety of conditions in a host such as a human, e.g., including but not limited to, conditions associated with angiogenesis and/or which are mediated by CDK8 and/or CDK19 kinase activity. Also provided are methods of modulating the β-catenin pathway, methods of modulating STAT1 activity, methods of modulating the TGFβ/BMP pathway, methods of modulating HIF-1-alpha activity in a cell, and methods of increasing BIM expression to induce apoptosis, using an effective amount of a compound of Formula (A′), (B′), (C′), (D′), (E′), (A″), (B″), (C″), (D″), (E″), (G1), or (G2).
