A racemic mixture of GSK3 inhibitor XV isomers; (R)-enantiomer inhibits GSK3α, GSK3β, and PIM-1 (IC50s = 0.35, 0.55, and 35 nM, respectively); the (R)-enantiomer disrupts development of the anterior and posterior termini in zebrafish embryos; (S)-enantiomer inhibits PIM-1, GSK3α, and GSK3β (IC50s = 3, 80, and 90 nM, respectively),