Cephaeline is a pyridoisoquinoline comprising emetam having a hydroxy group at the 6'-position and methoxy substituents at the 7'-, 10- and 11-positions. It is a conjugate base of a cephaeline(2+). It derives from a hydride of an emetan. Cephaeline was highly active against protected primary CLL cells (relative IC50's 35 nM ) and acted by repressing HIF-1α and disturbing intracellular redox homeostasis.