Rottlerin is a principal phenolic compound of the Kamala plant Mallotus philippinensis. It is a widely-used selective inhibitor of PKCδ (protein kinase Cδ). It also inhibits PKCα, PKCβ, PKCγ, PKCε, PKCη, PKCζ and eEF2K (CaMK III).

In HT1080 human fibrosarcoma cells, rottlerin induces apoptosis and autophagy via a PKCδ-independent pathway. When tested on HERG (human Ether-á-go-go) channels, rottlerin increased both step and tail HERG current by leftward shifting the voltage and dependence of HERG activation and slowing channel deactivation.

Rottlerin is an inhibitor of Chk2, MAPKAPK-2, Pim-3, PKCλ, PKCθ, Plk, PRAK, SRPK1 and an activator of AMPK and HERG. There have been a number of studies published with evidence against the role of Rotterlin as a specific PKCδ inhibitor.