A new isoquinoline and ceramide from the stem barks of (Pax) Prain (Euphorbiaceae) with antiproteinase and cytotoxic activities.

Two new compounds, an isoquinoline () and caloneuramide (), a ceramide were isolated from the stem bark of together with seven known compounds namely aurantiamide acetate (), acetylaleuritolic acid (), 3-hydroxylaleuritolic acid 2-p-hydroxybenzoate (), mixture of stigmasterol () and -sitosterol (), mixture of 7-oxo-stigmasterol () and 7-oxo--sitosterol (). Their structures were determined based on data from literature and spectroscopic methods. Derivatization reactions on the isoquinoline led to two new compounds, the methylated () and acetylated () derivatives.