Bursin is a peptide that can be isolated from the bursa of Fabricius of chicken. Bursin induces the phenotypic differentiation of mammalian and avian B precursor cells. Bursin also increases cyclic guanosine monophosphate in cells of the human B-cell line Daudi, its derivatives are able to protect against infection by amplifying the immune response induced by H9N2.

Tetradehydropodophyllotoxin has anti-tumor activity.

A compound consisting of dark green crystals or crystalline powder, having a bronze-like luster.