Mururins A-C, three new lignoids from Brosimum acutifolium and their protein kinase inhibitory activity.

Two new flavonolignans, mururins A and B (1 and 2), and a new lignan, mururin C (3), were isolated from the bark of Brosimum acutifolium Huber together with three known lignans. Their structures were elucidated by spectroscopic means and chemical modifications. They were tested for protein kinase A (PI(A) and protein kinase C (PKC) inhibitory activity. Mururin A showed 3% and 63% inhibition to PKA and PKC, respectively, at 20 muM. Mururin B showed 58% and 38% inhibition, respectively. Mururin C did not have significant activity.