Fridericia Mart. emend L.G. Lohmann is one of the largest and most complex genera of neotropical lianas comprising species that are morphologically variable and taxonomically complicated. Phytochemical investi-gation of leaves of Fridericia prancei (A.H.Gentry) L.G. Lohmann led to the isolation and identification of one alkaloid, trigonelline (1), and five unusual dimeric flavonoids, i.e., brachydin D (2), brachydin E (3), brachydin A (4), brachydin J (5), and brachydin C (6). We describe these rare dimeric flavonoids in F. prancei for the first time and show that they represent chemical synapomorphies of the Acrodromous venation clade.