SP-303, an antiviral oligomeric proanthocyanidin from the latex of Croton lechleri (Sangre de Drago).

Ubillas R, Jolad SD, Bruening RC, Kernan MR, King SR, Sesin DF, Barrett M, Stoddart CA, Flaster T, Kuo J, Ayala F, Meza E, Castañel M, McMeekin D, Rozhon E, Tempesta MS, Barnard D, Huffman J, Smee D, Sidwell R, Soike K, Brazier A, Safrin S, Orlando R, Kenny PT, Berova N, Nakanishi K