Dipeptide synthesis in biphasic medium: evaluating the use of commercial porcine pancreatic lipase preparations and the involvement of contaminant proteases - Liria, Cleber Wanderlei; Romagna, Carolina Domeniche; Rodovalho, Nicolas Nishikido; Marana, Sandro Roberto; Miranda, Maria Terêsa Machini de (Journal of the Brazilian Chemical Society, 2008)