Abstract The aim of our study was to investigate structure activity relationship following the replacement of the 6-phenyl substituent at the 6, 7-diaryl-2, 3-dihydropyrrolizine template by various heteroaromatic residues. In this context we developed a new, efficient, and highly sensitive test method for the screening of dual cyclooxygenase-1 (COX-1) and 5- lipoxygenase (5-LOX) inhibitors. We used human platelets as a source of COX-1 and ...