the azide group was then reduced with et 3 nh sn sph 3 and the linear pentapeptide was completed with condensation of fmoc allgly at the n terminal as from this intermediate product on the synthesis of the cyclopentapeptide continues as described in example 1 96 well plates were subjected overnight to coating with 0 5 u03bcg ml of integrin u03b1 v u03b2 3 chemicon cat cc1020 on the next day the wells were washed and incubation was performed with 0 05 nm of 125 i echistatin amersham cat im304 in the absence or presence of compounds according to the invention after a 3 hour incubation and a series of washings the integrin from each well bound to the radioactive substance was solubilised with naoh 2n and the radioactivity was then measured using a gamma counter non specific binding to be subtracted from all samples was determined in the presence of echistatin 1 u03bcm 96 well plates were subjected overnight to coating with 1 u03bcg ml of integrin u03b1 v u03b2 5 chemicon cat cc1022 on the next day the wells were washed and incubation was performed with 0 05 nm of 125 i echistatin amersham cat im304 in the absence or presence of compounds according to the invention the process then proceeded as described in the previous case the affinity of the compounds according to the present invention for vitronectin receptors was expressed as the ic 50 u00b1 sd value nm which is.