STUDIES ON THE SYNTHESIS AND STRUCTURE-ACTIVITY RELATION OF DELTORPHIN I ANALOGUES

Endogenous opioid deltorphin I(DEL I)and its three analogues(progressive,stepwise repositioning of Asp from 5 to 7)were synthesized solid phase method. DEL I at 10^-14～10^-10 mol·L^-1 in vitro and at 0.5～5μg·kg^-1 in vivo was found to increase the percentages of erythrocyte rosette forming cells(E-RFC) and red blood cell C3b receptor garland(RBC-CR1).Thisaugmentative effect of DEL I was antagonized by naloxone. The results indicate that DEL I enhancedthe immune function of rats. The order(from strong to weak)of the analgesic and immune activitywas shown to be Asp⁴, Asp⁷, Asp⁵,Asp⁶ and Asp⁴,asp⁷,Asp⁶,Asp⁵ respectively.