SYNTHESIS OF SYRINGOLIDE-1 KETALS AND ESTERS FOR RECEPTOR STUDIES

The syringolides, specified by avirulence gene D from Pseudomonas syri ngae, elicit a disease defense reaction only in soybean cultivars carr ying the Rpg4 disease resistance gene. In order to identify structural features important for elicitor activity and construct highly labelle d elicitor-active probes, several syringolide esters and ketals were s ynthesized. Alteration of the C-3 hemiketal group of syringolide 1 abo lished elicitor activity, but ester derivatives based on the C-4' hydr oxy group all retained activity. [I-125]4'-(2-iodo-3,4,5-trimethoxyphe nylacetyl) syringolide 1 was prepared for receptor studies. Copyright (C) 1996 Elsevier Science Ltd