Development of a novel hapten for radioimmunoassay of the lignan, enterolactone in plasma (serum). Total synthesis of (+/-)-trans-5-carboxymethoxyenterolactone and several analogues

A recently developed method for the analysis of the mammalian lignan, enter olactone 1, is based on time-resolved fluoroimmunoassay (TR-FIA) using an e uropium chelate as a label. This RIA utilizes enterolactone derivatives car rying a carboxylic acid appendage for the production of antiserum and trace r. The synthesis of 5-carboxymethoxyenterolactone 6 and analogues 5, 7 and 8 is described, and their suitability for the method are discussed. (C) 200 0 Elsevier Science Ltd. All rights reserved.