d-Glucaric Acid as a Prospective Tumor Marker

d -Glucaric acid (GA) 1s a natural, apparently nontoxic compound produced in small amounts by mammals, including humans (1 ) and by some plants. Specifically, GA or Its derlvatlves have been found in the latex of a succulent plant (2 ); mung bean seedlmgs (3 ); seedlings and needles of gymnosperms (4 ), latex, leaves, or stems of different succulent plants (5 ), and tomato leaves (6 ). GA has been detected in sweet cherry fruits (7 ) and citrus fruits (8 ). The formation of GA from d -glucuronic acid has been demonstrated in Phaseolus aureus , I.e., mung bean sprouts (3 ) and Euphorbium canariensis (9 ). d -Glucuronic acid is also readily converted to GA in young needles of Larynx decidua , but the pathway 1s less active in older needles (4 ). Recently, a number of fruits and vegetables have been analyzed for the purpose of identifying plant foods rich in GA (10 ).