title: Studies on antianaphylactic agents. 6. Synthesis of some metabolites of 6-ethyl-3-(1H-tetrazol-5-yl)chromone and their analogues.
abstract: The metabolites of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) (1), an orally effective antiallergic agent, and their analogues were synthesized to confirm the proposed structures and to determine their activity in the rat passive cutaneous anaphylaxis (PCA) test. A glucuronic acid metabolite (6) was assigned the structure 24b, 1-deoxy-1-[5-(6-ethylchromon-3-yl)tetrazol-1-yl]-beta-D-glucopyranuronate, by the comparison of 13C NMR, mass spectra, and TLC of isomeric compounds. In 13C NMR spectra, the shift difference of the tetrazole ring carbons between a pair of isomers was more remarkable than that of the glycosidic carbons. Therefore, the former is a useful criterion for distinguishing between such isomers. Some of the metabolities and analogues were active when administered intravenously, and two metabolites (2 and 3) were also effective upon oral administration.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002867:Chromones / Q000138:chemical synthesis* / Q000494:pharmacology; D008297:Male; D010323:Passive Cutaneous Anaphylaxis / Q000187:drug effects; D051381:Rats; D013777:Tetrazoles / Q000138:chemical synthesis / Q000494:pharmacology
chemical_list: D002867:Chromones; D013777:Tetrazoles