71117-22-1 K 76 Carboxylic acid K 76 Cooh K-76 Monocarboxylic acid K-76COOH K76 COOH K76COOH MX-1 Spiro(benzofuran-2(3H),1'(2'H)-naphthalene)-7-carboxylic acid, 6-formyl-3',4',4'a,5',6',7',8',8'a-octahydro-4,6',7'-trihydroxy-2',5',5',8'a-tetramethyl-