[' ', ' ', ' ', ' ', ' ', ' ', 'Footnote', '253', '254', '255', '256', '257', '258', '259', '260', '261', '262', '263', '264', '265', 'U.S.', 'Patent', 'No.', '4,638,816', '4,635,652', '4,592,373', '4,578,486', '5,017,235', '4,859,775', '4,588,813', '4,607,118', '4,612,391', '4,701,282', '4,620,004', '4,728,738', '4,974,609', 'Year', 'of', 'Filing/Issue', '85/87', '83/87', '83/86', '85/86', '86/91', '85/89', '83/86', '81/86', '80/86', '85/87', '83/86', '85/86', '86/90', '40', 'PM', 'U.S,', 'Patents', "(cont'd)", 'Subject', 'Matter', '_', 'Glycosylamine', 'Monoacylpyrazine', 'Heterocyclichydroxy-', 'substitute', 'Carboxylic', 'Acid', 'Dioxane', 'Diacylpyrazine', 'Acylpyrazine', 'Ether', 'Monoacylpyrazine', 'Betahydroxy', 'Ester', 'Oxycarboxylic', 'Acid', 'Betahydroxy', 'Gamma', 'Keto', 'Ester', 'Polyheterocylic', 'Acylpyrazine', 'Ether', 'Thieno', 'Pyranone', ' ', ' ', 'L699', 'TT8@S']