• Journal of Pharmaceutical Investigation
• /
• 제40권4호
• /
• pp.213-218
• /
• 2010

In a previous paper, we showed that 5-aminosalicyl-L-aspartic acid (5-ASA-Asp) has much greater deconjugation efficiency in the cecal contents than does 5-aminosalicyl-L-glutamic acid (5-ASA-Glu). To explore a reason for ineffective deconjugation of 5-ASA-Glu, structural analysis of the conjugate was performed. Aromatic acyl-L-glutamic acid derivatives, N-benzoyl-glumatic acid (BA-Glu), N-(2-hydroxybenzoyl)-glutamic acid (SA-Glu), N-(3-aminobenzoyl)-glutamic acid (3-ABA-Glu) and N-(4-aminobenzoyl)-glutamic acid (4-ABA-Glu), were prepared and incubated in the cecal contents. The deconjugation rates were compared with that of 5-ASA-Glu. The order of the rates was BA-Glu $\approx$ 4-ABA-Glu $\approx$ 3-ABA-Glu $\gg$ SA-Glu $\approx$ 5-ASA-Glu. The deconjugation of the aromatic acyl-L-glutamic acid derivatives was carried out by enzyme(s) in the cecal contents since the deconjugation did not occur in the autoclaved cecal contents and on incubation with N-benzoyl-D-glutamic acid. Our data suggest that the 2-hydroxyl group in 5-ASA is ascribed to the poor deconjugation of 5-ASA-Glu in the cecal contents.

• YAKHAK HOEJI
• /
• 제42권1호
• /
• pp.5-11
• /
• 1998

5-Aminosalicyl-L-aspartic acid (5-ASA-Asp) and 5-aminosalicyl-L-glutamic acid (5-ASA-Glu) were synthesized as new colon-specific prodrugs of 5-aminosalicylic acid (5-ASA), their apparent partition coefficients, and the extent of conversion in the homogenates of tissue and contents of various G.I. Tract segments of rats were evaluated. These prodrugs were stable in the homogenate of tissue and contents of stomach, proximal small intestine (PSI) or distal small intestine (DSI). Release of 5-ASA from 5-ASA-Asp after incubation with the cecal and colonic contents for 8hrs at $37^{\circ}C$ was 18%, and 8%, respectively. No significant conversion of prodrug was observed in the cecal and colonic contents of rats pretreated with kanamycin sulfate, which indicated that microbial enzymes were responsible for the cleavage of these prodrugs.