Determination of 4-Hydroxy-3-Methoxy Benzoic Acid by RP-HPLC and Inhibitory Effectof Phloroglucinol on Catecholamine-O-Methyl Transferase / 医药导报

ABSTRACT

Objective To detect content of 4-hydroxy-3-methoxy benzoic acid by RP-HPLC and observe the inhibitory effect of phloroglucinol on catecholamine-O-methyl transferase (COMT). Methods This study used the principle of 3,4-dihydroxy benzoic acid transforming to 4-hydroxy-3-methoxy benzoic acid under COMT’ s catalytic action. COMT (20 μL) was extracted from mouse liver homogenate. In a reaction system,10 μL catecol (1í10-3 mol·L-1 ) and 10 μL phloroglucinol (5í10-3 , 1í10-3 and 2í10-4 mol·L-1 ,respectively) were added. Products were determined by RP-HPLC to analyze effects of 4-hydroxy-3-methoxy benzoic acid on COMT. Results Phloroglucinol had inhibitory effect on COMT activity at concentrations of 5í10-3 mol·L-1 ,1í10-3 mol·L-1 and 2 í10-4 mol ·L-1 ,with the inhibition rate being 25. 3% ,17. 6% and 8. 9% ,respectively. Conclusion Phloroglucinol has an inhibitory effect on COMT activity,which is weaker than the effect of catechol of the same concentration.