o NH COOH N CH 3 N COOH H CH CH H2N H3C 异烟肼体内主要代谢途径N N H NH2 O N COOH N N H H N O CH3 O H2N H N CH3 O N H H N CH3 O H3C O N N H COOH O 异烟肼体内主要代谢途径