Keller W J
J Pharm Sci. 1979 Jan;68(1):85-7. doi: 10.1002/jps.2600680126.
The biosynthetic conversion of epinephrine to normacromerine in Coryphantha macromeris (Engelm.) Br. and R. var. runyonii (Br. and R.) L. Benson (Cactacae) has been studied. Metanephrine, which has been isolated from this cactus and is a normal metabolite of epinephrine in mammalian systems, appeared to be the likely intermediate between epinephrine and normacromerine. Normacromerine turnover studies suggested a 16-day interval between metanephrine administration and harvest of the cacti. During this incubation period, the cacti specifically converted 4.77% of the administered DL-7-3H-metanephrine to normacromerine. Based on biochemical precedents, the postulated metabolic fate of normacromerine in the cactus was an enzymatic N-methylation to give macromerine. However, radiolabeled normacromerine was a very ineffecient precursor to macromerine.
对大花菠萝球属植物（Coryphantha macromeris (Engelm.) Br. and R.）变种鲁尼恩氏菠萝球（Coryphantha macromeris (Engelm.) Br. and R. var. runyonii (Br. and R.) L. Benson，仙人掌科）中肾上腺素生物合成转化为去甲大花麦角碱的过程进行了研究。从这种仙人掌中分离出的变肾上腺素，它是肾上腺素在哺乳动物系统中的正常代谢产物，似乎是肾上腺素和去甲大花麦角碱之间可能的中间产物。去甲大花麦角碱周转研究表明，在给变肾上腺素后16天收获仙人掌。在此孵育期间，仙人掌将所施用的4.77%的DL-7-³H-变肾上腺素特异性转化为去甲大花麦角碱。根据生化先例，推测去甲大花麦角碱在仙人掌中的代谢命运是通过酶促N-甲基化生成大花麦角碱。然而，放射性标记的去甲大花麦角碱是生成大花麦角碱的低效前体。
