Mammalian Alkaloids:O-methylation of (S)- and (R)-dideoxynorlaudanosoline-1-carboxylic acid by catecholO-methyltransferase and identification of a yellow pigment obtained at physiological pH
作者:Maria Danuta Rozwadowska、Maria Chrzanowska、Arnold Brossi、Cyrus R. Creveling、Michael E. Bembenek、Creed W. Abell
DOI:10.1002/hlca.19880710703
日期:1988.11.2
optically active 3′,4′-dideoxynorlaudanosoline-l-carboxylic acids 1 with O-methyltransferase in vitro afforded almost exclusively the 7-O-methylated acids 3. A similar result was obtained with the yellow quinonemethide 4A obtained from 1 at neutral or slightly alkaline pH by oxidative decarboxylation and affording the 3,4-dihydroisoquinoline 15 on methylation with catechol O-methyltransferase (COMT). The structure
ø的-Methylation光学活性的3',4'- dideoxynorlaudanosoline -1-羧酸1与ö -methyltransferase体外得到几乎完全的7- ø甲基化的羧酸3。在中性或弱碱性条件下,通过氧化脱羧从1获得黄色醌甲基化物4A,并通过邻苯二酚O-甲基转移酶(COMT)甲基化得到3,4-二氢异喹啉15,获得了相似的结果。醌甲基化物4A的结构根据光谱数据,通过将其转化为已建立结构的异喹啉并通过合成来确定。发现醌甲基化物4A是单胺氧化酶A(MAO A)的弱抑制剂,但不是底物。多巴胺衍生的四氢异喹啉-1-羧酸的非酶氧化脱羧为醌甲基化物可能是生化实验中的主要因素,应在数据解释中加以考虑。