METABOLISM OF MONOTERPENES - OXIDATION OF ISOPIPERITENOL TO ISOPIPERITENONE, AND SUBSEQUENT ISOMERIZATION TO PIPERITENONE BY SOLUBLE ENZYME PREPARATIONS FROM PEPPERMINT (MENTHA-PIPERITA) LEAVES
METABOLISM OF MONOTERPENES - OXIDATION OF ISOPIPERITENOL TO ISOPIPERITENONE, AND SUBSEQUENT ISOMERIZATION TO PIPERITENONE BY SOLUBLE ENZYME PREPARATIONS FROM PEPPERMINT (MENTHA-PIPERITA) LEAVES
复制标题
DOI：
10.1016/0003-9861(85)90139-0
复制
发表时间：
1985-01-01
影响因子：
3.9
通讯作者：
CROTEAU, R
中科院分区：
文献类型：
--
作者：
KJONAAS, RB;VENKATACHALAM, KV;CROTEAU, R
Soluble enzyme extracts from peppermint leaves, when treated with polystyrene resin to remove endogenous monoterpenes and assayed with unlabeled substrates coupled with capillary GLC/mass spectrometric detection methods, were shown to oxidize isopiperitenol to isopiperitenone, and to isomerize isopiperitenone to piperitenone. The enzymes responsible for the monoterpenol dehydrogenation and the subsequent allylic isomerization were separated and partially purified by chromatography on Sephadex G-150, and were shown to have MW of approximately 66,000 and 54,000, respectively. The general properties of the NAD-dependent dehydrogenase were examined, and specificity studies indicated that a double bond adjacent to the carbinol carbon was a required structural feature of the monoterpenol substrate. General properties of the isomerase were also determined, and it was demonstrated that the double bond migration catalzyed by this enzyme involved an intramolecular 1,3-hydrogen transfer. These enzymatic transformations represent 2 key steps in the metabolic pathway for the conversion of the initially formed cyclic olefin, (.+-.)-limonene, to (-)-menthol and related monoterpenes characteristic of peppermint. Some stereochemical features of these reactions, and of the overall biogenetic scheme, are described.
