The Compatibility of <scp>d</scp>‐Pinitol and 1<scp>d</scp>‐1‐O‐Methyl‐Muco‐Inositol with Malate Dehydrogenase Activity

Abstract

Abstract Pinitol (1 d ‐3‐O‐methyl‐chiro‐inositol) and 1 d ‐1‐O‐methyl‐muco‐inositol, two cyclitols wide‐spread in the plant kingdom, were isolated from plant sources in order to test their compatibility with malate dehydrogenase activity. Both compounds had no inhibitory effect on malate dehydrogenase from Rhizophora mangle in a range of 100 to 1000 mol . m −3 . Their influence on malate dehydrogenase activity from different plant sources ( Rh. mangle L., Mesembryanthemum crystallinum L., Cicer arietinum L. and Spinacia oleracea L.) was also small and similar to that observed for a number of well established compatible solutes (e.g. proline, glycine betaine). A possible role of cyclitols as cryoprotectants or radical scavengers is discussed.