The shikimate pathway. Part I. Introduction; preparation of stereospecifically labelled 2-deuterio-derivatives of 3-dehydroquinic acid

Abstract

In this paper, shikimic acid is numbered systematically, with the double bond in the 1,2-position; quinic acid is numbered according to the ' Tentative Rules for Cyclitol Nomenclature ' (I.

A Convenient Method for the Synthesis of Dehydroquinic Acid

“…[12] Hydrolysis of the methyl ester 4, with aqueous KOH, furnished the potassium dehydroquinate 5 as an off-white solid that did not require further purification. [6] The optical rotation was equivalent to that reported by Grewe and Jeschke at a similar concentration and in the same solvent. The potassium salt 5 was finally stirred over amberlite [3] to give dehydroquinic acid 6 (hygroscopic solid) in excellent yield (Sch.…”

“…[2,3] Therefore, a convenient synthetic source of dehydroquinic acid 6, and its corresponding methyl ester 4, is required for use in enzyme inhibition assays [3] and to provide convenient starting materials for the preparation of new inhibitors. Literature methods for the synthesis of dehydroquinic acid, notably oxidation of quinic acid 1 using a platinum-oxygen system [5,6] or nitric acid, [7,8] are difficult to reproduce, invariably require tedious purification, and afford the desired acid in variable yield. Literature methods for the synthesis of dehydroquinic acid, notably oxidation of quinic acid 1 using a platinum-oxygen system [5,6] or nitric acid, [7,8] are difficult to reproduce, invariably require tedious purification, and afford the desired acid in variable yield.…”

Enzymes that exploit imines – one way or the other

“…The question then arises as to what is the stereochemical course of the reaction catalysed by the type I1 enzyme, because there is no conserved lysine in the sequence and so the mechanism is unlikely to involve imine formation. It seemed probable that the stereochemistry would be trans, as this is the stereochemistry observed in the acid-or base-catalysed conversion of 3-dehydroquinate into 3-dehydroshikimate [4].…”

Progress in type II dehydroquinase inhibitors: From concept to practice

“…[32][33][34] The reaction proceeds via a multi-step mechanism involving covalent imine intermediates 35 between a conserved Lysine (Lys170 in E. coli) 23 and the carbonyl group of the substrate. The role of the Schiff base is to act as an electron sink and also to distort the cyclohexyl ring of the substrate to make the equatorial C2 proton more reactive.…”