Evidence on the constitution of melezitose through degradation to sucrose by bacterial action

Abstract

Crystalline sucrose has been isolated as a Product of the action of Proteus vulgaris OX2 bacteria upon the trisaccharide melezitose. The identity of the product was conclusively established by a series of physical, chemical, and biological analyses made in comparison with natural sucrose and related sugars. Evidence was obtained, from the action on melezitose of cell-free extracts prepared from “aged” Proteus 0X2 suspensions, that the formation of sucrose is the result of enzymatic hydrolysis. This new evidence of degradation to sucrose furnishes proof that the d-fructose unit in melezitose has the β-configuration, and thus permits the full structure of melezitose to be written as 3-[α- d-glucopyranosyl]-β- d-fructofuranosyl α- d-glucopyranoside. Melezitose can now be placed (with raffinose and gentianose) among the “sucrose-ended” sugars of nature, the sucrose part of which has been obtained in pure, crystalline form after hydrolytic cleavage of the parent sugar by a biological system.