protopectinn.
/ˌprəʊtə(ʊ)ˈpɛktɪn/, U.S. /ˌproʊdoʊˈpɛkt(ə)n/ Biochemistry.
A water-insoluble pectic substance containing glucuronic acid monomers, which is present as a binding substance between plant cell walls, and which breaks down during the ripening of fruits and fleshy roots, giving rise to pectin. Also called pectose.
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the world > matter > chemistry > organic chemistry > carbohydrates > sugars > polysaccharides > [noun] > cellulose > related substance
pectose1851
protopectin1908
1908 Chem. Abstr. 2 431 (heading) On pectin and protopectin.
1922 Biochem. Jrnl. 16 704 The soluble pectin probably develops from an insoluble pectic substance contained in the cell wall... This insoluble pectin corresponds to the protopectin of Fellenberg, and to the pectose of earlier investigators.
1962 S. M. Siegel Plant Cell Wall i. 16 The constitutional differences between protopectin and the other pectic substances remain unclear. Empirically, the protopectins are distinguished by their insolubility, and, in general, by a higher molecular weight.
1993 Food Chem. 46 289 The increase of protopectin before physiological maturity, and its subsequent decrease with fruit ripening and softening, indicated the involvement of this [pectin] fraction in the texture maintenance of eggplant fruits.
This entry has been updated (OED Third Edition, September 2007; most recently modified version published online March 2022).
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n.1908