Salts of galacturonic acid and their application to the preparation of galacturonic acid from pectic substances

Abstract

Twelve new salts of galacturonic acid have been prepared and their properties investigated. Crystalline sodium, potassium, ammonium, cadmium, and ' sIlver galacturonates have been found to contain the beta pyranose modification, and crystalline calcium and strontium galacturonates, the alpha modification. A unique type of double salt containing a monovalent and a divalent metal in combination with the alpha pyranose modification of galacturonic acid has been obtained, and the following members of this class have been crystallized and studied: Sodium calcium, sodium strontium, sodium barium, sodium cadmium, sodium lead, and potassium calcium galacturonates. Mutarotation studies have been conducted in order to determine the structure of the galacturonate component in the salts. The crystallizing properties of the normal calcium and strontium galacturonates, and especially of the sodium calcium and sodium strontium galacturonates, makes these salts particularly suitable for the separation of galacturonic acid from the hydrolytic liquors of plant materials.

Synthesis, physicochemical and pharmacokinetic characterization of calcium uronates

“…Although there are numerous data in the literature on calcium complexes with bioligands (see for example [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]), the relationship between, e.g., calcium coordination geometry and the solubility of its compounds in water and lipids seems to be far from being fully understood. Such problems are interesting for potential pharmacological applications.…”

Synthesis of vitamin C from pectic substances

“…The investigation, which was conducted with Harriet L. Frush [10], led to the preparation of 12 new salts of galacturonic acid, including at least 4 which can be used for separating galacturonic acid from the hydrolytic liquor. The double salts of sodium and calcium, and of sodium and strontium, appear to be most satisfactory.…”

“…(8) FROM CALCIUM GALACTURONATE Seventy grams of calcium galacturonate [10], 400 ml of water, and a nickel catalyst were placed in a bomb and treated with hydrogen at a pressure of 1,000 lb. and a temperature of 80° to 100° C. The catalyst was prepared from 20 g of Raney nickel alloy by digesting it with 200 ml of 25-percent aqueous sodium hydroxide for a period of 2 hours, and washing it with water.…”

Preparation of sodium strontium galacturonate from citrus products

“…In previous papers from this laboratory it has been shown that galacturonic acid can be separated directly from the hydrolyzates of pectic substances in the form of certain new salts, particularly calcium galacturonate, sodium calcium galacturonate and sodium strontium galacturonate [2]. Some of the studies on the preparation of galacturonic acid have been conducted on hydrolyzates of beet pulp [3] .…”