Physicochemical Studies of Glucuronic Acid and Some Glucuronates Salts from Acacia polyacantha Gum

Abstract

The gum of Acacia polyacantha and its glucuronic acid and some salts of glucuronates were subjected for physicochemical characterization methods. Standard methods were used to obtain average value of moisture, ash, pH, optical rotation, equivalent weight and intrinsic viscosity in 1 M NaCl , of Acacia polyacantha gum, they were found to be 9.13%, 3.51%, 4.18, -23.70,1345.11 and 12.88 ml/gm respectively. The cationic composition analysis was conducted for Acacia polyacantha gum using Atomic Absorption technique, they were found to be 53.35, 40.69, 106.84, 37.01, 24.30 ppm for Na, K, Ca, Mg and Fe respectively. Glucuronic acid was prepared from Acacia polyacantha by removal of metal ions using ion exchange chromatography. Glucuronates of Na, K, Ca, Mg and Fe were prepared to glucuronic acid by adding respective cation to glucuronic acid. The physicochemical characterization were conducted for glucuronic acid and glucuronates of Na, K, Ca, Mg and Fe. Moisture content was found to be 12.69, 12.45, 11.52, 12.38,13.44 and 11.27% for glucuronic acid and glucuronates of Na, K, Ca, Mg and Fe respectively. The total ash values were found to be 0.043, 2.34, 3.02, 2.43, 1.50 and 2.53% for glucuronic acid and glucuronates of Na, K, Ca, Mg and Fe respectively. The pH values of samples were found to be 3.08, 3.80, 3.87, 3.54, 3.63 and 3.49 for glucuronic acid and glucuronates of Na, K, Ca, Mg and Fe respectively. The optical rotation of the samples were found to be -29ᵒ,-14.2ᵒ, -17.5ᵒ, -17.2ᵒ -15.0ᵒ and -15.3ᵒ 49ᵒ for glucuronic acid and glucuronates of Na, K, Ca, Mg and Fe respectively. The intrinsic viscosities in 1M NaCl were found to be 9.29, 7.90, 5.21, 6.17, 7.31 and 9.29 ml/gm for glucuronic acid and glucuronates of Na, K, Ca, Mg and Fe. The cationic composition analysis was conducted for glucuronic acid using Atomic Absorption technique, they were found to be 4.98, 1,92, 10.34, 9.46 and 1.66 ppm for cations of Na, K, Ca, Mg and Fe respectively. The concentration of sodium in sodium glucuronates was found to be 191, and concentration of potassium in potassium glucuronates was found to be 239, and concentration of calcium in calcium glucuronates was found to be 184, and concentration of magnesium in magnesium glucuronates was found to be 112, and concentration of iron in Ferrous glucuronates was found to be 223.