Title: Melibiose
CAS Registry Number: 585-99-9
CAS Name: 6-O-a-D-Galactopyranosyl-D-glucose
Additional Names: 6-(a-D-galactosido)-D-glucose
Molecular Formula: C12H22O11
Molecular Weight: 342.30
Percent Composition: C 42.11%, H 6.48%, O 51.41%
Literature References: Prepd from raffinose by fermentation with top yeast which removes the fructose: Hudson, Harding, J. Am. Chem. Soc. 37, 2734 (1915); Fletcher, Diehl, ibid. 74, 5774 (1952). Structure: Haworth, Leitch, J. Chem. Soc. 113, 188 (1918); Charlton et al., ibid. 1926, 99; Charlton et al., ibid. 1927, 1527; Haworth et al., ibid. 3146; Levene, Jorpes, J. Biol. Chem. 86, 403 (1930). Synthesis: Helferich, Bredereck, Ann. 465, 166 (1928).
Derivative Type: Dihydrate
Properties: Monoclinic crystals from water or dil alcohol. mp 84-85°. Shows mutarotation. [a]D20 +111.7° ® +129.5° (c = 4). One gram dissolves in 0.4 ml water, 8.5 ml methanol, 220 ml abs alcohol. Dilute acids hydrolyze melibiose to D-glucose and D-galactose. Also split by emulsin and by bottom yeast. Reduces Fehling's soln. 3.5 g melibiose dihydrate are about as sweet as 1.0 g sucrose.
Melting point: mp 84-85°
Optical Rotation: [a]D20 +111.7° ® +129.5° (c = 4)
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