Lactulose, 乳果糖

Lactulose is a synthetic and non-digestible sugar. It reduces colonic pH to 3.5 and stimulates circular muscle activity and propulsion of fluid in isolated guinea pig ileum and colon. Formulations containing lactulose have been used to treat constipation.

Lactulose is a disaccharide (sugar) synthesized from fructose and galactose, Lactulose is used to treat constipation and some liver diseases. Nondigestible in mammals, lactulose passes unabsorbed down to the large intestine where resident bacteria consume it and produce lactic, acetic, and formic acids, which draw fluid into the bowel to soften the stool (laxative effect). Acidification of the colon contents attracts ammonia from the bloodstream, assisting stool excretion; helpful in liver failure when ammonia cannot be detoxified. (NCI04)

Lactulose, also known as lactulosum or cephulac, belongs to the class of organic compounds known as o-glycosyl compounds. These are glycoside in which a sugar group is bonded through one carbon to another group via a O-glycosidic bond. Lactulose is a drug which is used for the treatment of constipation and hepatic encephalopathy. Lactulose exists as a solid, soluble (in water), and a very weakly acidic compound (based on its pKa). Lactulose has been found in human intestine and spleen tissues, and has also been primarily detected in blood. Within the cell, lactulose is primarily located in the cytoplasm. Lactulose has been linked to the inborn metabolic disorders including celiac disease.

Lactulose is a synthetic galactosylfructose disaccharide used in the treatment of constipation and hepatic encephalopathy. It has a role as a laxative and a gastrointestinal drug.

Lactulose is a non-absorbable sugar used in the treatment of constipation and hepatic encephalopathy. It is used by mouth for constipation and either by mouth or in the rectum for hepatic encephalopathy. It generally begins working after 8-12 hours, but may take up to 2 days to improve constipation.

Title: Lactulose

CAS Registry Number: 4618-18-2

CAS Name: 4-O-b-D-Galactopyranosyl-D-fructose

Additional Names: 4-D-galactopyranosyl-4-D-fructofuranose; 4-O-b-D-galactosyl-D-fructose; 4-b-D-galactosido-D-fructose

Trademarks: Cephulac (Aventis); Cholac (Alra); Constilac (Alra); Duphalac (Solvay); Generlac (Morton Grove); Lactuflor (Chephasaar); Laevilac (Fresenius); Normase (Molteni)

Molecular Formula: C12H22O11

Molecular Weight: 342.30

Percent Composition: C 42.11%, H 6.48%, O 51.41%

Literature References: Prebiotic, synthetic disaccharide composed of galactose and fructose. Prepn: E. M. Montgomery, C. S. Hudson, J. Am. Chem. Soc. 52, 2101 (1930); Oosten, Rec. Trav. Chim. 86, 673 (1967); K. B. Hicks, F. W. Parrish, Carbohydr. Res. 82, 393 (1980). Clinical evaluation of effects on fecal bifidobacteria and selected metabolic indices: Y. Bouhnik et al., Eur. J. Clin. Nutr. 58, 462 (2004).

Properties: Hexagonal clustered plates from methanol, mp 168-171°. Sweeter than lactose, but not as sweet as sucrose. Shows mutarotation; constant value after 24 hrs: [a]D22 -51.5°. Soly in water (w/w) at 30°: 76.4%; at 60°: 81%; at 90°: >86%. Acid hydrolysis yields galactose and fructose.

Melting point: mp 168-171°

Optical Rotation: [a]D22 -51.5°

Therap-Cat: Laxative.

Keywords: Laxative/Cathartic.