Sinistrin

• Polyfructosan
• Polyfructosan -S
• Inulin analog
• Inutest

V04CH01

Pale yellow colored, flour -like powder

Fixed

Decomposition at 160-170 ° C

• Readily soluble in water
• Insoluble in ethanol

Sinistrin (also polyfructosan ) is a naturally occurring polysaccharide found in many plants. Sinistrin serves as the fructan inulin similar as energy storage ( storage carbohydrate ) of the plants.

History of discovery and production

Schmiedeberg succeeded in 1879, the isolation of a new carbohydrate from the tuber of red squill ( Urginea maritima ). He gave the levorotatory substance the name " sinistrin ", after the Latin word for sinister 'left'. Hammarsten found the sinistrin 1885 in mucins of the snail ( Helix pomatia). Today sinistrin is industrially extracted primarily from the red squill over several extraction and purification steps.

Chemical structure and properties

Sinistrin is a β -D - fructan inulin - type with branches at position 6, it counts as inulin to produce fructans and is also part of the fructooligosaccharides ( FOS) calculated. Sinistrin consists of about 97% fructose and about 3 % of glucose, in which the chain is composed of fructose molecules that have a terminal glucose residue. The degree of polymerization of sinistrin averages around 15, the molar mass at 3500 Da, Da with a fluctuation between 2000 and 6000.

Sinistrin differs from inulin by high water solubility ( even in cold water ) and better stability to alkali. On the addition of an aqueous Sinistrinlösung with copper sulfate solution and then with potassium hydroxide produces a deep blue colored solution. If this heated immediately separates out a light blue, flocculent precipitate; the reaction can be used as sensitive detection of sinistrin. With calcium hydroxide or lime Sinistrinlösung forms a precipitate.

Use in medicine

Sinistrin as inulin in physiological research used for the determination of the extracellular space, since it easily penetrates into the interstitial spaces, but not in the cells. Sinistrin is completely filtered at the glomerulus, but not secreted reabsorbed in the tubule system, neither. Therefore, it is excreted by the kidneys unchanged and complete. The measurement of the clearance therefore renal sinistrin is used for the exact determination of the glomerular filtration rate (GFR). This excretion rate provides information about the activity or the health of the kidneys. The quantitative determination of sinistrin in urine and plasma is identical to that of inulin. For this application sinistrin is approved as an aqueous solution under the trade name " Inutest " as a drug.