What is the specific rotation of alpha D fructose?

(+)-Sucrose has a specific rotation of +66.5, while D-(+)-glucose and D-(-)-fructose have specific rotations of +52.5 and -92.4 respectively.

What is the formula for specific rotation?

The CRC Handbook of Chemistry and Physics defines specific rotation as: For an optically active substance, defined by [α]θλ = α/γl, where α is the angle through which plane polarized light is rotated by a solution of mass concentration γ and path length l.

What is the specific rotation of glucose?

The alpha (α) anomer of D-glucose has a specific rotation of +112 degrees in water.

What is the specific rotation of cane sugar?


Chemical name Specific rotation[α]20D
D-galactose +80.2
Sucrose +66.5
Maltose +130.5
Dextrin +195

What is optical rotation of glucose and fructose in invert sugar?

The specific rotation of glucose is +52.5°, but fructose is strongly levorotatory (-92°). While inverting, the specific rotation gradually undergoes a change in direction of polarized light from +66.5° to -19.7°. The inverted solution is levorotatory and displays a specific rotation of -19.7°.

Does fructose show mutarotation?

Fructose (hemiketal) and Glucose (hemiacetal) undergo mutarotation. But sucrose and cellulose are not performing mutarotation, because of the absence of OH functional group at the anomeric position.

How do you calculate the specific rotation of sucrose?

The specific rotation for any one wavelength, solute, and solvent could be defined by the equation [allT = A(l + D(T – 25)) + BC, where Tis temperature in “C, Cis concentration in grams of solute per 100 ml of solution, and A, B, and D are constants.

What is unit of specific rotation?

Specific rotation of a compound is a characteristic property of the compound as long as the temperature, the wave length of the light, and, if a solution is used for the experiment, the solvent are specified. The units of specific rotation are degreesmLg-1dm-1.

How is glucose converted to fructose?

A method for converting glucose to fructose is described. It involves chemical reduction of glucose to sorbitol and oxidation of the sorbitol to fructose in a coupled enzyme reaction. Fruc- tose is formed in 90% yield in the enzymatic reaction.

What is the specific rotation of sucrose?

In the circumstance of 20 °C, the specific optical rotation of sucrose is known to be 66.6°, whereas that of glucose and fructose is 52.2° and −92.4°, respectively.

What is Mutarotation of fructose?

Mutarotation in Fructose

The change from one form of fructose to another form occurs in the presence of acidic protons (change in pH) or thermal excitations (temperature change). The open-chain form of fructose molecule forms two different structures, β-fructopyranose, and β-fructofuranose.

What is meant by specific rotation?

Definition of specific rotation
: the angle of rotation in degrees of the plane of polarization of a ray of monochromatic light that passes through a tube 1 decimeter long containing the substance in solution at a concentration of 1 gram per millimeter in a polarimeter.

Which sugar does not show mutarotation?

Mutarotation is not shown by Sucrose.

Is sucrose Dextrorotatory or Levorotatory?

Sucrose is dextrorotatory but the mixture obtained after hydrolysis is laevorotatory.

What does specific rotation depend on?

The observed specific rotation [α]obs depends on the length of the tube, the wavelength that it is used for the acquisition, the concentration of the optical active compound (enantiomer), and to a certain degree on the temperature as well.

Is Levorotatory R or S?

Since the pure S enantiomer ((+) 61o) is dextrorotatory (positive, clockwise), the R enantiomer must be levorotatory. The observed rotation of the mixture is levorotatory since its negative (counterclockwise). This means the mixture must contain more of the R enantiomer than the S enantiomer.

Is all fructose converted to glucose?

Under one percent of ingested fructose is directly converted to plasma triglyceride. 29% – 54% of fructose is converted in liver to glucose, and about a quarter of fructose is converted to lactate. 15% – 18% is converted to glycogen. Glucose and lactate are then used normally as energy to fuel cells all over the body.

What type of reaction converts glucose to fructose?

The isomerization of glucose to fructose is part of the glycolysis cycle that converts glucose to pyruvate. The way this is done is to isomerize the aldehyde (hemiacetal) glucose to the ketone (as a hemiacetal) fructose,and make another phosphate ester.

What is the specific rotation of maltose?


Chiral rotation ([α]D) +140.7° (H2O, c = 10)
Safety data sheet (SDS) External MSDS
Related compounds

Why is specific rotation called specific?

Specific rotation gives the angle of rotation of plane-polarized light by a certain compound at a certain temperature. This is the key difference between optical rotation and specific rotation. The standard measurement for optical rotation for a specific chemical compound is called the specific rotation.

Which test can differentiate glucose and fructose?

Seliwanoff’s Test
(d) Seliwanoff’s Test: It is used to distinguish between the aldose and ketose. So, from this it is clear that we can distinguish between the fructose and glucose by Seliwanoff’s test because fructose is a ketose and glucose is an aldose.

Is fructose Levo or Dextro?

Fructose is laevorotatory. It rotates the plane of polarized light in anticlockwise direction. Thus it is also called as levulose and is named as D-(-)-fructose.

Is fructose a Levorotatory?

Fructose is a levorotatory monosaccharide and an isomer of glucose. Although fructose is a hexose (6 carbon sugar), it generally exists as a 5-member hemiketal ring (a furanose).

Are sugars usually D or L?

Almost all sugars found in nature are D-sugar. Like R and S, D and L indicate the configuration of an asymmetric carbon, but they do not indicate whether the compound rotates polarized light to the right or to the left.

What is Dextro and Levo rotation?

From the point of view of the observer, dextrorotation refers to clockwise or right-handed rotation, and laevorotation refers to counterclockwise or left-handed rotation.