Name | L-rhamnose monohydrate |
Synonyms | L-rhamnose monohydrate a-L-Rhamnose Monohydrate 6-deoxy-L-mannopyranose hydrate 5,5-dimethyl-2-[(phenylcarbamoyl)amino]-4,7-dihydro-5H-thieno[2,3-c]pyran-3-carboxamide |
CAS | 6155-35-7 |
EINECS | 639-370-9 |
InChI | InChI=1/C6H12O5.H2O/c1-2-3(7)4(8)5(9)6(10)11-2;/h2-10H,1H3;1H2/t2-,3-,4+,5+,6?;/m0./s1 |
Molecular Formula | C6H12O5· H2O |
Molar Mass | 182.17 |
Melting Point | 90-95℃ |
Boling Point | 323.9°C at 760 mmHg |
Specific Rotation(α) | [α]D20 +7.7~+8.5゜ (c=5, H2O) |
Flash Point | 149.7°C |
Solubility | Soluble in water and methanol, insoluble in ether. |
Vapor Presure | 1.99E-05mmHg at 25°C |
Appearance | Crystallization |
Storage Condition | Sealed in dry,Room Temperature |
MDL | MFCD00071591 |
Physical and Chemical Properties | Bioactive α-L-Rhamnose monohydrate is a component of plant cell wall pectin polysaccharide rhamnose galacturonoglycan 1 and rhamnose galacturonoglycan 2. α-L-Rhamnose monohydrate is also a component of bacterial polysaccharide and plays an important role in pathogenicity. |
Use | The application of rhamnose can be used to determine the intestinal permeability, synthesis of cardiac drugs, can be used as sweeteners, can also be used for the production of flavors, edible. Cardiotonic drugs: many natural cardiotonic drugs have an L-rhamnose group attached to the end of the molecular structure. In the synthesis of such cardiotonic drugs, L-rhamnose is an essential basic raw material. At present, using L-rhamnose as one of the basic raw materials, synthetic cardiotonic drugs are still in the research and development stage and have not yet been put into the market. Synthetic fragrance: L-rhamnose is mainly used in the industrial production of synthetic fragrance Furaneol. Furaneol occupies a very important position in the field of fruit spices. In addition to its direct use as a spice product, it is the basic raw material for the synthesis of many fruit flavors. Food additive: L-rhamnose is more special than ribose and glucose in the reaction with other substances to produce flavor substances. Up to five species of flavor substances were formed from L-rhamnose. |
WGK Germany | 3 |
FLUKA BRAND F CODES | 3 |
Downstream Products | BETA-PHENYLPROPIOPHENONE ENZYMATICALLYDECOMPOSEDRUTIN |
saccharides
Rhamnose, also known as mannyl sugar, is a methyl five-carbon sugar with two isomers of L-type and D-type. In water, the [α]D16.5 of D-rhamnose is -8.25 °, and the [α]D15 of L-rhamnose is 9.1 °. L-rhamnose is a kind of deoxyhexalose, 6-deoxyL-mannose, which is a component of plant cell walls and various glycosides. Alpha formula: colorless crystal. Crystallized from aqueous solution are crystals containing crystal water. Melting point 105 ℃. Soluble in water and methanol. There is optical rotation activity and variable rotation phenomenon. The abundance in marine plankton is generally greater than arabinose. It is also found in seawater, particulate matter and sediments. It can exist in free or combined form.
Rhamnose is divided into α-type and β-type: α-type, a component of multiple glycosides. The melting point is 82~92 ℃, which will change the spin effect. Optical rotation [α]D20-7.7 ° & rarr;+8.9 °. β-type, from acetone to form needle crystals. Melting point 122~126 ℃. Optical rotation [α]D20 31.5 °, soon the same as α-type. β-type is hygroscopic and becomes α-type crystal when exposed to humid air. The sweetness is 33% of sucrose.
rhamnose is widely distributed in plants as a trace sugar. It can be found in many kinds of plant glycosides (such as quercetin, isohesperidin, etc.), polysaccharides, especially pectin and gum, and can also be found in sumac tree toxin. Rhamnose can be used to determine the permeability of the intestine, can be used as a sweetener, can reduce Ferin (Fehling) solution, and sodium amalgam can react to produce rhamnol. It can be hydrolyzed by rhamnoside (Xanthorhamnin) and quercetin (Quercitin).
physical and chemical properties
when crystallizing from aqueous solution, there is a molecule of crystal water with a melting point of 93 ℃ and an anhydrous melting point of 122-124 ℃. Soluble in water and methanol, insoluble in ether. The crystalline form is divided into two types: α-type and β-type: α-type, a component of various glycosides. The melting point is 82~92 ℃, which will change the spin effect. Optical rotation [α]D20-7.7 ° & rarr;+8.9 °. β-type, from acetone to form needle crystals. Melting point 122~126 ℃. Optical rotation [α]D20 31.5 °, soon the same as α-type. β-type is hygroscopic and becomes α-type crystal when exposed to humid air. The sweetness is 33% of sucrose. There are D-type and L-type isomers. In water, the [α]D16.5 of D-rhamnose is -8.25, and the [α]D15 of L-rhamnose is 9.1. It can reduce Ferin (Fehling) solution and react with sodium amalgam to produce rhamnol.
Preparation method
The traditional method of producing rhamnose is to extract from natural plants, such as quercetin from oak bark, naringin from citrus peel or vitamin A from bark of Carpinus. The molecules of these substances contain rhamnose groups, which can be hydrolyzed to obtain rhamnose. The pure rhamnose product is obtained through extraction and other chemical unit process operations.
Rutin (quercetin-3-o-glucose-o-rhamnose) is hydrolyzed in 2% dilute H2SO4 for 2h to obtain a mixture of rhamnose and glucose and quercetin.
hydrolysis: rutin is placed in a round bottom flask, 30 times the amount of 2% dilute H2SO4 is added, a reflux device is installed, heated and refluxed for about 2 hours, and the substance in the flask changes from light yellow to bright yellow. Stop heating reflux, cool the substance in the bottle, filter (the filter residue is quercetin), decolorize the filtrate with activated carbon, and then neutralize to neutral with Ca(OH)2.
fermentation: pour the neutralized hydrolysate into the fermentation flask, and add yeast dry powder for constant temperature culture.