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Preparation method of alpha-arbutin

A technology of arbutin and glucopyranoside, which is applied in the field of preparation of α-arbutin, can solve the problem of low yield of the target product of α-arbutin, and achieve the effect of easy preparation

Inactive Publication Date: 2006-01-25
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This shows that the chemical preparation method of existing α-arbutin has the defect that the yield of target product is low

Method used

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Examples

Experimental program
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Effect test

preparation example Construction

[0013] The preparation method of said α-arbutin of the present invention comprises the steps:

[0014] (1) Synthesis of 4-hydroxyphenyl-2', 3', 4', 6'-tetra-O-benzyl-1'-O-α-D-glucopyranoside:

[0015] Under the protection of an inert gas, the active sugar donor 2,3,4,6-tetra-O-benzyl-1-O-α-D-glucosyl trichloroacetimidate was dissolved in a solvent, and the Lewis acid Under catalysis, carry out glycosylation reaction with hydroquinone at -80°C-30°C to obtain the intermediate 4-hydroxyphenyl-2',3',4',6'-tetra-O-benzyl- 1'-O-α-D-glucopyranoside;

[0016] Wherein: the used solvent of glycosylation reaction is dichloromethane (CH 2 Cl 2 ), chloroform (CHCl 3 ), 1,2-dichloroethane (CH 3 ClCH 3 Cl), acetonitrile (CH 3 CN), benzene (C 6 h 6 ), toluene, tetrahydrofuran or acetone; said Lewis acid is trimethylsilyl trifluoromethanesulfonate (TMSOTf), boron trifluoride ether (BF 3 ·Et 2 O), aluminum chloride (AlCl 3 ), zinc chloride (ZnCl 2 ), tin tetrachloride (SnCl 4 ), p...

Embodiment 1

[0022] 205.4mg (0.3mmol) 2,3,4,6-tetra-O-benzyl-1-O-α-D-glucosyl trichloroacetimidate, 49.5mg (0.45mmol) hydroquinone and Add an appropriate amount of 4 Å MS to 15ml of dry dichloromethane, stir for 15 minutes, cool to -60°C, and add 29.0μl (33.3mg, 0.15mmol) trimethylsilyltrifluoromethanesulfonate dropwise under the protection of argon. The dichloromethane solution of the acid ester was added dropwise in 20 minutes, and the temperature was naturally raised to 20°C, and the reaction was continued for about 1.5 hours, and detected by TLC. Wash with brine (10ml×3), collect the lower layer, dry over anhydrous magnesium sulfate, filter with suction, rotary evaporate, separate by column chromatography, and elute with petroleum ether (60-90°C): ethyl acetate = 9-7:1 , to obtain 122.7mg of 4-hydroxyphenyl-2',3',4',6'-tetra-O-benzyl-1'-O-α-D-glucopyranoside, with a yield of 64.7%. R f =0.48 (petroleum ether:ethyl acetate=3:1). m.p.149-151°C.

[0023] Elemental analysis: calculated...

Embodiment 2

[0030] 136.9mg (0.2mmol) 2,3,4,6-tetra-O-benzyl-1-O-α-D-glucosyl trichloroacetimidate, 26.4mg (0.24mmol) hydroquinone and Add an appropriate amount of 4 Å MS to 15ml of dry dichloromethane, and add dropwise the dichloromethane solution containing 11.6μl (13.3mg, 0.06mmol) trimethylsilyltrifluoromethanesulfonate at 30°C under the protection of argon After 20 minutes, the dropwise addition was completed, and the reaction was continued for about 1 hour, and TLC was detected. After the reaction was complete, suction filtration was added, 2ml of saturated aqueous sodium bicarbonate solution was added, stirred for 10 minutes, washed with saturated saline (10ml×3), and the lower layer was collected. Magnesium sulfate over water was dried overnight, filtered with suction, rotary evaporated, separated by column chromatography, and eluted with petroleum ether (60-90°C): ethyl acetate = 9-7: 1 to obtain 72.1 mg of colorless transparent syrup 4-hydroxyphenyl -2', 3', 4', 6'-tetra-O-benzyl...

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Abstract

The invention relates to a process for preparing niacin which mainly comprises the following steps, at the presence of inert gas, charging active sugar donor 2,3,4,6-tetra-benzyl-1-O-alpha-D glucosly tri-chloroacetyl imine into solvent, at the presence of Lewis acid catalysis, carrying out glycosylated reaction with hydroquinone at -100 ~ 35 deg. C, thus obtaining intermediate compound 4-hydroxyphenyl-2',3',4',6'-tetra-O-benzyl-1'-O-alpha-D-glucopyranoside, finally carrying out hydro-genolysis reaction to obtain the destination product.

Description

Technical field [0001] The invention relates to a preparation method of α-arbutin. Background technique [0002] Arbutin, usually referred to as 4-hydroxyphenyl-1’-O-β-D-glucopyranoside, is widely found in Ericaceae and Rosaceae plants. In addition to having a variety of pharmacological effects, arbutin is also an inhibitor of tyrosinase in human melanocytes. It competes with dopa for the acceptance site on tyrosinase, which can significantly reduce the production of melanin and prevent epidermal The pigmentation on the skin makes the skin fair and tender. Therefore, it is a safe and efficient whitening agent. [0003] α-Arbutin (α-Arbutin) is 4-hydroxyphenyl-1’-O-α-D-glucopyranoside. Its inhibitory activity against human tyrosinase is significantly better than β-arbutin, and its IC 50 value (concentration at which 50% of enzyme activity is inhibited) is 2.1mM, while the IC of β-arbutin 50 The value is greater than 30mM. In addition, α-arbutin is easier to maintain a s...

Claims

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Application Information

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IPC IPC(8): C07H15/203
Inventor 陈国荣王朝霞施小新
Owner EAST CHINA UNIV OF SCI & TECH
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