Method for preparing thioalkyl/alkenyl cysteine sulfoxide by fractional crystallization

A cysteine ​​sulfoxide, fractional crystallization technology, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve problems such as by-products and impurities, affecting product purity, toxicity, etc., to avoid Effect of complex process, high product purity and increased yield

Active Publication Date: 2014-11-12
JIANGNAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, there are also some disadvantages: firstly, because the free mercapto and allyl groups in the reactant are too reactive, many by-products and impurities are easily generated, and the purity of the product cannot be guaranteed; secondly, the product is an enantiomer with left-handed (-) and The two forms of dextrorotation (+) affect the purity of the product
Moreover, the product is easy to form a racemate, which has no optical activity, and its physiological activity is uncertain compared with natural products, and may even be toxic. Therefore, the enantiomers in the product must be separated, and only natural D-cysteine ​​sulfoxide

Method used

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  • Method for preparing thioalkyl/alkenyl cysteine sulfoxide by fractional crystallization
  • Method for preparing thioalkyl/alkenyl cysteine sulfoxide by fractional crystallization
  • Method for preparing thioalkyl/alkenyl cysteine sulfoxide by fractional crystallization

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] Example 1: Preparation of (+)S-methyl-L-cysteine ​​sulfoxide ((+)MCSO)

[0046] (1) Take L-cysteine ​​hydrochloride (1mol) and evenly disperse in 3L absolute ethanol, add 3.5mol sodium hydroxide solution (20mol / L) dropwise under magnetic stirring at room temperature, and continue stirring for 5min ; Then add 1.1mol methyl bromide and keep the temperature constant for 6 hours to generate a crude solution of deoxythiomethylcysteine ​​sulfoxide (MCS). The solution was transferred to a clean container, and the pH was adjusted to 5.2 with acid at 30°C. White deoxygenated MCS crystals were formed at 4°C for 12h.

[0047] (2) Filter the MCS crystals obtained in step (1), dry them at 40°C, redissolve them in 10 mL of distilled water containing 1% glacial acetic acid, and heat to boiling. Pour the solution into 150 mL of boiling absolute ethanol for recrystallization. At this time, the MCS crystals will stand upside down in the solvent and the solution will become cloudy. The ...

Embodiment 2

[0052] Example 2: Preparation of (+) S-allyl-L-cysteine ​​sulfoxide ((+) 2-PeCSO)

[0053] (1) Take L-cysteine ​​(1mol) and evenly disperse it in 3L absolute ethanol, add 3.5mol sodium hydroxide solution (20mol / L) dropwise under magnetic stirring at room temperature, and continue stirring for 10min; then add 1.1mol of allyl bromide was reacted at room temperature for 6 hours to generate a crude solution of deoxythioallyl cysteine ​​sulfoxide (2-PeCS). The solution was transferred to a clean container, and the pH was adjusted to 5.5 with acid at 30°C. White deoxygenated 2-PeCS crystals were formed at 4°C for 12h.

[0054] (2) Filter the 2-PeCS crystal obtained in step (1), dry it at 50°C, then redissolve it in 10 mL of distilled water containing 1% glacial acetic acid, and heat it to boiling. Pour the solution into 150 mL of boiling ethanol for recrystallization. The solution was placed at 4°C for 12 hours for recrystallization, and the crystals were filtered and dried at 50°...

Embodiment 3

[0058] Example 3: Preparation of (+) S-propyl-L-cysteine ​​sulfoxide ((+) PCSO)

[0059] (1) Take L-cysteine ​​(1mol) and evenly disperse it in 3L absolute ethanol, add 3.5mol sodium hydroxide solution (20mol / L) dropwise under magnetic stirring at room temperature, and continue stirring for 10min; then add 1.1mol of 1-bromopropane was reacted at room temperature for 6h to generate a crude solution of deoxythiopropyl cysteine ​​sulfoxide (PCS). The solution was transferred to a clean container, and the pH was adjusted to 5.18 with acid at 30°C. White deoxidized PCS crystals were formed at 4°C for 12h.

[0060] (2) Filter the PCS crystals obtained in step (1), dry them at 50°C, then redissolve them in 10 mL of distilled water containing 1% glacial acetic acid, and heat to boiling. Pour the solution into 150 mL of boiling ethanol for recrystallization. The solution was placed at 4°C for 12 hours for recrystallization, and the crystals were filtered and dried at 50°C to obtain a...

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Abstract

The invention discloses a method for preparing thioalkyl / alkenyl cysteine sulfoxide by fractional crystallization, belonging to the technical field of compound preparation. The method comprises the following steps: adding cysteine or cysteine salts, a sodium hydroxide solution and an R group (alkyl or alkenyl)-derived material into absolute ethanol in sequence for reaction to synthesize coarse ACSs, re-crystallizing ACSs, purifying, oxidizing to form ACSOs, and fractionally crystallizing to obtain natural dextrorotatory ACSOs, wherein the R group-derived material is replaced to synthesize different types of ACSOs in allium; enantiomers in racemes are separated by adopting the fractional crystallization method to obtain natural dextrorotatory ACSOs with optical activity. Compared with a conventional extraction method, the method has the characteristics that the yield and the purity are high, a conventional complicated extraction process is avoided, the product has the optical activity, and the physical property is close to that of natural extract; the product is used in the fields of health products, pharmaceuticals and the like, the effects of resisting bacteria and cancers, reducing blood fat and the like of ACSOs are brought into play, or the product serves as an intermediate such as an active ingredient-diallyl thiosulfinate for synthesizing allium.

Description

technical field [0001] The invention relates to a method for chemically preparing thioalkyl (alkenyl) cysteine ​​sulfoxides (ACSOs), belonging to the technical field of compound preparation. Background technique [0002] Studies have confirmed that the thioalkyl (alkenyl) cysteine ​​sulfoxides (ACSOs) rich in allium plants have antibacterial, antiviral, blood lipid-lowering, anti-aging, anti-tumor, and promotion of cancer cell apoptosis, etc. Physiologically active, with strong medicinal value. [0003] Common ACSOs in Alliums include: S-methyl-L-cysteine ​​sulfoxide (MCSO); S-ethyl-L-cysteine ​​sulfoxide (ECSO); S-propyl-L- Cysteine ​​sulfoxide (PCSO); S-propenyl-L-cysteine ​​sulfoxide (2-PeCSO); S-allyl-L-cysteine ​​sulfoxide (1-PeCSO); S -Butyl-L-cysteine ​​sulfoxide (BCSO). [0004] Alliin is the most important ACSOs in allium plants. Alliin, ginkgo leaf extract and ginsenoside are known as the three most important and promising drugs in the 21st century. [0005] At...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C317/48C07C315/02
Inventor 孔祥珍陈海桥华欲飞丁秀臻张彩猛陈业明
Owner JIANGNAN UNIV
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