Application and Synthesis of Thiol β - Cyclodextrin

The full name of mercapto β - cyclodextrin is 6-mercapto β - cyclodextrin, and its chemical formula is C ₄₂ H ₇₀ O ∝₄ S. It appears as a white to light yellow crystalline powder and is easily soluble in water.

application

Thiol β - cyclodextrin (CDs SH) can be used for surface modification of nanoparticles such as gold, platinum, and silver, giving these nanocomposite systems both the electrical, magnetic, and catalytic properties of metal nanoparticles and the molecular recognition ability of supramolecular host compounds [1]. In addition, it can improve the solubility and stability of drugs, achieve stable drug transport and controlled release, and be used for delivering hydrophobic drugs. By encapsulating drug molecules, its solubility in water can be increased. It can be combined with fluorescent dyes or other probes for biological imaging and molecular tracking.

synthesis

Step 1: Synthesis of Mono-6-O-tosyl β - CD

Add 30.0 g of β - cyclodextrin and 7.8 g of p-toluenesulfonyl chloride to 720 mL of deionized water. After stirring for 2-3 hours, add 120 mL of 2.5 mol · L-1 NaOH aqueous solution and continue stirring for about 30 minutes. Filter to remove insoluble substances and collect the filtrate. Add approximately 36.0g of ammonia water to the filtrate and adjust the pH to 8. Place the solution in the refrigerator for 12 hours. Then filter the solution to obtain a white insoluble solid. After washing the solid three times with deionized water, it was recrystallized with water to obtain bright white plate-like crystals. The crystals were vacuum dried and dried at 50 ℃ to obtain 6.0 g of white powdery solid. The molecular structure of the product is determined by 1H-NMR spectrum and IR spectrum.

Step 2: Synthesis of 6-SH - β - CD

Weigh 4.0 g of mono-6-O-tosyl β - CD and 4.4 g of thiourea, add 200 mL of mixed solvent (methanol: water=80:20), and reflux for 2 days. Evaporate the solvent under reduced pressure, add 60mL of methanol to the residue and stir for 1.5 hours, then soak for 1 day and filter to obtain a white solid. The obtained solid was dissolved in 140mL of 10% NaOH solution, stirred at 50 ° C for 5 hours, and then adjusted to pH 2 with 10% HCl solution. 10 mL of trichloroethylene was added and stirred for 1 day. A white solid precipitated, filtered, and the obtained solid was vacuum dried at 50 ° C to obtain 2.2 g of white powdery solid mercapto-β - cyclodextrin. The product is recrystallized using water.

reference

[1]Liu J,Alvarez J,Ong W,et al.Phase transfer of hydrophilic,cyclodextrin-modif-ied gold nanoparticles to chloroform solutions[J].Journal of the American Chemical Society,2001,123(45):11148-11154.