NEWS

Why is methyl beta cyclodextrin soluble in water? Because there are still many oxygen atoms in methyl beta cyclodextrin, it can form hydrogen bonds with water molecules, so it is easy to dissolve in water. The solubility of methyl beta cyclodextrin is 15 times higher than that of beta cyclodextrin.

The solubility of three cyclodextrins was compared. β- The solubility of cyclodextrin is much lower than that of alpha cyclodextrin and gamma cyclodextrin. 

This is because beta cyclodextrin（β- The hydroxyl position in cyclodextrin) is more suitable to form stronger intermolecular hydrogen bonds as a whole, so it is easy to form larger aggregates, so as to reduce the solubility.

Why does the formation of stronger hydrogen bonds reduce the solubility? If it forms stronger hydrogen bonds with water molecules, the solubility will increase, because the force with water is stronger, and it is easier to disperse in water; However, if a stronger hydrogen bond is formed between beta cyclodextrin molecules, it is easy to form larger aggregates. In this way, beta cyclodextrin is easier to aggregate and settle, thus reducing the solubility.

And when beta cyclodextrin（β- After a small amount of hydroxyl hydrogen in cyclodextrin) is replaced by methyl, methyl- β- Hydrogen bonds are no longer easy to form between cyclodextrin molecules; But methyl- β- Cyclodextrin can still form considerable hydrogen bonds with water molecules, so methyl- β- Cyclodextrins have excellent solubility, even 15 times that of other cyclodextrins.