Supramolecular amino acid or salt thereof, and preparation method therefor and application thereof

A method for preparing an N-long-chain acyl amino acid dipeptide and/or a salt thereof or a composition comprising the N-long-chain acyl amino acid dipeptide and/or the salt thereof, wherein comprising:

• reacting an amino acid and/or a salt thereof with a long-chain acid halide in the presence of a base, wherein throughout the reaction, the molar ratio of the amino acid to the base is 3:1 to 1:2, preferably 2:1 to 1:1.8, more preferably 1.7:1 to 1:1.7, and most preferably 1.5:1 to 1:1.5.

A method for removing an impurity from a crude N-long-chain acyl amino acid product, wherein comprising:

• mixing the crude N-long-chain acyl amino acid product with a solvent, optionally stirring, and controlling the temperature T of the mixture system in a range of the melting point of a long-chain fatty acid to the melting point of the N-long-chain acyl amino acid, wherein the solvent is water, an organic solvent, or a mixed solution of water and an organic solvent;
• and after the temperature control in the system, separating the solid and liquid phases.

A method for separating components in a solid mixture using the difference in melting point, comprising:

• (a) adding a solvent to the solid mixture, (b) after the addition of the solvent, controlling the temperature T of the system in a range of the melting point of a low-melting-point component to the melting point of a high-melting-point component, (c) after the temperature control in the system, separating the solid and liquid phases, wherein the solvent is a solvent in which the components to be separated are slightly soluble, practically insoluble, or insoluble, wherein slightly soluble, practically insoluble, or insoluble refers to that the solubility of the components to be separated in the solvent at 20° C. is less than 1 g/100 g, preferably less than 0.01 g/100 g, and more preferably less than 0.001 g/100 g;
• the boiling point of the solvent is greater than the melting point of the low-melting-point component, and the temperature T of the system is not higher than the boiling point of the solvent.

An amino acid supramolecule, comprising a supramolecular structure self-assembled by an N-long-chain acyl amino acid and an N-long-chain acyl amino acid dipeptide, wherein the percentage content by weight of the N-long-chain acyl amino acid dipeptide is 3% or greater, preferably 5% or greater, more preferably 8% or greater, and most preferably 10% or greater.