Surfactant and preparation method thereof

Abstract

The invention provides a surfactant and a preparation method thereof. The method comprises reformation of a surfactin, wherein the reformation of the surfactin comprises the sub-steps of: sequentially adding a 1-ethyl-(3-dimethylaminopropyl) carbonyl diimine hydrochloride catalyst, a 4-dimethylamino-pyridine catalyst and an N-glycol reactant into a surfactin solution; after materials are added, mixing the mixture at 18-35 DEG C for a reaction for 10-30 hours to obtain a surfactin esterification product with hydroxyl; an adding catalysts accounting for 1-10 times by molar weight and the N-glycol accounting for 2-10 times by molar weight into each mole of the surfactin. The preparation method disclosed by the invention has the advantages of complete reaction and little side reaction; and the obtained esterification product has a simple structure. Compared with original surfactin, the surfactin esterification product with the hydroxyl has the advantages of being in higher in surface activity (CMC(Critical Micelle Concentration) is reduced by one order of magnitude), forming a hole-shaped structure on a phospholipid double-layer membrane more efficiently and having a steadier pore membrane structure as well as better biomembrane activity.

Description

technical field [0001] The invention relates to a surfactant and a preparation method thereof, in particular to a modification method of surfactin. Background technique [0002] Lipopeptides are an important class of biosurfactants, which have attracted people's attention due to their excellent surface activity and biological activity. Surfactin is one of the most well-known lipopeptides. In order to improve the surface activity and biological activity of surfactin, scientists have modified the primary structure of surfactin. The methods currently used include lactone ring opening ring, peptide ring amino acid substitution, side chain carboxylic acid group esterification, amidation and total synthesis methods. At present, the more commonly used esterification method mainly adopts the method of Lewis acid catalysis to realize, and its main reaction process is as follows: Surfactant (10mg) is dissolved in the chloroform / methanol (2: 1, v / v) of 20mL, Then, different volumes o...

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Problems solved by technology

[0004] As can be seen from the above, the esterification method reported in the prior art is mainly the hydrochloric acid catalyzed methyl esterification method, the reaction takes a long time, and the alcohol consumption is large and excessive, which not only causes waste of chemicals but also brings environmental pollution; The side chain includes two carboxylic acid groups, which leads to the existence of two possible structural compounds of monoester and diester in the product obtained by the prior art, and the product is not single; at the same time, the result of monomethylation destroys the saddle shape of surfactin Structural characteristics, while the dimethyl esterification product makes the peptide ring lose two hydrophilic sites on the side chain, resulting in a decrease in biological activity or interface activity

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