CN104774254A

CN104774254A - Method for extracting keratin in feather by using imidazole chloride ionic liquid

Info

Publication number: CN104774254A
Application number: CN201510144957.8A
Authority: CN
Inventors: 陈晋阳; 丁巳芫; 邹米华; 季益梅; 杨玄宇
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2015-07-15

Abstract

The invention relates to a method for extracting keratin in a feather, which belongs to the technical field of extraction technology for keratin. According to the invention, an imidazole chloride ionic liquid is used as a main medium, and a small amount of Na2SO3 is added for dissolving and extraction of keratin in the feather. The method comprises the following steps: adding, by weight, 3 to 10% of the feather, 60 to 80% of the imidazole chloride ionic liquid [Bmim]Cl or [Amim]Cl, 5 to 15% of Na2SO3 and 10 to 20% of water into a beaker; placing the beaker on a magnetic stirrer, carrying out stirring and heating to 80 to 110 DEG C, wherein stirring and heating time is 50 to 80 min, and carrying out pumping filtration while the obtained mixture is still hot; cooling the obtained filtrate to room temperature, adding pure water 2 to 5 times of the volume of the filtrate under stirring, continuing slow stirring for 0.5 to 1 h and then carrying out standing for 1 to 3 h, wherein due to decrease of the concentration of the ionic liquid in a system, feather keratin dissolved in the system is precipitated anew; subjecting the precipitated keratin to pumping filtration and carrying out separating so as to obtain a keratin solid, wherein the yield of the keratin solid is 50.6 to 78.3%; and subjecting the filtrate from which the keratin is separated to rotary evaporation so as to remove water, wherein the obtained ionic liquid and Na2SO3 can be reused.

Description

Adopt keratic method in imidazolitm chloride class ionic liquid extract feather

Technical field

The present invention relates to one from feather, extract keratic method, belong to keratin protein extraction process technology field.

Background technology

The molecular structure of alpha-helix and beta sheet, so the process extracting wherein protein is very difficult.Traditional dissolving feather extracts keratic method mechanical process, chemical method and biological degradation method.More or less there is the shortcomings such as the keratin molecule amount obtained is lower, productive rate is low, contaminate environment, cost are high, difficult solvent recovery in these methods.Therefore, keratic extracting method in the feather of efficient green is developed necessary.

Ionic liquid is also referred to as ionic liquid at room temperature or low temperature molten salt, owing to being composed entirely of ions, there is the much character being different from common molecular solvent, as non-volatile, liquid journey wide ranges, Heat stability is good, dissolving power is strong, character is adjustable, nonflammable etc., thus be regarded as solvent the most rising in Green Chemistry and cleaning procedure, be widely used in electrochemistry, separation, chemical reaction and material are prepared etc.Therefore, employing ionic liquid extracts the Keratin sulfate in feather under mild conditions, highly studies.

Summary of the invention

1, a kind of keratic method in employing imidazolitm chloride class ionic liquid extract feather, is characterized in that having following process and step:

A. feather is clean, dry;

B. by feather, imidazolitm chloride class ionic liquid [Bmim] Cl or [Amim] Cl, Na ₂sO ₃add in beaker by certainweight per-cent with water.Each component proportion is: ionic liquid (60 ~ 80%), water (10 ~ 20%), Na ₂sO ₃(5 ~ 15%), feather (3 ~ 10%);

C. above-mentioned beaker is positioned on magnetic stirring apparatus and is stirred and heated to 80 ~ 110 DEG C, make feather dissolve 50 ~ 80min under agitation, stop stirring, while hot by above-mentioned mixed system suction filtration, isolate undissolved feather solid residue;

D. by above-mentioned isolated filtrate, after cool to room temperature, under the condition constantly stirred, add the pure water of filtrate volume 2 ~ 5 times, after water injection continue afterwards slowly to stir 0.5 ~ 1h, then leave standstill 1 ~ 3h; Due to the reduction of system intermediate ion strength of fluid, the feather keratin be dissolved in wherein can be separated out again;

E. by the feather keratin suction filtration of above-mentioned precipitation, be separated and obtain Keratin sulfate solid; Put it in baking oven dry, its yield is 50.6 ~ 78.3%; Filtrate is removed after moisture through rotary evaporation, ionic liquid and Na ₂sO ₃can reuse.

feature for the present invention and mechanism

The Na of keratolysis is promoted for opening cystine linkage ₂sO ₃adding water in the keratic process of precipitation, the cystine linkage opened recovers, Na ₂sO ₃then separate from keratin molecule chain and be dissolved in ionic liquid/aqueous solution.

Accompanying drawing explanation

Fig. 1 is hydrogen bond and ionic liquid [Bmim] Cl effect schematic diagram between mesoptile keratin molecule of the present invention;

Fig. 2 is the feather dissolution process photo in the present invention;

Fig. 3 is that in the present invention, Keratin sulfate adds water the photo of middle precipitation;

Fig. 4 is the keratic infrared spectrum extracted in the present invention;

Fig. 5 is the chromatography of ions figure of mesoptile of the present invention and the keratin hydrolysate extracted and standard amino acid.

Embodiment

Embodiment one

Drake feather is clean with deionized water rinsing, dry 24h at putting into 40 DEG C, baking oven.Take the drake feather 0.5g of clean dry, add in 100ml beaker.8g ionic liquid [Bmim] Cl, 2g deionized water and 1gNa is added in beaker ₂sO ₃.Beaker is placed on magnetic force heating stirrer, is warming up to 90 DEG C under agitation, at this temperature stirring and dissolving 60min.After 60min, suction filtration while hot, isolates filtrate.When liquid to be filtered is cooled to room temperature, under the condition stirred, in filtrate, slowly add about 30ml deionized water, first slowly stir about 0.5h after water injection, then leave standstill about 2h.By the Keratin sulfate suction filtration of separating out, be separated and obtain Keratin sulfate solid, place 40 DEG C of baking ovens and dry 24h, Keratin sulfate yield is 75.1%.

Isolate the filtrate of Keratin sulfate solid, removed moisture with Rotary Evaporators, ionic liquid and Na ₂sO ₃mixture can reuse.

In order to understand protein contingent change in leaching process, respectively feather and the hydrochloric acid soln of the Keratin sulfate 6mol/L extracted are hydrolyzed 24 hours at 110 DEG C, hydrolyzed solution amino acidanalyser carries out amino acid analysis.

to the explanation explanation of each accompanying drawing

Fig. 1 is the schematic diagram acted between hydrogen bond and ionic liquid [Bmim] Cl between keratin molecule.Due to Intermolecular Forces complicated between feather keratin molecular chain, it is difficult to dissolve in most of solvent, its Intermolecular Forces of effective destruction is the prerequisite that keratolysis is extracted, therefore, first solvent used needs to destroy the effect between keratin molecule, makes keratin molecule free out.Glyoxaline ion liquid keratin has good dissolving power, wherein with Cl ^-for the glyoxaline ion liquid of negatively charged ion, due to Cl ^-strong polarity, easily form hydrogen bond, be very beneficial for destroying the hydrogen bond between keratin molecule, thus accelerate dissolution.

Fig. 2 shows the photo of 0.5g feather 90 DEG C of dissolution process in 8g ionic liquid, 2g water and 1gNa2SO3 system.Along with the increase of time, the accessory pinna of feather dissolves quickly, and when 20min, accessory pinna major part is dissolved.When 40min, undissolved mainly feather bar, dissolves completely when 60min.

Fig. 3 is that in the present invention, Keratin sulfate adds water the photo of middle precipitation.

For the Keratin sulfate extracted, Fig. 4 is its infrared spectrogram.It is at 3295cm ^-1near have the charateristic avsorption band of polypeptide (-CO-NH-), 1646,1524,1233cm ^-1namely amide Ⅰ, acid amides II are with and Amide Ⅲ band place also has and absorbs more by force, and visible extract has peptide characteristic, containing amido linkage, belongs to protein.Be with and Amide Ⅲ band in conjunction with amide Ⅰ, acid amides II, be shown to be the protein of secondary structure that there is beta sheet, random coil.Therefore, this method is extracted Keratin sulfate and can be kept well with beta sheet for main secondary structure from feather.In dissolution process just cystine linkage, hydrogen bond, salt type bond etc. maintain three, the destruction of quaternary structure.

Fig. 5 is the chromatography of ions figure of feather and keratin hydrolysis liquid and standard amino acid, feather and the main amino acid appearance time of Keratin sulfate substantially identical, showing that the keratic amino acid composition extracted does not change compared with feather, should be identical protein.

Claims

1. adopt a keratic method in imidazolitm chloride class ionic liquid extract feather, it is characterized in that there is following process and step:

A. feather is clean, dry;

B. by feather, imidazolitm chloride class ionic liquid [Bmim] Cl or [Amim] Cl, Na ₂sO ₃add in beaker with water by certainweight per-cent; Each component proportion is: imidazolitm chloride class ionic liquid (60 ~ 80%), water (10 ~ 20%), Na ₂sO ₃(5 ~ 15%), feather (3 ~ 10%);