A catalyst for degrading polysaccharides, its preparation method and application
By using fumaric acid and hydrogen peroxide to prepare a catalyst to generate hydroxyl radicals, the problems of low polysaccharide degradation efficiency and high cost were solved, achieving efficient and low-cost polysaccharide degradation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGZHOU UNIV
- Filing Date
- 2024-01-17
- Publication Date
- 2026-05-05
AI Technical Summary
Existing polysaccharide degradation methods suffer from high costs and low efficiency. In particular, enzymatic hydrolysis is time-consuming, and organic acid degradation methods involve high temperatures and metal ion residues, which affect industrial production.
A catalyst was prepared using fumaric acid and hydrogen peroxide, and hydroxyl radicals were generated through a mixed reaction to degrade polysaccharides, thereby improving efficiency and reducing costs.
It improves the degradation efficiency of polysaccharides, increases the yield of low molecular weight galactomannan and oligosaccharides, and reduces production costs.
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Figure BDA0004669025530000051 
Figure BDA0004669025530000052
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polysaccharide degradation technology, specifically relating to a catalyst for degrading polysaccharides, its preparation method, and its application. Background Technology
[0002] Currently, small molecule galactomannan and galactomannan oligosaccharides have attracted increasing attention due to their excellent immune-enhancing effects. Their main production processes include enzymatic hydrolysis, acid hydrolysis, and oxidation.
[0003] In enzymatic hydrolysis, the galactose side chains create steric hindrance to β-mannanase's attack on the mannose backbone, necessitating the addition of α-galactosidase to assist in degradation. Furthermore, to improve the yield of galactomannan oligosaccharides, the activity of β-mannanase in the enzyme solution needs to be minimized. Additionally, the long hydrolysis time leads to reduced production efficiency and increased production costs. In recent years, organic acid-catalyzed oligosaccharide preparation technology has been widely studied due to its relatively safe reaction conditions and environmentally friendly process. However, organic acid degradation methods suffer from the drawback of high reaction temperatures (>100℃), which is unfavorable for industrial production. Oxidation methods often utilize hydrogen peroxide, but its degradation efficiency is low. These methods each have their advantages and disadvantages, and all involve cost issues, including time costs and subsequent separation costs. Therefore, there is an urgent need to develop a low-cost, high-efficiency method for oligosaccharide preparation.
[0004] With continuous technological advancements, advanced oxidation techniques, such as the Fenton reaction, have been applied to the degradation of polysaccharides and are constantly being improved and optimized. The Fenton reaction refers to the degradation of organic matter using a strongly oxidizing mixed solution of hydrogen peroxide and ferrous ions. However, this method suffers from the problem of residual metal ions, thereby increasing the subsequent separation costs. Summary of the Invention
[0005] To address the problems existing in the prior art, the present invention aims to design and provide a catalyst for degrading polysaccharides, its preparation method, and its application. The present invention uses fumaric acid and hydrogen peroxide to prepare a catalyst for degrading polysaccharides, significantly improving the polysaccharide degradation efficiency.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] On one hand, the present invention provides a method for preparing a catalyst for degrading polysaccharides, characterized by comprising the following steps:
[0008] Weigh out fumaric acid and hydrogen peroxide, mix them, and prepare the catalyst.
[0009] In the preparation method described above, the molar ratio of fumaric acid to hydrogen peroxide is 0.5-2:0.5-2.
[0010] Secondly, the present invention provides a catalyst for degrading polysaccharides, obtained by the preparation method described above.
[0011] The application of the catalyst in the degradation of polysaccharides.
[0012] The aforementioned application, wherein the degradation method is as follows: weigh the polysaccharide, add a catalyst, carry out degradation, and prepare a degraded polysaccharide solution;
[0013] Preferably, the degradation conditions are: temperature 70-120℃, time 30-120min.
[0014] In the aforementioned application, the polysaccharide is galactomannan.
[0015] In the aforementioned application, the galactomannan is degraded to obtain high molecular weight galactomannan, low molecular weight galactomannan, and galactomannan oligosaccharides.
[0016] The specific process of galactomannan degradation in the aforementioned application is as follows:
[0017] (1) Weigh galactomannan, add a catalyst, and degrade it to obtain a polysaccharide degradation solution;
[0018] (2) Centrifuge the polysaccharide degradation solution to obtain the first supernatant, add an organic solvent to obtain the second supernatant and the precipitate, namely high molecular weight galactomannan.
[0019] (3) Add an organic solvent to the second supernatant obtained in step (2) to obtain a third supernatant and a precipitate, namely low molecular weight galactomannan;
[0020] (4) The third supernatant obtained in step (3) is concentrated and dried to obtain galactomannan oligosaccharide.
[0021] In the aforementioned application, the organic solvent is selected from one of ethanol, acetone, or butanol;
[0022] In step (2), the content of organic solvent in the first supernatant is 40%;
[0023] In step (3), the content of organic solvent in the second supernatant is 65%;
[0024] The concentration temperature in step (4) is 50-100℃.
[0025] The application described herein, the preparation method of the galactomannan is as follows: take the seeds of galactomannan, crush them, extract them with hot water to obtain an extract, add an organic solvent to the extract to obtain precipitate A, dry and redissolve it, add protease and centrifuge to obtain supernatant, add an organic solvent to obtain precipitate B, wash and dry precipitate B to obtain galactomannan solid.
[0026] Preferably, the seeds containing galactomannan are Leucaena leucocephala seeds;
[0027] Preferably, the organic solvent is selected from ethanol, acetone or butanol;
[0028] Preferably, the amount of protease added is 5-20 U / g.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] This invention uses a catalyst prepared from fumaric acid and hydrogen peroxide to degrade galactomannan, which can improve the degradation efficiency of polysaccharides, and the yield of low molecular weight galactomannan and galactomannan oligosaccharides is high, thus improving the yield. Detailed Implementation
[0031] The technical solution of the present invention will be further explained and illustrated through the following embodiments.
[0032] Example 1:
[0033] Preparation method of catalyst for degrading polysaccharides:
[0034] Weigh 0.464 g of fumaric acid and measure 419 μL of 30% hydrogen peroxide to prepare the catalyst.
[0035] Example 2:
[0036] The determination of the role of the catalyst of the present invention in the degradation of galactomannan specifically includes the following steps:
[0037] S1. Preparation of catalyst:
[0038] Weigh 0.464 g of fumaric acid and measure 419 μL of 30% hydrogen peroxide to prepare the catalyst.
[0039] S2. Extraction of galactomannan:
[0040] Dry acacia seeds were mechanically pulverized to obtain acacia seed powder. Distilled water was added at a mass ratio of 1:20, and the mixture was extracted at 54℃ for 12 h. The extract was then centrifuged at 7000 rpm for 10 min to obtain the extract. 30% acetone was added to the extract, and the resulting precipitate was frozen at -20℃ for 3 h and then freeze-dried under vacuum for 12 h. The resulting solid was redissolved in distilled water at a mass ratio of 1:20, and protease was added at 10 U / g. The mixture was centrifuged at 7000 rpm for 10 min to obtain the supernatant. Two volumes of 95% ethanol were added to the supernatant, and the resulting precipitate was freeze-dried under vacuum to obtain galactomannan powder. The galactomannan was added to distilled water and stirred at 53℃ and 500 rpm for 12 h to obtain a 5 g / L galactomannan solution.
[0041] S3, Degraded galactomannan:
[0042] Measure 20 mL of 5 g / L galactomannan solution, add catalyst, react at 90 °C for 75 min, and obtain degradation solution after centrifugation.
[0043] S4. Preparation of high molecular weight galactomannan:
[0044] The degradation solution was centrifuged at 7000 rpm for 10 min to obtain the first supernatant. 10 mL of the first supernatant was taken and 7 mL of 95% ethanol was added to make the ethanol content 40%. The mixture was centrifuged at 7000 rpm for 10 min to obtain a 40% precipitate. Precipitate A and the second supernatant were prepared. Precipitate A is a high molecular weight galactomannan.
[0045] S5. Preparation of low molecular weight galactomannan:
[0046] 15 mL of 95% ethanol was added to the second supernatant obtained in step S4 to make the ethanol content 65%. The mixture was centrifuged at 7000 rpm for 10 min to obtain a 65% precipitate, thus preparing precipitate B and the third supernatant. Precipitate B is a low molecular weight galactomannan.
[0047] S6. Preparation of galactomannan fractionation solution:
[0048] The third supernatant obtained in step S5 is concentrated at 70°C and then dried to prepare galactomannan oligosaccharide.
[0049] Comparative Example 1:
[0050] The catalyst is prepared by the following steps: weighing 0.7045 g of ascorbic acid and measuring 419 μL of 30% hydrogen peroxide to obtain the catalyst.
[0051] Example 3: Detection Test
[0052] 1. The catalysts prepared in Example 1 and Comparative Example 1 were tested by alizarin violet method. The control group of Example 1 and the control group of Comparative Example 1 were set up and tested by alizarin violet method. After alizarin violet undergoes redox reaction with hydroxyl radicals, the color of alizarin violet can be lightened or even faded, and the absorbance value gradually decreases.
[0053] The detection method is as follows: Prepare 50 mL of Tris-HCl buffer solution with a pH of 8.9, add alizarin violet to make the concentration 0.5 mM, take the catalyst from the above examples and comparative examples, dilute it 20 times, take 2.5 mL, mix it with 2.5 mL of alizarin violet solution, heat at 70℃ for 2 min, and measure the absorbance using a UV spectrophotometer at a wavelength of 560 nm; the control group is prepared according to the same procedure, except that hydrogen peroxide is replaced with distilled water. Blank examples 1 and 2 are prepared according to the same procedure, except that blank example 1 is alizarin violet solution, and blank example 2 is prepared by replacing the acid solution with water. The results are shown in Table 1.
[0054] Table 1. Results of Alizarin Violet Detection Method
[0055] sample absorbance Blank example 1 1.336 Blank example 2 1.323 Example 1 0.725 Example 1 Control Group 1.319 Comparative Example 1 1.328 Comparative Example 1 (Control Group) 1.332
[0056] As shown in Table 1, a large number of hydroxyl radicals are present in the catalyst of Example 1 of the present invention, while no hydroxyl radicals are detected in the catalyst prepared in Comparative Example 1. This indicates that fumaric acid can react with hydrogen peroxide to generate hydroxyl radicals. This is because the carbon-carbon double bond in fumaric acid reacts with hydrogen peroxide, while ascorbic acid, which has strong reducing properties, does not exhibit this characteristic.
[0057] 2. The degradation product obtained in Example 2 is designated as Sample 1. The catalyst prepared in Comparative Example 1 is subjected to fractional degradation using the same method as in Example 2, and the resulting degradation product is designated as Control 1.
[0058] (1) The sugar content of the high molecular weight galactomannan, low molecular weight galactomannan and galactomannan oligosaccharides obtained in Example 2 and Comparative Example 1 was determined by acid hydrolysis and ion chromatography, and the monosaccharide content was determined by ion chromatography.
[0059] The determination method is as follows:
[0060] Take 0.01–0.02 g of high molecular weight galactomannan, low molecular weight galactomannan and galactomannan oligosaccharide samples and place them in a 5 mL centrifuge tube. Add 1.5 mL of distilled water and 1.5 mL of 8% H2SO4 and react at 121 °C for 1 h. After the reaction is complete, adjust the pH of the reaction solution to neutral with 40% NaOH solution and centrifuge (7000 rpm, 10 min). Take the supernatant and dilute it 50 times with deionized water.
[0061] The concentrations of mannose and galactose in the hydrolysate were determined using an ICS-5000 ion exchange chromatograph.
[0062] The ion chromatography test conditions were as follows: Chromatograph: Dionex ICS-5000 ion chromatograph; Column: 4×250mm Dionex AminoPac PA10; Guard column: 4×50mm Dionex AminoPac PA10; Detector: Electrochemical detector; Column temperature: 30℃; Mobile phase: 8mmol sodium hydroxide; Flow rate: 0.40mL / min; Injection volume: 1000μL; External standard method was used for determination. The elution program was: 0–25min, 8mM NaOH; 25–35min: 25–8mM NaOH (linear decrease); 35–50min: 8mM NaOH. The content of galactomannan degradation products in the sample was calculated as follows (Formula I), and the detection results are shown in Table 2 below.
[0063] Table 2 Results of Experiment 2
[0064]
[0065] The test results are shown in Table 2. The yields of small molecule galactomannan and galactomannan oligosaccharides in sample 1 were much higher than those in control 1. This may be due to the degradation of polysaccharides by hydroxyl radicals generated in Example 1.
[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been shown above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A method for preparing a catalyst for degrading polysaccharides, characterized in that, Includes the following steps: Weigh out fumaric acid and hydrogen peroxide, mix them, and prepare the catalyst.
2. The preparation method according to claim 1, characterized in that, The molar ratio of fumaric acid to hydrogen peroxide is 0.5-2:0.5-2.
3. A catalyst for degrading polysaccharides, characterized in that, Obtained by the preparation method described in claim 1.
4. The application of the catalyst as described in claim 3 in the degradation of polysaccharides.
5. The application as described in claim 4, characterized in that, The degradation method is as follows: weigh the polysaccharide, add a catalyst, carry out degradation, and prepare a degraded polysaccharide solution; The degradation conditions are: temperature 70-120℃, time 30-120 min.
6. The application as described in claim 4, characterized in that, The polysaccharide is galactomannan.
7. The application as described in claim 6, characterized in that, The degradation of the galactomannan yields high molecular weight galactomannan, low molecular weight galactomannan, and galactomannan oligosaccharides.
8. The application as described in claim 7, characterized in that, The specific process of galactomannan degradation is as follows: (1) Weigh galactomannan, add a catalyst, and degrade it to obtain a polysaccharide degradation solution; (2) Centrifuge the polysaccharide degradation solution to obtain the first supernatant, add an organic solvent to obtain the second supernatant and the precipitate, namely high molecular weight galactomannan; (3) Add an organic solvent to the second supernatant obtained in step (2) to obtain the third supernatant and the precipitate, namely, low molecular weight galactomannan; (4) The third supernatant obtained in step (3) is concentrated and dried to obtain galactomannan oligosaccharide.
9. The application as described in claim 8, characterized in that, The organic solvent is selected from one of ethanol, acetone or butanol; In step (2), the volume content of the organic solvent in the first supernatant is 40%; In step (3), the volume content of the organic solvent in the second supernatant is 65%; The concentration temperature in step (4) is 50-100℃.
10. The application as described in claim 8, characterized in that, The preparation method of the galactomannan is as follows: take seeds containing galactomannan, crush them, extract them with hot water to obtain an extract, add an organic solvent to the extract to obtain precipitate A, dry and redissolve it, add protease and centrifuge to obtain supernatant, add an organic solvent to obtain precipitate B, wash and dry precipitate B to obtain galactomannan solid. The seeds containing galactomannan are Leucaena leucocephala seeds; The organic solvent is selected from one of ethanol, acetone or butanol; The amount of protease added is 5-20 U / g.