CN1687144A - Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide - Google Patents

Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide Download PDF

Info

Publication number
CN1687144A
CN1687144A CNA2005100736995A CN200510073699A CN1687144A CN 1687144 A CN1687144 A CN 1687144A CN A2005100736995 A CNA2005100736995 A CN A2005100736995A CN 200510073699 A CN200510073699 A CN 200510073699A CN 1687144 A CN1687144 A CN 1687144A
Authority
CN
China
Prior art keywords
chitosan
pacu
cmps
molecular weight
acid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CNA2005100736995A
Other languages
Chinese (zh)
Other versions
CN100447161C (en
Inventor
张岐
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hainan University
Original Assignee
Hainan University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hainan University filed Critical Hainan University
Priority to CNB2005100736995A priority Critical patent/CN100447161C/en
Publication of CN1687144A publication Critical patent/CN1687144A/en
Application granted granted Critical
Publication of CN100447161C publication Critical patent/CN100447161C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Landscapes

  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Abstract

The present invention relates to a method for preparing chitosan oligosaccharide with narrow molecular weight distribution by utilizing microwave-aided degradation. Said method includes the following steps: using edible acetic acid, citric acid, tartaric acid and lactic acid to dissolve high-molecular chitosan solid to obtain solution, adding the chemically-synthetic and pulverized and sieve copper p-dibenzoate (II) solid metal coordination high polymer granule PACu-CMPS particles into the above-mentioned solution under the condition of stirring, regulating pH value to make the amino-group in the chitosan and PACu-CMPS granule surface bare metal ion have weak coordination bond formation, adding oxidant at room temperature, uniformly mixing them, microwave irradiation to make degradation, filtering and separating out degraded liquor, low-temperature or room-temperature concentrating so as to obtain the solid powder product.

Description

A kind of method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide
Technical field
The present invention relates to a kind of fast and convenient method for preparing narrow molecular weight distributed Chitosan poly oligosaccharide.
Background technology
The present invention relates to a kind of utilize amino and chemosynthesis in the chitosan to dibenzoic acid copper (II) solid metal coordination polymer particle (be called for short: PACu-CMPS) the surface exposure metal ion combines by weak coordination bond, through add the oxidizer catalytic oxidation and degraded under microwave irradiation, filter, and other aftertreatments preparations be rich in the method for narrow molecular weight distributions oligosaccharide.More specifically saying so goes out the template adsorbing base of dibenzoic acid copper (II) solid metal coordination polymer particle as the absorption chitosan with chemosynthesis, reaches certain particle size through grinding efflorescence.The undissolved PACu-CMPS of slightly acidic joined be dissolved in the plain chitosan aqueous solution after deacetylated of the biological carapace that contains 0.5% acetic acid; with the PACu-CMPS particle surface is matrix; make part in the chitosan amino be exposed to the PACu-CMPS particle surface, free hapto the is arranged metallic ion coordination of (or replacing water molecules), promptly the mode of the metal formation weak coordination bond by amino of chitosan and PACu-CMPS particle surface is adsorbed in tiny PACu-CMPS surface with the chitosan superpolymer.By the distance between the PACu-CMPS particle surface bare metal ion, promptly metal ion is at the equal distribution density of PACu-CMPS stromal surface.Low temperature adds complex-catalyzed oxidation of available metal and responsive to temperature type oxygenant, stirs, and microwave irradiation starts catalytic oxidation, near the rapid cracking chitosan macromolecular chain all metal ions position of PACu-CMPS stromal surface.The size and the range of molecular weight distributions of oligosaccharides number-average molecular weight after distance between each bare metal ion of PACu-CMPS particle surface and the big young pathbreaker of equal distribution density determine to degrade.Because used PACu-CMPS is the slightly acidic insolubles, can product be separated with catalytic matrix by filtering, obtain number-average molecular weight and range of molecular weight distributions through necessary aftertreatment again and meet peculiar bio-physiological activity, medical health care function requirement, improve effects such as animals and plants immunity etc., the oligosaccharide of extensive use is arranged.PACu-CMPS can use repeatedly simultaneously.
At present, the method that domestic and international degradation of chitosan prepares low-molecular water-soluble chitosan mainly contains enzyme liberating method, oxidation degradation method, acid degradation method, secondly also has microwave method, supersonic method, radiation method etc.Existing enzyme liberating method mainly depends on chitoanase, lipase, N,O-Diacetylmuramidase and other non-specificity lytic enzymes, although can single-minded cut-out glycosidic link, the whole piece macromolecular chain is evenly cut to obtain aspect the homogeneous oligosaccharides also powerless.Its mechanism that obtains the oligosaccharides homogeneity is the distribution of enzyme molecule in chitosan solution, and influence factor is a lot.It is reported that this method can obtain six to eight sugar of certain yield, product food and medical aspect (cancer therapy drug) of many uses, but, promptly lack the possibility of carrying out large-scale industrial production with Financial cost selecting suitable enzyme to remain in difficulty to be fit to large-scale industrialization production and effectively to dispel on the technology that mixes enzyme in the degraded after product; And now be used for the oxidation degradation method of the suitability for industrialized production (produce as " treasured of sturgeon " capsule one Shanghai big health biological products company etc.) of chitosan product, comprise H 2O 2Oxidation style, H 2O 2-NaClO 2Method, H 2O 2-HCl method and some other oxidation degradation method.Oxidation style also can obtain the oligosaccharides than narrow molecular weight distributions of molecular weight about 1000 under the condition exacting terms, but at this moment follow the ratio of degraded generation by product monose to increase greatly (1: 1, or more).In addition, this method is to have introduced various reaction reagents in degradation process to the greatest problem that degradation of chitosan exists, and makes to the control of its degraded side reaction and is increasing difficulty aspect the separation and purification of degraded product; The acid degradation method, it comprises HCl edman degradation Edman, acid-nitrite method, peroxyacetic acid method, reaches other acid hydrolyzations.Wherein the molecular weight distribution of the low-molecular water-soluble chitosan-hydrochloride that obtains with the HCl edman degradation Edman compares broad, but there is report can prepare relatively slightly high-load 12 to 19 (molecular weight is at 2000-3000, and it is narrow relatively to distribute) low-molecular water-soluble chitosan with acid-nitrite method.Acid hydrolyzation and simple oxidation degradation method all are nonspecific degradation processes, the difficult control of its degradation process, though successively be used for suitability for industrialized production, and the chitosan product of various molecular weight ranges can both obtain, but will expect the specified molecular weight scope and have higher yields and chitosan product that can widespread use difficulty relatively then; Other edman degradation Edmans such as microwave method, supersonic method, radiation method etc. also can obtain low-molecular water-soluble chitosan, but still belong to non-specific degradation process, still belong to the fundamental research exploratory stage at present.This shows that the product that all non-specific degradation process degradeds obtain all has a same insurmountable difficult problem: molecular-weight average distributes wide.
Summary of the invention
The method that the purpose of this invention is to provide a kind of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide.What this method was avoided adopting in the present industrial production is all drawbacks and the deficiency that the preparation low-molecular water-soluble chitosan process of mechanism is shown with non-specific degradation process, and a kind of atmosphere of artificial manufacturing specificity degraded is provided.Product can be isolated by filtering, the purpose that makes preparation obtain the narrow molecular weight distributions oligosaccharides is achieved eventually.
The objective of the invention is to be achieved through the following technical solutions:
[1]. the present invention utilizes the template adsorbing base to dibenzoic acid copper (II) solid metal coordination polymer particle (PACu-CMPS) conduct absorption chitosan of chemosynthesis, to be dissolved in the high molecular weight chitosan absorption and the stromal surface of weakly acidic solution, the pH value of regulation system, amino in the chitosan is combined with stromal surface bare metal ion coordination, add oxygenant, use microwave to be output as 10-2500 (W), operating frequency is the microwave generation equipment of 2450 (MHz), the pH value stirs under the condition of 3-7, at 0.5 minute to 72 hours time range degrade chitosan, obtain the narrow molecular weight distributions oligosaccharides.
[2]. the method in the scheme [1], use therein raw materials of chitosan are one of the main extract of shrimp, crab shell and insect, algae and bacterium generation from aquaculture, the marine organisms deacetylated products of chitin.
[3]. the method in the scheme [1] is wherein as follows as the solid metal coordination high polymer compounds process for production thereof of matrix:
Take by weighing terephthalic acid 16.8g and put into stirring tank, add 15cm 3Deionized water is wetting, drips 1%NaOH (weight ratio) under the agitation condition in stirring tank, just dissolves to terephthalic acid, filter, filtrate add again 36% acetate to precipitation fully, suction strainer, filter cake is washed washing 3 times with deionized water.With slowly adding 1%NaOH (weight ratio) filter cake is just dissolved, in the terephthalic acid ammonia soln, add 40 grams, one water acetic acid copper, stirred 0.5-6 hour, the back drips 36% acetate to precipitation and separates out, suction strainer, filter cake moves in the Glass Containers after washing three times with 0.5% acetic acid, add strong aqua to container and make the filter cake dissolving, seal (staying a spilehole), room temperature was placed 1-15 days, separate out particular design and synthetic to dibenzoic acid copper (II) solid metal coordination polymer crystal grain (PACu-CMPS).
[4]. the preparation method in the scheme [3], wherein relating to all raw materials of synthetic and reagent is commercially available technical pure or the higher purity grade of purity.
[5]. the preparation method in the scheme [3], obtain to dibenzoic acid copper (II) solid metal coordination polymer crystal (PACu-CMPS) again drying, grind to collect 50-250 purpose particle, dry back is standby.
[6]. the described method in one of scheme [1] and [2] is characterized in that 0.1-100 is restrained the 10-400cm that the exsiccant chitosan joins 0.1-10% (weight ratio) 3In the aqueous acetic acid, under 0-100 ℃ temperature, the high-molecular weight chitosan is dissolved through 20 minutes-48 hours.
[7]. the method for scheme [1]-[6], it is characterized in that wherein PACu-CMPS is when adding the chitosan aqueous acetic acid, add-on is the 1-80 gram.
[8]. the described method of one of scheme [7], it is characterized in that in system adding medical hydrogen peroxide (commercially available 30%, the weight ratio) oxygenant of the 0.01-25% (weight ratio) of chitosan dosage, under 0-100 ℃ of temperature, stir degraded.
[9]. the method for scheme [8] is characterized in that wherein oxygenant is hydrogen peroxide, dioxide peroxide, oxalic acid, sodium oxalate, hypochlorous acid, clorox, Periodic acid, perchloric acid and using with of different ratios each other thereof.
The technical process of PACu-CMPS template of the present invention absorption control length/catalytic oxidation cracking method can be sketched and is: dissolving high chitosan solid with edible acetic acid, citric acid, lactic acid, the tartrate of 0.5-1.0% becomes solution, add the PACu-CMPS particulate stirring of chemosynthesis and crushing screening in the above-mentioned solution down, regulating the pH value makes amino and PACu-CMPS particle surface bare metal ion in the chitosan have weak coordination bond to form, room temperature adds oxygenant and mixes, degraded heats up, filter to isolate degradation solution, low temperature or room temperature concentrate and obtain solid phase prod; Reuse after filter residue washing, the drying.
Principle of the present invention is: make dissolving chitosan macromolecular chain be adsorbed in insoluble micron order PACu-CMPS surface in the weakly acidic water solution, heightening pH value makes the amino metal ion with the PACu-CMPS surface exposure of the part in the polymer chitosan form weak coordination bond again, low temperature adds has the oxygenant of coordination ability also to be adsorbed in the bare metal ion surface, microwave irradiation starts the Fenton reaction and produces hydroxyl radical free radical, presses Fenton reaction mechanism catalytic oxidative cracking polysaccharide chain from these haptos.Add entry and make the product oligosaccharides after the degraded soluble in water, filtering separation is collected solution, concentrates, obtains narrow molecular weight distributed Chitosan poly oligosaccharide product (as number-average molecular weight 1230, dispersion index 1.06, the scope intensive amount reaches more than 85%).Want to reach this purpose, must in preparation process, accurately hold each preparation each details in link, and PACu-CMPS template absorption control length/catalytic oxidative cracking method to need the deacetylation of chitosan be more than 70%.Through exploring repeatedly, optimized the characteristic of each step of degradation process, obtained reliable parameter, degraded is simple and easy to do with purification step.
Owing to adopted technique scheme, PACu-CMPS template absorption control length/catalytic oxidation cracking method of the present invention has following excellent characteristics:
What 1, avoided adopting in the present industrial production on principle is all drawbacks and the deficiency of mechanism with non-specific degradation process, artificial manufacturing the atmosphere of specificity degraded.
2, degradation process very rapidly, oligosaccharide molecular amount certain limit is adjustable.
3, can pass through filtering separation degraded product chitosan oligomer, method is easy, and is easy to operate.
4, selected raw material reagent is cheap and easy to get, and products obtained therefrom is stable, reliable.
4, PACu-CMPS matrix can be used repeatedly, saves material.
5, required production unit is simple, easily satisfies different suitability for industrialized production in batches.
Embodiment
For principle, process and the result of PACu-CMPS template absorption control length/catalytic oxidation cracking method of the present invention further are described, now described in detail with embodiment.
Take by weighing chitosan 50 grams and put into the reactor of belt stirrer, add 4000cm 30.5% acetic acid stirred 60 minutes, made the chitosan dissolving.Take by weighing 5 grams and grind the 100 order PACu-CMPS that sieve, add in the reactor after the water-wet, stir.Na with 5% 2CO 3Regulating the pH value is 6.5.Add 100cm 330% hydrogen peroxide, stirring at room 80 minutes.Mixture was transferred in the microwave equipment of microwave output power 750 (W)/operating frequency 2450 (W) reaction 30 minutes.Mixture filters also and washs 3 times, filtrate normal temperature or be refrigerated to dried.Product HAc-NH 4The dissolving of Ac (pH=4.5) damping fluid, and use HAc-NH 4Ac makes moving phase, and the molecular weight that provides with Sigma company is that 186,2500,7100,21400 and 41100 water-soluble glucan standard specimens are made typical curve, and regression coefficient is 0.9976.Detecting the mean number average molecular weight that shows degraded Chitosan poly oligosaccharide product through water-soluable gel high performance liquid chromatography (GFC) is 1230, and molecular weight distributing index is 1.04.Product after the freezing or drying at room temperature dissolves the molecular weight parameter that detects the back does not once more have obvious variation.

Claims (7)

1, a kind of method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide, it is characterized in that: with chitosan is basic parent, its can with the coordination when the pH value 5-7 of template stromal surface metal ion, template matrix be meant chemosynthesis after grind efflorescence reach certain particle size to dibenzoic acid copper II solid metal coordination polymer particle PACu-CMPS, by the mean length between the PACu-CMPS surface metal ion apart from Chitosan poly oligosaccharide behind the control degradation; One of characteristics of PACu-CMPS are that slightly acidic is not dissolved, two be can combine with the amino weak coordination in the chitosan at pH value surface metal ion when the 4-7, with the PACu-CMPS particle be dissolved in the plain high molecular weight chitosan mixed at room temperature after deacetylated of the biological carapace that contains 0.5% acetum, regulating the pH value is 4-7, add an amount of oxygenant, stir, microwave irradiation, start catalytic oxidation, keep under this temperature and stirred 0.5 minute-72 hours; Under this condition, oxygen is changed cracking chitosan macromolecular chain rapidly simultaneously near PACu-CMPS stromal surface all metal ions position; The size and the range of molecular weight distributions of oligosaccharides number-average molecular weight after distance between each bare metal ion of PACu-CMPS surface and the big young pathbreaker of equal distribution density determine to degrade; Because used PACu-CMPS is the slightly acidic insolubles, can product be separated with catalytic matrix by filtering, convenient stable to obtain the mean number average molecular weight be 400-2500, and molecular weight distributing index is the Chitosan poly oligosaccharide product of 1.02-1.10, and the PACu-CMPS catalytic matrix can use repeatedly.
2, method according to claim 1 is characterized in that: the chitosan of use is the product of one of the main extract of shrimp, crab shell and insect, algae and bacterium generation from aquaculture, marine organisms de-acetyl chitin.
3, method according to claim 2 is characterized in that: wherein must add 0.1~10% acetic acid or citric acid or tartrate or lactic acid aqueous solution in the chitosan, under 0~100 ℃ temperature, dissolve through 20 minutes~48 hours.
4, method according to claim 3, it is characterized in that: after the PACu-CMPS after will handling joins dissolved chitosan acetic acid or citric acid or tartrate or lactic acid aqueous solution, under 0-100 ℃ of temperature, stir, adding weight ratio is the 25-250% of chitosan, system evenly stirs and is suspension liquid, whipping temp 0-100 ℃; The yellow soda ash or the sodium hydroxide that add 0.5-10% are subsequently regulated the pH value to 4-7, stir.
5, method according to claim 4 is characterized in that: add the oxygenant of the 0.01-70% weight ratio of chitosan dosage in system, degrade through stirring in 2-72 hour under 0-100 ℃ of temperature.
6, method according to claim 5 is characterized in that: said mixture was transferred in the microwave equipment of microwave output power 10-2000W/ operating frequency 2450W reaction 0.5 minute to 12 hours.
7, method according to claim 5 is characterized in that: use therein oxygenant is hydrogen peroxide, dioxide peroxide, oxalic acid, sodium oxalate, hypochlorous acid, clorox, Periodic acid, perchloric acid and using with of different ratios each other thereof.
CNB2005100736995A 2005-05-16 2005-05-16 Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide Expired - Fee Related CN100447161C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNB2005100736995A CN100447161C (en) 2005-05-16 2005-05-16 Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB2005100736995A CN100447161C (en) 2005-05-16 2005-05-16 Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide

Publications (2)

Publication Number Publication Date
CN1687144A true CN1687144A (en) 2005-10-26
CN100447161C CN100447161C (en) 2008-12-31

Family

ID=35305186

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2005100736995A Expired - Fee Related CN100447161C (en) 2005-05-16 2005-05-16 Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide

Country Status (1)

Country Link
CN (1) CN100447161C (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101643516A (en) * 2009-09-08 2010-02-10 殷国铭 Method for preparing chitosan into water-soluble chitooligo saccharide
CN103044574A (en) * 2013-01-11 2013-04-17 河北工业大学 Process for preparing narrow-distribution chitosan with controllable molecular weight through microwave-H2O2 combined degradation method
CN106423271A (en) * 2016-09-08 2017-02-22 江苏大学 Oligomeric chitosan structure-based binaphthalene-containing axial chiral quaternary ammonium salt phase transfer catalyst and preparation method thereof
CN106942683A (en) * 2017-03-17 2017-07-14 湖南科技大学 A kind of brined areca and preparation method

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1126756C (en) * 2000-01-05 2003-11-05 中国科学院大连化学物理研究所 Process for preparing chitoligose by coupling enzyme degradation of chitosan with membrane separation
CN1108311C (en) * 2000-04-17 2003-05-14 武汉大学 High concentration process of preparing water soluble oligomerized chitosan
KR100396833B1 (en) * 2000-12-15 2003-09-02 주식회사 효성 Process for Producing Chitooligosaccharide by Chitosanase that Secreted from Bacillus sp HSB-21
CN1177856C (en) * 2001-08-14 2004-12-01 华东理工大学 Process for industrial production of oligochitose and chitooligose
KR100483847B1 (en) * 2002-07-11 2005-04-20 주식회사 건풍바이오 The chitin/chitosan oligosaccharide which mitigating the cold symptoms of hands and foot
KR20040018890A (en) * 2002-08-27 2004-03-04 최종욱 The method of manufacturing chitin oligoer powder and food composition comprising chitin oligomer powder for improving liver activity

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101643516A (en) * 2009-09-08 2010-02-10 殷国铭 Method for preparing chitosan into water-soluble chitooligo saccharide
CN101643516B (en) * 2009-09-08 2014-02-12 殷国铭 Method for preparing chitosan into water-soluble chitooligo saccharide
CN103044574A (en) * 2013-01-11 2013-04-17 河北工业大学 Process for preparing narrow-distribution chitosan with controllable molecular weight through microwave-H2O2 combined degradation method
CN106423271A (en) * 2016-09-08 2017-02-22 江苏大学 Oligomeric chitosan structure-based binaphthalene-containing axial chiral quaternary ammonium salt phase transfer catalyst and preparation method thereof
CN106423271B (en) * 2016-09-08 2018-10-09 江苏大学 A kind of quaternary ammonium salt phase transfer catalyst containing axial chiral binaphthyl and preparation method thereof based on chitosan oligomer structure
CN106942683A (en) * 2017-03-17 2017-07-14 湖南科技大学 A kind of brined areca and preparation method

Also Published As

Publication number Publication date
CN100447161C (en) 2008-12-31

Similar Documents

Publication Publication Date Title
CN101200505B (en) Method for preparing high deacetylate degree and high viscosity chitosan by using shrimp shell
KR100894374B1 (en) Processes for Producing Cellooligosaccharide
CN101993867B (en) Immobilization method using chitosan as carrier
EP2225387B1 (en) Process for producing saccharide
CN100447161C (en) Method of microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide
CN101397580A (en) Method for preparing low molecular weight chitosan under steady magnetic field condition
CN108559763A (en) A kind of preparation method improving chitosan oligosaccharide degree of polymerization 3-6 sugared contents
Kaushal et al. Efficacious bioconversion of waste walnut shells to xylotetrose and xylopentose by free xylanase (Xy) and MOF immobilized xylanase (Xy-Cu-BTC)
CN102321194B (en) Method for preparing water-soluble chitosan with low molecular weight
CN1332984C (en) Method for preparing chitosan/chitose in molecular weight narrow distributed
CN107029791A (en) A kind of fenton catalyst and preparation method thereof, the application in lignocellulosic pretreatment
Zhu et al. Influence of native cellulose, microcrystalline cellulose and soluble cellodextrin on inhibition of starch digestibility
CN111569943A (en) Enzyme-metal nucleotide compound and controllable construction method and application thereof
CN100447162C (en) Method of PACu-A5 adsorption microwave assistant degradation for preparing narrow molecular weight distributed Chitosan poly oligosaccharide
CN108213459B (en) Preparation method of glucan/nano gold-silver alloy compound
CN116621647A (en) Method for preparing humic acid slow-release trace element fertilizer by efficiently activating lignite through MOF derivative
Wang et al. Green synthesis of Hesperitin dihydrochalcone glucoside by immobilized α-l-rhamnosidase biocatalysis based on Fe3O4/MIL-101 (Cr) metal-organic framework
CN107236054B (en) Preparation method and application of low-molecular-weight ascophyllan
CN110102774B (en) Green preparation method and application of copper nanoparticles based on citrus pectin
CN111053756B (en) Method for separating 5-methyltetrahydrofolic acid and improving stability and wall material used by same
CN114700111A (en) Method for preparing nano palladium catalyst by using protein assembly
CN111974367A (en) Preparation method of polylysine modified cellulose material for adsorbing copper ions
CN113024676A (en) Lotus seed resistant starch with high bifidobacterium breve adhesion rate and preparation method and application thereof
Alkhatib et al. Enzymatic hydrolysis of oil palm empty fruit bunch using immobilized cellulase enzyme
CN105660620A (en) Silver nanoparticle-embedded carbon microsphere preparation method

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
C17 Cessation of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20081231

Termination date: 20140516