KR20050097215A - Immobilized cyclodextrin on solid support and method for preparation thereof - Google Patents

Abstract

The present invention relates to a fixture in which a cyclodextrin is bonded to a solid substrate, and a method of manufacturing the same. The fixed body of the present invention is manufactured by a simple manufacturing method, can efficiently remove cholesterol, can be recycled can be used semi-permanently.

Description

Immobilized Cyclodextrin on solid support and method for preparation etc.

The present invention relates to a fixture in which cyclodextrin is bound to a solid substrate and a method for producing the same.

Cyclodextrin (hereinafter referred to as CyD) and its derivatives are known to have the property of enclosing a variety of chemicals by acting as a host molecule, in particular, α-, β- and γ -CyD has been studied a lot because of its effective size and characteristics.

Β-CyD of CyD is a cyclic polysaccharide composed of seven glucose, similar to donut, and the central part of the molecule is similar in diameter to cholesterol and hydrophobic circular space, so it can bind to cholesterol, which is a nonpolar molecule. It has a structure. In addition to cholesterol, β-CyD can bind to or include a variety of substances having molecular size and nonpolar similarity to cholesterol.

Since β-CyD is inexpensive, high in human safety, and allowed to be used as a food additive in various countries, attempts have been made to remove cholesterol in liquid samples using β-CyD ( J. Food. Sci . 64, 629-632; J. Dairy Sci . 76 (Suppl. 1) 143 (Abst.)

In Japanese Patent Laid-Open No. 04168198, 1.2 g of β-CyD was added to 20 g of cream containing 50% moisture, stirred at 30 ° C. for 60 minutes, warmed, and centrifuged to recover the cream layer. 84.9%. In addition, as a result of treating the cream under conditions such as β-CyD 0.1M, stirring temperature of 40 ° C., and stirring time of 120 minutes, up to 83% of cholesterol could be removed ( J. Dairy Sci , 76, ( Suppl. 1), D158 (Abst.)).

Korean Patent Application Nos. 1997-18599, 1997-37127, and 1997-37128 also describe a method for removing cholesterol from β-CyD from liquid samples such as milk or cream.

In these inventions, the study was made to suggest the optimal conditions for removing cholesterol by conducting research to improve the shortcomings of the previous method for removing cholesterol. In the present invention, the main method is to add β-CyD to the liquid sample and then stir. By centrifugation to remove cholesterol bound to β-CyD, using a host molecule such as β-CyD as described above, by using a guest molecule such as cholesterol to remove from the liquid sample food It's a skill.

However, these methods perform the inclusion reaction of the host molecule and the guest molecule directly in the liquid sample. Therefore, in order to actually remove the resultant host molecule-guest molecule conjugate from the liquid sample, a cumbersome process such as centrifugation is required. There is a disadvantage.

In addition to the cumbersome procedures, the centrifugation process may be detrimental to the quality of the original liquid sample as a result of the centrifugal action. This process is quite complicated considering the need to centrifuge a large amount of liquid sample at the production site. It's a cumbersome process.

In addition, in the process of recycling the host molecule by separating the host molecule-guest molecule conjugate from the liquid sample and then separating the host molecule and the guest molecule again, there are inconveniences inherent in the procedures known in the art.

Therefore, a method of removing cholesterol in milk or an aqueous emulsion solution using a column simply attached β-CyD to silica has been studied. Since this method does not undergo centrifugation, the process is simplified, but since the fine particles of silica may be dissolved in milk or an aqueous emulsion solution after removing cholesterol, there is considerable concern in terms of food safety.

In addition, Korean Patent Application No. 2001-67376 discloses a method for removing cholesterol in milk or an aqueous emulsion solution by using a fixing body in which β-CyD derivatives are bonded to a solid substrate composed mainly of silicon oxide or the like to solve the above problems. A breakthrough method is presented. However, in order to prepare the gastric fixture, β-CyD derivatives in which the hydroxyl group of β-CyD is converted to an amine group or an aldehyde group are required. This process has a disadvantage in that it is a complicated process that requires a lot of cost and time ( Tetrahedron Lett 1984, 25, 3331-3334; Tetrahedron Lett . 1995, 36, 8371-8374).

It is an object of the present invention to provide a fixed body in which cyclodextrin is bound to a solid substrate and a method for preparing the cyclodextrin, which can be easily removed and at the same time easily recycled cyclodextrin in a liquid sample.

The fixed body (A) of the present invention is characterized in that β-CyD, the main molecule, is bonded to a solid substrate (C) into which a support (B) of an isocyanate (isocyanate) group is introduced.

The preparation method of the fixture of the present invention (i) reacts a silanization reaction material having an isocyanato group such as 3-isocyanatoproyltriethoxysilane to a solid substrate (C). To introduce a support (B) of an isocyanate group and (ii) reacting the host molecule which is β-CyD and the solid substrate (C) into which the isocyanate group of (i) is introduced.

The host molecule (A) used in the present invention is a substance selected from α-, β- and γ-CyD. Alternatively, Calix [n] -arenes or Cucurbituril may be used instead of CyD.

In addition, some of the hydroxyl groups of CyD, such as HP-CyD (hydroxypropyl-CyD), Maltosyl-CyD, Gulcosyl-CyD, Methylated-CyD, may be selected from substituted CyD.

The support (B) used in the present invention is a substance that can be referred to as a linker (linker) is a substance that serves to attach the host molecule (A) to the solid substrate (C). At this time, the support (B) is composed of 1 to 15 main skeleton chain sites, except for the side chain (side chain), can be selected by combining one or two or more components.

As the solid substrate (C) used in the present invention, a material selected from glass, silicon wafer, or quartz mainly containing silicon oxide (SiO ₂ ) may be used.

Hereinafter, the present invention will be described in detail.

The solid substrate (C) having an isocyanate group was pretreated with a piranha solution (H ₂ SO ₄ : H ₂ 0 ₂ = 3: 1, v / v) and the solid substrate (C) and 3-isocyanatopropyl. Prepared easily by reacting triethoxysilane.

Thereafter, β-CyD (A) and the solid substrate (C) having the prepared isocyanate group introduced therein were reacted at 100 ° C. in dry dimethyl sulfoxide for 24 hours to prepare a fixture of the present invention (FIG. 2).

Although glass beads were used as the solid substrate (C) in the following examples, even if the size or shape of the solid substrate (C) is different, such as using an organic substrate instead of glass beads, it is appropriate for the purpose or use of the present invention. It can be easily inferred that it can be used.

Hereinafter, the present invention will be described in more detail with reference to the following examples, which are intended to illustrate the present invention but are not intended to limit the scope of the present invention.

Example 1 Preparation of Solid Substrate (C) Incorporating Isocyanate Group

100 g of glass beads 2.5 mm in diameter, which were previously washed with purified water, were added to 160 ml of piranha solution (H ₂ SO ₄ : H ₂ 0 ₂ = 3: 1, v / v) and stirred for 30 minutes. After that, the glass balls were removed from the solution, and 100 ml of purified water was poured into the glass balls and sonicated for 5 minutes. Then purified water was removed and the glass was dried at room temperature for 12 hours. After drying, 100 ml of 20 mM 3-isocyanatopropyltriethoxysilane was added to the glass eggs under dry toluene and stirred for 4 hours. Thereafter, the 3-isosaanatopropyltriethoxysilane solution was removed, and the glass eggs were washed three times with 100 ml of dry toluene to prepare a solid substrate (C) having an isocyanate group introduced therein.

Example 2 Preparation of Solid Substrate (C) Incorporating Isocyanate Group

Instead of the 20mM 3-isocyanatopropyltriethoxysilane of Example 1, 4mM 3-isocyanatopropyltriethoxysilane was used, and the rest of the solid substrate (C) having the isocyanate group introduced therein was prepared in the same manner as in Example 1. Prepared.

Example 3 Preparation of Fixture Having β-CyD Using Solid Substrate (C) of Example 1

100 ml of a 30 mM β-Cyd solution was added to an isocyanate group-introduced glass prepared in Example 1 under anhydrous dimethyl sulfoxide (DMSO), and heated to 100 ° C. for overnight reaction. The glass eggs were then collected by filtration and washed three times with 100 ml of ethanol. Thereafter, the product was dried under reduced pressure to prepare a fixed body.

The structure of the fixture is shown in FIG.

Example 4 Preparation of Fixture Having β-CyD Using Solid Substrate (C) of Example 2

The fixed body was manufactured by the method of Example 3 using the glass grain which the isocyanate group prepared in Example 2 was introduce | transduced.

Example 5-1 Measurement of Cholesterol Removal Efficiency

In order to measure cholesterol removal efficiency of the fixed bodies prepared in Examples 3 and 4, the following experiment was performed.

A fixed amount of the fixed body was added to a test tube containing 100 mL of milk, and the test tube was shaken at a temperature of 10 ° C. for 3 hours, and then the amount of cholesterol contained therein was measured by the following method using 1 ml of this milk.

First, in order to extract cholesterol from milk, 1 mL of the treated milk is placed in a test tube, and 1 mL of 5α-cholestane is added as an internal standard, followed by 5 mL of 2M ethanolic potassium fortium hydroxide solution for 30 minutes. The reaction was saponified at 60 ° C. After cooling to room temperature, cholesterol was extracted with 5 mL of hexane. The hexane layer was transferred to an appropriate container and then vacuum dried. Thereafter, the dried product was dissolved in 1 mL of hexane solution, and the amount of cholesterol was measured by gas chromatography under the following conditions.

Column: silica-fused capillary column (HP-5)

        (Length 30m, inner diameter 0.32mm, thickness 0.25μm)

Detector: FID (flame-ionization detector)

Temperature: Injection temperature 170 ℃, Detection temperature 300 ℃

-Oven temperature: 200 ℃ to 300 ℃ for 10 minutes / minute and then maintained at 300 ℃

Carrier gas: nitrogen (2 mL / min)

Sample injection volume: 2 μL

The cholesterol removal efficiency is expressed as the amount of cholesterol in the milk treated with the fixation (%) relative to the amount of cholesterol in the milk not treated with the fixation.

Example 5-2 Measurement of Cholesterol Removal Efficiency According to Reaction Time

The reaction temperature is fixed at 10 ° C. Then, using the fixture prepared in Example 3, the reaction was carried out for 3 hours, 6 hours, and 9 hours by the method of Example 5-1, and then the content of cholesterol was measured by the method of Example 5-1.

Example 5-3 Measurement of Cholesterol Removal Efficiency According to Reaction Temperature

After the reaction product was prepared in Example 3 using the fixture of Example 5-1 at 5 ° C., 10 ° C., and 15 ° C. for 6 hours, the content of cholesterol was measured by the method of Example 5-1.

The experimental results of Examples 5-1, 5-2 and 5-3 are shown in the table below.

As shown in the results, the reaction time and reaction temperature of the fixed body and the milk did not have a significant effect on the cholesterol removal efficiency, and the concentration of 3-isocyanatopropyltriethoxysilane in the process for preparing glass beads containing isocyanate group was introduced. Had an effect on the removal efficiency of cholesterol.

Example 6 Evaluation of Recyclability of the Fixture

It was evaluated whether the used fixture was recycled through a cholesterol separation process. The fixed glass pellets prepared and used in Example 3 were immersed in an acetic acid: butanol (3: 1, v / v) solution at room temperature for 24 hours and then dried at room temperature. Then, cholesterol removal efficiency was measured according to the method of Example 5. This used glass egg was again treated to measure cholesterol removal efficiency, and the process was repeated five times in total.

As can be seen from the above results, the fixed body of the present invention can be recycled, so the economic value can be very large.

The present invention can be prepared by a simple method of fixing a cyclodextrin bonded to a solid substrate (C) that can easily remove cholesterol from the liquid sample without going through a centrifugal separation process, the fixture is a liquid sample Cholesterol can be removed without compromising quality. In addition, the economic value is very large because the fixture can be recycled.

1 is a view schematically showing the fixture of the present invention in which cyclodextrin is bound to a solid substrate. In Fig. 1, A represents a host molecule, B represents a support, and C represents a solid substrate.

Figure 2 is a schematic diagram showing the coupling reaction of the third and fourth steps of the present invention.

Claims (13)

The hydroxy group of the host molecule (A), which is a cyclodextrin, is produced by being bonded to an isocyanate group of the support (B). The fixture according to claim 1, wherein the host molecule (A) is β-cyclodextrin. 2. The fixture according to claim 1, wherein the host molecule (A) is a cyclodextrin derivative substituted with a hydroxyl group of cyclodextrin. The fixed body according to claim 1, wherein the support (B) is composed of 1-15 main skeleton chain regions excluding side chains. 2. The fixture according to claim 1, wherein the solid substrate (C) is a material selected from glass, silicon wafer, or quartz mainly composed of silicon oxide (SiO ₂ ). i) introducing a support (B) having an isocyanate group into the solid substrate (C); ii) a method of producing a fixed body comprising reacting a cyclodextrin host molecule (A) with a solid substrate (C) into which isocyanate groups of i) are introduced. The method of claim 6, wherein step i) is a step of introducing a support (B) having an isocyanate group by reacting 3-isocyanatopropyltriethoxysilane with a solid substrate (C). Way. The method of claim 6 or 7, wherein the reaction of step ii) is carried out by heating to 80 ~ 120 ℃ under dimethyl sulfoxide to react. A method for removing cholesterol using the fixation of any one of claims 1 to 5. 10. The method of claim 9, wherein cholesterol is removed from milk or dairy products. The method of claim 10, wherein the reaction temperature is maintained between 5 and 15 ° C. 12. After enclosing cholesterol using the fixer according to any one of claims 1 to 5, the fixer is reacted with a mixed solution of an organic acid and an organic solvent, separated from cholesterol, washed with alcohol and purified water, dried and reused. Cholesterol removal method characterized in that. The method of claim 12, wherein the organic acid is acetic acid, chloroform, hexane or citric acid, the organic solvent is methanol, ethanol, furopanol or butanol, the organic acid and the organic solvent is 2: 1-4: 1 (v / v) Method for removing cholesterol, characterized in that using a mixed solvent mixed with.