Disclosure of Invention
The invention aims to overcome the problems in the prior art and provides a starch-based colon-targeted controlled-release crystal clathrate compound and a preparation method thereof, wherein the obtained clathrate compound has colon-targeted release performance, the release rate of fat-soluble nutrients in small intestine digestion is not more than 20%, and the starch-based colon-targeted controlled-release crystal clathrate compound can be applied to prevention and treatment of colon diseases.
Some fat-soluble nutrients are required to be absorbed in the upper digestive tract as functional factors capable of effectively preventing and treating chronic diseases such as cardiovascular and cerebrovascular diseases, hypertension and the like. But the fat-soluble nutrient with strong effect for preventing and treating lower digestive tract diseases such as colitis, such as resveratrol, vitamin D3, beta-carotene, etc. although the fat-soluble nutrient has stronger biological activity, the water solubility is poor, the property is unstable, the metabolism is rapid, the bioavailability of the oral nutrient is almost zero, and especially the nutrient can play the effect by overcoming the defect that the upper digestive tract is digested and enters the colon. Therefore, if the inclusion compound structure of the helical dextrin and the fat-soluble nutrient can be regulated again, the inclusion compound is prepared into a colon-targeted controlled-release system of the fat-soluble nutrient, so that the stability and the bioavailability of the fat-soluble nutrient can be improved, the fat-soluble nutrient can be delivered to the colon in a targeted manner to play the anti-oxidation and anti-inflammation effects, the colitis and certain colon diseases can be effectively prevented, and the application range of the starch is remarkably expanded.
The invention adopts an in-vitro simulated digestion system to explore the digestion resistance of the crystal inclusion compound in gastric juice and small intestinal juice, and monitors the enzymolysis rate of the helical dextrin and the release rate of fat-soluble nutrients in the digestion process. The cyclodextrin/fat-soluble nutrient crystal inclusion compound obtained by the preparation method breaks through the characteristics that the previously researched cyclodextrin/fat-soluble nutrient crystal inclusion compound can only convey nutrients to the small intestine and can be completely released in the small intestine, and the cyclodextrin/fat-soluble nutrient crystal inclusion compound can convey the fat-soluble nutrients to the colon in a targeted mode to play the roles of resisting oxidation and inflammation, so that colon-related diseases can be effectively prevented and treated.
The purpose of the invention is realized by the following technical scheme:
a preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound comprises the following steps:
(1) preparing starch milk with the mass percentage concentration of 5-10% from starch raw materials, and stirring and pasting for 60-80 min at 100-150 ℃ in a closed container;
(2) cooling the gelatinized liquid obtained in the step (1), adding debranching enzyme, wherein the dosage of debranching enzyme is 7.5-25U per gram of dry starch, and stirring and reacting for 10-12 h at 45-60 ℃; completely debranching dextrin, inactivating enzyme, and cooling to obtain debranched dextrin solution;
(3) placing the debranched dextrin solution in the step (2) in a rotary evaporator for concentration, and precipitating debranched dextrin in the concentrated solution; carrying out centrifugal drying on the debranched dextrin, preparing the debranched dextrin into an aqueous solution, dissolving the aqueous solution for 3-4 hours at the temperature of 60-80 ℃, centrifuging, and drying the precipitate to obtain the helical dextrin;
(4) dispersing the obtained helical dextrin in a 140-160 ℃ water solution to be completely dissolved, cooling to 80-100 ℃, adding a fat-soluble nutrient ethanol solution preheated to 80-100 ℃ under the condition of introducing nitrogen in the whole process to isolate oxygen, and stirring at constant temperature;
(5) and (4) slowly cooling the mixed solution obtained in the step (4) to room temperature at a cooling rate of 0.49-0.59 ℃/h for 5-7 days to obtain the cyclodextrin/fat-soluble nutrient crystal inclusion compound.
In order to better implement the present invention, preferably, the starch in step (1) is one of high amylose corn starch, potato starch and tapioca starch.
Preferably, the debranching enzyme in step (2) is isoamylase or pullulanase.
Preferably, the debranching dextrin in the precipitation concentrated solution is obtained by adding 8-10 times of volume of absolute ethyl alcohol into the concentrated solution to completely precipitate the debranching dextrin.
Preferably, the mass concentration of the aqueous solution prepared from the debranched dextrin is 0.5-1%; the drying of the precipitate is normal pressure drying, reduced pressure drying or spray drying.
Preferably, the fat-soluble nutrient in step (4) is resveratrol, vitamin D3 or beta-carotene.
Preferably, in the step (4), the concentration of the cyclodextrin in the aqueous solution is 4-6 mg/mL; the stirring time is 30-60 min.
Preferably, in the step (4), the concentration of the fat-soluble nutrient in the fat-soluble nutrient ethanol solution is 3-5 mg/mL, the dry basis mass ratio of the spirodextrin to the fat-soluble nutrient is 10: 1-5: 1, and the stirring time at constant temperature is 1-3 h.
Preferably, in the step (5), the slow cooling to the room temperature is to place the mixed solution in the step (4) in a Dewar flask filled with boiling water together with the reaction vessel after the reaction is completed to cool to the room temperature.
A starch-based colon-targeted controlled-release crystal inclusion compound, which is prepared by the preparation method; the starch-based intestinal-connected targeted controlled-release crystal clathrate compound is composed of starch and fat-soluble nutrients, has a faint yellow crystal structure and a regular shape, has a relative crystallinity of 90-100%, and controls the release rate of the fat-soluble nutrients in small intestine digestion to be not more than 20%.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) the invention provides a preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound, which solves the problem that the traditional helical dextrin/fat-soluble nutrient inclusion compound can only deliver active ingredients to the small intestine for absorption. The cyclodextrin/fat-soluble nutrient crystal inclusion compound prepared by the co-crystallization method can improve the stability of fat-soluble nutrients, realize the colon-targeted release function of the fat-soluble nutrients, achieve the aim of preventing and treating colon diseases and bring gospel to patients with the colon diseases.
(2) The invention adopts a co-crystallization method of refined solid chemicals to prepare the cyclodextrin/fat-soluble nutrient crystal inclusion compound, and the method is mostly applied to the chemical industry and is not applied to amylose and hydrophobic object molecules in the food industry. In the stirring process before the co-crystallization, fat-soluble nutrient molecules enter a hydrophobic cavity of the helical dextrin through hydrophobic interaction to obtain the helical dextrin/fat-soluble nutrient inclusion compound, the co-crystallization process aims at arranging the inclusion compound molecules in the aqueous solution in a highly ordered way to form a perfect crystal form with the crystallinity close to 100 percent, and the slow cooling crystallization process is the key of whether the helical dextrin/fat-soluble nutrient crystal inclusion compound can realize colon-targeted release.
(3) The invention has the characteristics of environmental protection and simple process, adopts the helical dextrin and the fat-soluble nutrient as raw materials to prepare the sustained and controlled release crystal inclusion compound, improves the targeting property, the solubility and the sustained release performance of the sustained and controlled release crystal inclusion compound, and provides favorable conditions for the fixed-point release of functional active substances.
(4) The invention uses natural polysaccharide macromolecules as raw materials, is cheap and easy to obtain, has good biocompatibility and mild preparation process conditions, and widens the application field of starch to a great extent.
Detailed Description
For a better understanding of the present invention, reference is made to the following description taken in conjunction with the accompanying drawings and examples. There are many successful embodiments of the invention, 5 specific examples are listed below, but the scope of the invention as claimed is not limited to the scope of the examples presented.
Preparing an artificial simulated gastrointestinal solution:
artificial gastric juice: the pH of the gastric juice is 1.2 +/-0.02, and the gastric juice contains 2g/L NaCl and 3.2g/L pepsin and is prepared by 0.1mol/L HCl solution.
Artificial small intestine liquid: the artificial small intestine solution consists of 187.5mg/2.5mL pancreatin solution, 3.5mg/2.5mL cholate solution and 1.5mL salt solution, wherein the salt solution contains 10mM CaCl2And 150mM NaCl.
Simulation of gastrointestinal tract: a sample of 1g of the inclusion complex of the cyclodextrin/fat-soluble nutrient crystals was added to a stoppered conical flask, 20mL of simulated gastric juice prepared as described above and adjusted to pH 1.2. + -. 0.2 was added thereto at a constant flow rate, the mixture was placed in a magnetic stirrer water bath at 37 ℃ and stirred at a constant speed of 100rpm, and the pH in the mixture was controlled to 1.2. + -. 0.2 with 0.1 HCl for 2 hours, whereupon the pH was adjusted to 7.0. + -. 0.2 with 2M NaOH, followed by addition of 7mL of bile salt extract, 3mL of salt solution and 5mL of pancreatin solution, and the reaction was carried out under the same conditions for 2 hours. And taking out samples at intervals in the digestion process at preset time intervals to inactivate enzyme for glucose content determination and fat-soluble nutrient release amount analysis.
Example 1
A preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound comprises the following steps:
(1) preparing 5% starch milk from high amylose corn starch, placing in a closed container, stirring at 150 deg.C, and gelatinizing for 80 min;
(2) cooling the gelatinized liquid obtained in the step (1) to 50 ℃, adding 7.5U/g (200000U/g, Hubei Hongyun Biotech Co., Ltd.), stirring for reaction for 12h, inactivating enzyme at 100 ℃ for 20min, and cooling to obtain debranched dextrin solution.
(3) And (3) concentrating the debranched dextrin solution in the step (2) in a rotary evaporator, and adding 9 times of volume of absolute ethyl alcohol into the concentrated solution to precipitate all debranched dextrin in the concentrated solution. Drying, preparing the obtained debranched dextrin into an aqueous solution with the mass concentration of 1%, dissolving for 4 hours at 60 ℃, centrifuging, taking the precipitate, and drying under normal pressure to obtain the helical dextrin;
(4) preparing 80mL of 5mg/mL aqueous solution from the helical dextrin obtained in the step (3), stirring at 160 ℃ for 30min to completely dissolve the helical dextrin, cooling to 90 ℃, then adding 10mL of resveratrol-ethanol solution preheated at 90 ℃ in advance for 10min with the concentration of 4mg/mL while stirring, exhausting air by introducing nitrogen from the liquid level for 10min, and stirring at constant temperature for reaction for 1 h;
(5) and (3) placing the mixed solution obtained in the step (4) into a Dewar flask filled with boiling water after the mixed solution is completely reacted, strictly controlling the cooling rate to be 0.58-0.59 ℃/h, and slowly cooling the mixed solution to room temperature for crystallization for 5 days to obtain the helical dextrin/resveratrol crystal inclusion compound with a perfect crystal form.
The samples of the inclusion complexes of cyclodextrin/resveratrol crystals were analyzed for crystallinity using X-ray diffraction techniques (fig. 1) and the apparent morphology of the inclusion complex of cyclodextrin/resveratrol crystals in example 1 was determined using Scanning Electron Microscopy (SEM) (fig. 2). As can be seen from fig. 1 and fig. 2, the obtained cyclodextrin/resveratrol crystal inclusion compound presents a regular plate-like crystal morphology, and the crystallinity is as high as 93.37%, which is close to 100%, which indicates that the cyclodextrin and the resveratrol really form a perfect crystal structure of the crystal form. In the stirring process before co-crystallization, fat-soluble nutrient molecules enter a hydrophobic cavity of the helical dextrin through hydrophobic interaction to obtain the helical dextrin/fat-soluble nutrient inclusion compound, the co-crystallization process aims at arranging the inclusion compound molecules in the aqueous solution in a highly ordered way to form a perfect crystal form with the crystallinity close to 100%, and the slow cooling crystallization process is the key of whether the helical dextrin/fat-soluble nutrient crystal inclusion compound can realize colon-targeted release.
According to the literature reports (Pingging Wang, ZhuangLuo, and Xichun Peng. encapsulation of Vitamin E and Soy Iso plastic Vitamin Using Spiral Dextrin: comprehensive Structural Characterisation, Release Kinetics, and antibiotic Capacity dual ring structured polypeptide. journal of Agricultural and Food Chemistry,2018,66, 10598. 10607), the traditionally prepared cyclodextrin/fat-soluble nutrient inclusion compound is a V-type semi-crystalline irregular powdery structure, the crystallinity of which does not exceed 40%, and studies show that the V-type structure cyclodextrin/fat-soluble nutrient is destroyed by the fat-soluble enzyme of the pancreatic juice during digestion, and the fat-soluble nutrient Release amount of the V-type structure is almost 100% after digestion of the small intestine.
The cyclodextrin/resveratrol crystal inclusion compound obtained in example 1 was subjected to simulated gastrointestinal digestion, and as a result, as shown in fig. 3 and 4, after digestion of the small intestine, the sample of the cyclodextrin/resveratrol crystal inclusion compound had a glucose content of 38.93% and a released amount of resveratrol of 15.76%. The results show that the cyclodextrin/resveratrol crystal inclusion compound can resist digestion of stomach and small intestine, 84.24% of resveratrol can be delivered to colon at fixed point, and the effect of colon-targeted controlled release carrier is realized. Compared with the traditional method that the cyclodextrin/liposoluble nutrient inclusion compound is used for conveying liposoluble nutrients to enable almost 100% of the liposoluble nutrients to be released in small intestines, the resveratrol is used as a nutrient substance for effectively preventing and treating colitis and colon cancer, the cyclodextrin/resveratrol crystal inclusion compound prepared by the embodiment can convey most of resveratrol to colon parts to enable the resveratrol to more effectively exert the nutrition and medicine characteristics, brings good news to patients with colon diseases, achieves the primary purpose of the invention, and does not achieve similar effects in the prior art.
The crystallinity of the samples of the following examples was analyzed and the scanning electron micrographs were substantially in accordance with example 1; the glucose content change diagram of the cyclodextrin/resveratrol crystal inclusion compound in the simulated digestion process of the gastrointestinal tract and the release rate diagram of the resveratrol in the simulated digestion process of the gastrointestinal tract are close to those in the figures 3 and 4, and the specific test results of the glucose content and the release amount of the resveratrol are not provided in the embodiment.
Example 2
A preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound comprises the following steps:
(1) preparing 10% starch milk from cassava starch, placing in a closed container, stirring at 100 deg.C, and gelatinizing for 70 min;
(2) cooling the gelatinized liquid obtained in the step (1) to 45 ℃, adding pullulanase 25U/g (OPTIMAX L-1000, Jenenaceae bioengineering Co., Ltd.), stirring for reaction for 11h, inactivating enzyme at 100 ℃ for 20min, and cooling to obtain a debranching dextrin solution.
(3) And (3) concentrating the debranched dextrin solution in the step (2) in a rotary evaporator, and adding 8 times of volume of absolute ethyl alcohol into the concentrated solution to precipitate all debranched dextrin in the concentrated solution. Drying, preparing dextrin into a solution with the mass concentration of 0.5%, dissolving for 3.5h at 70 ℃, centrifuging, taking the precipitate, and spray-drying to obtain the helical dextrin;
(4) preparing 100mL of the spirodextrin obtained in the step (3) into 4mg/mL aqueous solution, stirring at 150 ℃ for 45min to completely dissolve the aqueous solution, cooling to 85 ℃, then adding 17.5mL of resveratrol-ethanol solution preheated in advance in a water bath kettle at 85 ℃ for 15min with the concentration of 3mg/mL while stirring, exhausting air by introducing nitrogen from the liquid surface for 10min, and stirring at constant temperature for reacting for 2 h;
(5) and (4) placing the mixed solution obtained in the step (4) into a Dewar flask filled with boiling water after the mixed solution is completely reacted, strictly controlling the cooling rate to be 0.55-0.56 ℃/h, and slowly cooling to room temperature for crystallization for 6 days to obtain the helical dextrin/resveratrol crystal inclusion compound with a perfect crystal form.
After digestion of the small intestine, the sample of the inclusion complex of the cyclodextrin/resveratrol crystal obtained in this example 2 had a glucose content of 36.34% and a released amount of resveratrol of 12.84%. The results show that the cyclodextrin/resveratrol crystal inclusion compound can resist digestion of stomach and small intestine, 87.16% of resveratrol can be delivered to colon at fixed point, and the effect of colon-targeted controlled release carrier is realized.
Example 3
A preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound comprises the following steps:
(1) preparing potato starch into 8% starch milk, placing in a sealed container, stirring at 100 deg.C, and gelatinizing for 60 min;
(2) cooling the gelatinized liquid obtained in the step (1) to 60 ℃, adding 25U/g (200000U/g, Hongyun biological technology limited in Hubei), stirring for reaction for 10h, inactivating enzyme at 100 ℃ for 20min, and cooling to obtain debranching dextrin solution.
(3) And (3) concentrating the debranched dextrin solution in the step (2) in a rotary evaporator, and adding 10 times of volume of absolute ethyl alcohol into the concentrated solution to precipitate all debranched dextrin in the concentrated solution. Preparing the obtained debranched dextrin into 0.75% solution, dissolving for 3h at 80 ℃, centrifuging, taking precipitate, and drying under reduced pressure to obtain the helical dextrin;
(4) preparing 70mL of 6mg/mL aqueous solution from the helical dextrin obtained in the step (3), stirring at 140 ℃ for 60min to completely dissolve the helical dextrin, cooling to 80 ℃, then adding 12mL of vitamin D3-ethanol solution preheated in advance in a 80 ℃ water bath kettle for 12min with stirring and with the concentration of 5mg/mL, exhausting air by introducing nitrogen from the liquid surface for 10min, and stirring at constant temperature for reaction for 3 h;
(5) and (4) placing the mixed solution obtained in the step (4) into a Dewar flask filled with boiling water after the mixed solution is completely reacted, strictly controlling the cooling rate to be 0.49-0.50 ℃/h, slowly cooling to room temperature, and crystallizing for 7 days to obtain the cyclodextrin/vitamin D3 crystal inclusion compound with a perfect crystal form.
After digestion of the small intestine, the sample of the inclusion complex of the crystal of the cyclodextrin/vitamin D3 obtained in this example 3 had a glucose content of 31.15% and a vitamin D3 release amount of 17.34%. The results show that the cyclodextrin/vitamin D3 crystal inclusion compound can resist digestion of stomach and small intestine, can transport 82.66% of vitamin D3 to colon at fixed point, and realizes the effect of colon-targeted controlled release carrier.
Example 4
A preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound comprises the following steps:
(1) preparing 7% starch milk from high amylose corn starch, placing in a closed container, stirring at 135 deg.C, and gelatinizing for 75 min;
(2) cooling the gelatinized liquid obtained in the step (1) to 50 ℃, adding pullulanase 20U/g (OPTIMAX L-1000, Jenenaceae bioengineering Co., Ltd.), stirring for reaction for 11h, inactivating enzyme at 100 ℃ for 20min, and cooling to obtain a debranching dextrin solution.
(3) And (3) concentrating the debranched dextrin solution in the step (2) in a rotary evaporator, and adding 9.5 times of volume of absolute ethyl alcohol into the concentrated solution to precipitate all debranched dextrin in the concentrated solution. Preparing the obtained debranched dextrin into a 1% solution, dissolving for 4h at 60 ℃, centrifuging, taking the precipitate, and drying under reduced pressure to obtain the helical dextrin;
(4) preparing 90mL of the water solution with the concentration of 4.5mg/mL by using the helical dextrin obtained in the step (3), stirring at 155 ℃ for 35min to completely dissolve the helical dextrin, cooling to 100 ℃, then adding 11mL of beta-carotene-ethanol solution which is preheated in advance in a 100 ℃ water bath kettle for 14min and has the concentration of 4.5mg/mL while stirring, exhausting air by introducing nitrogen from the liquid level for 10min, and stirring at constant temperature to react for 1.5 h;
(5) and (4) placing the mixed solution obtained in the step (4) into a Dewar flask filled with boiling water after the mixed solution is completely reacted, strictly controlling the cooling rate to be 0.52-0.53 ℃/h, slowly cooling to room temperature, and crystallizing for 6 days to obtain the helical dextrin/beta-carotene crystal inclusion compound with a perfect crystal form.
After digestion of the small intestine, the cyclodextrin/β -carotene crystal inclusion compound sample obtained in example 4 had a glucose content of 39.39% and a β -carotene release amount of 14.65%. The results show that the cyclodextrin/beta-carotene crystal inclusion compound can resist digestion of stomach and small intestine, 85.35% of beta-carotene can be transported to colon at fixed point, and the effect of colon-targeted controlled release carrier is realized.
Example 5
A preparation method of a starch-based colon-targeted controlled-release crystal inclusion compound comprises the following steps:
(1) preparing 9% starch milk from potato and corn starch, placing in a sealed container, stirring at 110 deg.C, and gelatinizing for 60 min;
(2) cooling the gelatinized liquid obtained in the step (1) to 50 ℃, adding 12.5U/g (200000U/g, Hubei Hongyun Biotech Co., Ltd.), stirring for reaction for 12h, inactivating enzyme at 100 ℃ for 20min, and cooling to obtain debranched dextrin solution.
(3) And (3) concentrating the debranched dextrin solution in the step (2) in a rotary evaporator, and adding 8.5 times of volume of absolute ethyl alcohol into the concentrated solution to precipitate all debranched dextrin in the concentrated solution. Preparing the obtained debranched dextrin into a 1% solution, dissolving for 3h at 70 ℃, centrifuging, taking the precipitate, and drying under reduced pressure to obtain the helical dextrin;
(4) preparing 80mL of the water solution with the concentration of 6mg/mL by using the helical dextrin obtained in the step (3), stirring for 50min at 150 ℃ to completely dissolve the helical dextrin, cooling to 80 ℃, then adding 19.2mL of beta-carotene-ethanol solution which is preheated in advance at 80 ℃ for 14min with the concentration of 5mg/mL while stirring, exhausting air by introducing nitrogen for 10min from the liquid surface, and stirring and reacting at constant temperature for 1.5 h;
(5) and (4) placing the mixed solution obtained in the step (4) into a Dewar bottle filled with boiling water after the mixed solution is completely reacted, strictly controlling the cooling rate to be 0.55-0.56 ℃/h, and slowly cooling to room temperature for crystallization for 5 days to obtain the cyclodextrin/beta-carotene crystal inclusion compound with a perfect crystal form.
The sample of the cyclodextrin/β -carotene crystal inclusion compound obtained in this example 5 had a glucose content of 35.72% and a β -carotene release amount of 15.14% after the digestion of the small intestine was completed. The results show that the cyclodextrin/beta-carotene crystal inclusion compound can resist digestion of stomach and small intestine, 84.86% of beta-carotene can be transported to colon at fixed point, and the effect of colon-targeted controlled release carrier is realized.
The above-described embodiments are intended to be illustrative, rather than restrictive, and all such changes, modifications, substitutions, combinations, and simplifications that may be made without departing from the spirit and principles of the invention are intended to be included within the scope of the invention.