Method for extracting 1-deoxynojirimycin from fresh mulberry leaves

Abstract

The invention discloses a method for extracting 1-deoxynojirimycin from fresh mulberry leaves, and relates to the technical field of pharmacological active ingredient extraction. The method comprises the following steps: S1, collecting fresh mulberry leaves, airing, crushing and sterilizing; s2, water is used as a solvent, continuous countercurrent extraction is adopted, and a pre-extracting solution is prepared; s3, removing impurities from the pre-extracting solution by using a micro-filtration membrane to prepare a micro-filtration permeate liquid; s4, pressurizing the microfiltration permeate liquid to permeate through a large-aperture nanofiltration membrane to prepare a nanofiltration permeate liquid; s5, pressurizing the nanofiltration permeate liquid, and concentrating the nanofiltration permeate liquid through a small-aperture nanofiltration membrane to prepare a concentrated extracting solution; and S6, performing multi-effect concentration on the concentrated extracting solution, and performing spray drying to obtain a finished product. The method is beneficial to resource conservation, energy conservation and environmental protection, and is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of pharmacological active ingredient extraction technology, specifically, a method for extracting 1-deoxynojirimycin from fresh mulberry leaves. Background Technology

[0002] 1-Deoxynojirimycin is a polyhydroxy natural alkaloid found in various parts of the mulberry tree. Its molecular formula is C6H13NO4, and its molecular weight is 163.17. It is currently the only internationally recognized zero-harm biological agent in the market for the prevention and treatment of diabetes, and it has broad application prospects in medicine, health products, and functional foods. Although 1-Deoxynojirimycin is found in relatively high concentrations in mulberry leaves (approximately 0.1-0.2%), there is still significant room for improvement.

[0003] Currently, the extraction of 1-deoxynojirimycin typically involves the use of large amounts of organic solvents. This method not only places significant demands on the recovery of the organic solvents but also makes cost control difficult due to the large volume of solvent used.

[0004] Patent No. 201511020693.1 discloses a method for extracting 1-deoxynojirimycin from mulberry leaves, including steps such as pulverization, microwave extraction, centrifugation, water extraction and alcohol precipitation, concentration and drying, membrane separation, and drying to extract 1-deoxynojirimycin. Microwave extraction technology is used to improve extraction efficiency and ensure that the molecular structure of 1-deoxynojirimycin is not destroyed, resulting in a higher medicinal value of the product. However, the content of the product is <10%, and it cannot be mass-produced.

[0005] Patent No. 202111639914.9 discloses a process for extracting and preparing 1-deoxynojirimycin from mulberry leaves. Although this method does not use a large amount of organic solvents, its extensive use of centrifuges may lead to huge energy consumption and high production costs. Summary of the Invention

[0006] The purpose of this invention is to provide a method for extracting 1-deoxynojirimycin from fresh mulberry leaves, so as to achieve the goals of resource conservation, energy saving and environmental protection, and suitability for industrial production.

[0007] To achieve the above objectives, the present invention employs the following technical means: A method for extracting 1-deoxynojirimycin from fresh mulberry leaves, comprising the following steps: S1. Collect fresh mulberry leaves, rinse them slightly with clean water, spread them in a thin layer on a ventilated trough for an appropriate time, then crush or pulp them and sterilize them; S2. Using water as a solvent, mulberry leaves were subjected to continuous countercurrent extraction to obtain a pre-extract; S3. Remove impurities from the pre-extract using a microfiltration membrane to obtain the microfiltration permeate; S4. The microfiltration permeate is pressurized and passed through a large-pore nanofiltration membrane to obtain the nanofiltration permeate; S5. The nanofiltration permeate is pressurized and concentrated through a small-pore nanofiltration membrane to obtain a concentrated extract; S6. After multi-effect concentration of the concentrated extract, spray drying is performed to obtain the finished product.

[0008] Preferably, the thin layer of leaves spread on the ventilation trough includes the following steps: spreading fresh mulberry leaves 3-6mm thick on the ventilation trough, controlling the humidity at 70%-80%, the temperature at 20%-30℃, the wind speed at 0.1-0.3m / s, and the time at 12-36h.

[0009] Further continuous countercurrent extraction includes the following steps: continuous countercurrent extraction with pure water at 70–85°C for 2 hours to obtain a processed solution. The processed solution is then filtered using a plate and frame filter press to obtain the pre-extracted solution.

[0010] Furthermore, before microfiltration, the treatment liquid needs to be subjected to plate and frame filtration, which requires the use of 200-500 mesh filter cloth at 50-60°C to obtain a pre-extract.

[0011] Furthermore, in step S3, a 0.1μm to 0.2μm ceramic microfiltration membrane is used, with an inlet pressure / outlet pressure of 4 / 3 bar and a temperature of 30 to 60°C to obtain the microfiltration permeate.

[0012] Furthermore, in step S4, a polyamide nanofiltration membrane with an intercept molecular weight of 300 Dal to 900 Dal is used, and the membrane is treated at a pressure of 30 bar and a temperature of 30 to 45°C to concentrate the solution by 12 to 15 times, thereby obtaining the nanofiltration permeate.

[0013] Furthermore, in step S5, a polyamide nanofiltration membrane with an intercepting molecular weight of 75 Dal to 150 Dal is used, and the mixture is treated at a pressure of 30 bar and a temperature of 30 to 45°C to concentrate it 15 to 18 times, thereby obtaining a concentrated extract.

[0014] The present invention has the following beneficial effects during use: Spreading a thin layer of fresh mulberry leaves on a ventilated trough for an appropriate time before extraction can significantly increase the content of 1-deoxynojirimycin.

[0015] Water is used as a solvent throughout the extraction process, which significantly reduces the production cost and improves the extraction rate of 1-deoxynojirimycin.

[0016] By using a selected nanofiltration membrane and applying the nanofiltration membrane twice to separate other water-soluble substances with properties significantly different from the target substance, the goal of simply and cost-effectively increasing the content of 1-deoxynojirimycin can be achieved. Detailed Implementation

[0017] 004. To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0018] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. Example 1

[0020] A method for extracting 1-deoxynojirimycin from fresh mulberry leaves, comprising the following steps: S1. Collect fresh mulberry leaves, rinse them slightly with clean water, spread them in a thin layer on a ventilated trough for an appropriate time, then crush or pulp them and sterilize them; S2. Using water as a solvent, mulberry leaves were subjected to continuous countercurrent extraction to obtain a pre-extract; S3. Remove impurities from the pre-extract using a microfiltration membrane to obtain the microfiltration permeate; S4. The microfiltration permeate is pressurized and passed through a large-pore nanofiltration membrane to obtain the nanofiltration permeate; S5. The nanofiltration permeate is pressurized and concentrated through a small-pore nanofiltration membrane to obtain a concentrated extract; S6. After multi-effect concentration of the concentrated extract, spray drying is performed to obtain the finished product.

[0021] Preferably, the thin layer of leaves spread out on the ventilation trough includes the following steps: spreading fresh mulberry leaves 3-6 mm thick on the ventilation trough, controlling the humidity at 80%, the temperature at 30°C, the wind speed at 0.3 m / s, and the time at 36 h.

[0022] Further continuous countercurrent extraction includes the following steps: continuous countercurrent extraction with pure water at 70°C for 2 hours to obtain a processed solution. The processed solution is then filtered using a plate and frame filter press to obtain the pre-extracted solution.

[0023] Furthermore, before microfiltration, the treatment liquid needs to be subjected to plate and frame filtration, which requires the use of 200-500 mesh filter cloth at 50-60°C to obtain a pre-extract.

[0024] Furthermore, in step S3, a 0.1μm to 0.2μm ceramic microfiltration membrane is used, with an inlet pressure / outlet pressure of 4 / 3 bar and a temperature of 30 to 60°C to obtain the microfiltration permeate.

[0025] Furthermore, in step S4, a polyamide nanofiltration membrane with a molecular weight of 300 Da is used, and the equipment is treated at a pressure of 30 bar and a temperature of 30-45°C to concentrate the solution by 12-15 times, thereby retaining water-soluble substances with a relative molecular weight greater than 1-deoxynojirimycin in the microfiltration permeate to obtain the nanofiltration permeate.

[0026] Furthermore, in step S5, a polyamide nanofiltration membrane with an intercepting molecular weight of 150 Da is used, and the equipment is treated at a pressure of 30 bar and a temperature of 30-45°C to concentrate the solution by 15-18 times, removing water-soluble substances with a relative molecular weight smaller than 1-deoxynojirimycin from the nanofiltration permeate, thereby obtaining a concentrated extract.

[0027] The powder obtained by drying in step S6 has a content of not less than 10% of 1-deoxynojirimycin. Example 2

[0028] A method for extracting 1-deoxynojirimycin from fresh mulberry leaves, comprising the following steps: S1. Collect fresh mulberry leaves, rinse them slightly with clean water, spread them in a thin layer on a ventilated trough for an appropriate time, then crush or pulp them and sterilize them; S2. Using water as a solvent, mulberry leaves were subjected to continuous countercurrent extraction to obtain a pre-extract; S3. Remove impurities from the pre-extract using a microfiltration membrane to obtain the microfiltration permeate; S4. The microfiltration permeate is pressurized and passed through a large-pore nanofiltration membrane to obtain the nanofiltration permeate; S5. The nanofiltration permeate is pressurized and concentrated through a small-pore nanofiltration membrane to obtain a concentrated extract; S6. After multi-effect concentration of the concentrated extract, spray drying is performed to obtain the finished product.

[0029] Preferably, the thin layer of leaves spread out on the ventilation trough includes the following steps: spreading fresh mulberry leaves 3-6 mm thick on the ventilation trough, controlling the humidity at 75%, the temperature at 25°C, the wind speed at 0.2 m / s, and the time at 24 hours.

[0030] Further continuous countercurrent extraction includes the following steps: continuous countercurrent extraction with pure water at 80°C for 2 hours to obtain a processed solution. The processed solution is then filtered using a plate and frame filter press to obtain the pre-extracted solution.

[0031] Furthermore, before microfiltration, the treatment liquid needs to be subjected to plate and frame filtration, which requires the use of 200-500 mesh filter cloth at 50-60°C to obtain a pre-extract.

[0032] Furthermore, in step S3, a 0.1μm to 0.2μm ceramic microfiltration membrane is used, with an inlet pressure / outlet pressure of 4 / 3 bar and a temperature of 30 to 60°C to obtain the microfiltration permeate.

[0033] Furthermore, in step S4, a polyamide nanofiltration membrane with a molecular weight of 600 Da is used, and the equipment is treated at a pressure of 30 bar and a temperature of 30-45°C to concentrate the solution by 12-15 times, thereby retaining water-soluble substances with a relative molecular weight greater than 1-deoxynojirimycin in the microfiltration permeate to obtain the nanofiltration permeate.

[0034] Furthermore, in step S5, a polyamide nanofiltration membrane with a molecular weight of 100 Da is used, and the equipment is treated at a pressure of 30 bar and a temperature of 30-45°C to concentrate the solution by 15-18 times, removing water-soluble substances with a relative molecular weight smaller than 1-deoxynojirimycin from the nanofiltration permeate, thereby obtaining a concentrated extract.

[0035] The powder obtained by drying in step S6 has a content of not less than 8.5% of 1-deoxynojirimycin. Example 3

[0036] A method for extracting 1-deoxynojirimycin from fresh mulberry leaves, comprising the following steps: S1. Collect fresh mulberry leaves, rinse them slightly with clean water, spread them in a thin layer on a ventilated trough for an appropriate time, then crush or pulp them and sterilize them; S2. Using water as a solvent, mulberry leaves were subjected to continuous countercurrent extraction to obtain a pre-extract; S3. Remove impurities from the pre-extract using a microfiltration membrane to obtain the microfiltration permeate; S4. The microfiltration permeate is pressurized and passed through a large-pore nanofiltration membrane to obtain the nanofiltration permeate; S5. The nanofiltration permeate is pressurized and concentrated through a small-pore nanofiltration membrane to obtain a concentrated extract; S6. After multi-effect concentration of the concentrated extract, spray drying is performed to obtain the finished product.

[0037] Preferably, the thin layer of leaves spread on the ventilation trough includes the following steps: spreading fresh mulberry leaves 3-6 mm thick on the ventilation trough, controlling the humidity at 70%, the temperature at 20℃, the wind speed at 0.1 m / s, and the time at 12 hours.

[0038] Further continuous countercurrent extraction includes the following steps: continuous countercurrent extraction with pure water at 85°C for 2 hours to obtain a processed solution. The processed solution is then filtered using a plate and frame filter press to obtain the pre-extracted solution.

[0039] Furthermore, before microfiltration, the treatment liquid needs to be subjected to plate and frame filtration, which requires the use of 200-500 mesh filter cloth at 50-60°C to obtain a pre-extract.

[0040] Furthermore, in step S3, a 0.1μm to 0.2μm ceramic microfiltration membrane is used, with an inlet pressure / outlet pressure of 4 / 3 bar and a temperature of 30 to 60°C to obtain the microfiltration permeate.

[0041] Furthermore, in step S4, a polyamide nanofiltration membrane with a molecular weight of 900 Da is used, and the membrane is treated at a pressure of 30 bar and a temperature of 30-45°C to concentrate the solution by 12-15 times, thereby retaining water-soluble substances with a relative molecular weight greater than 1-deoxynojirimycin in the microfiltration permeate to obtain the nanofiltration permeate.

[0042] Furthermore, in step S5, a polyamide nanofiltration membrane with an intercepting molecular weight of 75Dal is used, and the process is carried out at a pressure of 30 bar and a temperature of 30-45°C to concentrate the solution by 15-18 times, thereby removing water-soluble substances with a relative molecular weight smaller than 1-deoxynojirimycin from the nanofiltration permeate to obtain a concentrated extract.

[0043] The powder obtained by drying in step S6 has a content of not less than 7% of 1-deoxynojirimycin.

[0044] By spreading a thin layer of fresh mulberry leaves on a ventilated trough for an appropriate time before extraction, the content of 1-deoxynojirimycin can be significantly increased.

[0045] Water is used as a solvent throughout the extraction process, which significantly reduces the production cost and improves the extraction rate of 1-deoxynojirimycin.

[0046] It was found that changing the extraction temperature and the choice of membrane for the two nanofiltration purifications, especially when a membrane with a high molecular weight cutoff was used for the first nanofiltration, although it accelerated the outflow of the permeate, it had a significant impact on the content of 1-deoxynojirimycin in the finished product.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for extracting 1-deoxynojirimycin from fresh mulberry leaves, characterized in that, Includes the following steps: S1. Collect fresh mulberry leaves, rinse them slightly with clean water, spread them in a thin layer on a ventilated trough for an appropriate time, then crush or pulp them and sterilize them; S2. Using water as a solvent, mulberry leaves were subjected to continuous countercurrent extraction to obtain a pre-extract; S3. Remove impurities from the pre-extract using a microfiltration membrane to obtain the microfiltration permeate; S4. The microfiltration permeate is pressurized and passed through a large-pore nanofiltration membrane to obtain the nanofiltration permeate; S5. The nanofiltration permeate is pressurized and concentrated through a small-pore nanofiltration membrane to obtain a concentrated extract; S6. After multi-effect concentration of the concentrated extract, spray drying is performed to obtain the finished product.

2. The method for extracting 1-deoxynojirimycin from fresh mulberry leaves according to claim 1, characterized in that, The step S1 of spreading the thin layer on the ventilation trough includes the following steps: spreading fresh mulberry leaves 3-6mm thick on the ventilation trough, controlling the humidity at 70%-80%, the temperature at 20%-30℃, the wind speed at 0.1-0.3m / s, and the time at 12-36h.

3. The method for extracting 1-deoxynojirimycin from fresh mulberry leaves according to claim 1, characterized in that, In step S2, continuous countercurrent extraction is performed by continuously extracting pure water in a countercurrent manner at 70-85°C for 2 hours to obtain a processed liquid. Then, while the liquid is still hot, plate and frame filtration is performed. The plate and frame filtration requires a 200-500 mesh filter cloth and is treated at 50-60°C to obtain a pre-extracted liquid.

4. The method for extracting 1-deoxynojirimycin from fresh mulberry leaves according to claim 1, characterized in that, In step S3, a 0.1μm–0.2μm ceramic microfiltration membrane is used, with an inlet / outlet pressure of 4 / 3 bar and a temperature of 30–60°C. In step S4, a polyamide nanofiltration membrane with a molecular weight interception of 300–900 Da is used, with an equipment pressure of 30 bar and a temperature of 30–45°C, resulting in a concentration of 12–15 times. The characteristic feature is that in step S5, a polyamide nanofiltration membrane with a molecular weight interception of 75–150 Da is used, with an equipment pressure of 30 bar and a temperature of 30–45°C, resulting in a concentration of 15–18 times.