CN109942657B

CN109942657B - Method for extracting dehydroepiandrosterone from sweet potatoes

Info

Publication number: CN109942657B
Application number: CN201910176270.0A
Authority: CN
Inventors: 王鲁峰; 邹丹; 潘思轶; 徐晓云
Original assignee: Huazhong Agricultural University
Current assignee: Huazhong Agricultural University
Priority date: 2019-03-08
Filing date: 2019-03-08
Publication date: 2021-11-05
Anticipated expiration: 2039-03-08
Also published as: CN109942657A

Abstract

The invention discloses a method for extracting dehydroepiandrosterone from sweet potatoes, which comprises the steps of pre-conversion treatment, acid hydrolysis, extraction, purification and the like. Aiming at the defect that the traditional acid hydrolysis can not completely separate the combined dioscin and cellulose, so that the product yield is very low, the sweet potato pulp is stirred by using the treatment solution, so that the cellulose of the sweet potato pulp is fully swelled, hydrogen bonds and partial glucoside bonds of the combination of the sweet potato cellulose and the dioscin are broken after the mechanical grinding treatment, and the dioscin is separated out, thereby improving the subsequent acid hydrolysis rate and the extraction rate of DHEA (dehydroepiandrosterone), and achieving the aim of quickly and efficiently extracting DHEA from the sweet potatoes.

Description

Method for extracting dehydroepiandrosterone from sweet potatoes

Technical Field

The invention relates to a method for extracting dehydroepiandrosterone, in particular to a method for extracting dehydroepiandrosterone from sweet potatoes.

Background

Dehydroepiandrosterone (DHEA) is one of the most abundant hormones in human body, has the effects of resisting aging, resisting tumor, inhibiting obesity, regulating hormone of human body, etc., and is also an intermediate for preparing steroid hormone medicines. The natural plants containing DHEA are few, and sweet potatoes are rich in DHEA.

DHEA exists in plant cell walls mainly in the sweet potatoes in a dioscin form and is combined with cellulose, a common method for extracting DHEA from the sweet potatoes is an acid hydrolysis method, but because the dioscin exists in close combination with the cellulose in the sweet potatoes, the combined dioscin and the cellulose cannot be completely separated by the traditional acid hydrolysis method, so the extraction rate of DHEA from the sweet potatoes obtained by the traditional method is low, the consumed time is long, and the efficiency is low. Therefore, the natural fermentation treatment of the sweet potatoes is performed before hydrolysis, so that the yield of the products can be improved, the yield can reach five ten-thousandth, but the method takes longer time, only two days are needed for fermentation, and the fermentation process is uncontrollable, so that the product quality is unstable.

Disclosure of Invention

The invention aims to provide a method for extracting dehydroepiandrosterone from sweet potatoes aiming at overcoming the defects in the prior art and aims to improve the yield of the dehydroepiandrosterone and shorten the extraction period.

The above purpose is realized by adopting the following technical scheme:

a method for extracting dehydroepiandrosterone from sweet potatoes comprises the following steps:

1) cleaning fresh sweet potato, removing impurities, pulping, adding 10-40 wt% treatment solution into sweet potato pulp, stirring at room temperature for 1-5 hr, washing with water to neutrality, filtering, adding 1-2 times of water, grinding with colloid mill for 10-100min, centrifuging, precipitating at 50-80 deg.C in water bath for 8-24 hr,

the treatment liquid is a mixed solution of strong base, urea and inorganic salt, and the weight concentrations of the strong base, the urea and the inorganic salt in the mixed solution are respectively 5-10%, 5-10% and 1-5%;

2) subsequently adding concentrated H of 1-5 wt% to the precipitate₂SO₄Hydrolyzing at 80-100 deg.C for 8-16h, cooling to room temperature, adjusting pH to neutral with NaOH solution, centrifuging, and collecting precipitate;

3) adding petroleum ether with the weight of 5-10 times of that of the precipitate obtained in the step 2), carrying out ultrasonic leaching for 0.5-2h, filtering, collecting the extracting solution, and carrying out reduced pressure concentration;

4) and (3) applying the concentrated solution to a silica gel column, eluting by using a non-polar organic solvent, collecting eluent, and performing spray drying to obtain the dehydroepiandrosterone.

Preferably, the strong base is at least one of potassium hydroxide, sodium hydroxide and lithium hydroxide.

Preferably, the inorganic salt is at least one of zinc salt, calcium salt, iron salt and magnesium salt.

Preferably, the nonpolar organic solvent is a mixed solution of acetone and petroleum ether.

Further preferably, the volume ratio of acetone to petroleum ether is 0.5-5: 1.

according to one embodiment of the invention, the best effect technical scheme is as follows:

1) cleaning fresh sweet potato, removing impurities, pulping, adding 20 wt% treatment solution into sweet potato pulp, stirring at room temperature for 4 hr, washing with water to neutrality, filtering, adding 1.6 times of water, grinding with colloid mill for 30min, centrifuging, collecting precipitate, soaking in 60 deg.C water for 12 hr,

the treatment liquid is NaOH, urea and CaCl₂Mixed solution of NaOH, urea and CaCl₂The weight concentrations of the components are respectively 8%, 8% and 3%;

2) subsequently, 2% by weight of concentrated H were added to the precipitate₂SO₄Hydrolyzing at 90 ℃ for 12h, cooling to room temperature, adjusting the pH to be neutral by using NaOH solution, centrifuging, and taking a precipitate;

3) adding petroleum ether with the weight 8 times that of the precipitate obtained in the step 2), carrying out ultrasonic leaching for 1h, filtering, collecting an extracting solution, and carrying out reduced pressure concentration;

4) the concentrated solution was applied to a silica gel column, and the mixture was purified by mixing with a mixed solution of acetone and petroleum ether (volume ratio 1: 1) eluting, collecting eluent, and spray drying to obtain dehydroepiandrosterone.

The invention has the beneficial effects that:

aiming at the defect that the traditional acid hydrolysis can not completely separate the combined dioscin and cellulose, so that the product yield is very low, the sweet potato pulp is stirred by using the treatment solution, so that the cellulose of the sweet potato pulp is fully swelled, hydrogen bonds and partial glucoside bonds of the combination of the sweet potato cellulose and the dioscin are broken after the mechanical grinding treatment, and the dioscin is separated out, thereby improving the subsequent acid hydrolysis rate and the extraction rate of DHEA (dehydroepiandrosterone), and achieving the aim of quickly and efficiently extracting DHEA from the sweet potatoes. Compared with the prior fermentation pretreatment, the pretreatment time is shorter, the process conditions are more controllable, and the product quality is more stable.

The invention improves the extraction rate of the DHEA of the sweet potatoes and shortens the extraction period.

Detailed Description

The present invention will be described in detail below with reference to specific examples.

Example 1

1) pre-transformation treatment:

cleaning fresh sweet potato, removing impurities, pulping, adding 20% treatment solution by weight into sweet potato pulp, stirring at constant temperature of 8 ℃ for 4h, washing the sweet potato pulp with water to neutrality, filtering, adding 1.6 times of water by weight into the sweet potato pulp, grinding for 30min with a colloid mill, centrifuging, and subjecting the obtained precipitate to water bath at 60 ℃ for 12h, wherein the water bath has the main function of converting a part of furostanol saponin into spirostanol saponin through enzymolysis, and the latter is more easily converted into diosgenin, thereby further improving the saponin yield.

The treatment liquid is NaOH, urea and CaCl₂Mixed solution of NaOH, urea and CaCl₂The weight concentrations of (A) and (B) were 8%, 8% and 3%, respectively.

2) Acid hydrolysis:

subsequently, 2% by weight of concentrated H were added to the precipitate₂SO₄Hydrolyzing at 90 deg.C for 12h, cooling to room temperature, adjusting pH to neutral with NaOH solution, centrifuging, and collecting precipitate. The main effect of acid hydrolysis is to obtain diosgenin, and the traditional method has the disadvantages of long time consumption, incomplete acid hydrolysis, overhigh hydrolysis temperature and overlong hydrolysis time, which easily causes safety problems.

3) Extraction:

adding petroleum ether with the weight 8 times of that of the precipitate obtained in the step 2), carrying out ultrasonic leaching for 1h, filtering, collecting an extracting solution, and carrying out reduced pressure concentration. The ultrasonic leaching aims to fully extract the biological effective components by increasing the movement speed of medium molecules and the penetrating power of the medium by utilizing the mechanical effect, the cavitation effect and the thermal effect of ultrasonic waves.

4) And (3) purification:

and (3) passing the concentrated solution through a silica gel column, eluting with a mixed solution of acetone and petroleum ether (the volume ratio is 1: 1), collecting eluent, and performing spray drying to obtain the dehydroepiandrosterone.

Example 2

1) cleaning fresh sweet potatoes, removing impurities, pulping, adding 15 wt% of treatment solution into sweet potato pulp, stirring at constant temperature of 0 ℃ for 5h, washing the sweet potato pulp with water to neutrality, filtering, adding 2 times of water by weight into the sweet potato pulp, grinding for 60min with a colloid mill, centrifuging, and carrying out water bath on the obtained precipitate at 80 ℃ for 8 h.

The treatment solution is lithium hydroxide, urea and ZnCl₂A mixed solution of lithium hydroxide, urea and ZnCl₂The weight concentrations of (A) and (B) were 5%, 10% and 5%, respectively.

2) Then 3% by weight of concentrated H were added to the precipitate₂SO₄Hydrolyzing at 80 deg.C for 16h, cooling to room temperature, adjusting pH to neutral with NaOH solution, centrifuging, and collecting precipitate.

3) Adding petroleum ether with the weight 5 times of that of the precipitate obtained in the step 2), carrying out ultrasonic leaching for 2h, filtering, collecting the extracting solution and carrying out reduced pressure concentration.

4) The concentrated solution was applied to a silica gel column, and the mixture was purified by dissolving acetone and petroleum ether in a mixed solution (volume ratio 0.5: 1) eluting, collecting eluent, and spray drying to obtain dehydroepiandrosterone.

Example 3

1) cleaning fresh sweet potatoes, removing impurities, pulping, adding 40% by weight of treatment solution into sweet potato pulp, stirring at constant temperature of 5 ℃ for 2h, washing the sweet potato pulp with water to neutrality, filtering, adding 1 time by weight of water into the sweet potato pulp, grinding for 10min with a colloid mill, centrifuging, and carrying out water bath on the obtained precipitate at 50 ℃ for 24 h.

The treatment liquid is potassium hydroxide, urea and MgCl₂Mixed solution of potassium hydroxide, urea and MgCl₂The weight concentrations of (A) were 10%, 7%, and 2%, respectively.

2) Subsequently, 1% by weight of concentrated H was added to the precipitate₂SO₄Hydrolyzing at 100 deg.C for 8h, cooling to room temperature, adjusting pH to neutral with NaOH solution, centrifuging, and collecting precipitate.

3) Adding 10 times of petroleum ether by weight into the precipitate obtained in the step 2), carrying out ultrasonic leaching for 0.5h, filtering, collecting the extracting solution and carrying out reduced pressure concentration.

4) The concentrated solution was applied to a silica gel column, and the mixture of acetone and petroleum ether (volume ratio 5: 1) eluting, collecting eluent, and spray drying to obtain dehydroepiandrosterone.

Example 4

1) cleaning fresh sweet potato, removing impurities, pulping, adding 30 wt% of treatment solution into sweet potato pulp, stirring at constant temperature of 3 deg.C for 1h, washing with water to neutrality, filtering, adding 1.5 times of water, grinding with colloid mill for 100min, centrifuging, and soaking the obtained precipitate in 70 deg.C water for 18 h.

The treatment liquid is NaOH, urea and CaCl₂Mixed solution of NaOH, urea and CaCl₂The weight concentrations of (A) and (B) were 6%, 10% and 2%, respectively.

2) Then 5% by weight of concentrated H were added to the precipitate₂SO₄Hydrolyzing at 90 deg.C for 16h, cooling to room temperature, adjusting pH to neutral with NaOH solution, centrifuging, and collecting precipitate.

3) Adding petroleum ether with the weight 6 times of that of the precipitate obtained in the step 2), carrying out ultrasonic leaching for 1.5h, filtering, collecting the extracting solution and carrying out reduced pressure concentration.

4) The concentrated solution was applied to a silica gel column, and the mixture of acetone and petroleum ether (volume ratio 2: 1) eluting, collecting eluent, and spray drying to obtain dehydroepiandrosterone.

The samples prepared in examples 1-4 were subjected to quantitative detection by HPLC: re-dissolving the sample with acetonitrile, filtering with 0.45 μ M filter membrane, and separating with C18 chromatographic column with mobile phase of acetonitrile: and (3) detecting the wavelength of 210nm, the column temperature of 40 ℃, the flow rate of 1.0mL/min and the injection volume of 10 mu L by using a water-based detection method, measuring the DHEA content in the sample by using an external standard method, and calculating the extraction rate according to the DHEA content in the sample and the raw material sweet potato, wherein the result is shown in the following table 1.

TABLE 1 DHEA content and extraction in the samples of examples 1-4

	Sample content (%)	Extraction ratio (%)
			Example 1	96.7	0.055
Example 2	96.2	0.048
			Example 3	95.4	0.045
Example 4	95.8	0.052

Claims

1. A method for extracting dehydroepiandrosterone from sweet potatoes is characterized by comprising the following steps:

2) subsequently, 2% by weight of concentrated H were added to the precipitate₂SO₄Hydrolyzing at 90 deg.C for 12h, cooling to room temperature, adjusting pH to neutral with NaOH solution, and separatingTaking out the sediment from the heart;

4) and (3) applying the concentrated solution to a silica gel column, and mixing the concentrated solution with a solvent with the volume ratio of 1: 1, eluting with a mixed solution of acetone and petroleum ether, collecting the eluent, and spray-drying to obtain the dehydroepiandrosterone.