A kind of notoginseng stem and leaf extract and preparation method thereof

Abstract

The present invention provides a Panax notoginseng stem and leaf extract and a preparation method and application thereof, and relates to the field of traditional Chinese medicine extraction. The preparation method of the Panax notoginseng stem and leaf extract of the present invention comprises the following steps: (1) extraction; (2) extraction; (3) microbial transformation; and (4) extracting the fermentation liquid to obtain an extract C, and concentrating and drying to obtain the Panax notoginseng stem and leaf extract; wherein, glucan-degrading Bacillus and Hansenula are used in combination in the microbial transformation process, and the transformation liquid is optimized to finally obtain the Panax notoginseng stem and leaf extract with better antioxidant performance. The preparation method is more efficient and has lower cost, and is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the field of traditional Chinese medicine extraction, and in particular to a notoginseng stem and leaf extract and a preparation method thereof. Background Art

[0002] The underground part of Panax notoginseng includes rhizomes, taproots, branch roots and fibrous roots, and the aboveground part includes stems, leaves, flowers and fruits (seeds). The traditional Chinese medicine Panax notoginseng in the prior art is the dried root of the plant Panax notoginseng, while the stems and leaves of Panax notoginseng are the dried stems and leaves of Panax notoginseng. It is warm in nature and spicy in taste, and can effectively lower blood pressure, blood lipids, blood sugar, improve body microcirculation, and also has the effects of trauma hemostasis, blood circulation and blood stasis, and anti-aging. However, since the content of total saponins is less than that of roots, the relevant research on the extraction of Panax notoginseng stems and leaves is also relatively scarce.

[0003] Book: Xu Dongying. Pharmacy and Clinical Research on Panax Notoginseng [J]. China Traditional Chinese Medicine Press, 2008. Records the anti-aging effects of Panax Notoginseng stem and leaf extracts. Literature: Zhou Jiaming, Cui Xiuming, Zeng Hongchao, et al. Comprehensive Development and Utilization of Panax Notoginseng Stems and Leaves [J]. Modern Chinese Medicine Research and Practice, 2009, 023(003): 32-34. Summarizes the research on saponin components of Panax Notoginseng stem and leaf extracts and the pharmacological effects and clinical applications of Panax Notoginseng stem and leaf extracts. Literature: Gao Lifang, Pu Jianhui, Yang Lixian, et al. Research Progress on Chemical Components of Panax Notoginseng Stems and Leaves [J]. Journal of Wenshan College, 2021, 34(6): 7. Records that the chemical components of Panax Notoginseng stem and leaves mainly include triterpenoid saponins and flavonoid compounds, as well as rich nutrients and mineral elements, and proposes the possibility of its development as a new resource food.

[0004] A series of studies have been conducted in the field on how to efficiently obtain extracts containing effective ingredients from the stems and leaves of Panax notoginseng. For example, patent CN110548057A discloses a process for extracting components from the stems and leaves of Panax notoginseng. The process in the invention mainly uses water extraction and alcohol extraction, and then passes through a 732 type cationic chromatography column to obtain notoginseng, and then passes through a D101 resin chromatography column and a D941 column to obtain total saponins from the stems and leaves of Panax notoginseng, and then further chromatographs on an activated D101 column, and after reduced pressure concentration and freeze drying, obtains a notoginseng flavonoid extract. The process in the invention can simultaneously extract three components: total saponins from the stems and leaves of Panax notoginseng, total flavonoids from Panax notoginseng, and notoginseng, with high yields and contents. However, the process in the invention consumes a large amount of water, resulting in great waste, and the purity of the various effective ingredients extracted is also low.

[0005] Patent CN112451554A discloses a preparation method and application of a Panax notoginseng stem and leaf extract, specifically including: S1 extraction step: using ethanol to hot-immerse and extract the Panax notoginseng stem and leaf to obtain an extract; S2 pre-conversion extraction step: using petroleum ether to extract the extract, taking the aqueous phase to obtain extract I; using chloroform to extract the extract, taking the aqueous phase to obtain extract II; concentrating extract II into an extract to be converted; S3 microbial conversion step: dispersing the extract to be converted in the conversion liquid, and using glucan-degrading Bacillus to ferment the extract to be converted to obtain a fermented conversion liquid. The Panax notoginseng stem and leaf extract obtained by this preparation method can be used to prepare health products, medicines and cosmetics. However, the process in this invention has the possibility of further development, so as to more efficiently obtain a Panax notoginseng stem and leaf extract with better performance.

[0006] In view of the problems existing in the prior art, it is necessary to find a method for preparing Panax notoginseng stem and leaf extract with high efficiency, low cost and better antioxidant performance. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a Panax notoginseng stem and leaf extract and a preparation method thereof. The preparation method is more efficient and has lower cost, can effectively prepare the Panax notoginseng stem and leaf extract with excellent antioxidant properties, and is suitable for industrial production.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] The present invention provides a method for preparing a Panax notoginseng stem and leaf extract, comprising the following steps:

[0010] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol, perform hot extraction, and then concentrate under reduced pressure to obtain a concentrated extract;

[0011] (2) Extraction: The concentrated extract is subjected to a first extraction to obtain an extract A, and then the extract A is subjected to a second extraction to obtain an extract B, which is concentrated to obtain an extract;

[0012] (3) Microbial transformation: After the extract is mixed with the transformation liquid, it is inoculated with Bacillus dextranase and Hansenula, and fermented to obtain a fermentation liquid;

[0013] (4) extracting the fermentation liquid to obtain extract C, concentrating and drying to obtain Panax notoginseng stem and leaf extract; the conversion liquid in step (3) comprises yeast extract, peptone, dipotassium hydrogen phosphate, sodium acetate, ferric citrate, xylose, tyrosine, and blueberry anthocyanins.

[0014] Furthermore, the temperature of the hot extraction in step (1) is 60-80°C.

[0015] Furthermore, the volume of the concentrated extract in step (1) is 1 / 3 of the volume before concentration.

[0016] Furthermore, in step (2), the extracting liquid used in the first extraction is petroleum ether, and the extracting liquid used in the second extraction is chloroform.

[0017] Furthermore, the density of the extract in step (2) is 1.1±0.05 g / mL.

[0018] Furthermore, the conversion solution in step (3) comprises: 0.2-0.5 g / L yeast extract, 2-3 g / L peptone, 0.3-0.7 g / L dipotassium hydrogen phosphate, 0.2-0.5 g / L ferric citrate, 0.3-0.8 g / L xylose, 0.06-0.08 g / L tyrosine, and 0.1-0.25 g / L blueberry anthocyanin.

[0019] Preferably, the conversion solution in step (3) comprises: 0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L dipotassium hydrogen phosphate, 0.3 g / L ferric citrate, 0.6 g / L xylose, 0.07 g / L tyrosine, and 0.15 g / L blueberry anthocyanin.

[0020] Furthermore, in step (3), the weight ratio of the glucanolytic Bacillus to Hansenula is 5-7:1, preferably 6:1.

[0021] Furthermore, in step (3), the fermentation temperature is 35-40° C. and the fermentation time is 48 hours.

[0022] Furthermore, the total inoculation amount of the glucanolytic Bacillus and Hansenula in step (3) accounts for 3-5% of the total weight of the extract and the conversion solution; preferably 3.5%.

[0023] Furthermore, the dosage ratio of the Panax notoginseng stem and leaf powder and ethanol in step (1) is 1kg:5-7L, and the dosage ratio of the extract and the conversion liquid in step (3) is 1g:18-22mL.

[0024] Furthermore, the extraction in step (3) is carried out using n-butanol.

[0025] Furthermore, the present invention also provides a Panax notoginseng stem and leaf extract obtained by the above-mentioned preparation method.

[0026] The technical effects achieved by the present invention are:

[0027] The present invention uses a biotransformation method to obtain a Panax notoginseng stem and leaf extract with a strong free radical scavenging ability. The present invention further studies and optimizes the strains and the conversion liquid and finds that compared with the patent CN112451554A mentioned that "the common yeast or other Bacillus used in biotransformation cannot convert the purified and enriched Panax notoginseng stem and leaf alcohol extract into a form with strong antioxidant capacity". The present invention uses Bacillus dextran and Hansenula for use in combination, and at the same time, with a specific conversion liquid, a Panax notoginseng stem and leaf extract with better antioxidant performance can be obtained. In addition, compared with CN112451554A, the present invention further reduces the amount of each substance in the conversion liquid, can effectively save raw materials, and further promote the realization of industrialization. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention.

[0030] When the embodiment gives a numerical range, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs.

[0031] It is worth noting that the glucanolytic Bacillus used in the present invention is specifically ATCC49278, the Hansenula is specifically Hansenula ATCC66057, the yeast extract is purchased from Wuhan Jiyesheng Chemical Co., Ltd., and the remaining raw materials are common commercial products, so their sources are not specifically limited.

[0032] Example 1

[0033] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0034] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 5 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 60°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0035] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0036] (3) Microbial transformation: The extract was mixed with a transformation solution (0.2 g / L yeast extract, 2 g / L peptone, 0.3 g / L potassium dihydrogen phosphate, 0.2 g / L ferric citrate, 0.3 g / L xylose, 0.06 g / L tyrosine, and 0.1 g / L blueberry anthocyanin) (18 mL of transformation solution was used for every 1 g of extract), and then inoculated with 3% of the total weight of the extract and the transformation solution of Paenibacillus dextran and Hansenula (the weight ratio of the two was 5:1), and fermented at 35°C for 48 h. The supernatant was collected by centrifugation to obtain a fermentation solution;

[0037] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0038] Example 2

[0039] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0040] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (7 L of ethanol is added for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 80°C, and then concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0041] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0042] (3) Microbial transformation: The extract was mixed with a transformation solution (0.5 g / L yeast extract, 3 g / L peptone, 0.7 g / L potassium dihydrogen phosphate, 0.5 g / L ferric citrate, 0.8 g / L xylose, 0.08 g / L tyrosine, and 0.25 g / L blueberry anthocyanin) (22 mL of transformation solution was used for every 1 g of the extract), and then inoculated with 5% of the total weight of the extract and the transformation solution of Paenibacillus dextranosus and Hansenula sp. (the weight ratio of the two was 7:1), and fermented at 40°C for 48 h. The supernatant was collected by centrifugation to obtain a fermentation solution;

[0043] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0044] Example 3

[0045] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0046] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 6 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 70°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0047] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0048] (3) Microbial transformation: The extract was mixed with a transformation solution (0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L potassium dihydrogen phosphate, 0.3 g / L ferric citrate, 0.6 g / L xylose, 0.07 g / L tyrosine, and 0.15 g / L blueberry anthocyanin) (20 mL of transformation solution was used for every 1 g of the extract), and then inoculated with 4% of the total weight of the extract and the transformation solution of Paenibacillus dextranosus and Hansenula sp. (the weight ratio of the two was 6:1), and fermented at 37°C for 48 h. The supernatant was collected by centrifugation to obtain a fermentation solution;

[0049] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0050] Comparative Example 1

[0051] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0052] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 6 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 70°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0053] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0054] (3) Microbial transformation: The extract was mixed with a transformation solution (0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L potassium dihydrogen phosphate, 0.3 g / L ferric citrate, 0.07 g / L tyrosine, and 0.75 g / L blueberry anthocyanin) (20 mL of transformation solution was used for every 1 g of the extract), and then inoculated with 4% of the total weight of the extract and the transformation solution of Paenibacillus dextranosus and Hansenula sp. (the weight ratio of the two was 6:1), and fermented at 37°C for 48 h. The supernatant was collected by centrifugation to obtain a fermentation solution;

[0055] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0056] That is, the only difference from Example 3 is that xylose is not added, but xylose is replaced by an equal amount of blueberry anthocyanins.

[0057] Comparative Example 2

[0058] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0059] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 6 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 70°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0060] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0061] (3) Microbial transformation: The extract was mixed with a transformation solution (0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L potassium dihydrogen phosphate, 0.3 g / L ferric citrate, 0.75 g / L xylose, and 0.07 g / L tyrosine) (20 mL of transformation solution was used for every 1 g of the extract), and then inoculated with 4% of the total weight of the extract and the transformation solution of Paenibacillus dextranosus and Hansenula sp. (the weight ratio of the two was 6:1), and fermented at 37°C for 48 h. The supernatant was collected by centrifugation to obtain a fermentation solution;

[0062] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0063] That is, the only difference from Example 3 is that no blueberry anthocyanins are added, and the blueberry anthocyanins are replaced by an equal amount of xylose.

[0064] Comparative Example 3

[0065] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0066] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 6 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 70°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0067] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0068] (3) Microbial transformation: After the extract was mixed with a transformation solution (1 g / L yeast extract, 3 g / L peptone, 1.5 g / L diammonium hydrogen citrate, 0.3 g / L magnesium sulfate, 1.5 g / L dipotassium hydrogen phosphate, and 4 g / L sodium acetate) (20 mL of transformation solution was used for every 1 g of the extract), 4% of the total weight of the extract and the transformation solution was inoculated with Paenibacillus dextranosphaeroides and Hansenula sp. (the weight ratio of the two was 6:1), and the mixture was fermented at 37°C for 48 h. The supernatant was collected by centrifugation to obtain a fermentation solution;

[0069] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0070] That is, the only difference from Example 3 is that the components of the conversion liquid are replaced.

[0071] Comparative Example 4

[0072] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0073] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 6 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 70°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0074] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0075] (3) Microbial transformation: The extract was mixed with a transformation solution (0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L potassium dihydrogen phosphate, 0.3 g / L ferric citrate, 0.6 g / L xylose, 0.07 g / L tyrosine, and 0.15 g / L blueberry anthocyanin) (20 mL of transformation solution was used for every 1 g of the extract), and then inoculated with 4% of the total weight of the extract and the transformation solution. The mixture was fermented at 37°C for 48 h, and the supernatant was collected by centrifugation to obtain a fermentation solution.

[0076] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0077] That is, the only difference from Example 3 is that only a single Hansen yeast was used for fermentation.

[0078] Comparative Example 5

[0079] A method for preparing a Panax notoginseng stem and leaf extract comprises the following steps:

[0080] (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol (add 6 L ethanol for every 1 kg of the stem and leaf powder of Panax notoginseng), heat extract at 70°C, and concentrate under reduced pressure to obtain a concentrated extract (the volume is 1 / 3 of the volume before concentration);

[0081] (2) Extraction: The concentrated extract was subjected to a first extraction using a volume of petroleum ether equal to that of the concentrate, and the aqueous phase was collected after standing and stratification to obtain an extract A, and then the extract A was subjected to a second extraction using a volume of chloroform equal to that of the extract A, and the aqueous phase was collected after standing and stratification to obtain an extract B, which was concentrated to obtain an extract with a density of 1.1±0.05 g / mL;

[0082] (3) Microbial transformation: The extract was mixed with a transformation solution (0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L potassium dihydrogen phosphate, 0.3 g / L ferric citrate, 0.6 g / L xylose, 0.07 g / L tyrosine, and 0.15 g / L blueberry anthocyanin) (20 mL of transformation solution was used for every 1 g of the extract), and then inoculated with 4% of the total weight of the extract and the transformation solution of Paenibacillus dextran, and fermented at 37°C for 48 h. The supernatant was centrifuged to obtain a fermentation solution;

[0083] (4) After extracting the fermentation broth with an equal volume of n-butanol, the aqueous phase was taken to obtain extract C, which was concentrated under reduced pressure and then dried to obtain the Panax notoginseng stem and leaf extract.

[0084] That is, the only difference from Example 3 is that only a single Paenibacillus dextranase was used for fermentation.

[0085] 1. Yield of Panax notoginseng stem and leaf extract of the present invention

[0086] The weight of the Panax notoginseng stem and leaf powder in each example and the weight of the Panax notoginseng stem and leaf extract finally obtained were weighed, and the yield was calculated as follows: weight of the Panax notoginseng stem and leaf extract (kg) / weight of the Panax notoginseng stem and leaf powder (kg) × 100%. The results are shown in Table 1.

[0087] Table 1 Yield of Panax notoginseng stem and leaf extract

[0088] Examples Yield Example 1 12.6％ Example 2 13.7％ Example 3 15.1％ Comparative Example 1 14.2％ Comparative Example 2 13.5％ Comparative Example 3 9.7％ Comparative Example 4 8.9％ Comparative Example 5 7.3％

[0089] This experiment focused on the overall yield of the extract in the aqueous phase after the fermentation broth was extracted. The results showed that the preparation method of the present invention can effectively obtain a high yield of Panax notoginseng stem and leaf extract. By the method of the present invention, about 126-151g of extract can be extracted from every 1kg of Panax notoginseng stem and leaf powder. In comparison, the yield of the Panax notoginseng stem and leaf extract is more affected by the type of strain.

[0090] 2. Scavenging of free radicals by the Panax notoginseng stem and leaf extract of the present invention

[0091] Test method: 2mL of ABTS solution with a concentration of 4.7mmol / L was mixed with 0.2mL of K2S2O8 solution with a concentration of 2.6mmol / L, and placed at room temperature and dark room conditions for 12h, and then diluted 50 times with methanol to obtain a test solution. 0.8mL of the test solution was mixed with 0.2mL of inositol and allowed to stand for 10min, and the absorbance at a wavelength of 734nm was measured to obtain A0. Then the sample to be tested (0.2mg of the Panax notoginseng stem and leaf extract obtained in each example was mixed with 1mL of deionized water) was mixed with 0.8mL of the test solution, and allowed to stand for 10min, and the absorbance at a wavelength of 734nm was measured to obtain A, and the free radical scavenging rate was calculated, wherein the free radical scavenging rate = (1-A / A0) × 100%, and the results are shown in Table 2.

[0092] Table 2 Free radical scavenging

[0093] Examples Clearance Example 1 88.57％ Example 2 90.00％ Example 3 94.29％ Comparative Example 1 61.43％ Comparative Example 2 72.86％ Comparative Example 3 57.14％ Comparative Example 4 60.00％ Comparative Example 5 38.57％

[0094] The above results show that the Panax notoginseng stem and leaf extract obtained by the present invention has a good ability to scavenge free radicals. When Paenibacillus dextranase and Hansenula are used in combination, a Panax notoginseng stem and leaf extract with excellent antioxidant capacity can be effectively obtained by preparing a specific conversion liquid. For conventional conversion liquid, even if Paenibacillus dextranase and Hansenula are used, the Panax notoginseng stem and leaf extract obtained in the end may not have a good free radical scavenging effect. In addition, the study found that even if the content of each component in the conversion liquid is increased, the free radical scavenging effect of the Panax notoginseng stem and leaf extract obtained in the end is also reduced due to the mismatch between the specific components of the conversion liquid and the corresponding strains.

[0095] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a Panax notoginseng stem and leaf extract, characterized in that: The following steps are involved: (1) Extraction: Wash and dry the stems and leaves of Panax notoginseng, grind them to obtain the stem and leaf powder of Panax notoginseng, add ethanol, perform hot extraction, and then concentrate under reduced pressure to obtain a concentrated extract; (2) Extraction: The concentrated extract is subjected to a first extraction using petroleum ether, and the aqueous phase is collected after standing and stratification to obtain an extract A. The extract A is then subjected to a second extraction using chloroform, and the aqueous phase is collected after standing and stratification to obtain an extract B, which is concentrated to obtain an extract; (3) Microbial transformation: After the extract is mixed with the transformation liquid, it is inoculated with Bacillus dextranase and Hansenula for fermentation to obtain a fermentation liquid; (4) After extracting the fermentation broth with n-butanol, the aqueous phase is taken to obtain extract C, which is concentrated and dried to obtain a Panax notoginseng stem and leaf extract; The conversion solution in step (3) comprises: 0.2-0.5 g / L yeast extract, 2-3 g / L peptone, 0.3-0.7 g / L dipotassium hydrogen phosphate, 0.2-0.5 g / L ferric citrate, 0.3-0.8 g / L xylose, 0.06-0.08 g / L tyrosine, and 0.1-0.25 g / L blueberry anthocyanin.

2. The preparation method according to claim 1, characterized in that: The temperature of the hot extraction in step (1) is 60-80°C.

3. The preparation method according to claim 1, characterized in that: The conversion solution in step (3) comprises: 0.3 g / L yeast extract, 2.5 g / L peptone, 0.5 g / L dipotassium hydrogen phosphate, 0.3 g / L ferric citrate, 0.6 g / L xylose, 0.07 g / L tyrosine, and 0.15 g / L blueberry anthocyanin.

4. The preparation method according to claim 1, characterized in that: In step (3), the weight ratio of the glucan-degrading Bacillus to Hansenula is 5-7:

1.

5. The preparation method according to claim 1, characterized in that: The fermentation temperature in step (3) is 35-40°C and the fermentation time is 48 hours.

6. The preparation method according to claim 1, characterized in that: The usage ratio of the Panax notoginseng stem and leaf powder to ethanol in step (1) is 1kg:5-7L, and the usage ratio of the extract to the conversion solution in step (3) is 1g:18-22mL.

7. The Panax notoginseng stem and leaf extract obtained by the preparation method according to any one of claims 1 to 6.