Mannan M16, anti-dandruff composition containing mannan M16, and preparation method and use thereof

Abstract

The application discloses a mannan M16, a dandruff-removing composition containing the mannan M16 and a preparation method and application thereof. The soil bacillus pumilus NUST16 is inoculated into a fermentation medium with starch as a carbon source, and a mannan M16 is obtained through fermentation and purification. The dandruff-removing composition formed by compounding the mannan M16 with mainstream dandruff removers can realize a synergistic dandruff-removing effect, simultaneously repairs a scalp barrier and maintains a microecological balance of the scalp, and has a wide application prospect in hair washing and hair care products.

Description

Technical Field

[0001] This invention belongs to the technical field of shampoo and hair care products, specifically relating to a mannan M16, an anti-dandruff composition containing mannan M16, its preparation method, and its application. Background Technology

[0002] Dandruff is a common scalp problem, mainly caused by the overgrowth of Malassezia furfur, which leads to a series of inflammations and abnormal keratinization. Excessive sebum secretion provides nutrients for the proliferation of Malassezia furfur, which can break down human triglycerides into unsaturated fatty acids, further causing scalp inflammation and disrupting the scalp's microecological balance, ultimately leading to a vicious cycle.

[0003] Currently, mainstream anti-dandruff agents on the market can be divided into the following categories: First, antibacterial anti-dandruff agents, represented by piroctone olamine salt, zinc pyrithione, and clomiphene; second, keratolytic anti-dandruff agents, represented by salicylic acid and azelaic acid; and third, keratinocyte proliferation inhibitory anti-dandruff agents, represented by coal tar and selenium disulfide. Among these, zinc pyrithione (ZPT) was banned in the EU in 2023 due to its toxicity to aquatic organisms, and China also plans to include it in the list of prohibited ingredients in cosmetics. The anti-dandruff effect of piroctone olamine salt, which is safer, has consistently been weaker than that of zinc pyrithione. Furthermore, traditional anti-dandruff agents also have drawbacks such as potential long-term scalp dryness, the indiscriminate killing of beneficial bacteria by broad-spectrum antibacterial ingredients, and negative impacts on the overall microecological balance.

[0004] Mannan is a type of natural polysaccharide with reported applications in the cosmetics field. Currently, mannan or its derivatives are primarily used as moisturizers, thickeners, film-forming agents, or hair conditioners. For example, cationic modified guar gum (a galactomannan derivative) is often added to shampoos to improve wet combability; certain plant-derived mannans are also used in skincare products to provide moisturizing and film-forming effects. Although studies have shown that mannans with specific structures possess anti-inflammatory or soothing effects, current technologies have not yet demonstrated the application of these bioactive mannans in the dandruff treatment field, nor have they disclosed technical solutions for combining them with chemical dandruff agents to achieve synergistic effects, simultaneously alleviating dandruff agent irritation, repairing the scalp barrier, and regulating the scalp microecology. Existing applications of mannan mainly focus on improving physical properties, lacking the development and utilization of its bioactivity in dandruff treatment scenarios. Chinese patent CN108060187A discloses an extracellular polysaccharide produced by fermentation of strain Paenibacillus edaphicus NUST16 (accession number CCTCC No. M2016542) and its applications. The polysaccharide has specific structural and molecular weight characteristics, but its applications are mainly focused on anti-oxidation and emulsification, and its fermentation medium uses sucrose as the main carbon source. Summary of the Invention

[0005] This invention provides mannan M16, an anti-dandruff composition containing mannan M16, its preparation method, and its application.

[0006] The mannan M16 described in this invention has a main chain repeating unit composed of β-D-glucanopyranose (β-D-Glcp) and two β-D-mannopyranoses (β-D-Manp), in the order of glucose-mannose-mannose; wherein, the C1 position of glucose is linked to the C3 position of the first mannose via a β-1,3 glycosidic bond, the C1 position of the first mannose is linked to the C4 position of the second mannose via a β-1,4 glycosidic bond, and the C1 position of the second mannose is linked to the C3 position of the second mannose via a β-1,4 glycosidic bond. A 3-glycosidic bond connects to the C3 position of glucose in the next repeating unit; at the C2 position of the first mannose residue, an α-D-mannopyranoside side chain is connected via an α-1,2-glycosidic bond, the structure of which is α-D-Manp-(1→2)-α-D-Manp, i.e., two α-D-mannoses are sequentially connected via α-1,2-glycosidic bonds; the number of repeating units is 600~10000, the molecular weight ranges from 500,000~6,000,000 Da, and the structural formula is:

[0007] .

[0008] This invention provides a method for preparing the above-mentioned mannan M16, comprising the following steps:

[0009] (1) Fermentation culture: The seed culture of Paenibacillusedaphicus NUST16 (preservation number CCTCC No. M2016542) was inoculated into the fermentation medium at an inoculation rate of 1%~10% (v / v). Fermentation culture was carried out at 30~37℃, aeration rate of 0.5~2.0 vvm, and stirring speed of 100~300 rpm for 48~120 hours to obtain the fermentation broth. The fermentation medium used starch as the main carbon source and its composition was: starch 20~80 g / L, NaNO3 2~10 g / L, NaH2PO4 0.5~3.0 g / L, CaCl2 0.01~0.5 g / L, MgCl2 0.01~0.5 g / L, KCl 0.01~0.5 g / L, FeCl2 0.001~0.05 g / L, CuSO4 0.001~0.05 g / L, MnSO4 0.001~0.05 g / L, ZnCl2 0.001~0.05 g / L, CoCl2 0.001~0.05 g / L, pH 6.0~9.0.

[0010] (2) Preparation of crude polysaccharide: The fermentation broth was centrifuged at 8000~12000 rpm for 20~30 minutes to remove the cells and collect the supernatant; then 3~5 times the volume of anhydrous ethanol was added to the supernatant, and the mixture was allowed to stand overnight at 4℃. The precipitate was collected by centrifugation; the precipitate was washed 2~3 times with anhydrous ethanol and then vacuum dried or freeze-dried to obtain crude mannan.

[0011] (3) Purification: The crude mannan was reconstituted with deionized water to a final concentration of 5-20 mg / mL. The Sevage reagent was used as a mixture of chloroform and n-butanol in a volume ratio of 4:1 (i.e., chloroform: n-butanol = 4:1). The protein was removed 3-5 times using the Sevage method. The supernatant was collected by centrifugation. The supernatant was dialyzed with a dialysis bag with a molecular weight cutoff of 100,000-300,000 Da for 48-72 hours. After the dialysate was freeze-dried, it was further purified using a DEAE-Sepharose Fast Flow ion exchange chromatography column with a linear gradient elution of 0-1.0 M NaCl solution. The main peak was collected and then purified by a Sepharose CL-6B gel filtration chromatography column with 0.2 M NaCl solution. The target peak was collected and freeze-dried to obtain purified mannan M16.

[0012] Further, in step (1), the fermentation medium consists of: starch 50 g / L, NaNO3 5 g / L, NaH2PO4 1.5 g / L, CaCl2 0.1 g / L, MgCl2 0.1 g / L, KCl 0.1 g / L, FeCl2 0.01 g / L, CuSO4 0.01 g / L, MnSO4 0.01 g / L, ZnCl2 0.01 g / L, CoCl2 0.01 g / L, pH 7.0~7.5.

[0013] This invention provides the application of the above-mentioned mannan M16 in the preparation of anti-dandruff compositions.

[0014] The present invention also provides an anti-dandruff composition containing mannan M16, comprising mannan M16 and an anti-dandruff agent, wherein the mass ratio of mannan M16 to anti-dandruff agent is 0.1 to 50:1, and the anti-dandruff agent is selected from one or more of piroctone olamine salt, clomiphene, hexamidine dichloride, salicylic acid, and selenium disulfide.

[0015] Furthermore, the anti-dandruff agent is one or more of piroctone ethanolamine salt and clomiphene citrate.

[0016] Furthermore, the mass ratio of mannan M16 to the anti-dandruff agent is 1~20:1.

[0017] Furthermore, the anti-dandruff composition also includes water and excipients; the excipients are selected from one or more of surfactants, thickeners, humectants, pH adjusters, preservatives, and fragrances.

[0018] Furthermore, the surfactant is a non-cationic surfactant to ensure the stability of the ingredients and the effectiveness of the product, and is selected from one or more of sodium lauryl ether sulfate, cocamidopropyl betaine, and sodium lauroyl glutamate. Furthermore, the moisturizer is selected from one or more of glycerin, hyaluronic acid, panthenol, and aloe vera extract.

[0019] Furthermore, citric acid is used as the pH adjuster to adjust the system pH to 5.5-6.5, which matches the slightly acidic environment of the scalp and ensures the stability of mannan M16.

[0020] The present invention provides the application of the above-mentioned anti-dandruff composition containing mannan M16 in the preparation of shampoo and hair care products.

[0021] Furthermore, in shampoo and conditioner products, the amount of anti-dandruff composition added is 0.5% to 10%.

[0022] Furthermore, hair care products include, but are not limited to, shampoos, conditioners, scalp serums, and hair masks.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) This invention found that mannan M16 itself has a certain direct inhibitory activity against Malassezia furfur (inhibition zone diameter 8.5 mm, relative inhibition rate 41.2%), which can provide auxiliary support for basic dandruff removal effect. Mannan M16 can significantly protect scalp keratinocytes and immune cells, and reduce cell apoptosis induced by surfactants (such as SLES) and antidandruff agents. Mannan M16 also has anti-inflammatory activity and excellent barrier repair and hydration effects.

[0025] (2) The present invention has demonstrated through flow cytometry experiments that the anti-dandruff composition formed by combining mannan M16 and an anti-dandruff agent can significantly reduce the cell apoptosis rate from 38.6% in the model control group to below 12%, while restoring mitochondrial membrane potential and inhibiting Caspase-3 activation. This cell protection effect is one of the key mechanisms for maintaining scalp health and reducing the recurrence of dandruff from the source.

[0026] (3) ELISA detection revealed that the anti-dandruff composition formed by combining mannan M16 and an anti-dandruff agent significantly downregulated the release of pro-inflammatory factors IL-1β (from 86.4 pg / mL to 24.3 pg / mL), IL-6 (from 112.5 pg / mL to 21.6 pg / mL), and TNF-α (from 98.7 pg / mL to 28.4 pg / mL), while upregulating the anti-inflammatory factor IL-10 (from 18.6 pg / mL to 62.5 pg / mL). By inhibiting scalp inflammation, this invention breaks the vicious cycle of inflammation and dandruff at the pathophysiological level.

[0027] (4) Unlike traditional anti-dandruff agents that cause scalp dryness and barrier damage, the composition of this invention, as demonstrated by the tape peeling method, can improve transepidermal water loss (TEWL) by more than 70% and increase the stratum corneum moisture content by more than 80%. Its unique three-dimensional water-retaining network structure can achieve long-lasting moisture retention, effectively alleviating and repairing problems such as scalp dryness, tightness, and flaking caused by chemical anti-dandruff agents and surfactants, and improving the comfort of product use.

[0028] (5) Based on the above-mentioned multiple effects such as cell protection, anti-inflammation, barrier repair, and moisturizing, the dandruff-reducing composition of the present invention creates a healthy scalp microenvironment for chemical dandruff-reducing agents to exert their effectiveness. Human trial evaluation results show that the dandruff reduction rate of the composition of the present invention can reach more than 90%, the scalp itching improvement rate exceeds 88%, the scalp dryness improvement rate exceeds 85%, and the overall satisfaction rate is as high as 90%~96.7%. All indicators are significantly better than using dandruff-reducing agents alone or using mannan M16 alone. In addition, the composition of the present invention can completely replace traditional dandruff-reducing ingredients such as ZPT, which are toxic to aquatic organisms and have been or will soon be banned, in line with the industry's green and safe development trend. Attached Figure Description

[0029] Figure 1 The image shows a gas chromatogram of the hydrolysis products of mannan M16.

[0030] Figure 2 The image shows the infrared spectrum of mannan M16.

[0031] Figure 3 Nuclear magnetic resonance of mannan M16 1 H spectrum. Detailed Implementation

[0032] The present invention will be described in detail below through specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0033] The soil-borne Bacillus NUST16 described in this invention was deposited at the China Center for Type Culture Collection (CCTCC) on October 8, 2016, with accession number CCTCC No. M2016542, and has been fully disclosed in Chinese patent CN108060187B.

[0034] Example 1

[0035] The preparation of mannan M16 includes the following steps:

[0036] (1) Fermentation culture: The seed culture of soil-borne Bacillus NUST16 was inoculated into the fermentation medium at an inoculation rate of 5% (v / v) and fermented at 35℃, aeration rate of 1.0 vvm and stirring speed of 200 rpm for 48 hours to obtain the fermentation broth. The composition of the fermentation medium was: starch 50 g / L, NaNO3 5 g / L, NaH2PO4 1.5 g / L, CaCl2 0.1 g / L, MgCl2 0.1 g / L, KCl 0.1 g / L, FeCl2 0.01 g / L, CuSO4 0.01 g / L, MnSO4 0.01 g / L, ZnCl2 0.01 g / L, CoCl2 0.01 g / L, pH 7.0~7.5.

[0037] (2) Preparation of crude polysaccharide: The fermentation broth was centrifuged at 10,000 rpm for 30 minutes to remove the cells and the supernatant was collected. Four times the volume of anhydrous ethanol was added to the supernatant, and the mixture was allowed to stand overnight at 4°C. The precipitate was collected by centrifugation. The precipitate was washed three times with anhydrous ethanol and dried under vacuum to obtain crude mannan.

[0038] (3) Purification: The crude mannan was reconstituted with deionized water to a final concentration of 15 mg / mL. The protein was removed four times using the Sevage method (chloroform: n-butanol = 4:1), and the supernatant was collected by centrifugation. The supernatant was dialyzed for 48 hours using a dialysis bag with a molecular weight cutoff of 100,000~300,000 Da. After the dialysate was freeze-dried, it was further purified using a DEAE-Sepharose Fast Flow ion exchange chromatography column (2.6×50 cm) with a linear gradient elution of 0~1.0 M NaCl solution. The main peak was collected. Then it was purified by Sepharose CL-6B gel filtration chromatography column (2.6×100 cm) with elution of 0.2 M NaCl solution. The target peak was collected and freeze-dried to obtain purified mannan M16.

[0039] The fermentation medium used in Chinese patent CN108060187A uses sucrose as the main carbon source. However, this invention changes the type of carbon source and uses starch as the main carbon source. As a result, the polysaccharide produced by the strain during fermentation is changed to mannan M16. Figure 1 The gas chromatogram of the hydrolysis products of M16 shows that the ratio of mannose (Man) to glucose (Glc) is 5 / 1. Figure 2 The infrared spectrum of mannan M16 is shown below. Figure 3 Nuclear magnetic resonance of mannan M16 1 H spectrum.

[0040] Example 2

[0041] An anti-dandruff composition containing mannan M16, comprising the following components by weight percentage:

[0042] Mannan M16 0.5%, piroctone ketone ethanolamine salt 0.1%, sodium lauryl ether sulfate 12.0%, cocamidopropyl betaine 4.0%, glycerol 2.0%, panthenol 0.5%, citric acid as needed, adjust pH to 5.5~6.5, phenoxyethanol 0.5%, deionized water balance.

[0043] The preparation is carried out through the following steps: Weigh each component according to the formula. First, add mannan M16 to a portion of deionized water and stir at 50-60°C until completely dissolved to obtain a mannan M16 solution; simultaneously, add the anti-dandruff agent to the remaining deionized water and stir until completely dissolved to obtain an anti-dandruff agent solution; then mix the mannan M16 solution and the anti-dandruff agent solution and stir evenly; subsequently, add other excipients and continue stirring until homogeneous; adjust the pH to 5.5-6.5 with citric acid to obtain the anti-dandruff composition.

[0044] Example 3

[0045] An anti-dandruff composition containing mannan M16, comprising the following components by weight percentage:

[0046] Mannan M16 1.0%, clotrimazole 0.2%, sodium lauryl ether sulfate 14.0%, cocamidopropyl betaine 5.0%, hyaluronic acid 0.1%, aloe vera extract 1.0%, citric acid as needed, pH adjusted to 5.5~6.5, phenoxyethanol 0.5%, deionized water balance.

[0047] The preparation method is the same as in Example 2.

[0048] Example 4

[0049] An anti-dandruff composition containing mannan M16, comprising the following components by weight percentage:

[0050] Mannan M16 2.0%, hexamididine disalt 0.05%, salicylic acid 0.3%, sodium lauryl ether sulfate 10.0%, sodium lauroyl glutamate 3.0%, glycerol 1.0%, citric acid as needed, pH adjusted to 5.5~6.5, phenoxyethanol 0.5%, deionized water balance.

[0051] The preparation method is the same as in Example 2.

[0052] Comparative Example 1

[0053] The difference from Example 2 is that mannan M16 is not added, and only 0.1% pyroxone ethanolamine salt is contained, while other components are the same.

[0054] Comparative Example 2

[0055] The difference from Example 2 is that: no piroctone ethanolamine salt is added, only 0.5% mannan M16 is contained, and the other components are the same.

[0056] Comparative Example 3

[0057] The difference from Example 3 is that mannan M16 is not added, only 0.2% clomiphene is contained, and the other components are the same.

[0058] Performance test examples

[0059] 1. Malassezia inhibition rate test

[0060] Experimental objective: Referring to the "Test Methods for Antibacterial Properties of Cosmetics", the agar diffusion method was used to determine the basic inhibitory effect of each sample on Malassezia furfur. The experimental results are shown in Table 1.

[0061] Table 1

[0062] sample Diameter of the inhibition zone (mm) Relative inhibition rate (%) Example 2 22.5 99.2 Example 3 21.8 98.7 Example 4 20.6 96.5 Comparative Example 1 16.2 78.3 Comparative Example 2 8.5 41.2 Comparative Example 3 15.8 76.5

[0063] As shown in Table 1, mannan M16 itself possesses limited direct antibacterial activity. The anti-dandruff composition of the examples exhibits excellent antibacterial effects due to the presence of chemical anti-dandruff agents, and its effect mainly stems from these agents. The role of mannan M16 is not to directly synergistically enhance bactericidal efficacy, but rather to protect cells, reduce inflammation, and repair the scalp barrier, thereby optimizing the scalp microenvironment.

[0064] 2. Scalp immune cell apoptosis protection experiment

[0065] Experimental objective: To verify whether mannan M16 can reduce the apoptosis-inducing effects of surfactants (such as sodium laureth sulfate, SLES) and antidandruff agents on scalp immune cells (such as macrophages and keratinocytes).

[0066] Experimental methods: HaCaT cells / human primary scalp keratinocytes were co-cultured as subjects. A cell apoptosis model was constructed by inducing cell apoptosis with surfactants and anti-dandruff agents. The experiment included a blank control, a model control (0.05% SLES + 0.1% piroctone olamine salt), Examples 2-3, and Comparative Examples 1-2. The treatment methods for each group were as follows: (1) Blank control group: only culture medium was added; (2) Model control group: culture medium containing 0.05% SLES + 0.1% piroctone ethanolamine salt was added to construct a cell apoptosis model; (3) Example 2 group: based on the model control group, 0.5% mannan M16 was added; (4) Example 3 group: based on the model control group, 1.0% mannan M16 was added; (5) Comparative example 1 group: based on the model control group, 0.1% piroctone ethanolamine salt was added (i.e., no mannan group); (6) Comparative example 2 group: based on the model control group, 0.5% mannan M16 was added (no anti-dandruff agent). After 24 hours of treatment, the cell apoptosis rate, Caspase-3 activity, and mitochondrial membrane potential were detected. The experimental results are shown in Table 2.

[0067] Table 2

[0068] sample Apoptosis rate (%) Caspase-3 relative activity Mitochondrial membrane potential (ΔΨm, normalized) Blank control group 5.2 ± 1.1 1.0 1.00 Model control group 38.6 ± 3.2 4.2 0.52 Example 2 12.3 ± 2.0 1.5 0.89 Example 3 10.8 ± 1.8 1.3 0.92 Comparative Example 1 35.1 ± 3.0 4.0 0.55 Comparative Example 2 18.5 ± 2.4 2.1 0.78

[0069] The results in Table 2 show that the anti-dandruff agent alone (Comparative Example 1) had no significant protective effect against apoptosis; the use of mannan M16 alone (Comparative Example 2) showed a certain protective effect; while the combination of mannan M16 and the anti-dandruff agent (Examples 2 and 3) could significantly inhibit apoptosis induced by the surfactant and the anti-dandruff agent, making the apoptosis rate close to the level of the blank control group, and could effectively restore mitochondrial membrane potential and inhibit Caspase-3 activation.

[0070] 3. Inflammatory factor release experiment

[0071] Experimental objective: To detect the inhibitory effect of various samples on the inflammatory response of scalp cells induced by chemical stimulation.

[0072] Experimental methods: After treating cells with the above-described groupings, the supernatant was collected, and the levels of IL-1β, IL-6, TNF-α, and IL-10 were detected using ELISA. The experimental results are shown in Table 3.

[0073] Table 3

[0074] sample IL-1β (pg / mL) IL-6 (pg / mL) TNF-α (pg / mL) IL-10 (pg / mL) Blank control group 12.5 8.2 15.3 45.2 Model control group 86.4 112.5 98.7 18.6 Example 2 24.3 21.6 28.4 62.5 Example 3 21.8 19.5 25.1 68.2 Comparative Example 1 79.2 104.3 90.2 22.1 Comparative Example 2 48.6 56.3 52.4 40.3

[0075] The results in Table 3 indicate that, compared with the model control group, mannan M16 alone (Comparative Example 2) can alleviate chemically induced inflammatory responses and optimize the scalp microenvironment by modulating cellular immune function. Compared with the model control group and the comparative example group, the example group significantly reduced the release of pro-inflammatory factors (IL-1β, IL-6, TNF-α) and simultaneously increased the level of the anti-inflammatory factor IL-10, indicating that mannan M16 combined with the antidandruff agent can synergistically enhance the anti-inflammatory effect.

[0076] 4. Scalp barrier repair and moisturizing effect test

[0077] Experimental objective: To verify the repair effect of each sample on the scalp barrier and its effect on improving dryness.

[0078] Experimental methods: A mildly damaged scalp model was constructed using the tape peeling method. Samples were applied to each sample, and the transepidermal water loss rate (TEWL) and stratum corneum moisture content were measured. The experimental results are shown in Table 4.

[0079] Table 4

[0080] sample TEWL Improvement Rate (%) Increase rate of stratum corneum moisture content (%) Example 2 65.2 78.3 Example 3 70.5 82.1 Comparative Example 1 12.3 8.6 Comparative Example 2 58.6 70.2

[0081] The results in Table 4 show that mannan M16 alone can significantly repair the damaged scalp barrier and improve the skin's moisturizing ability, thereby effectively alleviating and improving the side effects of dry scalp and dandruff caused by traditional anti-dandruff agents. Furthermore, the combination of mannan M16 and anti-dandruff agents can further enhance the scalp barrier repair and moisturizing effects.

[0082] 5. Human trial evaluation

[0083] Sixty participants with moderate dandruff (dandruff rating 2-3) were randomly divided into 6 groups of 10 each. They used the shampoo samples prepared in Examples 2-4 and Comparative Examples 1-3, respectively, three times a week for four consecutive weeks, followed by evaluation. The results are shown in Table 5.

[0084] Table 5

[0085] Evaluation indicators (%) Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reduced dandruff 95.6 93.2 90.1 78.5 42.3 76.8 Improved scalp itching 92.3 90.5 88.6 70.2 55.6 68.9 Improved dry scalp 88.5 85.2 86.3 45.6 80.2 42.1 Satisfaction 96.7 93.3 90.0 70.0 63.3 66.7

[0086] The results in Table 5 show that the dandruff-reducing composition of the present invention is significantly superior to each individual component in terms of dandruff reduction rate, scalp itching improvement rate, scalp dryness improvement rate, and overall satisfaction. In particular, the scalp dryness improvement rate is far superior to that of traditional dandruff agent formulations, indicating that mannan M16 effectively alleviates the scalp dryness problem caused by traditional dandruff agents.

Claims

1. Mannan M16, characterized in that, The main repeating unit consists of β-D-glucanopyranose and two β-D-mannopyranose residues in the sequence glucose-mannose-mannose. The C1 position of the glucose residue is linked to the C3 position of the first mannose residue via a β-1,3 glycosidic bond, the C1 position of the first mannose residue is linked to the C4 position of the second mannose residue via a β-1,4 glycosidic bond, and the C1 position of the second mannose residue is linked to the C3 position of the glucose residue in the next repeating unit via a β-1,3 glycosidic bond. At the C2 position of the first mannose residue, an α-D-mannopyranobiose side chain is linked via an α-1,2 glycosidic bond. The structure of this side chain is α-D-Manp-(1→2)-α-D-Manp, meaning two α-D-mannose residues are sequentially linked via α-1,2 glycosidic bonds. The number of repeating units ranges from 600 to 10,000, and the molecular weight ranges from 500,000 to 6,000,000 Da. The structural formula is as follows: 。 2. The method for preparing mannan M16 according to claim 1, characterized in that, Includes the following steps: (1) Fermentation culture: The seed culture of Paenibacillusedaphicus NUST16 (preservation number CCTCC No. M2016542) was inoculated into the fermentation medium at an inoculation rate of 1%~10% (v / v). Fermentation culture was carried out at 30~37℃, aeration rate of 0.5~2.0 vvm, and stirring speed of 100~300 rpm for 48~120 hours to obtain the fermentation broth. The fermentation medium used starch as the main carbon source and its composition was: starch 20~80 g / L, NaNO3 2~10 g / L, NaH2PO4 0.5~3.0 g / L, CaCl2 0.01~0.5 g / L, MgCl2 0.01~0.5 g / L, KCl 0.01~0.5 g / L, FeCl2 0.001~0.05 g / L, CuSO4 0.001~0.05 g / L, MnSO4 0.001~0.05 g / L, ZnCl2 0.001~0.05 g / L, CoCl2 0.001~0.05 g / L, pH 6.0~9.

0.

3. (2) Preparation of crude polysaccharide: The fermentation broth was centrifuged at 8000-12000 rpm for 20-30 minutes to remove the cells and collect the supernatant; then 3-5 times the volume of anhydrous ethanol was added to the supernatant, and the mixture was allowed to stand overnight at 4℃. The precipitate was collected by centrifugation; the precipitate was washed 2-3 times with anhydrous ethanol and then vacuum dried or freeze-dried to obtain crude mannan. (3) Purification: The crude mannan was reconstituted with deionized water to a final concentration of 5-20 mg / mL. The Sevage reagent was used as a mixture of chloroform and n-butanol in a volume ratio of 4:

1. The protein was removed 3-5 times using the Sevage method. The supernatant was collected by centrifugation. The supernatant was dialyzed with a dialysis bag with a molecular weight cutoff of 100,000-300,000 Da for 48-72 hours. After the dialysate was freeze-dried, it was further purified by DEAE-Sepharose Fast Flow ion exchange chromatography column with a linear gradient elution of 0-1.0 M NaCl solution. The main peak was collected and then purified by Sepharose CL-6B gel filtration chromatography column with 0.2 M NaCl solution. The target peak was collected and freeze-dried to obtain purified mannan M16.

4. The preparation method according to claim 2, characterized in that, In step (1), the fermentation medium consists of: starch 50 g / L, NaNO3 5 g / L, NaH2PO4 1.5 g / L, CaCl2 0.1 g / L, MgCl2 0.1 g / L, KCl 0.1 g / L, FeCl2 0.01 g / L, CuSO4 0.01 g / L, MnSO4 0.01 g / L, ZnCl2 0.01 g / L, CoCl2 0.01 g / L, pH 7.0~7.

5.

5. The use of mannan M16 according to claim 1 in the preparation of anti-dandruff compositions.

6. An anti-dandruff composition comprising mannan M16 according to claim 1, characterized in that, It contains mannan M16 and an anti-dandruff agent, wherein the mass ratio of mannan M16 to anti-dandruff agent is 0.1 to 50:1, and the anti-dandruff agent is selected from one or more of piroctone ethanolamine salt, clomiphene, hexamidine disalt, salicylic acid, and selenium disulfide.

7. The anti-dandruff composition according to claim 5, characterized in that, The mass ratio of mannan M16 to the anti-dandruff agent is 1~20:

1.

8. The anti-dandruff composition according to claim 5, characterized in that, The anti-dandruff composition also includes water and excipients; the excipients are selected from one or more of surfactants, thickeners, humectants, pH adjusters, preservatives and fragrances.

9. The anti-dandruff composition according to claim 7, characterized in that, The surfactant is selected from one or more of sodium lauryl ether sulfate, cocamidopropyl betaine, and sodium lauroyl glutamate; the moisturizer is selected from one or more of glycerin, hyaluronic acid, panthenol, and aloe vera extract; the pH adjuster is citric acid, adjusting the pH of the system to 5.5~6.

5.

10. The use of the anti-dandruff composition containing mannan M16 according to any one of claims 5 to 8 in the preparation of shampoo and hair care products.

11. The application according to claim 9, characterized in that, In shampoo and hair care products, the amount of anti-dandruff composition added is 0.5% to 10%; shampoo and hair care products include shampoo, conditioner, scalp serum or hair mask.

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