Modified ganoderma lucidum polysaccharide, and preparation method and application thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- THE SEVENTH AFFILIATED HOSPITAL SUN YAT SEN UNIV SHENZHEN
- Filing Date
- 2026-02-03
- Publication Date
- 2026-06-09
Smart Images
Figure CN122167606A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of materials technology, and in particular relates to a modified Ganoderma lucidum polysaccharide, its preparation method and application. Background Technology
[0002] In the field of biomaterials, natural polysaccharides are widely used in biomedicine, drug delivery, and tissue engineering due to their excellent biocompatibility, biodegradability, and unique biological functions. Among them, Ganoderma lucidum polysaccharides, as an important natural polysaccharide, have attracted widespread attention due to their outstanding immunomodulatory and antitumor bioactivities. However, the poor hydrophobicity of Ganoderma lucidum polysaccharides limits their application in some areas, especially in the design of drug carriers and tissue engineering materials that require hydrophobic interactions.
[0003] Existing modification methods have limited effect on improving the hydrophobic properties of Ganoderma lucidum polysaccharides and are prone to destroying the original biological activity of Ganoderma lucidum polysaccharides. Summary of the Invention
[0004] The purpose of this application is to provide a modified Ganoderma lucidum polysaccharide, its preparation method and application, which aims to solve to some extent the problems of existing methods having poor effects on improving the hydrophobic properties of Ganoderma lucidum polysaccharides and easily destroying the original biological activity of Ganoderma lucidum polysaccharides.
[0005] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:
[0006] In a first aspect, this application provides a method for preparing modified Ganoderma lucidum polysaccharides, comprising the following steps: Obtaining Ganoderma lucidum polysaccharides, hydrophobic modifiers, and catalysts; wherein the hydrophobic modifiers include at least one of carboxylic acids, alkyl halides, acyl chlorides, and silane coupling agents with a carbon chain length of C8~C12; After dissolving the Ganoderma lucidum polysaccharide, the hydrophobic modifier, and the catalyst in a solvent, the reaction is carried out at a temperature of 35℃~45℃ and a pH value of 7~8 to graft the hydrophobic modifier onto the Ganoderma lucidum polysaccharide, thereby obtaining modified Ganoderma lucidum polysaccharide.
[0007] In some possible implementations, the carboxylic acid includes at least one of octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, and lauric acid.
[0008] In some possible implementations, the alkyl halide includes at least one of 1-bromooctane, 1-bromodecane, and 1-chlorododecane.
[0009] In some possible implementations, the acyl chloride includes at least one of octanoyl chloride, decanoyl chloride, and lauroyl chloride.
[0010] In some possible implementations, the silane coupling agent includes at least one of octyltriethoxysilane, decyltrimethoxysilane, and dodecyltriethoxysilane.
[0011] In some possible implementations, the amount of the hydrophobic modifier is 5% to 15% of the amount of Ganoderma lucidum polysaccharide.
[0012] In some possible implementations, when the hydrophobic modifier is a carboxylic acid with a carbon chain length of C8 to C12, the reaction is an esterification reaction, and the reaction time is 4 to 6 hours.
[0013] In some possible implementations, the catalyst includes at least one of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide.
[0014] In some possible implementations, the amount of the catalyst is 1% to 5% of the amount of the hydrophobic modifier.
[0015] In some possible implementations, the hydrophobic modifier is grafted onto the hydroxyl site of at least one of the galactose D-Galp unit, glucose D-Glcp unit, and mannose D-Manp unit of the Ganoderma lucidum polysaccharide.
[0016] Secondly, this application provides a modified Ganoderma lucidum polysaccharide, which is prepared by the above-mentioned preparation method and includes a Ganoderma lucidum polysaccharide backbone and hydrophobic side chains grafted onto the Ganoderma lucidum polysaccharide backbone, wherein the carbon chain length of the hydrophobic side chains is C8~C12.
[0017] In some possible implementations, the hydrophobic side chain includes an octanoic acid group.
[0018] In some possible implementations, the hydrophobic side chain in the modified Ganoderma lucidum polysaccharide has a mass percentage content of 4.7% to 13.1%.
[0019] Thirdly, this application provides the application of modified Ganoderma lucidum polysaccharides, applying the modified Ganoderma lucidum polysaccharides to the fields of medicine, food, cosmetics and / or materials engineering.
[0020] The method for preparing modified Ganoderma lucidum polysaccharides provided in the first aspect of this application uses at least one of the following hydrophobic modifiers with a carbon chain length of C8-C12: carboxylic acids, alkyl halides, acyl chlorides, and silane coupling agents. These hydrophobic modifiers have relatively long carbon chains, providing stronger hydrophobic interactions. The hydrophobic microdomains formed by grafting this chain-length hydrophobic modifier into the Ganoderma lucidum polysaccharide are of moderate size, enabling efficient encapsulation of hydrophobic drugs and improving drug loading and encapsulation efficiency. The C8-C12 chain length provides sufficient hydrophobicity while maintaining appropriate molecular flexibility and solubility, facilitating the reaction and subsequent material molding. Hydrophobic modifiers with excessively long carbon chains are prone to crystallization, which may lead to poor solubility of the modified product in solvents and processing difficulties. By selecting modifiers of different chain lengths and types, the strength of hydrophobicity, self-assembly ability, and the size and morphology of nanoparticles of the product can be finely adjusted. On the other hand, the hydrophobic modifier is grafted onto the Ganoderma lucidum polysaccharide by reacting at a temperature of 35℃~45℃ and a pH of 7~8. Reacting under near-physiological temperature and neutral conditions maximizes the preservation of the molecular weight and degree of polymerization of the Ganoderma lucidum polysaccharide, and molecular weight is one of the key factors in its immune activity (such as macrophage activation). This avoids the hydrolytic breakage of the polysaccharide backbone glycosidic bonds caused by high temperatures and extreme pH, and avoids charring, Maillard reactions, and various degradation and isomerization side reactions catalyzed by strong acids and bases catalyzed by high temperatures, ensuring the integrity of the active sites on the polysaccharide backbone. The modified Ganoderma lucidum polysaccharide obtained in this way is more likely to retain its core immunomodulatory, antitumor, and other original biological activities while enhancing hydrophobicity, ensuring that the modified product has good biocompatibility and biological activity. Furthermore, the reaction rate is more gradual under mild conditions, making it easier to precisely control the degree of substitution by adjusting parameters such as reaction time and feed ratio.
[0021] The modified Ganoderma lucidum polysaccharide provided in the second aspect of this application, as a direct product of the aforementioned precise preparation method, successfully introduces hydrophobic side chains with carbon chain lengths of C8-C12 onto the Ganoderma lucidum polysaccharide molecule through carefully designed reaction conditions. Furthermore, it retains its original bioactive components to the maximum extent, such as immunomodulatory and antitumor active ingredients in the polysaccharide. This is crucial for ensuring the efficacy and safety of the modified Ganoderma lucidum polysaccharide in the biomedical field, especially in drug delivery and tissue engineering applications. The modified Ganoderma lucidum polysaccharide maintains good biocompatibility and biodegradability, ensuring its safety in vivo. After completing its function, the modified Ganoderma lucidum polysaccharide can be naturally degraded and absorbed by the body, reducing the risk of residues in the body. Moreover, after introducing hydrophobic groups with carbon chain lengths of C8-C12, the modified Ganoderma lucidum polysaccharide can self-assemble into a stable three-dimensional network structure through hydrophobic interactions. This structure is very useful for constructing drug carriers and biomaterials because it can provide a stable drug encapsulation environment and allow for specific biological responses. Furthermore, the modified Ganoderma lucidum polysaccharide exhibits stronger self-assembly capabilities, forming a stable three-dimensional network structure in aqueous solution. This provides new possibilities for preparing biocompatible hydrogels with specific functions. This enhanced self-assembly capability not only improves the mechanical stability of the material but also provides a more suitable three-dimensional growth framework for cells, promoting cell adhesion, proliferation, and differentiation, which is of great significance for promoting tissue repair and regeneration.
[0022] The third aspect of this application extends the application of modified Ganoderma lucidum polysaccharides to fields such as pharmaceuticals, food, cosmetics, and materials engineering. This strategic move profoundly reflects the multifunctional integration characteristics and broad commercial potential of this material. Its application feasibility is directly rooted in the unique combination of properties imparted by the aforementioned mild modification: in the pharmaceutical field, its self-assembling drug loading capacity and retained immune activity can be synergistically used for targeted delivery and combination therapy; in the food and cosmetic fields, its enhanced biocompatibility and stable functionalized structure are suitable as carriers or efficacy factors for high-end active ingredients; in the materials engineering field, the introduced hydrophobic segments can significantly improve its interfacial compatibility and processability in composite materials, paving the way for the development of functional biological scaffolds or coatings. This comprehensive application coverage realizes a transition from basic material innovation to diversified industrial applications. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1This is a schematic flowchart of the preparation method of modified Ganoderma lucidum polysaccharide provided in the embodiments of this application; Figure 2 The graph shows the hydrophobicity test results of the caprylic acid modified Ganoderma lucidum polysaccharide (labeled M-GLP) provided in Example 1 of this application and the unmodified Ganoderma lucidum polysaccharide (labeled GLP) provided in Comparative Example 1. Figure 3 These are the infrared spectra of the caprylic acid-modified Ganoderma lucidum polysaccharide (labeled M-GLP) provided in Example 1 of this application and the unmodified Ganoderma lucidum polysaccharide (labeled GLP) provided in Comparative Example 1; Figure 4 These are the nuclear magnetic resonance spectra of the caprylic acid-modified Ganoderma lucidum polysaccharide (labeled M-GLP) provided in Example 1 of this application and the unmodified Ganoderma lucidum polysaccharide (labeled GLP) provided in Comparative Example 1. Detailed Implementation
[0025] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0026] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0027] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.
[0028] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.
[0029] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.
[0030] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as µg, mg, g, or kg.
[0031] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.
[0032] Ganoderma lucidum polysaccharides, as important natural polysaccharides, have attracted widespread attention due to their excellent immunomodulatory and antitumor bioactivities. However, the poor hydrophobicity of Ganoderma lucidum polysaccharides limits their application in some fields, especially in drug carrier design and tissue engineering materials that require hydrophobic interactions. Current research on improving the hydrophobicity of polysaccharides mainly focuses on two directions: physical mixing and chemical modification. Physical mixing methods are simple and easy to implement, but often fail to achieve stable binding between polysaccharides and hydrophobic components, and may affect the bioactivity of the polysaccharides. Chemical modification methods, such as graft copolymerization and esterification, can introduce hydrophobic groups onto polysaccharide molecules, thereby improving their hydrophobicity. Among these, esterification is a widely used method due to its mild reaction conditions, simple operation, and easily controllable degree of modification. Currently, esterification modification typically uses shorter-chain carboxylic acids, such as acetic acid and propionic acid, to modify polysaccharides. These polysaccharides treated with short-chain carboxylic acids do exhibit a certain degree of improved hydrophobicity, but due to their short chain length, their hydrophobic properties and self-assembly capabilities remain limited, which to some extent restricts their application potential in scenarios requiring high hydrophobic performance.
[0033] Therefore, although the known hydrophobic modification methods have made some progress in improving the hydrophobicity of Ganoderma lucidum polysaccharides, some shortcomings still exist. For example, the improvement in hydrophobicity of Ganoderma lucidum polysaccharides modified with short-chain carboxylic acids is limited, and it may affect the original biological activity of Ganoderma lucidum polysaccharides; at the same time, the known methods also have certain limitations in terms of modification efficiency and product stability.
[0034] Based on the above considerations, in order to improve the hydrophobic properties of Ganoderma lucidum polysaccharides without affecting their original biological activity, the first aspect of this application provides a method for preparing modified Ganoderma lucidum polysaccharides, as shown in the attached figure. Figure 1 As shown, it includes the following steps: S10. Obtain Ganoderma lucidum polysaccharide, hydrophobic modifier and catalyst; wherein the hydrophobic modifier includes at least one of carboxylic acid, alkyl halide, acyl chloride and silane coupling agent with a carbon chain length of C8~C12; S20. Ganoderma lucidum polysaccharide, hydrophobic modifier and catalyst are dissolved in a solvent and then reacted at a temperature of 35℃~45℃ and a pH of 7~8 to graft the hydrophobic modifier onto the Ganoderma lucidum polysaccharide to obtain modified Ganoderma lucidum polysaccharide.
[0035] The method for preparing modified Ganoderma lucidum polysaccharides provided in the first aspect of this application uses at least one of the following hydrophobic modifiers with a carbon chain length of C8-C12: carboxylic acids, alkyl halides, acyl chlorides, and silane coupling agents. These hydrophobic modifiers have relatively long carbon chains, providing stronger hydrophobic interactions. The hydrophobic microdomains formed by grafting this chain-length hydrophobic modifier onto Ganoderma lucidum polysaccharides are of moderate size, enabling efficient encapsulation of hydrophobic drugs and improving drug loading and encapsulation efficiency. The C8-C12 chain length provides sufficient hydrophobicity while maintaining appropriate molecular flexibility and solubility, facilitating the reaction and subsequent material molding. Hydrophobic modifiers with excessively long carbon chains are prone to crystallization, which may lead to poor solubility of the modified product in solvents and processing difficulties. By selecting modifiers of different chain lengths and types, the strength of hydrophobicity, self-assembly ability, and the size and morphology of nanoparticles can be finely adjusted. On the other hand, the hydrophobic modifier is grafted onto Ganoderma lucidum polysaccharides by reacting at a temperature of 35℃~45℃ and a pH of 7~8. Reacting under near-physiological temperature and neutral conditions maximizes the preservation of the molecular weight and degree of polymerization of Ganoderma lucidum polysaccharides, and molecular weight is one of the key factors in its immune activity (such as macrophage activation). This avoids the hydrolysis and breakage of glycosidic bonds in the polysaccharide backbone caused by high temperatures and extreme pH, and avoids charring, Maillard reactions, and various degradation and isomerization side reactions catalyzed by strong acids and bases catalyzed by high temperatures, ensuring the integrity of the active sites on the polysaccharide backbone. The modified Ganoderma lucidum polysaccharides prepared in this way are more likely to retain their core immunomodulatory and antitumor biological activities while enhancing hydrophobicity, ensuring that the modified product has good biocompatibility and biological activity. Furthermore, the reaction rate is more gradual under mild conditions, making it easier to precisely control the degree of substitution by adjusting parameters such as reaction time and feed ratio.
[0036] The method for preparing modified Ganoderma lucidum polysaccharides in this application, through precise control of the type of hydrophobic modifier and reaction conditions (such as temperature and pH), as well as the use of suitable catalysts and reaction media, enables highly efficient grafting reactions. This successfully introduces long-chain hydrophobic side-chain groups into the molecular structure of Ganoderma lucidum polysaccharides, thereby significantly improving their hydrophobicity. Under specific reaction conditions, this not only ensures that the bioactivity of the Ganoderma lucidum polysaccharide molecular backbone is not impaired, but also significantly enhances the hydrophobic interaction ability of the polysaccharides by introducing specific hydrophobic side chains. This is of great significance for its application in drug delivery systems, especially for the encapsulation and controlled release of hydrophobic drugs. Furthermore, the modified Ganoderma lucidum polysaccharides also exhibit excellent self-assembly capabilities, providing new possibilities for the preparation of biocompatible hydrogels with specific functions. This solves the problem that the poor hydrophobicity of Ganoderma lucidum polysaccharides limits their application in biomedical fields, particularly in the design of drug delivery systems and tissue engineering materials, where the low hydrophobicity restricts their ability to load hydrophobic drugs and their application potential in hydrophobic biological environments.
[0037] In this embodiment, the pH value of the reaction is between 7.0 and 8.0, specifically any typical but non-limiting point value or a range between any two points, such as 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, and 8.0. Under these pH conditions, not only is the reaction catalyzed by the catalyst favored, but the protonation of hydroxyl groups is minimized, maintaining the activity of the carboxylic acid groups and thus improving reaction efficiency. Furthermore, it avoids other side reactions that may be caused by strong acids / bases, such as hydroxyl oxidation and removal, ensuring the integrity of the active sites on the polysaccharide backbone. A pH value that is too low or too high will affect the activity of the catalyst and the selectivity of the reaction, potentially leading to decreased yield or unnecessary side reactions.
[0038] For example, the reaction temperature can be any typical but non-limiting point value or an interval between any two point values, such as 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, 41℃, 42℃, 43℃, 44℃, 45℃.
[0039] In step S10 above: In some embodiments, galactose (D-Galp) is the main component of the main chain structure of Ganoderma lucidum polysaccharide, which also includes glucose (D-Glcp), mannose (D-Manp), etc., and its structural formula is as follows: .
[0040] In this application, Ganoderma lucidum polysaccharide is used as the main matrix material, and the amount used is calculated in the form of dry powder with a purity of not less than 95%.
[0041] In some embodiments, the hydrophobic modifier includes at least one of carboxylic acids, alkyl halides, acyl chlorides, and silane coupling agents with a carbon chain length of C8-C12. Examples of this application may use carboxylic acids of different chain lengths as hydrophobic modifiers, as carbon chain length generally affects the hydrophobic properties of the final product: the longer the chain, the stronger the hydrophobicity. Hydrophobic modifiers with medium-length carbon chains (C8-C12), such as carboxylic acids, alkyl halides, acyl chlorides, and silane coupling agents, provide both excellent hydrophobic properties and good reactivity. In addition to carboxylic acids, other chemical substances containing hydrophobic groups, such as alkyl halides, acyl chlorides, and silane coupling agents, may also be used as hydrophobic modifiers in examples of this application. These substances can introduce hydrophobic groups, such as alkyl or siloxane groups, by reacting with hydroxyl groups or other active groups in polysaccharides, further enhancing the hydrophobicity of the material.
[0042] In step S20 above: Ganoderma lucidum polysaccharide, hydrophobic modifier and catalyst are dissolved in a solvent, wherein the solvent can be water.
[0043] In some possible implementations, the hydrophobic modifier includes a carboxylic acid with a carbon chain length of C8-C12. In this case, the reaction between the hydrophobic modifier and Ganoderma lucidum polysaccharide is an esterification reaction. The hydrophobicity of Ganoderma lucidum polysaccharide introduced through the carboxylic acid is based on the chemical principle that the carboxylic acid group reacts with the hydroxyl groups in the Ganoderma lucidum polysaccharide to form ester bonds. The esterification reaction converts the hydrophilic hydroxyl group (-OH) into a hydrophobic ester group (-COOR), thereby reducing the hydrophilicity of the polysaccharide surface and increasing its hydrophobicity. The introduction of the carboxylic acid group enhances the hydrophobic properties of the modified Ganoderma lucidum polysaccharide, which is beneficial for its application in non-polar or weakly polar environments, such as drug carrier design and biomedical materials.
[0044] In some possible implementations, when the hydrophobic modifier is a carboxylic acid with a carbon chain length of C8-C12, the reaction is an esterification reaction with a reaction time of 4-6 hours. The choice of reaction temperature and time has a significant impact on the esterification efficiency and product quality. Too low a temperature or too short a time may result in a slow reaction rate, while too high a temperature or too long a time may lead to an increase in side reactions. A suitable temperature range (35-45℃) and time (4-6 hours) are beneficial for obtaining a highly efficient and selective esterification reaction. This 4-6 hour reaction time range achieves a precise balance between ensuring sufficient reaction and preventing over-reaction or structural damage: under low temperature conditions of 35-45℃ and weak catalytic conditions of pH 7-8, the lower limit of 4 hours ensures that the hydrophobic modifier (such as octanoic acid) can achieve a meaningful grafting rate, thereby obtaining a stable improvement in hydrophobic properties; while the upper limit of 6 hours effectively avoids the potential hydrolysis of polysaccharide chains in a warm water environment, the shedding or rearrangement of grafted hydrophobic chains, and the slow relaxation of the active conformation that may result from excessively long reaction times.
[0045] In some possible implementations, the carboxylic acid includes at least one of octanoic acid, nonanoic acid (C9), decanoic acid (C10), undecanoic acid (C11), and dodecanoic acid / lauric acid (C12). Among these, octanoic acid's moderate water solubility and chain length allow it to be efficiently and uniformly grafted onto the Ganoderma lucidum polysaccharide backbone in a near-physiological environment (mild reaction conditions of 35℃~45℃ and pH 7~8). This avoids the potential steric hindrance and poor solubility issues of long-chain fatty acids and provides a substantial hydrophobic driving force far exceeding that of short-chain modification, significantly enhancing the product's self-assembly and drug loading potential. Simultaneously, as a natural medium-chain fatty acid, octanoic acid has a well-defined metabolic pathway, ensuring excellent safety and biocompatibility of the modified product. Thus, while effectively endowing the material with functionality, it maximizes the protection of the inherent bioactive conformation of Ganoderma lucidum polysaccharides.
[0046] In some other possible implementations, the alkyl halide includes at least one of 1-bromooctane, 1-bromodecane, and 1-chlorododecane. In some other possible implementations, the acyl chloride includes at least one of octanoyl chloride, decanoyl chloride, and lauroyl chloride. In some other possible implementations, the silane coupling agent includes at least one of octyltriethoxysilane, decyltrimethoxysilane, and dodecyltriethoxysilane. These hydrophobic modifiers, such as alkyl halides, acyl chlorides, and silane coupling agents with medium carbon chain lengths of C8 to C12, provide both excellent hydrophobic properties and good reactivity. These substances can further enhance the hydrophobicity of the material by reacting with hydroxyl groups or other active groups in polysaccharides to introduce hydrophobic groups, such as alkyl and siloxane groups.
[0047] The amount of hydrophobic modifier used in the embodiments of this application needs to be precisely controlled to balance the modification effect and the physicochemical properties of the material. The amount is adjusted according to the amount of Ganoderma lucidum polysaccharide. Too little amount may not be enough to significantly improve hydrophobicity; while too much amount may damage the structural integrity of polysaccharide, affecting its biological activity or leading to reduced reaction efficiency and increased side reactions.
[0048] In some possible implementations, the amount of hydrophobic modifier used is 5% to 15% of the amount of Ganoderma lucidum polysaccharide. This ratio precisely matches the reactivity of Ganoderma lucidum polysaccharide under mild conditions of 35℃ to 45℃ and pH 7 to 8, as well as the material performance requirements after the introduction of C8 to C12 hydrophobic chains. Too low a dosage (<5%) may lead to insufficient modification, with limited improvement in hydrophobic driving force and self-assembly ability; too high a dosage (>15%) may make the reaction difficult to complete under mild conditions, or lead to poor solubility and processability of the product due to excessively dense hydrophobic chains, and may even affect the conformation of the polysaccharide's active backbone due to excessive substitution. Choosing the 5% to 15% range can ensure a significant improvement in hydrophobicity and micellarization ability while avoiding over-modification, thus achieving the optimal balance between improving material performance and preserving bioactivity.
[0049] For example, the amount of hydrophobic modifier used can be any typical but non-limiting point value or an interval between any two point values, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%.
[0050] In some possible implementations, when the hydrophobic modifier comprises a carboxylic acid with a carbon chain length of C8-C12, the catalyst comprises at least one of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). These catalysts can all be used to improve the efficiency of esterification reactions between carboxylic acids and hydroxyl groups, particularly in biomolecular reactions. They effectively promote the formation of active esters between carboxyl and hydroxyl groups, thereby accelerating the esterification reaction and improving yield and selectivity.
[0051] In some possible implementations, sodium bicarbonate and / or sodium carbonate act as acid scavengers to maintain the system pH at 7-8. Additionally, sodium carbonate and / or sodium bicarbonate can promote hydroxyl etherification; therefore, when the hydrophobic modifier is an alkyl halide, sodium carbonate and / or sodium bicarbonate can also be used as a catalyst.
[0052] In some possible implementations, the catalyst dosage is 1% to 5% of the hydrophobic modifier dosage. Too little catalyst will reduce catalytic efficiency, while too much may introduce excessive side reactions, such as cross-linking or unnecessary modifications, affecting product purity and function. The lower limit of 1% ensures sufficient catalytic activity to initiate and maintain the reaction under mild conditions, avoiding excessively low reaction rates or failure to proceed; the upper limit of 5% prevents cost waste and increased burden on subsequent purification caused by excessive catalyst, and may reduce the potential negative impact on the polysaccharide structure due to catalyst-related side reactions.
[0053] For example, the amount of catalyst used is 1%, 2%, 3%, 4%, 5% of the amount of hydrophobic modifier, or any typical but non-limiting point value or a range between any two point values.
[0054] In some possible implementations, when the hydrophobic modifier comprises a carboxylic acid with a carbon chain length of C8-C12, the hydrophobic modifier is grafted onto the hydroxyl site of at least one of the galactose D-Galp unit, glucose D-Glcp unit, and mannose D-Manp unit of the Ganoderma lucidum polysaccharide. In the embodiments of this application, the modification of the carboxylic acid hydrophobic modifier typically occurs at the hydroxyl position in the polysaccharide molecule, introducing a hydrophobic octanoic acid chain by forming an ester bond. In the provided Ganoderma lucidum polysaccharide structure, octanoic acid can be modified on any hydroxyl group of D-Galp (galactose), D-Glcp (glucose), or D-Manp (mannose), particularly those hydroxyl groups not involved in glycosidic bond linkage.
[0055] For example, for α-D-Galp and β-D-Glcp units, octanoic acid may modify the hydroxyl group at the C-6 position. For α-D-Manp, modification may occur at the C-2 or C-6 position. The exact position of modification depends on the reaction conditions, the catalyst used, and the selectivity of the reaction. In actual chemical synthesis, multiple positions may be modified unless special measures are taken to protect certain hydroxyl groups from participating in the reaction. The hydrophobically modified Ganoderma lucidum polysaccharides obtained by this method possess unique physicochemical properties and bioactivity, making them valuable biomaterials with wide applications in drug delivery, tissue engineering, biosensing, and other fields.
[0056] In some embodiments, the preparation of modified Ganoderma lucidum polysaccharides includes the following steps: dissolving Ganoderma lucidum polysaccharides in an appropriate amount of aqueous solvent and heating to 35°C~45°C to ensure complete dissolution. Adding a pre-prepared solution of caprylic acid and catalyst to the solution, controlling the pH value between 7.0 and 8.0. The reaction is carried out at 35-45°C for 4-6 hours, followed by adjusting the pH value to neutral, and removing unreacted caprylic acid and catalyst residue by dialysis. Finally, obtaining the modified Ganoderma lucidum polysaccharide powder by freeze-drying. The long-chain hydrophobic side groups introduced by the caprylic acid esterification reaction in this application significantly improve the hydrophobicity of Ganoderma lucidum polysaccharides, greatly enhancing their application potential in hydrophobic environments. The modified Ganoderma lucidum polysaccharides, by increasing the hydrophobic groups, can improve their compatibility with hydrophobic drug molecules, thereby increasing drug loading capacity. Enhanced hydrophobicity also helps control the drug release rate and improve drug loading efficiency. Therefore, the modified Ganoderma lucidum polysaccharides can effectively load more hydrophobic drugs and improve drug therapeutic efficiency by regulating the release rate. Furthermore, the mild reaction conditions and precise reaction control during the modification process ensured that the bioactivity of Ganoderma lucidum polysaccharides was not impaired, thus maintaining their excellent properties as biomaterials.
[0057] Secondly, this application provides a modified Ganoderma lucidum polysaccharide, which is prepared by the above-mentioned preparation method and includes a Ganoderma lucidum polysaccharide backbone and hydrophobic side chains grafted onto the Ganoderma lucidum polysaccharide backbone. The carbon chain length of the hydrophobic side chains is C8~C12.
[0058] The modified Ganoderma lucidum polysaccharide provided in this application, as a direct product of the aforementioned precise preparation method, successfully introduces hydrophobic side chains with carbon chain lengths of C8-C12 onto the Ganoderma lucidum polysaccharide molecule through carefully designed esterification reaction conditions. Furthermore, it retains its original bioactive components to the maximum extent, such as immunomodulatory and antitumor active ingredients in the polysaccharide. This is crucial for ensuring the efficacy and safety of the modified Ganoderma lucidum polysaccharide in the biomedical field, especially in drug delivery and tissue engineering applications. The modified Ganoderma lucidum polysaccharide maintains good biocompatibility and biodegradability, ensuring its safety in vivo. After completing its function, the modified Ganoderma lucidum polysaccharide can be naturally degraded and absorbed by the body, reducing the risk of residues in the body. Moreover, after introducing hydrophobic groups with carbon chain lengths of C8-C12, the modified Ganoderma lucidum polysaccharide can self-assemble into a stable three-dimensional network structure through hydrophobic interactions. This structure is very useful for constructing drug carriers and biomaterials because it can provide a stable drug encapsulation environment and allow for specific biological responses. Furthermore, the modified Ganoderma lucidum polysaccharide exhibits stronger self-assembly capabilities, forming a stable three-dimensional network structure in aqueous solution. This provides new possibilities for preparing biocompatible hydrogels with specific functions. This enhanced self-assembly capability not only improves the mechanical stability of the material but also provides a more suitable three-dimensional growth framework for cells, promoting cell adhesion, proliferation, and differentiation, which is of great significance for promoting tissue repair and regeneration.
[0059] In some possible implementations, the hydrophobic side chain includes an octanoic acid group; Ganoderma lucidum polysaccharides modified with octanoic acid groups have ester bonds formed between the octanoic acid group and the hydroxyl groups on the polysaccharide backbone. This structural modification introduces hydrophobic groups with carbon chain lengths of C8-C12, resulting in higher overall hydrophobicity of the molecule while maintaining the basic polysaccharide backbone. This structural change helps enhance the biological functionality of the polysaccharide, such as improving drug loading capacity and the ability to self-assemble into a stable three-dimensional network structure.
[0060] In some possible implementations, the modified Ganoderma lucidum polysaccharide contains hydrophobic side chains at a mass percentage of 4.7% to 13.1%. In the embodiments of this application, the modified Ganoderma lucidum polysaccharide significantly enhances its hydrophobic interaction capabilities by introducing specific hydrophobic side chains. A mass percentage of 4.7% to 13.1% for the hydrophobic side chains ensures a significant improvement in hydrophobicity and micellarization ability while avoiding over-modification, thus achieving an optimal balance between improved material performance and preservation of bioactivity. When the hydrophobic side chain content is within this range, the modified Ganoderma lucidum polysaccharide ensures the formation of a stable amphiphilic structure, possesses clear self-assembly ability and drug loading potential, while avoiding problems such as insufficient hydrophobicity due to excessively low grafting or loss of activity and decreased solubility due to excessively high grafting.
[0061] For example, in modified Ganoderma lucidum polysaccharides, the mass percentage of hydrophobic side chains can be any typical but non-limiting point value or an interval between any two point values, such as 4.7%, 4.76%, 4.8%, 4.9%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 13.04%, 13.05%, 13.1%.
[0062] In some possible implementations, the mass percentage of hydrophobic side chains in modified Ganoderma lucidum polysaccharides can be calculated using the following formula: w(%)=m 疏水侧链 / m 改性灵芝多糖 ×100%≈r / (1+r)×100%; where r=m 疏水改性剂 / m 灵芝多糖 For example, based on the dosage of the hydrophobic modifier being 5% to 15% of the Ganoderma lucidum polysaccharide dosage, when the dosage of the hydrophobic modifier is 5% of the Ganoderma lucidum polysaccharide dosage (r=5%), the mass percentage of the hydrophobic side chain in the modified Ganoderma lucidum polysaccharide can be calculated as w=0.05 / 1.05×100%=4.76%. When the dosage of the hydrophobic modifier is 15% of the Ganoderma lucidum polysaccharide dosage (r=15%), the mass percentage of the hydrophobic side chain in the modified Ganoderma lucidum polysaccharide can be calculated as w=0.15 / 1.15×100%=13.04%, the mass percentage of the hydrophobic side chain in the modified Ganoderma lucidum polysaccharide can be calculated as 13.04%.
[0063] Thirdly, embodiments of this application provide an application of modified Ganoderma lucidum polysaccharide, applying the above-mentioned modified Ganoderma lucidum polysaccharide to the fields of medicine, food, cosmetics and / or materials engineering.
[0064] This application demonstrates the application of modified Ganoderma lucidum polysaccharides in fields such as pharmaceuticals, food, cosmetics, and materials engineering. This approach profoundly reflects the multifunctional integration characteristics and broad commercial potential of this material. Its application feasibility is directly rooted in the unique combination of properties imparted by the aforementioned mild modification: in the pharmaceutical field, its self-assembling drug loading capacity and retained immune activity can be synergistically used for targeted delivery and combination therapy; in the food and cosmetic fields, its enhanced biocompatibility and stable functionalized structure are suitable as carriers or efficacy factors for high-end active ingredients; in the materials engineering field, the introduced hydrophobic segments can significantly improve its interfacial compatibility and processability in composite materials, paving the way for the development of functional biological scaffolds or coatings. This comprehensive application coverage realizes a transition from basic material innovation to diversified industrial applications.
[0065] In some embodiments, in the pharmaceutical field, modified Ganoderma lucidum polysaccharides can be used as drug carriers, anti-tumor drugs, and anti-inflammatory drugs. Ganoderma lucidum polysaccharides possess various biological activities, such as immunomodulation, antioxidation, and anti-tumor activity. After hydrophobic modification, their drug delivery efficiency and bioavailability may be improved. They can be administered via oral medication, injections, and other routes.
[0066] In some embodiments, modified Ganoderma lucidum polysaccharides can be used in the food industry as food additives, health foods, and functional foods. Because Ganoderma lucidum polysaccharides possess certain biological activity and nutritional and health benefits, hydrophobic modification can improve their stability and solubility in food, expanding their application range. They can be added as additives to beverages, health products, nutritional supplements, and other foods.
[0067] In some embodiments, within the cosmetics field, modified Ganoderma lucidum polysaccharides can be applied to skincare products, beauty products, and other cosmetics. Ganoderma lucidum polysaccharides possess moisturizing, antioxidant, and anti-aging effects. Hydrophobic modification can improve their stability and permeability in cosmetics, enhancing their skincare efficacy. They can be added as active ingredients to lotions, masks, serums, and other cosmetics.
[0068] In some embodiments, within the field of materials engineering, modified Ganoderma lucidum polysaccharides can be applied to biomaterials, biomedical materials, and biodegradable materials. Due to their biocompatibility and biodegradability, hydrophobic modification can improve their processing performance and stability in materials engineering, expanding their applications in the biomedical materials field. They can be added as material components to medical sutures, biomembranes, tissue engineering scaffolds, and other materials.
[0069] To ensure that the above-described implementation details and operations of this application can be clearly understood by those skilled in the art, and to demonstrate the significant advancements in the performance of the modified Ganoderma lucidum polysaccharide, its preparation method, and its application in the embodiments of this application, the following examples illustrate the above technical solutions.
[0070] Example 1 A modified Ganoderma lucidum polysaccharide, the preparation of which includes the following steps: Materials: Ganoderma lucidum polysaccharide powder (95% purity), caprylic acid (99% purity), EDC / NHS catalyst.
[0071] Dosage: 10 g of Ganoderma lucidum polysaccharide, 1.5 g of caprylic acid (15% of the weight of Ganoderma lucidum polysaccharide), and EDC / NHS calculated as 3% of the weight of caprylic acid.
[0072] Reaction conditions: Dissolve in 50 mL of aqueous solvent and control the pH value to 7.5.
[0073] Steps: React at 35℃ for 5 hours, then adjust to pH 7, dialyze to remove byproducts, and freeze-dry to obtain the product, namely modified Ganoderma lucidum polysaccharide dry powder.
[0074] Example 2 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the esterification reaction temperature is 40°C, while the amounts of other raw materials and reaction steps are the same as in Example 1.
[0075] Example 3 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the esterification reaction temperature is 45°C, while the amounts of other raw materials and reaction steps are the same as in Example 1.
[0076] Example 4 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the pH value of the esterification reaction is 7, while the amounts of other raw materials and reaction steps are the same as in Example 1.
[0077] Example 5 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the pH value of the esterification reaction is 8, while the amounts of other raw materials and reaction steps are the same as in Example 1.
[0078] Example 6 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the hydrophobic modifier octanoic acid is replaced with decanoic acid (a C10 carboxylic acid, used at 15% of the amount of Ganoderma lucidum polysaccharide), while the amounts of other raw materials and reaction steps are the same as in Example 1.
[0079] Example 7 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the hydrophobic modifier octanoic acid is replaced with dodecanoic acid / lauric acid (C12 carboxylic acid, used at 15% of the amount of Ganoderma lucidum polysaccharide). Since dodecanoic acid has low solubility in aqueous systems, it can be pre-dissolved in a small amount of ethanol / DMSO before being added dropwise to the reaction system, and the pH is controlled at 7-8 for the reaction. The amounts of other raw materials and the reaction steps are the same as in Example 1.
[0080] Example 8 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that: the hydrophobic modifier octanoic acid is replaced with 1-bromooctane (C8 alkyl halide, used at 15% of the amount of Ganoderma lucidum polysaccharide), and the catalyst is replaced with sodium carbonate and / or sodium bicarbonate (used to promote hydroxyl etherification and maintain the pH of the reaction system at 7-8); the remaining raw material amounts and reaction steps are the same as in Example 1.
[0081] Example 9 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that: the hydrophobic modifier is decanoyl chloride (C10 acyl chloride, used at 15% of the amount of Ganoderma lucidum polysaccharide); sodium bicarbonate / sodium carbonate is used as an acid scavenger during the reaction to maintain the pH of the system at 7-8; the amounts of other raw materials and the reaction steps are the same as in Example 1.
[0082] Example 10 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that: the hydrophobic modifier is replaced with octyltriethoxysilane (C8 silane coupling agent, used at 15% of the amount of Ganoderma lucidum polysaccharide); the pH of the reaction system is controlled at 7-8 to hydrolyze the silane and condense and graft it with the hydroxyl groups of the Ganoderma lucidum polysaccharide; the amounts of other raw materials and the reaction steps are the same as in Example 1.
[0083] Comparative Example 1 Unmodified Ganoderma lucidum polysaccharide was used as comparative example 1.
[0084] Comparative Example 2 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the hydrophobic modifier octanoic acid is replaced with acetic acid (C2 carboxylic acid, the amount of which is the same as that of octanoic acid in Example 1), while the amounts of other raw materials and reaction steps are the same as those in Example 1.
[0085] Comparative Example 3 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the hydrophobic modifier octanoic acid is replaced with propionic acid (C3 carboxylic acid, the amount of which is the same as that of octanoic acid in Example 1), while the amounts of other raw materials and reaction steps are the same as those in Example 1.
[0086] Comparative Example 4 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the esterification reaction temperature is 50°C, while the amounts of other raw materials, reaction steps, and conditions are the same as in Example 1.
[0087] Comparative Example 5 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the pH value of the esterification reaction is 8.5, while the amounts of other raw materials, reaction steps, and conditions are the same as in Example 1.
[0088] Comparative Example 6 A modified Ganoderma lucidum polysaccharide differs from Example 1 in that the hydrophobic modifier octanoic acid is replaced with tetradecanoic acid / myristic acid (C14 carboxylic acid, used at 15% of the amount of Ganoderma lucidum polysaccharide). To facilitate addition, tetradecanoic acid can be dissolved / dispersed in a small amount of ethanol or dimethyl sulfoxide (DMSO) before being added to the reaction system. However, the reaction temperature, pH, reaction time, etc. are the same as in Example 1.
[0089] Furthermore, to verify the progressiveness of the embodiments of this application, the following performance tests were performed on the above embodiments and comparative examples: 1. Hydrophobicity test: The hydrophobicity of a surface is evaluated by dropping water onto the surface and observing the contact angle of the water droplet. Common testing methods include contact angle measurement.
[0090] The hydrophobicity test results of the above embodiments and comparative examples are shown in Table 1 below. The test results of Example 1 (the caprylic acid-modified Ganoderma lucidum polysaccharide labeled as M-GLP) and Comparative Example 1 (the unmodified Ganoderma lucidum polysaccharide labeled as GLP) are attached. Figure 2 As shown:
[0091] From Table 1 and Appendix Figure 2 The test results show that after the Ganoderma lucidum polysaccharides in Examples 1-10 of this application were modified by esterification with a specific hydrophobic modifier, the contact angle changed significantly from 32.4° of the original unmodified Ganoderma lucidum polysaccharide in Comparative Example 1. This indicates that the embodiments of this application efficiently introduced hydrophobic groups (e.g., alkyl chains) through esterification, significantly reducing surface polarity, thus increasing the contact angle. The contact angles of the modified Ganoderma lucidum polysaccharides obtained in Examples 1-10 were 51.8°~62.0°. Among them, the contact angle of the Ganoderma lucidum polysaccharide after octanoic acid esterification modification in Example 1 became 56.1°. This result indicates that the hydrophobicity of the surface of Ganoderma lucidum polysaccharide increased after octanoic acid esterification modification, but a certain degree of hydrophilicity was still retained. This result shows that octanoic acid esterification modification is an effective surface modification method. Octanoic acid esterification modification increases the surface hydrophobicity of Ganoderma lucidum polysaccharide, which can regulate the hydrophilicity and hydrophobicity of Ganoderma lucidum polysaccharide, but does not completely lose the hydrophilicity. This indicates that the modification method has a certain effect on controlling the surface properties of Ganoderma lucidum polysaccharide, thereby meeting different application needs.
[0092] The Ganoderma lucidum polysaccharides modified with acetic acid and propionic acid in Comparative Examples 2 and 3 had shorter chains, resulting in only a small increase in hydrophobicity, which was insufficient to significantly improve the hydrophobicity of Ganoderma lucidum polysaccharides.
[0093] Excessive temperature or pH in the esterification reactions of Comparative Examples 4 and 5 can lead to increased side reactions, easier hydrolysis of activated intermediates, and easier hydrolysis / degradation of polysaccharide structures, thereby affecting grafting efficiency and modification effect, resulting in poor modification effect on Ganoderma lucidum polysaccharides and low effect on improving the hydrophobicity of Ganoderma lucidum polysaccharides.
[0094] In Comparative Example 6, the hydrophobic modifier used had an excessively long carbon chain length (greater than C12). On one hand, long-chain hydrophobic modifiers have poor solubility / dispersion in the reaction system, easily leading to aggregation or crystallization, which restricts mass transfer and reduces grafting site contact, resulting in lower grafting efficiency and uneven graft distribution. On the other hand, excessively long hydrophobic side chains easily cause strong intermolecular hydrophobic association or even phase separation, making the surface orientation and morphology unstable during film / molding, thus limiting the effective presentation of surface hydrophobicity. Therefore, Comparative Example 6's improvement in the hydrophobicity of Ganoderma lucidum polysaccharides was lower than that of the examples with carbon chain lengths of C8-C12, highlighting that hydrophobic modifiers with carbon chain lengths of C8-C12 are the preferred range.
[0095] The comparative examples 2-6 above did not significantly improve the hydrophobicity of Ganoderma lucidum polysaccharides, thus failing to significantly increase the drug loading or change the drug release rate. Furthermore, the improvement in the biocompatibility of Ganoderma lucidum polysaccharides was minimal, and their stability during storage and processing was similar to that of unmodified Ganoderma lucidum polysaccharides.
[0096] 2. Infrared spectroscopy (IR): Analyzing the changes in the chemical composition of Ganoderma lucidum polysaccharides can reveal the appearance of new functional groups in the modified Ganoderma lucidum polypeptides.
[0097] The infrared spectral results of Example 1 (Ganoderma lucidum polysaccharide modified with caprylic acid and labeled as M-GLP) and Comparative Example 1 (Ganoderma lucidum polysaccharide not modified and labeled as GLP) are attached. Figure 3 As shown: Infrared spectral characteristics of GLP (Comparative Example 1 Ganoderma lucidum polysaccharide): broad peak at 3400 cm⁻¹ -1 Left and right: This usually corresponds to the OH stretching vibration, indicating the presence of a large number of hydroxyl groups (-OH) in the sample, which is common in polysaccharides. At 2900 cm⁻¹ -1 The nearby weak peak: This is usually associated with CH stretching vibrations, indicating the presence of carbon-hydrogen bonds. At 1640 cm⁻¹ -1 The nearby absorption peak likely corresponds to the C=O stretching vibration, possibly due to the presence of carbon groups (such as carbonyl groups) in the polysaccharide. At 1150 cm⁻¹... -1 Up to 1000 cm -1 The strong peak is usually related to the vibration of COC and C-OH bonds, which is a characteristic peak of polysaccharide structure.
[0098] Infrared spectral characteristics of M-GLP (Ganoderma lucidum polysaccharide modified with caprylic acid in Example 1): at 3400 cm⁻¹ -1 A decrease in peak intensity near the 2900 cm⁻¹ peak may indicate partial esterification of hydroxyl groups, leading to reduced OH absorption. -1 Enhanced absorption peaks nearby: This may be related to the CH stretching vibration of the alkyl chain in octanoic acid, indicating that octanoic acid esterification successfully introduced a hydrophobic alkyl chain. At 1740 cm⁻¹ -1A prominent peak nearby: This is typically a characteristic absorption peak for the ester group (C=O), indicating successful octanoic acid esterification. At 1150 cm⁻¹ -1 Up to 1000 cm -1 The absorption peaks have changed: this may reflect some structural changes in the polysaccharide, but the basic characteristics of the polysaccharide are still retained.
[0099] Comparison of the infrared spectra of GLP and M-GLP revealed that the caprylate-modified Ganoderma lucidum polysaccharide (M-GLP) exhibited a new absorption peak (e.g., 1740 cm⁻¹). -1 The presence of characteristic peaks of the ester group nearby and other changes (such as a decrease in OH absorption intensity and an increase in CH absorption intensity) indicate that the octanoic acid esterification modification was successful. The infrared spectral characteristics of M-GLP are consistent with the expected characteristics after esterification modification, indicating that the hydrophobic octanoic acid group was successfully introduced into Ganoderma lucidum polysaccharide.
[0100] 3. Nuclear Magnetic Resonance Spectroscopy (NMR): Analyzing the changes in the chemical structure of Ganoderma lucidum polysaccharides can reveal the presence of hydrophobic modifier groups in the modified Ganoderma lucidum polysaccharide molecules.
[0101] The nuclear magnetic resonance spectra of Example 1 (Ganoderma lucidum polysaccharide modified with caprylic acid and labeled as M-GLP) and Comparative Example 1 (Ganoderma lucidum polysaccharide unmodified and labeled as GLP) are attached. Figure 4 As shown: NMR results of GLP (Comparative Example 1: Ganoderma lucidum polysaccharide): Peak positions (chemical shifts, δ): Multiple peaks are observed in the 4.0–5.5 ppm region, which are generally associated with hydrogen atoms in the polysaccharide (e.g., hydrogen atoms on the sugar ring). Other smaller peaks appear in the 3.0–4.0 ppm range, possibly related to other hydrogen atoms in the polysaccharide structure. Peak intensity and distribution: A relatively strong peak is observed around 4.5 ppm, which is likely due to hydrogen atoms in a specific sugar ring.
[0102] NMR results of M-GLP (Ganoderma lucidum polysaccharide modified with caprylic acid from Example 1): Peak positions (chemical shifts, δ): in Figure 2 In the 4.0–5.5 ppm region, the peaks still exist, but their intensity and distribution have changed. Some new peaks appear in the 1.0–2.0 ppm region, which are generally related to hydrogen atoms in alkyl chains (e.g., the methyl and methylene groups of octanoic acid), indicating the introduction of octanoic acid groups. Peak intensity and distribution: The peak around 4.5 ppm still exists, but its intensity has changed compared to GLP, indicating that the chemical environment of some hydrogen atoms in the sugar ring has changed during esterification. The new peaks in the 1.0–2.0 ppm region indicate that octanoic acid esterification successfully introduced hydrophobic alkyl chains.
[0103] By comparing the NMR spectra of GLP and M-GLP, a new peak appeared in the 1.0 to 2.0 ppm region of M-GLP, indicating that octanoic acid esterification successfully introduced an alkyl chain. Furthermore, changes in the peak intensity and distribution in the original 4.0 to 5.5 ppm region also support the conclusion that the esterification reaction was successful. These changes are consistent with the introduction of the octanoic acid group and the modification of the polysaccharide structure.
[0104] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for preparing modified Ganoderma lucidum polysaccharide, characterized in that, Includes the following steps: Obtaining Ganoderma lucidum polysaccharides, hydrophobic modifiers, and catalysts; wherein the hydrophobic modifiers include at least one of carboxylic acids, alkyl halides, acyl chlorides, and silane coupling agents with a carbon chain length of C8~C12; After dissolving the Ganoderma lucidum polysaccharide, the hydrophobic modifier, and the catalyst in a solvent, the reaction is carried out at a temperature of 35℃~45℃ and a pH value of 7~8 to graft the hydrophobic modifier onto the Ganoderma lucidum polysaccharide, thereby obtaining modified Ganoderma lucidum polysaccharide.
2. The method for preparing modified Ganoderma lucidum polysaccharide as described in claim 1, characterized in that, The carboxylic acid includes at least one of octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid / lauric acid; And / or, the alkyl halide includes at least one of 1-bromooctane, 1-bromodecane, and 1-chlorododecane; And / or, the acyl chloride includes at least one of octanoyl chloride, decanoyl chloride, and lauroyl chloride; And / or, the silane coupling agent includes at least one of octyltriethoxysilane, decyltrimethoxysilane, and dodecyltriethoxysilane.
3. The method for preparing modified Ganoderma lucidum polysaccharide as described in claim 1 or 2, characterized in that, The amount of the hydrophobic modifier is 5% to 15% of the amount of Ganoderma lucidum polysaccharide.
4. The method for preparing modified Ganoderma lucidum polysaccharide as described in claim 3, characterized in that, When the hydrophobic modifier is a carboxylic acid with a carbon chain length of C8 to C12, the reaction is an esterification reaction, and the reaction time is 4 to 6 hours.
5. The method for preparing modified Ganoderma lucidum polysaccharide as described in claim 4, characterized in that, The catalyst includes at least one of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide.
6. The method for preparing modified Ganoderma lucidum polysaccharide as described in claim 5, characterized in that, The amount of catalyst used is 1% to 5% of the amount of hydrophobic modifier used.
7. The method for preparing modified Ganoderma lucidum polysaccharide as described in claim 6, characterized in that, The hydrophobic modifier is grafted onto the hydroxyl site of at least one of the galactose D-Galp unit, glucose D-Glcp unit, and mannose D-Manp unit of the Ganoderma lucidum polysaccharide.
8. A modified Ganoderma lucidum polysaccharide, characterized in that, The modified Ganoderma lucidum polysaccharide is prepared by the preparation method described in any one of claims 1 to 7, comprising a Ganoderma lucidum polysaccharide backbone and hydrophobic side chains grafted onto the Ganoderma lucidum polysaccharide backbone, wherein the carbon chain length of the hydrophobic side chains is C8 to C12.
9. The modified Ganoderma lucidum polysaccharide as described in claim 8, characterized in that, The hydrophobic side chain includes an octanoic acid group; And / or, in the modified Ganoderma lucidum polysaccharide, the mass percentage of the hydrophobic side chain is 4.7%~13.1%.
10. An application of a modified Ganoderma lucidum polysaccharide, characterized in that, The modified Ganoderma lucidum polysaccharide as described in any one of claims 8 to 9 may be applied to the fields of medicine, food, cosmetics and / or materials engineering.