Composition of pectin-based polymeric films containing a boswellic acid derivative for improved functionality

Abstract

Composition of pectin-based polymer films containing a boswellic acid derivative for improved functionality, comprising: a) Pectin as the primary biopolymer matrix in an amount of 1.5% (w / v), b) a plasticizer in an amount of 1% (w / v) to increase flexibility, and c) a β-AKBA analog in an amount of 0.1% (w / v), uniformly dispersed in the pectin matrix, wherein the film has increased antioxidant activity, improved hydrophobicity, and modified mechanical properties compared to control pectin films.

Description

[0001] The present invention relates to pectin-based polymer films containing a boswellic acid derivative, particularly a β-AKBA analogue, for improved functional properties. The composition contains pectin as the polymer matrix, a plasticizer such as glycerin for flexibility, and a bioactive β-AKBA analogue for improved antioxidant activity. These films are designed for active packaging applications and offer biodegradable and sustainable alternatives with superior protective functions.

[0002] The growing demand for sustainable alternatives to synthetic packaging materials has led to increased interest in biopolymer-based films. Pectin, a natural polysaccharide derived from plant cell walls, has emerged as a promising candidate due to its biodegradability, biocompatibility, and film-forming properties. These properties make pectin an excellent material for food packaging, serving both as a protective barrier and as a medium for functional enhancements. Despite their advantages, however, pectin-based films face limitations such as low mechanical strength and a lack of inherent antimicrobial and antioxidant properties.These disadvantages hinder their full potential in active packaging applications, where packaging materials are expected to provide more than just physical protection by actively extending the shelf life of products and ensuring food safety.

[0003] To overcome these limitations, researchers have explored the incorporation of bioactive compounds into biopolymer films to enhance their functional properties. Acetyl-11-keto-beta-boswellic acid (AKBA), a potent bioactive compound extracted from Boswellia serrata, has attracted considerable attention due to its strong anti-inflammatory, antimicrobial, and antioxidant activities. The integration of AKBA into pectin-based films offers the opportunity to create a multifunctional packaging material that addresses critical food preservation issues, including microbial contamination and oxidative spoilage. This approach not only enhances the protective function of the film but also meets modern consumer demands for sustainable, health-conscious packaging solutions.The natural origin of both pectin and AKBA enhances the product's environmentally friendly appeal and makes it a viable alternative to synthetic packaging materials.

[0004] Despite the clear potential of pectin-AKBA films, there is a lack of comprehensive studies investigating their formulation and functional properties. Previous research has primarily focused on the incorporation of various bioactive agents into polymer films, but the specific combination of pectin and AKBA has not yet been sufficiently explored. To fill this gap, the present study aims to develop and characterize AKBA-loaded pectin-based polymer films, with a particular focus on their physicochemical and antioxidant properties. By optimizing the formulation and evaluating their performance, pectin-AKBA films will be established as an effective, sustainable, and functional packaging solution for food and biomedical applications.

[0005] An objective of the present disclosure is to develop pectin-based polymer films containing a β-AKBA analogue for improved functional properties in active packaging applications.

[0006] Another aim of the present disclosure is to improve the antioxidant properties of pectin films by incorporating a bioactive boswellic acid derivative.

[0007] A further object of the present disclosure is to improve the mechanical flexibility and durability of the films by incorporating a plasticizer such as glycerin.

[0008] Another objective of the present disclosure is to ensure uniform dispersion of the β-AKBA analogue in the pectin matrix by controlled sonication.

[0009] Another object of the present disclosure is to increase the hydrophobicity of the films, reduce moisture permeability and improve their barrier properties.

[0010] Another object of the present disclosure is to provide a biodegradable and environmentally friendly packaging solution that reduces the environmental impact compared to conventional plastic-based materials.

[0011] Another objective of the present disclosure is to optimize the physical and mechanical properties of the films and to ensure a balance between strength, flexibility and active functionality.

[0012] Another objective of the present disclosure is to provide a sustainable and high-performance alternative for food packaging that extends shelf life and increases food safety.

[0013] Further objects and advantages of the present disclosure will become apparent from the following description, which is not intended to limit the scope of the present disclosure.

[0014] The present invention relates to pectin-based polymer films containing a boswellic acid derivative for enhanced functionality, particularly in active packaging applications. These films are designed to provide improved barrier and protective properties while remaining biodegradable.

[0015] Another embodiment of the present invention is the incorporation of a β-AKBA analogue into the pectin matrix to enhance antioxidant properties. This bioactive agent is uniformly dispersed by controlled sonication, ensuring optimal functionality of the film.

[0016] Another embodiment of the present invention is the use of glycerin as a plasticizer to improve the mechanical flexibility and processability of pectin films. The addition of this component strikes a balance between structural integrity and practical usability.

[0017] Another embodiment of the present invention is the development of a controlled film formation process to obtain smooth, homogeneous, and stable films. This ensures consistent material properties suitable for packaging applications.

[0018] Another embodiment of the present invention is the modification of the surface properties of the film to increase hydrophobicity, improve moisture resistance and extend the protective functions of the packaging material.

[0019] Another embodiment of the present invention is the evaluation of the mechanical properties of the films to ensure that they exhibit an optimal balance between strength and flexibility. These properties contribute to durability in real-world applications.

[0020] Another embodiment of the present invention is the use of these films as active packaging materials that provide improved protection of food against oxidation and microbial contamination.

[0021] Another embodiment of the present invention is the development of a sustainable, biodegradable and environmentally friendly alternative to conventional packaging materials, which is in line with global efforts to reduce plastic waste.

[0022] The present invention relates to a pectin-based polymeric film composition containing a boswellic acid derivative, particularly a β-AKBA analogue, to improve its functional properties for active packaging applications. The composition contains pectin as the primary biopolymer, providing biodegradability, film-forming ability, and biocompatibility. To improve mechanical and functional properties, a plasticizer such as glycerin is included, which enhances flexibility and durability. The β-AKBA analogue, a bioactive compound with antioxidant and antimicrobial properties, is uniformly dispersed in the polymer matrix by controlled sonication to ensure uniform distribution and maximize its protective effect.

[0023] The polymeric film composition is designed to act as a barrier against oxidative damage and microbial contamination, extending the shelf life of packaged products. The incorporation of the β-AKBA analogue increases hydrophobicity, reduces moisture permeability, and improves water resistance. The optimized formulation provides a uniform structure with controlled thickness, contributing to mechanical stability while maintaining flexibility. By balancing biodegradability, strength, and active functionality, this composition meets the growing demand for environmentally friendly, high-performance packaging materials. EXAMPLE 1: COMPOSITION 1. A composition of pectin-based polymer films containing a boswellic acid derivative for improved functionality, comprising: a) Pectin as primary biopolymer matrix in an amount of 1.5% (w / v), b) a plasticizer in an amount of 1% (w / v) to increase flexibility, and c) a β-AKBA analogue in an amount of 0.1% (w / v) uniformly dispersed in the pectin matrix, whereby the film exhibits increased antioxidant activity, improved hydrophobicity and modified mechanical properties compared to control pectin films.

[0024] In the first step, the natural compound β-AKBA (1), derived from the gum resin of Boswellia sacra, serves as the starting material. It contains a free carboxylic acid group at position C-24. Compound 1 is reacted with propargylamine (2) in the presence of the HATU coupling agent to afford intermediate 3 in a high yield of 92%. In the next step, the desired 1H-1,2,3-triazole analogue of β-AKBA (5) is obtained by reacting compound 3 with 4-chlorophenyl azide (4). The reaction, which is carried out in the presence of copper iodide (CuI), triethylamine (Et3N) as the base, and acetonitrile (MeCN) as the solvent, proceeds at room temperature for 3 to 4 hours and leads to a high yield of 95%. EXAMPLE 2: Synthesis of (Prop-2-yn-1-ylcarbamoyl) 3a-Acetyloxy-11-oxo-urs-12-en-24-oate (3)

[0025] A representative protocol for the HATU-mediated coupling agent reaction of the carboxylic acid of β-AKBA (1) and propargylamine to produce the desired product (3) is as follows. β-AKBA (1) (1.0 equiv.) and [1-bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU) (1.2 equiv.) were added to propargylamine (2) (1.1 equiv.) in anhydrous DMF in the presence of N,N-diisopropylethylamine (DIPEA) (2.5 equiv.), and the reaction mixture was stirred at room temperature for 10–12 hours until reaction completion (monitored by TLC analysis). Upon completion of the reaction, the product was extracted with EtOAc (3 × 30 mL).The combined organic layer was dried over anhydrous MgSO4 and concentrated under reduced pressure on a rotary evaporator to obtain the crude product, which was purified by column chromatography on silica gel using n-hexane / ethyl acetate (85:15 v / v) as eluent to afford the desired pure compound 3 (92%). Light green solid (light green crystals from MeOH solvent); Yield = 90%; %; mp 196-198 °C, 1H NMR (600 MHz, chloroform-d) δ 5.68 (t, J = 4.5 Hz, 1H), 5.51 (s, 1H), 5.27 (s, 1H), 4. 03 - 3.95 (m, 2H), 2.51 (d, J = 13.2 Hz, 1H), 2.37 (s, 1H), 2.25 (t, J = 14.0 Hz, 1H), 2.18 (s, 1H), 2.04 (s, 4H), 1. 85 (dd, J = 12.6, 8.1 Hz, 1H), 1.75 (dd, J = 22.8, 12.7 Hz, 2H), 1.68 (dd, J = 17.6, 7.6 Hz, 1H), 1.58 (dd, J = 15. 2, 2.5 Hz, 1H), 1.51 - 1.38 (m, 5H), 1.36 (d, J = 10.9 Hz, 2H), 1.30 (s, 3H), 1.26 (d, J = 11.3 Hz, 1H), 1. 21 - 1.15 (m, 6H), 1.11 (s, 3H), 1.08 (s, 3H), 0.98 (d, J = 11.3 Hz, 1H), 0.90 (s, 3H), 0.78 (s, 3H), 0.76 (d, J = 6.4 Hz, 3H); 13C NMR (150 MHz, CDCl3) δ 199.0, 174.8, 170.1, 164.7, 130.5, 79.3, 73.3, 71.6, 60.3, 58. 9, 50.3, 46.6, 45.0, 43.7, 40.8, 39.3, 39.2, 37.3, 34.8, 33.9, 33.1, 30.8, 29.1, 28.8, 27.4, 27.2, 24.4, 23.8, 21.3, 21.1, 20.4, 19.4, 18.2, 17.3, 13.3; HRMS (ESI+): found [M+H]+: 550.39124 (calculated for C35H52NO4, 550.3912. EXAMPLE 3: Synthesis of (1-(4-Chlorophenyl)-1H-1,2,3-triazol-4-yl)methyl)carbamoyl)3α-acetyloxy-11-oxo-urs-12-en-24-oate (5)

[0026] Gummy white solid; yield = 95%; 1H NMR (600 MHz, chloroform-d) δ 7.95 (s, 1H), 7.64 - 7.59 (m, 2H), 7.48 - 7. 45 (m, 2H), 6.32 (t, J = 5.6 Hz, 1H), 5.49 (s, 1H), 5.31 (s, 1H), 4.59 - 4.50 (m, 2H), 2.49 - 2.45 (m, 1H), 2. 36 (s, 1H), 2.28 (dd, J = 18.8, 8.9 Hz, 1H), 2.07 - 2.04 (m, 4H), 1.85 (dd, J = 13.6, 8.7 Hz, 1H), 1.77 - 1. 73 (m, 2H), 1.58 (dd, J = 15.2, 3.1 Hz, 1H), 1.51 - 1.40 (m, 5H), 1.38 - 1.34 (m, 2H), 1.33 - 1.28 (m, 5H), 1.19 - 1. 15 (m, 3H), 1.11 (s, 3H), 1.10 (s, 3H), 1.00 - 0.98 (m, 1H), 0.91 (s, 3H), 0.88 (s, 3H), 0.78 (s, 3H), 0.76 (d, J = 6.4 Hz, 3H); 13C NMR (150 MHz, CDCl3) δ 199.0, 175.6, 170.1, 164.8, 145.2, 135.3, 134.6, 130.4, 129.9, 121.7, 120.7, 73. 4, 60.2, 59.0, 50.3, 46.5, 44.9, 43.7, 40.8, 39.3, 39.2, 37.3, 34.7, 33.9, 33.0, 30.8, 28.8, 27.4, 27.2, 24.5, 23.8, 21.3, 21.1, 20.4, 19.4, 18.2, 17.4, 12.9; HRMS (ESI+): found [M+H]+: 703.40092 (calculated for C41H56ClN4O4, 703.40076. EXAMPLE 4: Development of thin films

[0027] The pectin-based films were prepared by dissolving 1.5% pectin in distilled water. The mixture was stirred for two hours at 50 °C until a smooth, homogeneous solution was obtained. To increase the flexibility of the films, 1% glycerol was added as a plasticizer. The resulting film-forming solution was then divided into two beakers labeled PE1 and PE2. PE1 served as a control, while PE2 was loaded with the β-AKBA analogue to impart active properties to the film. To ensure that the β-AKBA analogue was evenly dispersed in the solution, the mixture in PE2 was sonicated for 10 minutes (Bandelin Sonoplus, LS 40, Berlin, Germany). Subsequently, 20 mL of each solution was dispensed into appropriately leveled and labeled Petri dishes and dried at room temperature under controlled conditions.After complete drying, the films were carefully peeled off and stored in a desiccator to stabilize them until further characterization.

[0028] The results show that the control film (PE1) exhibited a smooth and uniform surface, while the texture of the β-AKBA analogue-loaded film (PE2) was slightly rougher. The variation in these properties may be due to the interaction of the bioactive compound with the pectin matrix, which may have some effects on the polymer network formed during drying. EXAMPLE 5: Surface properties

[0029] To evaluate the surface hydrophobicity of the films, water contact angle measurements were performed. A 2 × 2 cm film sample was placed on a flat surface of an analyzer, and drops containing 1 µl of water were applied. The contact angle measurement was performed using a goniometer and the dpiMAX software.

[0030] The contact angle measurements showed a difference in hydrophobicity between the two films. The contact angle of the PE1 film was approximately 58°, while the angle of the PE2 film increased to 69°, indicating that the hydrophobicity was improved by the β-AKBA analogue. EXAMPLE 6: Physical and mechanical properties of the films

[0031] The physical and mechanical properties of PE1 and PE2 films were characterized through two main tests: film thickness measurement and mechanical strength analysis. Film thickness was first measured using a Mitutoyo digital micrometer. For each sample, measurements were taken randomly at five different points, and the average thickness (mm) was recorded. The mechanical strength of the films was evaluated using a standard universal tester with a 5 kg load cell. The mechanical properties were represented by two essential parameters, including TS (MPa), which represents the maximum stress of the films before failure, and EAB (%), which indicates the flexibility and extensibility of the films.

[0032] The results show that the thickness of the PE2 film (0.086 ± 0.005 mm) was significantly greater than that of the PE1 film (0.056 ± 0.0054 mm). This increase in thickness is most likely due to the incorporation of the bioactive compounds, which impart a higher solid content to the films. Regarding mechanical properties, the TS of the PE2 film (0.009 MPa) was lower than that of the PE1 film (0.019 MPa), confirming that the addition of the β-AKBA analogue slightly weakened the mechanical integrity of the film.

[0033] The results show that the elongation at break (EAB) also decreased from 102.79% in PE1 to 93.51% in PE2, indicating that the modified film was less flexible than the control film. This reduction in the flexibility of biopolymer films is due to the fact that the addition of bioactive substances alters the interactions between the polymer chains. EXAMPLE 7: Antioxidant activity

[0034] The antioxidant activity of PE1 and PE2 films was determined using DPPH radical scavenging activity. The reaction mixture was measured using a Vis spectrophotometer at a wavelength of 517 nm. The percentage inhibition was calculated as the average of three independent measurements for all samples.

[0035] Analysis of antioxidant activity revealed that the PE1 film had a DPPH scavenging activity of only 7.15%, while the PE2 film exhibited a significantly higher activity of 29.98%, confirming the presence of β-AKBA analogues. This enhancement highlights the effectiveness of natural bioactive compounds in enhancing the antioxidant properties of packaging materials. The superior antioxidant ability of PE2 can be attributed to the bioactivity of AKBA, a known radical scavenger. These results confirm the potential of pectin-based films as active packaging materials, providing both barrier protection and antioxidant function to improve food preservation. EXAMPLE 8: Statistical Analysis

[0036] Results are expressed as mean ± SD (standard deviation) calculated from three replicate measurements. Statistical significance between samples was determined using one-way ANOVA with Fisher's post-hoc test for further analysis. Examples 1. A composition of pectin-based polymeric films containing a boswellic acid derivative for improved functionality, comprising: a) Pectin as primary biopolymer matrix in an amount of 1.5% (w / v), b) a plasticizer in an amount of 1% (w / v) to increase flexibility, and c) a β-AKBA analogue in an amount of 0.1% (w / v) uniformly dispersed in the pectin matrix, whereby the film exhibits increased antioxidant activity, improved hydrophobicity and modified mechanical properties compared to control pectin films.

Claims

[1] Composition of pectin-based polymeric films containing a boswellic acid derivative for improved functionality, comprising: a) Pectin as primary biopolymer matrix in an amount of 1.5% (w / v), b) a plasticizer in an amount of 1% (w / v) to increase flexibility, and c) a β-AKBA analogue in an amount of 0.1% (w / v) uniformly dispersed in the pectin matrix, whereby the film exhibits increased antioxidant activity, improved hydrophobicity and modified mechanical properties compared to control pectin films. [2] The composition of claim 1, wherein the boswellic acid derivative is (1-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)-methyl)-carbamoyl)-3α-acetyloxy-11-oxo-urs-12-en-24-oate. [3] The composition of claim 1, wherein the plasticizer is glycerin added to improve the flexibility and mechanical integrity of the film. [4] The composition of claim 1, wherein the β-AKBA analogue is uniformly dispersed in the pectin matrix by sonication for 10 minutes to ensure homogeneity. [5] The composition of claim 1, wherein the film has a contact angle of about 69°, indicating improved hydrophobicity compared to control films. [6] The composition of claim 1, wherein the film has a DPPH scavenging activity of at least 29.98%, confirming improved antioxidant properties. [7] The composition of claim 1, wherein the thickness of the film is increased to about 0.086 ± 0.005 mm due to the incorporation of the boswellic acid derivative. [8] The composition of claim 1, wherein the tensile strength of the film is reduced to about 0.009 MPa due to the interaction between the β-AKBA analogue and the pectin matrix and the elongation at break is 93.51%.