Exploring Rhamnus alaternus Polysaccharides: Extraction, Characterization, and Analysis of Antioxidant and Antimicrobial Properties

• Published in: Polymers 2024-11, Vol.16 (22), p.3180
• Main Authors: Chokri, Souha, Ben Younes, Sonia, Ellafi, Ali, Mnif, Sami, López-Maldonado, Eduardo Alberto, Slaheddine Masmoudi, Ahmed
• Format: Article
• Language: English
• Subjects: Absorption spectroscopy; Analysis; Antiinfectives and antibacterials; Antimicrobial agents; Antioxidants; Arabinose; Bacterial infections; Biological properties; Carbohydrates; Chelation; Chromatography; Cosmetics; Dextrose; Ethanol; Fourier transforms; Functional foods; Functional foods & nutraceuticals; Galactose; Glucose; Herbal medicine; High performance liquid chromatography; Infrared analysis; Infrared spectroscopy; Leaves; Lipids; Mannose; Natural products; Polysaccharides; Proteins; Scavenging; Spectroscopic analysis; Sugar; Sustainable development; Water; Xylose
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym16223180

In the present study, polysaccharides were isolated from the leaves (WSPRaL) and stems (WSPRaS) of with yields of 3% and 3.25% for WSPRaS and WSPRaL, respectively. Crude WSPRaL was composed of proteins (260.740 ± 0.98 µg/mg), lipids (53.34 ± 2.38 µg/mg), total sugars (482.716 ± 3.02 µg/mg), and reducing sugars (420.240 ± 1.68 µg/mg). In contrast, WSPRaS contained proteins (269.629 ± 1.48 µg/mg), lipids (13.33 ± 0.28 µg/mg), total sugars (569.135 ± 3.82 µg/mg), and reducing sugars (531.732 ± 2.59 µg/mg). FTIR, TLC, and HPLC analyses revealed that the carbohydrate fraction of WSPRaS consisted mainly of glucuronic acid, glucose, galactose, xylose, mannose, and arabinose, whereas WSPRaL consisted of galacturonic acid, sucrose, glucose, rhamnose, xylose, mannose, and arabinose. Scanning electron microscopy (SEM) analysis was used to determine the microstructure of the water-soluble polysaccharides. The physicochemical properties were evaluated using Fourier transform infrared (FT-IR) spectroscopy and ultraviolet‒visible (UV‒visible) absorption spectroscopy. The total antioxidant activities of the crude polysaccharides were evaluated using various assays: DPPH radical scavenging (IC WSPRaL = 615 ± 2.05 µg/mL, IC WSPRaS = 628 ± 2.38 µg/mL), ABTS radical scavenging (470 ± 5.78 µg/mL and 559 ± 4.32 µg/mL for WSPRaL and WSPRaS, respectively), reducing power (IC WSPRaS = 141.76 ± 3.16 µg/mL, IC WSPRaL = 203.89 ± 1.07 µg/mL), and chelating capacity (IC WSPRaS = 225 ± 1.75 µg/mL, IC WSPRaL = 219 ± 2.51 µg/mL). In addition, the antibacterial and biofilm inhibitory activities of both polysaccharides were tested against pathogenic strains, and the polysaccharides significantly inhibited plant growth. Overall, the results indicate that the crude polysaccharides extracted from are promising for use as functional and bioactive ingredients in the food and nutraceutical industries. These results highlight the potential of both polysaccharides as natural products in various sectors, including food, cosmetics, pharmaceuticals, and medicine, due to their significant biological properties.