Analysis of Chemical Composition and Biological Activities of <i>Aloe vera</i> Rind Extract Obtained by Ultrasound‐Assisted Extraction

Ultrasound-assisted extraction of Aloe vera rind yielded significantly more extract (ARE) than conventional maceration, and was therefore selected for in-depth analysis. GC-MS profiling identified thieno\[2,3-c]furan-3-carbonitrile, 2-amino-4,6-dihydro-4,4,6,6-tetramethyl as the predominant compound (49.2%). FTIR spectroscopy confirmed functional groups characteristic of phenolic and flavonoid bioactives. Quantification revealed total phenolic content of 16.88 mg gallic acid equivalents (GAE)/g and total flavonoid content of 32.08 mg quercetin equivalents (QE)/g. Antioxidant efficacy was demonstrated via DPPH radical-scavenging and FRAP assays, indicating strong free-radical neutralization and reducing power. Antimicrobial activity assessed by disk diffusion and well diffusion methods showed potent inhibition of <i>Staphylococcus aureus</i> and <i>Listeria innocua</i>, with minimum inhibitory and bactericidal concentrations (MIC/MBC) of 18.75 mg/mL. Pseudomonas aeruginosa was least sensitive (MIC = 75 mg/mL). SEM examination of ARE-treated S. aureus and <i>Escherichia coli</i> revealed pronounced cell-wall disruption and nucleic acid leakage. Additionally, cytotoxicity assays against cancer cell lines yielded an IC50 of 27.37 mg/mL, demonstrating moderate anticancer potential. Overall, ultrasound extraction proves an efficient method for isolating bioactive compounds from <i>Aloe vera</i> rind. The resulting ARE exhibits notable antioxidant, antimicrobial, and anticancer activities, underscoring its promise for development in pharmaceutical formulations and functional food applications.