Abstract

The present study aimed to evaluate the chemical, biochemical, and phytochemical properties of the endemic Aloe vacillans Forsskål leaf extracts, focusing on populations cultivated in the Amran Governorate, Yemen, and determining their taxonomical significance. A total of 59 characteristics (26 qualitative and 33 quantitative) were analyzed. Numerical and statistical analyses confirmed the existence of two distinct morphological forms: red-flowered and yellow-flowered. Phytochemical screening confirmed the presence of alkaloids, flavonoids, phenolics, tannins, and saponins. (FT-IR) spectroscopy identified key functional groups, including hydroxyl (OH), C-H, C=C, and carbonyl (C=O) groups, in both forms. The antioxidant activity, assessed via the ferric-bipyridine reduction (FBRC) method, revealed high capacities of 244 ± 5.2 µg ASA/mg for the red form and 232 ± 4.8 µg ASA/mg for the yellow form, with statistically significant differences (P < 0.05). Antimicrobial potential was evaluated against four human pathogens (S. aureus, E. coli, P. aeruginosa, and C. albicans) using the agar well diffusion method. The red form consistently exhibited superior antimicrobial activity compared to the yellow form across all tested concentrations. These findings provide robust evidence for the taxonomical distinction between the two forms and highlight their potential as natural sources for pharmaceutical applications.