Organ-specific chemical diversity and differential bioactivity of Retama monosperma hexane extracts: Comparative analysis of stem and floral tissues as functional ingredient sources

Despite extensive ethnobotanical use of Retama monosperma in Algerian traditional medicine, organ-specific hexane extract characterization remains limited. This study compared chemical composition, antimicrobial activity, and antioxidant capacity of stem vs. floral extracts from western Algerian plants. Soxhlet extraction (hexane, 6-7 h, 300 mL/25-30 g) was followed by GC-MS (Agilent 7890A-5975C), disc diffusion assays (Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC29213; 50-100 mg/mL), DPPH IC₅₀, and Spearman correlations (ρ) with ANOVA/PCA/permutation validation. GC-MS identified 15 stems vs. 25 floral compounds. Stems showed superior anti-S. typhimurium activity (11.33 ± 4.00 mm zone vs. 8.45 ± 1.47 mm; ρ = 0.78, p = 0.032, R² = 0.61; sparteine-driven via LPS destabilization), no Gram-positive effect. Flowers excelled in antioxidants (IC₅₀ = 1.3 ± 0.1 mg/mL vs. 1.7 ± 0.13 mg/mL; ρ = −0.85, p = 0.011, R² = 0.72; unsaturated fatty acids). Anagyrine (16.14%, floral-only) lacked antimicrobial role (ρ = 0.31, p = 0.421). Stem lipids (78.5%; unsaturated 54.7%; sparteine 5.1%, lupanine 4.0%) support defense; floral hydrocarbons (42.7%; tetratriacontane 24.81%, heptacosane 13.00%)/esters aid reproduction/herbivory deterrence (PCA p = 0.003). Organ-selective harvesting optimizes antimicrobials (stems) or antioxidants (flowers), avoiding teratogens. Complementary assays (FRAP/TEAC/ORAC) and pharmacokinetics are recommended. KEY WORDS: Retama monosperma, Quinolizidine alkaloids, Organ-specific metabolites, Sparteine, Anagyrine, Salmonella typhimurium, Lipopolysaccharide (LPS) destabilization Bull. Chem. Soc. Ethiop. 2027, 41(1), 149-181. DOI: https://dx.doi.org/10.4314/bcse.v41i1.11