Organ-dependent phytochemical and pharmacological specialization in the endemic Adenocarpus decorticans Boiss

Adenocarpus decorticans Boiss. is a western Mediterranean shrub restricted to Morocco and Spain, whose phytochemistry and pharmacology remain unexplored despite ethnomedicinal records reported for other species of the genus. This study reports the first organ-resolved characterisation of the species.

Hydroethanolic extracts of flowers, leaves and stems were quantified for total phenolic, flavonoid and proanthocyanidin contents and profiled by ultra-high-performance liquid chromatography coupled with electrospray ionisation mass spectrometry in targeted selected-ion monitoring mode (UHPLC-ESI-MS/SIM). Radical-scavenging and reducing reactivity was determined by DPPH, ABTS and phosphomolybdenum assays. Antibacterial activity was assessed by disc diffusion with minimum inhibitory and bactericidal concentrations against four Gram-positive and two Gram-negative strains, and antiproliferative activity against P3X63Ag8.653 murine myeloma cells and normal splenocytes by MTT. Molecular docking, 100 ns molecular dynamics simulations and ADMET profiling were performed on the identified metabolites.

Profiling revealed pronounced organ-dependent specialization: flowers were dominated by rosmarinic acid, leaves by flavonol and flavanone glycosides, and stems by procyanidin B2 and diverse flavones. Leaves showed the highest phenolic content (526.90 mg gallic acid equivalents/g extract) and the strongest radical-scavenging reactivity (DPPH IC₅₀ 18.62 μg/mL); flowers were the most active against the Gram-positive strains, with bactericidal activity at MIC 0.78-2.08 mg/mL; and stems were the most antiproliferative against P3 cells (IC₅₀ 342.66 μg/mL) with the highest selectivity index (1.97). Docking and dynamics identified flavonoid glycosides and proanthocyanidins as the most stable binders, the EGFR-amentoflavone complex being the most stable over 100 ns.

These findings reveal clear organ-driven chemical and functional specialization in A. decorticans, consistent with the traditional medicinal use documented for the species. Because all assays were performed on crude extracts, the composition-activity correspondences identify candidate constituents rather than establish their contribution, and bioassay-guided fractionation and in vivo validation remain necessary.