Glycosylation Pattern Controls Solubility, Micellization, and Aggregation of Structurally Defined Ivy-derived Triterpenoid Saponins

Triterpenoid saponins are amphiphilic plant metabolites with broad agricultural applications. This study compares monodesmosidic α-hederin and hederacolchiside A1 (C3-glycosylated), and bidesmosidic hederacoside C (C3 and C28 glycosylated) to evaluate how glycosylation and pH affect solubility, micelle formation, partitioning, and stability. All three saponins were hydrolytically stable over six months. α-Hederin and hederacolchiside A1 were negligibly soluble in water at pH < 7, whereas hederacoside C maintained a water solubility above 100 μM across pH 2–10. Surface tension measurements in 1 % ethanol revealed critical micelle concentrations (CMCs) of 12 μM (α-hederin), 16 μM (hederacolchiside A1), and >500 μM (hederacoside C). Small-angle X-ray scattering (SAXS) showed α-hederin and hederacolchiside A1 formed ellipsoidal micelles (equatorial radius ∼1.5 nm), while hederacoside C formed spherical micelles above 500 μM (radius ∼0.7 nm). Atomic force microscopy (AFM) confirmed monodesmosidic saponins formed needle-like crystalline sediments. Glycosylation governs aggregation behavior and environmental mobility, informing formulation strategies for saponin-based biopesticides and functional food ingredients. • Glycosylation patterns control saponin aqueous solubility across pH 2–10. • Monodesmosidic saponins are far less soluble than bidesmosidic forms. • SAXS and AFM reveal micelles consisting of 6–108 saponin molecules. • Monodesmosidic saponins show low CMC (< 20 μM) and ellipsoidal micelles (∼1.5 nm). • Results predict limited bioavailability and transport of monodesmosidic saponins.