Molecular and thermodynamic insights into the enthalpy-entropy shift governing HILIC retention of labelled dextrans

Grčman, Matjaž (avtor), Podlipnik, Črtomir (avtor), Pompe, Matevž (avtor), Kočar, Drago (avtor)

Hydrophilic interaction liquid chromatography (HILIC) is widely used for the analysis of glycans and oligosaccharides, yet the molecular basis of retention remains incompletely understood. In this study, we investigated dextran ladders labelled with 2-aminobenzamide (2-AB) and Rapifluor-MS™ (Waters, Milford, MA, USA) across a wide range of degrees of polymerization (DP 2–15), temperature conditions (10 °C to 70 °C), and gradient programs using a Acquity™ Premier Glycan BEH Amide column (Bridged Ethylene Hybrid, Waters, Milford, MA, USA). Van’t Hoff analysis revealed distinct enthalpic and entropic contributions to retention, allowing identification of a mechanistic transition from enthalpy-dominated docking interactions at low DP to entropy-driven dynamic adsorption at higher DP. This transition occurred reproducibly between DP 4–6, depending on the fluorescent label, while gradient steepness primarily influenced the location of the minimum enthalpy. Molecular dynamics simulations provided additional evidence, showing increased conformational flexibility and end-to-end distance variability for longer oligomers. This finding is consistent with entropy-dominated adsorption accompanied by displacement of structured interfacial water. Together, these results establish a molecular-level framework linking retention thermodynamics, conformational behavior, and solvation effects, thereby advancing our mechanistic understanding of glycan separation in HILIC.

• Jezik: Angleški jezik
• Ključne besede: HILIC, dextran ladder, retention mechanism, enthalpy-entropy compensation
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2025
• Št. strani: 12 str.
• Številčenje: Vol. 30, iss. 24, art. 4711
• PID: 20.500.12556/RUL-176704
• UDK: 543.544.5
• ISSN pri članku: 1420-3049
• DOI: 10.3390/molecules30244711
• COBISS.SI-ID: 260633347
• Datum objave v RUL: 09.12.2025

Gradivo je del revije

• Naslov: Molecules
• Skrajšan naslov: Molecules
• Založnik: MDPI
• ISSN: 1420-3049
• COBISS.SI-ID: 18462981

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: HILIC, dekstranska lestvica, retencijski mehanizem, entalpijsko-entropijska kompenzacija

Projekti

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: P1-0153-2020
• Naslov: Raziskave in razvoj analiznih metod in postopkov