title: Thermal properties and nanodispersion behavior of synthesized β-sitosteryl acyl esters: a structure-activity relationship study.
abstract: The efficiency (dose response) of cholesterol-lowering effect of phytosterols in humans depends on their chemical forms (derived or non-derived) and formulation methods in a delivery system. With a series of synthesized β-sitosteryl fatty acid esters (C2:0-C18:0 and C18:1-C18:3), this work examined their thermal properties and applications in preparation of nanodispersion with β-sitosterol as a comparison. Inspection of the melting point (Tm) and the heat of fusion (ΔH) of β-sitosteryl fatty acid esters and the chain length and unsaturation degree of fatty acyl moiety revealed a pronounced structure-property relationship. The nanodispersions prepared with β-sitosterol and β-sitosteryl saturated fatty acid (SFA) esters displayed different particle size distribution patterns (polymodal vs bimodal), mean diameter (115 nm vs less than 100 nm), and polydispersity index (PDI) (0.50 vs 0.23-0.38). β-sitosteryl unsaturated fatty acid (USFA) esters showed a distinctly different dispersion behavior to form nanoemulsions, rather than nanodispersions, with more homogeneous particle size distribution (monomodal, mean diameter 27-63 nm and PDI 0.18-0.25). The nanodispersion of β-sitosteryl medium chain SFA ester (C14:0) demonstrated a best storage stability.
authors.affiliation: Department of Engineering, Faculty of Science and Technology, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark.
authors.forename: Worawan
authors.initials: W
authors.lastname: Panpipat
authors.forename: Mingdong
authors.initials: M
authors.lastname: Dong
authors.forename: Xuebing
authors.initials: X
authors.lastname: Xu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Guo
mesh_terms: D002152:Calorimetry, Differential Scanning; D004952:Esters / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D012855:Sitosterols / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013696:Temperature
chemical_list: D004952:Esters; D012855:Sitosterols; C025473:gamma-sitosterol
keywords: Nanodispersion; Nanoemulsion; Phytosterol; Thermal property; β-Sitosterol; β-Sitosteryl fatty acid ester