Structure and protective effect on UVB-induced keratinocyte damage of fructan from white garlic

The fructose polymer fructan was extracted from white garlic and fractionated using DEAE cellulose 52 and Sephadex G-100 columns to characterize its chemical composition and protective effect against ultraviolet radiation b (UVB) induced human keratinocyte (HaTaC) damage. Gel permeation chromatography, high performance anion exchange chromatography, infrared spectroscopy and 1D and 2D nuclear magnetic resonance spectroscopy were used to determine the chemical composition and functional characteristics of the garlic fructan (GF). GF was a homogeneous polysaccharide with a molecular weight of 4.54 × 103 Da. It was a member of the 1-kestose family, and it was composed of fructose and glucose at a ratio of 14:1. The main chain of GF was composed of (2 → 1)-β-d-fructopyranose linked to a terminal (2 → 1)-α-d-glucopyranose at the non-reducing end and a (2 → 6)-β-d-fructopyranose branched chain. The degree of polymerization was 28. Preliminary tests described herein indicated that GF may be effective in protecting HaTaC from UVB-induced damage.