Abstract:
OBJECTIVE To investigate the structural characterization and functional activities of oligosaccharides from Capparis spinosa L.
METHODS The oligosaccharides were extracted by water-ethanol extraction and purified sequentially with AB-8 macroporous resin, DEAE-650M cellulose column, and HW-40F gel filtration to obtain 2 fractions(C-O-1 and C-O-2). Their structures were characterized by 1-phenyl-3-methyl-5-pyrazolone(PMP) pre-column derivatization, methylation analysis, ultraviolet-visible spectroscopy(UV-Vis), Fourier transform infrared spectroscopy(FTIR), and high performance liquid chromatography(HPLC). Antioxidant activities were evaluated via 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) cationic radical(ABTS+·), 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical(DPPH·), hydroxyl radical scavenging assays, and Fe2+ reducing power. In vivo antioxidant and anti-melanogenic effects of C-O-1 were further assessed in zebrafish model.
RESULTS Both C-O-1 and C-O-2 contained O-H and C-H bonds. C-O-1 was composed of glucose and mannose(89.4 : 10.6), while C-O-2 consisted solely of glucose. Glycosidic linkage analysis indicated terminal glucopyranose(T-Glcp) linkages in both samples. C-O-1 was hypothesized to be a tetrasaccharide with a molecular weight of approximately 671.37; whereas C-O-2 was a disaccharide with a molecular weight of approximately 387.11. In vitro, C-O-1 and C-O-2 exhibited significantly stronger scavenging activities against ABTS+, DPPH, and hydroxyl radicals compared to the positive control(stachyose). At safe concentrations(0.25–2 mg·mL–1), C-O-1 reduced ROS generation by 43.8% and inhibited melanin synthesis by 35.2% in zebrafish.
CONCLUSION C-O-1 and C-O-2 both exhibit well-defined structures. C-O-1 demonstrates remarkable antioxidant and skin-whitening effects, suggesting its potential for functional applications.