High-performance liquid chromatography profiling of pigments from phalaenopsis hybrids and their contribution to antioxidant and antityrosinase activities

Phalaenopsis hybrids are economically one of the most important groups of orchids which are native to Asia with white, yellow and red flowers. In the present study, the major pigments of various Phalaenopsis hybrids with red colors were identified and the quantitative analyses of the crude extracts were accomplished. The compositions of flavones and anthocyanin were simultaneously detected at 375 and 530 nm with the aid of high performance liquid chromatography/ultraviolet detector (HPLC/UV). The major pigments and co-pigments characterized in different Phalaenopsis species were (3',7-di-O-sinapylglucosyl)-3-glucosyl cyanidin, apigenin 6-C-ribosido-7-O- glucoside, and saponarin. The differences between various Phalaenopsis hybrids were only in the contents of the pigments. In addition, the pigment constituents were also examined for their antioxidant properties using the scavenging of the α,α-diphenyl-β-picrylhydrazyl (DPPH) free radical assay and the antityrosinase activities. (3',7-di-O-sinapylglucosyl)-3-glucosyl cyanidin and saponarin exhibited moderate scavenging activity with the IC₅₀ values of 27.3 and 307.1 μM, respectively, and apigenin 6-C-ribosido-7-O- glucoside displayed significant antityrosinase activities with the IC ₅₀ values of 41.6 μM.