Jing Xie’s research while affiliated with Kunming University of Science and Technology and other places

Rosa rugosa Purple branch is a rare continuously flowering variety of R. rugosa and also is one of main cultivar varieties of R. rugosa in China. Although R. rugosa has been successfully used in the field of cosmetics, there are also many reports on its chemical components. The chemical composition and application value in cosmetics of R. rugosa Purple branch are still limited. The purpose of this study was to investigate the chemical components in the petals of R. rugosa Purple branch as well as evaluate their skincare and antibacterial potentials through DPPH radical scavenging, tyrosinase inhibition, elastase inhibition and antibacterial bioassays. Two new compounds, isorhamnetin-3-O-(2"-O-galloyl)-β-D-glucopyranoside (1), kaempferol-3-O-β-D-glucopyranosyl-(1→2)-(6''-O-trans-p-coumaroyl)-β-D-glucopyranoside (2) and thirteen known compounds (3-15) were isolated and identified from the petals by bioassay-guided fractionation. All the compounds were isolated and reported from R. rugosa Purple branch for the first time, in which twelve of them are discovered from R. rugosa for the first time. The tyrosinase inhibitory activities of 1, 2, rosarugoside B (3), kaempfero-3-O-β-D-glucopyranosyl(1→2)-β-D-glucopyranoside (4), astragalin-2'',6''-di-O-gallate (8), quercetin-3-O-β-D-glucopyranosyl(1→2)-β-D-glucopyranoside (10), 2-phenylethyl-β-D-glucopyranoside (13), 2-phenylethyl-6-O-α-L-arabinofuranosyl-β-D-glucopyranoside (14), and 2-phenylethyl-D-rutinoside (15) were firstly reported here, in which 8 showed strong tyrosinase inhibitory activity with IC50 of 187.32 ± 0.18 μg/mL. There were eight compounds (1, 6-12) showed strong antioxidant activity, with the scavenging rates of DPPH radical ranging from 88.59% to 94.30% and the IC50 ranging from 4.22 to 13.85 μg/mL, among them, 1 and quercetin-3-O-(6''-O-Z-p-coumaroyl)-β-D-glucopyranoside (11) exhibited antioxidant activity for the first time. 3 exhibited moderate elastase inhibitory activity with IC50 of 148.67 ± 0.11 μg/mL. In addition, seven compounds (2, 5-8, 10-11) showed varying degrees of antibacterial activity. These results indicated that R. rugosa Purple branch had anti-aging, whitening and antibacterial activities, which can be further applied to the development of functional cosmetics.

Rosa chinensis cv. ‘JinBian’, a cultivar of Rosa chinensis Jacq., is one of major raw material of rose tea and possesses sufficient plant resources in China. However, the studies on the chemical constituents and cosmetic activities of R. chinensis cv. ‘JinBian’ are almost blank. The main purpose of this study was to evaluate the anti-aging, skin-whitening, and antibacterial potentials of extracts and chemical constituents of the flower by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, elastase inhibition, anti-tyrosinase, and antibacterial assays. Bioassay results suggested both 95 % and 65 % ethanol extracts possessed significant antioxidant, elastase inhibition, and anti-tyrosinase activities. The combined active extract was studied with bioassay-guided fractionation to give a new compound, kaempferol 3-O-α-l-rhamnopyranosyl (1→6)-(2”,3”-O-digalloyl)-β-d-glucopyranoside (1) and fourteen known compounds (2–15). All compounds were firstly isolated from this species and subjected to the above mentioned bioassays. Ten compounds exhibited antioxidant activities with DPPH radical scavenging rate from 63.40 %–94.04 % under the concentration of 100 μg/mL. The antioxidant activities of 1, 2-phenylethyl 1-O-β-d-(6'-O-galloyl)-glucopyranoside (12), vomifoliol (14), and 4, 4'-dimethoxy-3'-hydroxy-7, 9': 7', 9-diepoxylignan-3-O-β-d-glucopyranoside (15) were firstly found with DPPH radical scavenging rate of 83.24 %, 91.10 %, 63.40 %, and 77.75 %, respectively. The moderate elastase inhibitory activities of 12, ethyl gallate (13), and 15 were firstly found with the inhibitory rate of 43.69 %, 43.25 %, and 35.34 % at the concentration of 100 μg/mL. Multiflorin B (3), 12, and 13 showed strong tyrosinase inhibitory activities with the inhibition rate at 43.83 %–55.80 %, comparing with the positive control, α-arbutin (22.15 %). In addition, 1 showed significant antibacterial activity against Staphylococcus aureus with the MIC50 of 8.51 ± 0.26 μg/mL. Compounds 2–4 and 12–14 showed moderate antibacterial activities against S. aureus. Compounds 6 and 13 also exhibited moderate inhibitory effects against Klebsiella pneumoniae. Above results manifested that R. chinensis cv. ‘JinBian’ possessed potential application values in the development of natural anti-aging, skin-whitening and antibacterial products.