To make full usage of resource and turn waste into treasure, the chemical constituents and bioactivity were firstly investigated on Damask rose (Rosa damascena) flower residue (DRFR). DPPH and ABTS experiments were applied to assess the antioxidant activity of DRFR. Then, column chromatography was used to purify compounds from an antioxidation extract (DRFR-A), and the chemical structure was identified using NMR. The total phenolic acid content was measured by Folin-Ciocalteu colorimetric method, and the content of gallic acid of the indicator ingredient was detected by HPLC. DRFR-A was found to show a high activity both on DPPH (IC₅₀: 2.760 µg/mL) and ABTS (IC₅₀: 2.258 µg/mL) compared to positive control V_C. Ten compounds were isolated and identified as quercetin (1), kaempferol (2), gallic acid (3), protocatechuic acid (4), pyrogallic acid (5), 2-phenylethyl 3,4,5-trihydroxybenzoate (6), methyl gallate (7), p-hydroxybenzoic acid (8), p-hydroxyphenethyl alcohol (9) and astragalin (10) from DRFR-A. Among them, pyrogallic acid, 2-phenylethyl-3, 4, 5-trihydroxybenzoate, p-hydroxybenzoic acid and p-hydroxyphenethyl alcohol are obtained from the plant for the first time. The content of total phenolic acids and gallic acid, main ingredient in DRFR-A was determined as 63.73% and 24.67%, respectively. This study provides a reliable data and lays the foundation for the development and utilization of rose residue, and hence for the full utilization of rose resources.

The purpose of this study is to investigate the anti-diabetic effects of linarin, a flavonoid extracted from Chrysanthemi Indici Flos (CIF), and its potential mechanisms. The effects of linarin on cell viability and glucose consumption in HepG2 cells were measured. Meanwhile, monosodium glutamate (MSG) mouse model was constructed to monitor the changes of insulin tolerance, glucose tolerance, triglyceride and cholesterol. The protein expression levels of p-AMPK, p-ACC, PEPCK and p-GS were detected by Western blot. Linarin could increase the relative glucose consumption of HepG2 cells, improve insulin tolerance and glucose tolerance, and decrease the levels of triglyceride and cholesterol of MSG mice. Simultaneously, the expression levels of p-AMPK and p-ACC in HepG2 cells and the liver tissue of MSG mice were increased, while the expression levels of PEPCK and p-GS were decreased after treatment with linarin. Insulin resistance could be ameliorated by linarin in type 2 diabetes, and its mechanism may be related to AMPK signaling pathway.

Two new compounds 1 and 2 have been isolated from the aerial parts of Urena lobata L. The structures of the two new compounds were established as ceplignan-4-O-β-d-glucoside (1) and 2,5-dihydroxy benzoic acid-7-(2,6-dimethyl-6-hydroxy-2,7-octadienoic acid) anhydride-5-O-β-d-apiofuranosyl(1 → 2)-β-d-glucoside (urenoside A) (2), on the basis of chemical and spectral evidence, including 1D and 2D NMR spectroscopic data as well as mass spectrometry (HR-ESI-MS).