Antioxidant and α-glucosidase inhibitiory active compounds of Cercis chinensis flowers were investigated with bio-assay guiding method. Ethyl acetate fraction (CLEa) and n-butanol fraction (CLBu) exhibited antioxidant and α-glucosidase inhibitiory activity in vitro, and the corresponding active fractions, EaFr.3, EaFr.5 and BuFr.1, exhibited higher antioxidant and α-glucosidase inhibitiory activity than those of other fractions. Eight compounds, ethyl gallate (1), stearic acid (2), docosanoic acid (3), 5α-stigmast-9(11)-en-3β-ol (4), kaempferol-3-O-α-rhamnopyranoside (5), vanillic acid (6), fisetin (7), and β-sitosterol (8), were isolated and identified from CLEa and CLBu. Ethyl gallate shown the highest antioxidant activity by scavenging DPPH radical and reducing ferric compared. Docosanoic acid and vanillic acid shown stronger α-glucosidase inhibitory activity than that of acarbose.

Ligustri lucidi Fructus is a traditional Chinese medicine and possesses various bioactivities, including hypoglycemic effect. Ligustrum lucidum Ait flowers are poorly investigated. Thus, we hypothesized that L. lucidum flowers also could have hypoglycemic effect. Chemical composition and glucose uptake effect of L. lucidum flowers on 3T3-L1 adipocytes were investigated. In this study, the components of L. lucidum flowers were investigated by various chromatographic and spectroscopic methods and the effects of L. lucidum flowers on the induction of glucose uptake were investigated by 3T3-L1 adipocytes. Seven compounds were isolated and identified from L. lucidum flowers, including ursolic acid (1), kaempferol-7-O-α-L-rhamnoside (2, KR), β-sitosterol (3), β-daucosterol (4), kaempferitrin (5, KF), 10-hydroxy oleuropein (6, HO), and kaempferol-3-O-β-D-glucopyranoside-7-α-L-rhamnopyranoside (7, KGR). The results of glucose uptake showed that total extract (TE), KR, KF and HO from L. lucidum flowers significantly enhanced glucose uptake. This study demonstrated that compounds 2, 5-7 were isolated for the first time from this plant and compounds 2 and 7 were isolated for the first time in genus Ligustrum, L. lucidum flowers, KR, KF and HO may possess potential hypoglycemic effect.

The present study was conducted to evaluate the chemical composition and antioxidant activity of the essential oils and ethanol extracts of Ocimum basilicum L. obtained from Assiut, Minia and BeniSuef of Egypt. The major constituents of sweet basil essential oils from three locations were linalool, estragole, methyl cinnamate, bicyclosesquiphellandrene, eucalyptol, α-bergamotene, eugenol, γ-cadinene and germacrene D by the method of GC–MS. The relative concentration of these compounds varies. The basil extracts contained appreciable levels of total phenolic contents and exhibited good DPPH radical scavenging capacity higher than that of essential oils. The highest TPC (82.45 mg PE/g) and maximum radical scavenging activity with IC₅₀ value (1.29 mg/mL) was obtained from Minia basil extract. High correlation between antioxidant activity and total phenolic contents of basil extracts was observed. High variation in free radical scavenging activity of essential oils was found. The essential oil from Minia basil showed high activity in DPPH radical scavenging with IC₅₀ (11.23 mg/mL) and contained the highest content of phenolic (41.3 mg PE/g). On contrary, low correlation between antioxidant activity and total phenolic contents of basil essential oils from different locations. The results of the present investigation demonstrated significant variations in the antioxidant activities of sweet basil essential oils and extracts from Egypt.