Aromatic Constituents from the Leaves of Actinidia arguta with Antioxidant and α-Glucosidase Inhibitory Activity

As the leaf of Actinidia arguta has shown antioxidant activity, a study was conducted to identify the active ingredients. Forty-eight compounds were isolated from the leaves of A. arguta through various chromatographic techniques. Further characterization of the structures on the basis of 1D and 2D NMR and MS data identified several aromatic compounds, including phenylpropanoid derivatives, phenolics, coumarins, flavonoids and lignans. Among them, five compounds were newly reported, naturally occurring, and named argutosides A–D (1–4), which consist of phenylpropanoid glycosides that are conjugated with a phenolic moiety, and argutoside E (5), which is a coumarin glycoside that is conjugated with a phenylpropanoid unit. The isolated compounds showed good antioxidant and α-glucosidase inhibitory activity with differences in activity depending on the structures. Molecular docking analysis demonstrated the interaction between the hydroxyl and carbonyl groups of compounds 1 and 5 with α-glucosidase. Taken together, the leaves of A. arguta are rich in aromatic compounds with diverse structures. Therefore, the leaves of A. arguta and their aromatic components might be beneficial for oxidative stress and glucose-related diseases.

Chemical Constituents from Stems of Pileostegia viburnoides

Phytochemical investigation on the stems of Pileostegia viburnoides Hook.f.et Thoms led to the isolation of twelve compounds, including two steroids (1 and 10), two fatty compounds (2 and 12), seven triterpenoids (3–9), and one coumarin glycoside (11). 24-methylene-5α-dammara-20(21)-en-3β-yl acetate (5), a rare dammarane-tetracyclic triterpene had been first reported just according to the typical 1H-NMR signals analysis, melting point and optical rotation in 1975. However, the complete and reliable NMR and mass data were still unknown. This is the first time to identify the planar and spatial structures of compound 5 by the analysis of 1D-, 2D-NMR, mass data and other physicochemical properties, as well as by comparison of the spectral data with the literature. Further more, the anti-inflammatory and anti-neuroinflammatory activities of dammarane-type triterpenes 4 and 5 were evaluated.