Active Constituents with Tyrosinase Inhibitory Activities from Waste Tobacco Leaves.

One novel compound, (R)-3, 6-diethoxy-4-hydroxycyclohex-3-en-1-one (1) and thirteen known compounds were isolated from the waste tobacco leaves. The structures of two compounds (1-2) were confirmed and attributed firstly by the extensive spectroscopic data, including 1D/2D NMR, IR, HR-ESI-MS, CD, and ECD spectra. Notably, seven compounds (2, 3, 9, 10, 11, 12, and 13) exhibited better tyrosinase inhibitory activity than the positive control kojic acid.

Active constituents with α-glucosidase inhibitory activities from Sabia parviflora.

To identify the active constituents with α-glucosidase inhibitory activities in Sabia parviflora, three new compounds, namely, sabiaparviflora A-C (1, 2 and 8), and seven known compounds were isolated from the plant by repeated column chromatography. The structures of the new compounds were identified by extensive application of spectroscopic methods, including H NMR, C NMR, IR and HR-ESI-MS. All compounds, except for compounds 3-5, 9 and 10 were isolated for the first time from S.

Pentacyclic Triterpenoids from Dunn and Their -Glycosidase Inhibitory Activities.

Four new pentacyclic triterpenoids named Sabiadiscolor A-D ( and -) together with eleven known ones were isolated by repeated column chromatography. Their structures were identified and characterized by NMR and MS spectral data as 6 oleanane-type pentacyclic triterpenoids (-), 7 ursane-type ones (-), and 2 lupanane-type ones (-). Except for compound , all other compounds were isolated from Dunn for the first time.

Hepatoprotective Constituents of Total Dibenzocyclooctadiene Lignans from Based on the Spectrum-Effect Relationship.

To scientifically clarify the hepatoprotective constituents of Fructus Schizandrae chinensis, eleven batches samples of total dibenzocyclooctadiene lignans (TDL) from were prepared by using the optimum extraction technique. Characteristic high-performance liquid chromatography (HPLC) chromatograms were obtained through HPLC analysis technology, and the hepatoprotective effects of the eleven batches of TDL were evaluated by MTT assay. Based on the chemical and biological activity results, the spectrum-effect relationship between the characteristic HPLC fingerprints and the hepatoprotective effect of TDL was established using Minitab 16.

Regioselective alkali metal reduction of dibenzocyclooctadiene lignan derivatives, demethoxylation followed by dehalogenation.

The regioselective demethoxylation and dehalogenation of dihalogenated dibenzocyclooctadiene lignans derivatives were realized in a one-step reaction with excellent yields in the sodium and t-butanol reaction system.

Schisanhenol derivatives and their biological evaluation against tobacco mosaic virus (TMV).

Schisanhenol (Sol) was isolated from Schisandra rubriflora, and a series of derivatives (1-16, 15a-16a, and 15b-16b) were designed and prepared by chemical modification. The curative and protective effects of these dibenzocyclooctadiene lignan analogues against tobacco mosaic virus (TMV) were evaluated. Most analogues exhibited stronger protective effects than the positive control ningnanmycin.

Hernsubanine E, a new hasubanan alkaloid from Stephania hernandifolia.

A new hasubanan alkaloid, hernsubanine E (1), as well as two known compounds p-hydroxybenzaldehyde (2) and (-)-syringaresinol (3) have been isolated from the whole plants of Stephania hernandifolia by various column chromatographic methods. Their structures were identified by physicochemical properties and spectral analyses. Compounds 2 and 3 were isolated from the genus of Stephania for the first time.