Insight into tetrahydrofuran lignans from Isatis indigotica fortune with neuroprotective and acetylcholinesterase inhibitor activity.

Nine tetrahydrofuran lignans, including three undescribed spiro-lignans, were isolated from Isatis indigotica Fortune (Brassicaceae). Extensive spectroscopic analyses achieved the structure elucidation of these tetrahydrofuran lignans, and quantum chemical calculation combined with the MAE parameter. Notably, isatispironeols A-B have a unique spiro[dienone-tetrahydrofuran] molecular core.

Polyketides with anti-inflammatory activity isolated from Rhodiola tibetica endophytic fungus Penicillium sp. HJT-A-10.

Seven undescribed polyketide compounds (1-4, 9-11) and six known polyketide compounds (5-8,12, 13) were isolated from Rhodiola tibetica endophytic Penicillium sp. HJT-A-10. The structural of seven undescribed polyketides metabolites were established on the basis of spectroscopic methods.

UV-guided isolation of enantiomeric polyacetylenes from Bupleurum scorzonerifolium Willd. with inhibitory effects against LPS-induced NO release in BV-2 microglial cells.

UV-guided fractionation led to the isolation of thirteen new polyacetylenes (1-13) from the roots of Bupleurum scorzonerifolium Willd. All polyacetylenes were analyzed as racemates since the lack of optical activity and Cotton effects in the ECD spectra. The sequent chiral-phase HPLC resolution successfully gave twelve pairs of enantiomers 1a/1b and 3a/3b-13a/13b.

Discovery of alkaloids from the leaves of Isatis indigotica Fortune with neuroprotective activity.

Seven alkaloids including five undescribed ones (1a/1b, 2, 3 and 5) were obtained from the leaves of Isatis indigotica Fortune. Their structures were established by extensive spectroscopic analyses. The absolute configurations of compounds 1a, 1b, 3 and 5 were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra.

Four pairs of alkaloid enantiomers from Isatis indigotica Fortune Ex Land with neuroprotective effects against HO-induced SH-SY5Y cell injury.

In the current study, four pairs of new enantiomeric alkaloids (1a/1b-4a/4b) were obtained from the leaves of Isatis indigotica Fortune Ex Land. Their structures were elucidated through spectroscopic methods and quantum mechanical calculations. Biologically, all isolates were evaluated for their neuroprotective effects against HO-induced SH-SY5Y cell injury.

Alkaloid Enantiomers from Isatis tinctoria with Neuroprotective Effects against H2O2-Induced SH-SY5Y Cell Injury.

Six pairs of alkaloid enantiomers including 11 new alkaloids (1A: /1B: -5A: /5B, 6A: ) were isolated from the leaves of . Their structures were established by extensive spectroscopic analyses. Enantiomers were separated successfully by chiral chromatographic column and the absolute configurations of all isolates were determined by comparison of experimental and calculated electronic circular dichroism spectra.

Diverse metabolites from corn silk with anti-Aβ aggregation activity.

Five pairs of enantiomeric compounds (1a/1b-5a/5b) including seven undescribed compounds (1a/1b-3a/3b, 4b) along with two known ones (. and .) have been isolated from corn silk (Stigma maydis).

Discovery of cycloneolignan enantiomers from Isatis indigotica Fortune with neuroprotective effects against MPP-induced SH-SY5Y cell injury.

A pair of new cycloneolignan enantiomers (1a and 1b) were isolated from the leaves of Isatis indigotica Fortune. Their structures were elucidated by extensive spectroscopic data analysis, including 1D and 2D NMR, HRESIMS, MS/MS analysis, together with theoretical electronic circular dichroism (ECD) calculations. Compounds 1a and 1b were then evaluated for their neuroprotective effects against MPP-induced SH-SY5Y cell injury.

Correction: Bioactive spiropyrrolizidine oxindole alkaloid enantiomers from Isatis indigotica fortune.

Correction for 'Bioactive spiropyrrolizidine oxindole alkaloid enantiomers from Isatis indigotica fortune' by Si-Fan Liu et al., Org. Biomol.

In Situ Construction of One-Dimensional Component-Interchange Organic Core/Shell Microrods for Multicolor Continuous-Variable Optical Waveguide.

The core/shell micro-/nanostructures with versatility, tunability, stability, dispersibility, and biocompatibility are widely applied in optics, biomedicine, catalysis, and energy. Organic micro-/nanocrystals have significant applications in miniaturized optoelectronics because of their controllable self-assembly behavior, tunable optical properties, and tailor-made molecular structure. Nevertheless, the advanced organic core/shell micro-/nanostructures, which possess multifunctionality, flexibility, and higher compatibility, are rarely demonstrated because of the dynamic nature of molecular self-assembly and the complex epitaxial relationship of material combination.

Bioactive spiropyrrolizidine oxindole alkaloid enantiomers from Isatis indigotica Fortune.

Four pairs of new spiropyrrolizidine oxindole enantiomers (1a/1b-4a/4b) were isolated from the leaves of Isatis indigotica Fortune. Their structures and absolute configurations were elucidated by a combination of NMR spectroscopic analyses, experimental and calculated electronic circular dichroism (ECD) and the assistance of quantum chemical predictions (QCP) of 13C NMR chemical shifts. Notably, all the isolated spiropyrrolizidine oxindoles are reported as natural products for the first time.

N-acylanthranilic acid derivatives with anti-Aβ aggregation activity from the leaves of Isatis indigotica fortune.

Seven new N-acylanthranilic acid derivatives (1-3, 4a/4b, 5a/5b) including two pairs of enantiomers (4a/4b and 5a/5b) were isolated from the leaves of Isatis indigotica Fortune. Their chemical structures were elucidated by extensive spectroscopic data analyses. The absolute configurations of compounds 4a/4b and 5a/5b were determined by comparison of the experimental and calculated ECD spectra.

Chiral resolution and bioactivity of enantiomeric benzofuran neolignans from the fruit of Rubus ideaus L.

Rubus ideaus L., a member of the Rosaceae family, is popular for its distinctive flavor and attractive red color. In order to explore the functional factors possibly presented in the fruit, seven new benzofuran neolignans (1a/1b-3a/3b and 4b), together with one known neolignan 4a, were isolated from the fruit of R.

Autophagy antagonizes apoptosis induced by flavan enantiomers from Daphne giraldii in hepatic carcinoma cells in vitro.

Enantiomers account for quite a large percentage of compounds in natural products. Our team is interested in the separation and biological activity of racemic compounds. In this report, four pairs of prenylated flavan enantiomers [(±)-1-(±)-4], including five new compounds, were isolated from the stem and root bark of Daphne giraldii, and separated successfully by using chiral chromatographic column.