Picrotoxane-type sesquiterpenoids from Dendrobium improve insulin resistance and increase glucose-stimulated insulin secretion.

Twelve picrotoxane-type sesquiterpenoids were isolated from Dendrobium wardianum, of which dendrowardins K-N (1-4) are new compounds and dendrowardins O and P (9, 10) are new natural products. Notably, the structure of dendrowardin K contains the rarely observed 10,11-γ-lactone ring. The structural configurations of these compounds were determined through comprehensive 1D and 2D nuclear magnetic resonance (NMR), single-crystal X-ray diffraction, and other spectroscopic analyses.

Isosativene and sativene sesquiterpene derivatives from Dendrobium nobile.

Two unusual isosativene sesquiterpene derivatives, named dendronobilol A (1) and dendronobilside A (2), and two unusual sativene sesquiterpene derivatives, named dendronobilsides B (3) and C (4), had been isolated from the stems of Dendrobium nobile. The structures of all the compounds were established using spectroscopic methods and by comparison with literature data, and their absolute configurations were confirmed via single-crystal X-ray diffraction data and electronic circular dichroism (ECD) calculations. Dendronobilol A (1) and dendronobilside A (2) possessed a unique tricyclo[4.

Structure characterization and immunoactivity on dendritic cells of two neutral polysaccharides from Dictyophora rubrovalvata.

Dictyophora rubrovalvata is a valuable fungus homologous to food and medicine, and its polysaccharide have been gaining increasing attention because of its plentiful activity. However, the structure and activity of its homogeneous polysaccharide have not been studied enough. In this study, two polysaccharides DRP-I and DRP-II were purified from D.

The bibenzyl derivatives of Dendrobium officinale prevent UV-B irradiation induced photoaging via SIRT3.

Dendrobium officinale is a valuable medicinal herb that is widely used in traditional Chinese medicine. The chemical constituents of D. officinale have attracted much attention and a large number of compounds have been reported including many bibenzyl derivatives.