Two new anthraquinone derivatives and one new triarylbenzophenone analog from <i>Selaginella tamariscina</i>

<p>Two new anthraquinone derivatives, selaginones A (<b>1</b>) and B (<b>2</b>), and one new triarylbenzophenone analog, selagibenzophenone B (<b>3</b>), were isolated from <i>Selaginella tamariscina</i> (Beauv.) Spring. Their structures were established by 1D-, 2D-NMR and HR-ESI-MS data. Compounds <b>1</b> and <b>2</b> represent the uncommon examples of aryl substituted anthraquinone derivatives. Especially, compound <b>2</b> is a unique anthranone with exceptional structural feature, in which a <i>p</i>-hydroxyphenyl moiety is attached to the C-10 position. Compound <b>3</b> is the second naturally occurring triarylbenzophenone and showed moderate activity against SMCC-7721 and MHCC97-H cell lines with IC₅₀ values of 39.8, 51.5 μM respectively.</p

Two new chromone derivatives from the rhizosphere soil fungus <i>Ilyonectria robusta</i>

Two new chromone derivatives (1 and 2), and two known compounds (3 and 4) were isolated from the rhizosphere soil fungus Ilyonectria robusta. Their planar structures and absolute configurations were determined by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. Additionally, all the isolated compounds were evaluated for their antibacterial activity against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli, but no obvious activity was observed at a concentration of 128 μg/mL.</p

A new neolignan from <i>Selaginella moellendorffii</i> Hieron

<p>A new neolignan, selamoellenin A (<b>1</b>), was isolated from the whole plants of <i>Selaginella moellendorffii</i> Hieron. The structure was elucidated on the basis of comprehensive spectroscopic methods (1D/2D NMR and HRMS). Compound <b>1</b> was evaluated for its protective effect against high glucose-induced human umbilical vein endothelial cells (HUVECs) damage <i>in vitro</i>.</p

New adenine analogues and a pyrrole alkaloid from <i>Selaginella delicatula</i>

<p>Phytochemical study on the <i>n</i>-BuOH extract of <i>Selaginella delicatula</i> lead to the isolation, characterization and structure elucidation of two new adenine analogues, delicatulines A (<b>1</b>) and B (<b>2</b>), one new pyrrole alkaloid (<b>4</b>), and five known compounds (<b>3</b>, <b>5</b>–<b>8</b>). These new substances all contain an aliphatic chain in their parent nucleus, which were unusual to find in plants. In the present study, they were identified from Selaginellaceae for the first time. The structures and absolute configurations of these new compounds were determined by a combination of NMR and CD spectroscopic analyses. Compounds <b>1</b>, <b>3</b> and <b>4</b> were evaluated for their inhibitory activities on HBV surface antigen and HBV DNA in HepAD38 cells. The results showed that these compounds had only weak or no inhibitive effects on HBV.</p