A new C₂₀-diterpenoid alkaloid from the lateral roots of <i>Aconitum carmichaeli</i>

<p>A new C₂₀-diterpenoid alkaloid carmichaedine (<b>1</b>) and six known alkaloids (<b>2</b>–<b>7</b>) were isolated from the lateral roots of <i>Aconitum carmichaeli</i>. Their structures were established on the basis of extensive spectroscopic analyses. Compound <b>1</b> exhibited potent antibacterial activity against <i>Bacillus subtilis</i> with minimum inhibitory concentration of 8 μg/mL.</p

New diterpenoid alkaloids from <i>Delphinium pachycentrum</i> Hemsl

Six diterpenoid alkaloids, namely, pachycentine (1), deacetylswinanine A (2), siwanine A (3), tatsiensine (4), deacetyltatsiensine (5), and 6-deoxydeltamine (6), were isolated from a China-specific Delphinium plant (family Ranunculaceae), Delphinium pachycentrum Hemsl. Their structures were established via detailed spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR techniques. Pachycentine (1) is a previously undescribed hetisine-type C20-diterpenoid alkaloid, and compounds 5 and 6 were synthetic intermediates newly identified as natural products. In addition, compounds 2–4 were isolated from this species for the first time. The chemotaxonomic significance of all the isolates was summarized. Moreover, the new compound was evaluated for its potential anti-inflammatory effect using LPS-stimulated RAW 264.7 macrophages.</p

A new polyketide glycoside from the rhizospheric <i>Clonostachys rogersoniana</i> associated with <i>Panax notoginseng</i>

<p>A new polyketide glycoside rogerson A (<b>1</b>), along with two known compounds, rogerson B (<b>2</b>) and (22E)-5<i>α</i>,8<i>α</i>-<i>epi</i>dioxyergosta-6,22-dien-3<i>β</i>-ol (<b>3</b>), was obtained from the solid fermentation of <i>Clonostachys rogersoniana</i>, which was isolated from the rhizosphere soil of <i>Panax notoginseng</i>. Rogerson B (<b>2</b>) was isolated for the first time from a natural source. Their structure was determined by extensive analyses of NMR and MS studies. Compounds <b>1</b> and <b>2</b> were tested for its cytotoxicity against five human cancer cell lines.</p

A new C₁₉-diterpenoid alkaloid from the roots of <i>Aconitum duclouxii</i>

<div><p>A new C₁₉-diterpenoid alkaloid, ducloudine F (<b>1</b>), was obtained from the roots of <i>Aconitum duclouxii</i>, along with eight known alkaloids (<b>2</b>–<b>9</b>) isolated from this species for the first time. Their structures were established on the basis of extensive spectroscopic analyses. The antimicrobial activities of these compounds were investigated.</p></div

A new flavone <i>C</i>-glycoside and a new bibenzyl from <i>Bulbophyllum retusiusculum</i>

<p>A new flavone <i>C</i>-glycoside, apigenin 6-<i>C</i>-<i>α</i>-arabinofuranosyl 8-<i>C</i>-<i>α</i>-arabinopyranoside (<b>1</b>) and a new bibenzyl, bulbotetusine (<b>2</b>), were isolated from the tubers of <i>Bulbophyllum retusiusculum</i>. Their structures were established on the basis of extensive spectroscopic analyses. The absolute configuration of <b>2</b> was determined by the comparison of experimental and calculated electronic circular dichroism. Compounds <b>1</b> and <b>2</b> showed no obvious cytotoxic activity against any five human tumour cell lines with IC₅₀ values >40 μM.</p