Key HMBC, ¹H-¹H COSY, and ROESY correlations of 1.

<p>Key HMBC, ¹H-¹H COSY, and ROESY correlations of 1.</p

¹H NMR spectra comparison of rubipodanin A (1, top) and RA-V (4, bottom).

<p>¹H NMR spectra comparison of rubipodanin A (1, top) and RA-V (4, bottom).</p

Chemical structures of 1–7.

<p>Chemical structures of 1–7.</p

New Labdane diterpenes from <i>Hedychium yunnanense</i> with cytotoxicity and inhibitory effects on nitric oxide production

<p>Two new labdane diterpenes, hedychenoids A (<b>1</b>) and B (<b>2</b>), were isolated from the rhizomes of <i>Hedychium yunnanense</i>, together with four known ones hedychenone (<b>3</b>), forrestin A (<b>4</b>), villosin (<b>5</b>) and calcaratarin C (<b>6</b>). Their structures were determined on the basis of NMR (1D and 2D) and mass spectroscopic analysis. Compounds <b>2</b>, <b>3</b> and <b>5</b> exhibited cytotoxicity against SGC-7901 with IC₅₀ values of 14.88 ± 0.52, 7.08 ± 0.21 and 7.76 ± 0.21 μg/ml, <b>3</b> and <b>5</b> against HeLa with IC₅₀ values of 9.76 ± 0.48 and 13.24 ± 0.63 μg/ml, respectively. Compounds <b>2</b>, <b>5</b> showed inhibitory effects against nitric oxide production in LPS and IFN-γ-induced RAW 264.7 murine macrophages with IC₅₀ values of 6.57 ± 0.88 and 5.99 ± 1.20 μg/ml, respectively.</p

New Cytotoxic Naphthohydroquinone Dimers from <i>Rubia alata</i>

Two novel naphthohydroquinone dimers with unprecedented skeletons, rubialatins A (<b>1</b>) and B (<b>2</b>), were isolated from the herbal plant <i>Rubia alata</i> together with their precursor, mollugin (<b>3</b>). The structures were elucidated on the basis of NMR spectra and crystal X-ray diffraction. Compound <b>1</b>, a racemate, was separated by chiral column chromatography, and the absolute configurations of the enantiomers were determined by the computational methods. Cytotoxicity of <b>1</b>–<b>3</b> was evaluated as well as the effect on the NF-κB pathway. Compound (+)-<b>1</b> showed cytotoxicity and could inhibit NF-κB pathway. Meanwhile, <b>2</b> showed cytotoxicity and a synergistic effect with TNF-α on NF-κB activation

Biologically Active Arborinane-Type Triterpenoids and Anthraquinones from <i>Rubia yunnanensis</i>

Twelve new arborinane-type triterpenoids (<b>1</b>–<b>12</b>) and four new anthraquinones (<b>13</b>–<b>16</b>), together with 50 known compounds, were isolated from the roots of <i>Rubia yunnanensis</i>. The structures of <b>1</b>–<b>16</b> were elucidated by spectroscopic data analysis and chemical methods. All compounds were evaluated for their cytotoxic, antibacterial, and antifungal activities. Rubiyunnanol C (<b>5</b>) is the first example of an arborinane-type triterpenoid with a double bond at C-8–C-9