Laevinoids A and B: Two Diterpenoids with an Unprecedented Backbone from <i>Croton laevigatus</i>

Chemical fractionation of the ethanolic extract of a Chinese herbal plant, <i>Croton laevigatus</i>, yielded laevinoids A (<b>1</b>) and B (<b>2</b>) with a new rearranged <i>ent</i>-clerodane scaffold named as laevinane. The structures of <b>1</b> and <b>2</b> were assigned on the basis of detailed spectroscopic analyses with their absolute configurations being established via single-crystal X-ray diffraction studies

A new lignan from the roots of <i>Syringa pinnatifolia</i>

<div><p>Phytochemical investigation of the roots of <i>Syringa pinnatifolia</i> has resulted in the isolation of a new lignan, pinnatifolin A (<b>1</b>), together with seven known compounds (<b>2</b>–<b>8</b>). The structures were elucidated on the basis of extensive spectroscopic methods, including NMR, MS, UV and IR spectra. The seven lignans were screened for their antioxidant activity (DPPH assay), and most of them showed potent antioxidant activity.</p></div

Dimeric Matrine-Type Alkaloids from the Roots of <i>Sophora flavescens</i> and Their Anti-Hepatitis B Virus Activities

Six unusual matrine-type alkaloid dimers, flavesines A–F (<b>1–6</b>, respectively), together with three proposed biosynthetic intermediates (<b>7–9</b>) were isolated from the roots of <i>Sophora flavescens</i>. Compounds <b>1–5</b> were the first natural matrine-type alkaloid dimers, and compound <b>6</b> represented an unprecedented dimerization pattern constructed by matrine and (−)-cytisine. Their structures were elucidated by NMR, MS, single-crystal X-ray diffraction, and a chemical method. The hypothetical biogenetic pathways of <b>1–6</b> were also proposed. Compounds <b>1–9</b> exhibited inhibitory activities against hepatitis B virus

Clerodane Diterpenoids from <i>Croton crassifolius</i>

Seven new clerodane diterpenoids (<b>1</b>–<b>7</b>) were isolated from roots of <i>Croton crassifolius</i>, along with six known compounds. The structures were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D NMR, and 2D NMR), and the structures of <b>1</b>, <b>3</b>, <b>4</b>, and <b>7</b> were confirmed by single-crystal X-ray diffraction analyses. Compounds <b>1</b>–<b>13</b> were evaluated for in vitro antiviral activity against herpes simplex virus type 1 using the cytopathic effect reduction assay

Clerodane Diterpenoids from <i>Croton crassifolius</i>

Seven new clerodane diterpenoids (<b>1</b>–<b>7</b>) were isolated from roots of <i>Croton crassifolius</i>, along with six known compounds. The structures were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D NMR, and 2D NMR), and the structures of <b>1</b>, <b>3</b>, <b>4</b>, and <b>7</b> were confirmed by single-crystal X-ray diffraction analyses. Compounds <b>1</b>–<b>13</b> were evaluated for in vitro antiviral activity against herpes simplex virus type 1 using the cytopathic effect reduction assay

Clerodane Diterpenoids from <i>Croton crassifolius</i>

Seven new clerodane diterpenoids (<b>1</b>–<b>7</b>) were isolated from roots of <i>Croton crassifolius</i>, along with six known compounds. The structures were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D NMR, and 2D NMR), and the structures of <b>1</b>, <b>3</b>, <b>4</b>, and <b>7</b> were confirmed by single-crystal X-ray diffraction analyses. Compounds <b>1</b>–<b>13</b> were evaluated for in vitro antiviral activity against herpes simplex virus type 1 using the cytopathic effect reduction assay

Clerodane Diterpenoids from <i>Croton crassifolius</i>

Seven new clerodane diterpenoids (<b>1</b>–<b>7</b>) were isolated from roots of <i>Croton crassifolius</i>, along with six known compounds. The structures were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D NMR, and 2D NMR), and the structures of <b>1</b>, <b>3</b>, <b>4</b>, and <b>7</b> were confirmed by single-crystal X-ray diffraction analyses. Compounds <b>1</b>–<b>13</b> were evaluated for in vitro antiviral activity against herpes simplex virus type 1 using the cytopathic effect reduction assay

Cipacinoids A–D, Four Limonoids with Spirocyclic Skeletons from <i>Cipadessa cinerascens</i>

Four limonoids, cipacinoids A–D (<b>1</b>–<b>4</b>), with spirocyclic skeletons were isolated from <i>Cipadessa cinerascens</i>. It is particularly notable that compounds <b>1</b>–<b>3</b> had a 17<i>S</i>-configuration for the first time in the limonoid family. Their structures with absolute configurations were assigned by spectroscopic data, X-ray crystallography, and CD analysis. Compound <b>1</b> showed moderate protein tyrosine phosphatase 1B (PTP1B) inhibition

Diterpenes and lignans from <i>Viburnum odoratissimum</i> var. <i>odoratissimum</i>

<div><p>A new diterpenoid, dehydrovibsanin G (<b>1</b>), a new lignan, (+)-9′-<i>O</i>-senecioyllariciresinol (<b>2</b>), and six known compounds (<b>3</b>–<b>8</b>) were isolated from the branches and leaves of <i>Viburnum odoratissimum</i> var. <i>odoratissimum</i>. The structures of these compounds were elucidated by analysis of spectroscopic data. Both new compounds showed moderate inhibitory activity against human A431 and T47D tumor cell lines.</p></div

11β-HSD1 Inhibitors from <i>Walsura cochinchinensis</i>

A search for inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) from <i>Walsura cochinchinensis</i> yielded 10 new limonoids, cochinchinoids A–J (<b>1</b>–<b>10</b>), and two new triterpenoids, 3-epimesendanin S (<b>11</b>) and cochinchinoid K (<b>12</b>). Their structures were assigned on the basis of spectroscopic data, with the absolute configurations of <b>1</b> and <b>12</b> being established by X-ray diffraction analysis. Of these compounds, cochinchinoid K (<b>12</b>) displayed inhibitory activity against mouse 11β-HSD1 with an IC₅₀ value of 0.82 μM