Rearranged 6/6/5/6-Fused Triterpenoid Acids from the Stems of <i>Kadsura coccinea</i>

Fourteen new rearranged 6/6/5/6-fused triterpenoid acids, namely, kadcoccine acids A–N (<b>1</b>–<b>14</b>), were isolated from an EtOAc-soluble extract of the stems of <i>Kadsura coccinea</i>. Their structures were characterized mainly by analyzing 1D and 2D NMR and HRESIMS data and were shown to feature a rare 14(13→12)-<i>abeo</i>-lanostane skeleton. Compounds <b>7</b> and <b>8</b> represented the first examples of a 5-substituted 2­(5<i>H</i>)-furanone motif on the C-17 side chain of this skeleton. The absolute configurations of C-23 for compounds <b>1</b>, <b>7</b>, and <b>8</b> were determined by comparison of their experimental electronic circular dichroism spectra. All the isolates were screened for their in vitro cytotoxicity against six human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW-480, and HeLa), and compounds <b>2</b> and <b>8</b> exhibited weak inhibitory effects with IC₅₀ values ranging from 3.11 to 7.77 μM

7α,20-Epoxy-<i>ent</i>-kaurane Diterpenoids from the Aerial Parts of <i>Isodon pharicus</i>

A phytochemical investigation of an ethyl acetate extract of the aerial parts of <i>Isodon pharicus</i> led to the isolation of 21 new 7α,20-epoxy-<i>ent</i>-kaurane diterpenoids, pharicins C–W (<b>1</b>–<b>21</b>), and 29 known (<b>22</b>–<b>50</b>) analogues. The structural characterization of <b>1</b>–<b>21</b> and assignment of their relative configurations were accomplished by spectroscopic data interpretation, while the structures of <b>1</b> and <b>16</b> were confirmed by X-ray crystallography. The absolute stereostructure of <b>1</b> was confirmed by electronic circular dichroism data analysis. Twenty-five of the diterpenoids were screened for their cytotoxic activities against a panel of tumor cell lines, including HL-60, SMMC-7721, A-549, MCF-7, and SW-480. Compounds <b>11</b>, <b>16</b>, <b>38</b>, and <b>48</b> exhibited inhibitory activities against these tumor cell lines with IC₅₀ values ranging from 1.01 to 9.62 μM, while <b>2</b>, <b>15</b>, <b>29</b>, and <b>47</b> exhibited moderate cytotoxic potency

Structural Characterization of Kadcoccinin A: A Sesquiterpenoid with a Tricyclo[4.4.0.0^3,10]decane Scaffold from <i>Kadsura coccinea</i>

Kadcoccinin A (<b>1</b>), a cage-like sesquiterpenoid possessing a tricyclo­[4.4.0.0^3,10]­decane scaffold, and the biosynthetically related kadcoccinin B (<b>2</b>) were isolated from the stems of <i>Kadsura coccinea</i>. Their structures and absolute configurations were determined from extensive spectroscopic analysis and quantum chemical calculations. Additionally, their cytotoxic and antifungal effects were initially evaluated, and a plausible biosynthetic pathway was proposed

Kadcoccinic Acids A–J, Triterpene Acids from <i>Kadsura coccinea</i>

Eleven triterpene acids including 10 new compounds (kadcoccinic acids A–J, <b>1</b>–<b>10</b>) were isolated from the stems of <i>Kadsura coccinea</i>. Except for <b>10</b>, these compounds feature a rearranged lanostane skeleton with a 6/6/5/6 tetracyclic ring system, and compounds <b>1</b> and <b>2</b> are the first examples of 2,3-<i>seco</i>-6/6/5/6-fused tetracyclic triterpenoids. Their structures were established primarily by spectroscopic and spectrometric methods. Additionally, the absolute configuration of <b>3</b> was determined by single-crystal X-ray diffraction. Several of the compounds isolated were tested for their anti-HIV-1 and cytotoxic activities

Kadcoccinones A–F, New Biogenetically Related Lanostane-Type Triterpenoids with Diverse Skeletons from <i>Kadsura coccinea</i>

Six new lanostane-related triterpenoids, kadcoccinones A–F (<b>1</b>–<b>6</b>), were isolated from <i>Kadsura coccinea</i>. Compound <b>3</b> possesses a novel 6/6/9-fused carbocyclic core containing a rare oxabicyclo[4.3.1]­decane system. Compounds <b>4</b> and <b>5</b> are isomers representing the first example of the 18(13 → 12)-<i>abeo</i>-26-norlanostane triterpenoid. The absolute configurations of <b>1</b> and <b>4</b>–<b>6</b> were defined by X-ray diffraction and experimental ECD spectra, and that of <b>3</b> was elucidated by quantum chemical calculations. The plausible biogenetic pathway of <b>1</b>–<b>6</b> is postulated