Artaboterpenoids A and B, Bisabolene-Derived Sesquiterpenoids from Artabotrys hexapetalus

Artaboterpenoids A and B (<b>1</b> and <b>2</b>), two novel bisabolene-derived sesquiterpenoids, were isolated from the roots of Artabotrys hexapetalus. Their structures with absolute configurations were elucidated by spectroscopic methods, and electronic circular dichroism (ECD) analyses. Notably, <b>1</b> featured a novel carbon skeleton with a new C-2–C-10 linkage, and <b>2a</b> and <b>2b</b>, a pair of enantiomers, represented the first examples of 1,2-seco-bisabolene-type sesquiterpene lactones. <b>2a</b> exhibited cytotoxic effects against HCT-116, HepG2, A2780, NCI-H1650, and BGC-823 cell lines with IC₅₀ values of 1.38–8.19 μM. Plausible biogenetic pathways for artaboterpenoids A and B were proposed

Antinociceptive Grayanoids from the Roots of <i>Rhododendron molle</i>

Nine new grayanoids (<b>1</b>–<b>9</b>), together with 11 known compounds, were isolated from the roots of <i>Rhododendron molle</i>. The structures of the new compounds (<b>1</b>–<b>9</b>) were determined on the basis of spectroscopic analysis, including HRESIMS, and 1D and 2D NMR data. Compounds <b>4</b>, <b>6</b>, <b>12</b>, and <b>14</b>–<b>20</b> showed significant antinociceptive activities in an acetic acid-induced writhing test. In particular, <b>14</b> and <b>15</b> were found to be more potent than morphine for both acute and inflammatory pain models and 100-fold more potent than gabapentin in a diabetic neuropathic pain model

Sesquiterpenes from the roots of <i>Illicium oligandrum</i>

<div><p>Two new sesquiterpenes, oligandrin (<b>1</b>) and oligandric acid (<b>2</b>), together with three analogues, tashironin A (<b>3</b>), tashironin (<b>4</b>), and oplodiol (<b>5</b>), were isolated from the roots of <i>Illicium oligandrum</i>. The structures of new compounds were determined based on 1D and 2D NMR experiments and X-ray diffraction. Compound <b>1</b> represents a presumed biosynthetic precursor of <i>seco</i>-prezizaane sesquiterpenes which consists of a novel 6/6/5 tricarbocyclic skeleton. Compound <b>2</b> is the first example of chamipinene-type sesquiterpene possessing a 6/4/6 tricyclic system from the genus <i>Illicium</i>. Compounds <b>1</b>–<b>5</b> were evaluated <i>in vitro</i> for their activity against coxsackie virus B3 (CVB3), influenza virus A/Hanfang/359/95 (H3N2), and influenza virus A/FM/1/47 (H1N1). Compound <b>1</b> showed selective antiviral activity against CVB3 with IC₅₀ value of 11.11 μM.</p></div

Mollanol A, a Diterpenoid with a New C‑Nor-D-homo­grayanane Skeleton from the Fruits of Rhododendron molle

Two new grayanoids, mollanol A (<b>1</b>) and rhodomollein XXV (<b>2</b>), were isolated from the fruits of Rhododendron molle. Their structures were elucidated by spectroscopic methods and X-ray diffraction analyses. Mollanol A (<b>1</b>) possesses a new C-nor-D-homo­grayanane carbon skeleton, while rhodomollein XXV (<b>2</b>) is the first example of an 11,16-epoxy­grayanane and features a caged oxa-tricyclo­[3.3.1.0^3.7]­nonane ring system. Plausible biogenetic pathways for <b>1</b> were proposed. Compound <b>1</b> exhibited transcriptional activation effects on the <i>xbp1</i> upstream promoter in IEC-6, 293T, and RAW264.7 cells

Antiviral Spirotriscoumarins A and B: Two Pairs of Oligomeric Coumarin Enantiomers with a Spirodienone–Sesquiterpene Skeleton from <i>Toddalia asiatica</i>

Two pairs of oligomeric coumarin enantiomers, spirotriscoumarin A [(+)-<b>1</b> and (−)-<b>1</b>] and spirotriscoumarin B [(+)-<b>2</b> and (−)-<b>2</b>], with a spirodienone-sesquiterpene fused skeleton were isolated from <i>Toddalia asiatica</i>. Their structures were unambiguously established using spectroscopic data, X-ray diffraction analysis, and the electronic circular dichroism (ECD) method. The racemic mixtures (±)-<b>1</b> and (±)-<b>2</b> exhibit 3-to-6-fold stronger antiviral activity against influenza virus A (H3N2) (IC₅₀: 3.13 and 2.87 μM, respectively) than their corresponding optically pure enantiomers

Lycojaponicumins D and E: Two New Alkaloids from <i>Lycopodium japonicum</i>

Two new alkaloids, lycojaponicumins D (<b>1</b>) and E (<b>2</b>), were isolated from the club moss <i>Lycopodium japonicum</i>. Their structures were elucidated by spectroscopic methods, calculated ECD, CD experiments and X-ray diffraction analysis. Lycojaponicumin D (<b>1</b>) possesses an unprecedented 5/7/6/6 tetracyclic skeleton formed by an unusual C3–C13 linkage, which is first reported in <i>Lycopodium</i> alkaloids. The plausible biogenetic pathway of <b>1</b> is proposed

Antiviral Triterpenes from the Twigs and Leaves of Lyonia ovalifolia

Eleven new 9,10-<i>seco</i>-cycloartan triterpene glycosides (<b>1</b>–<b>11</b>), seven new lanostane triterpene glycosides (<b>12</b>–<b>18</b>), and two new ursane triterpenoids (<b>19</b>–<b>20</b>) were isolated from the twigs and leaves of Lyonia ovalifolia. The structures of these compounds were elucidated by extensive MS and NMR spectroscopic analysis. The absolute configuration of compound <b>1a</b> (the aglycone of <b>1</b>) was established by X-ray crystallography, and that of C-24 in compounds <b>2</b>, <b>7</b>, and <b>12</b> was established by Mo₂(OAc)₄-induced electronic circular dichroism experiments. All compounds were evaluated for their antiviral [herpes simplex virus-1 (HSV-1), influenza A/95–359 (A/95–359), and Coxsackie B3 (CVB3)] activity. Compounds <b>1</b>, <b>1a</b>, <b>2a</b>, <b>12a</b>, <b>13</b>, and <b>16</b> exhibited potent activity against HSV-1, with IC₅₀ values from 2.1 to 14.3 μM, while compounds <b>1a</b>, <b>2a</b>, <b>12a</b>, <b>13</b>, and <b>12–2a</b> exhibited potent activity against A/95–359, with IC₅₀ values from 2.1 to 11.1 μM. In turn, compounds <b>1</b>, <b>1a</b>, <b>2a</b>, <b>12a</b>, and <b>13</b> exhibited potent activity against CVB3, with IC₅₀ values from 2.1 to 11.1 μM

Antinociceptive Diterpenoids from the Leaves and Twigs of <i>Rhododendron decorum</i>

Three new leucothane-type (<b>1</b>–<b>3</b>), two new micrathane-type (<b>4</b>, <b>5</b>), eight new grayanane-type diterpenoids (<b>6</b>–<b>13</b>), and four known compounds were obtained from the ethanol extract of the leaves and twigs of <i>Rhododendron decorum</i>. The structures were determined based on NMR spectra, quantum chemical calculations, and X-ray crystallography. The antinociceptive activities of compounds <b>1</b>, <b>3</b>, <b>4</b>, <b>6</b>, <b>8</b>, <b>10</b>–<b>13</b>, and <b>15</b>–<b>17</b> were evaluated via the acetic acid-induced writhing test. Compounds <b>1</b>, <b>8</b>, <b>11</b>–<b>13</b>, and <b>15</b> exhibited significant antinociceptive activities. In particular, <b>12</b> and <b>15</b> were found to be effective at doses of 0.8 and 0.08 mg/kg, respectively

Antinociceptive Diterpenoids from the Leaves and Twigs of <i>Rhododendron decorum</i>

Three new leucothane-type (<b>1</b>–<b>3</b>), two new micrathane-type (<b>4</b>, <b>5</b>), eight new grayanane-type diterpenoids (<b>6</b>–<b>13</b>), and four known compounds were obtained from the ethanol extract of the leaves and twigs of <i>Rhododendron decorum</i>. The structures were determined based on NMR spectra, quantum chemical calculations, and X-ray crystallography. The antinociceptive activities of compounds <b>1</b>, <b>3</b>, <b>4</b>, <b>6</b>, <b>8</b>, <b>10</b>–<b>13</b>, and <b>15</b>–<b>17</b> were evaluated via the acetic acid-induced writhing test. Compounds <b>1</b>, <b>8</b>, <b>11</b>–<b>13</b>, and <b>15</b> exhibited significant antinociceptive activities. In particular, <b>12</b> and <b>15</b> were found to be effective at doses of 0.8 and 0.08 mg/kg, respectively

Lycojaponicumins D and E: Two New Alkaloids from <i>Lycopodium japonicum</i>

Two new alkaloids, lycojaponicumins D (<b>1</b>) and E (<b>2</b>), were isolated from the club moss <i>Lycopodium japonicum</i>. Their structures were elucidated by spectroscopic methods, calculated ECD, CD experiments and X-ray diffraction analysis. Lycojaponicumin D (<b>1</b>) possesses an unprecedented 5/7/6/6 tetracyclic skeleton formed by an unusual C3–C13 linkage, which is first reported in <i>Lycopodium</i> alkaloids. The plausible biogenetic pathway of <b>1</b> is proposed