Nitrogen Oxide Inhibitory Trimeric and Dimeric Carbazole Alkaloids from Murraya tetramera

Two new structurally unique trimeric carbazole alkaloids, murratrines A and B (<b>1</b>, <b>2</b>), and 11 new carbazole dimers, murradines A–K (<b>3</b>–<b>13</b>), and four known analogues (<b>14</b>–<b>17</b>) were isolated from the leaves and stems of Murraya tetramera. The structures and relative configurations of <b>1</b>–<b>13</b> were elucidated on the basis of comprehensive 1D and 2D NMR spectroscopy, high-resolution mass spectrometry, and electronic circular dichroism (ECD) data analysis. Murratrines A and B (<b>1</b>, <b>2</b>) both contain an unprecedented carbazole trimeric skeleton, and murradines A and D (<b>3</b>, <b>6</b>) are the first natural C-1–C-3′-methyl-linked and C-6–C-3′-methyl-linked dimeric carbazole alkaloids, respectively. Compounds <b>4</b>, <b>10</b>, <b>14</b>, <b>15</b>, and <b>17</b> exhibited inhibition of nitric oxide production stimulated by lipopolysaccharide in BV-2 microglial cells with IC₅₀ values in the range of 11.2–19.3 μM

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

Anti-inflammatory Coumarin and Benzocoumarin Derivatives from <i>Murraya alata</i>

Two new rare 8-methylbenzo­[<i>h</i>]­coumarins, muralatins A and B (<b>1</b>, <b>2</b>), nine new C-8-substituted coumarins, muralatins C–K (<b>3</b>–<b>11</b>), and 22 known analogues (<b>12</b>–<b>33</b>) were isolated from the leaves of <i>Murraya alata</i>. The absolute configurations of compounds <b>5</b>, <b>11</b>, <b>23</b>, <b>24</b>, <b>27</b>, <b>30</b>, and <b>33</b> were assigned via comparison of their specific rotations, by Mosher’s method, and by single-crystal X-ray diffraction and electronic circular dichroism (ECD) data of the in situ formed transition metal complexes. A putative biosynthesis pathway to <b>1</b> and <b>2</b> is proposed, and the chemical synthesis of <b>1</b> was accomplished through electrocyclization of 5,7-dimethoxy-8-[(<i>Z</i>)-3-methylbut-1,3-dienyl)]­coumarin (<b>12</b>). Compounds <b>1</b>, <b>2</b>, <b>8</b>, <b>12</b>, and <b>31</b> showed inhibition of nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages with IC₅₀ values of 6.0–14.5 μM

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

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

Diterpenoids and Sesquiterpenoids from the Roots of <i>Illicium majus</i>

Five new diterpenoids (<b>1</b>–<b>5</b>), five new sesquiterpenoids (<b>6</b>–<b>10</b>), and three known compounds (<b>11</b>–<b>13</b>) were isolated from the roots of <i>Illicium majus</i>. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of <b>1</b> was assigned by X-ray crystallography, whereas those of the 1,2-diol moieties in <b>3</b> and <b>4</b> were determined using Snatzke’s method. The abietane acids <b>1</b>, <b>2</b>, <b>11</b>, <b>12</b>, and <b>13</b> displayed antiviral activity against the Coxsackie B3 virus, with IC₅₀ values of 3.3–51.7 μM/mL