Ligand-Accelerated Gold-Catalyzed Addition of in Situ Generated Hydrazoic Acid to Alkynes under Neat Conditions

The direct addition of in situ generated hydrazoic acid to alkynes is realized without solvent by using a gold catalyst derived from a recently designed remotely functionalized biaryl-2-ylphosphine ligand (i.e., WangPhos). With terminal alkynes, the additions are mostly realized with 0.1 mol% catalyst loadings and at 40 °C. With more challenging internal alkynes devoid of direct EWG substitution, the one-step transformation is realized for the first time with generally high efficiency at ambient temperature

Antifungal New Oxepine-Containing Alkaloids and Xanthones from the Deep-Sea-Derived Fungus <i>Aspergillus versicolor</i> SCSIO 05879

Phytopathogenic fungi remain a continuous and huge threat in the agricultural fields. The agrochemical industry has made great development of the use of microbial natural products, which has been regarded as an effective strategy against phytopathogenic fungi. Antifungal bioassay-directed fractionation was used to isolate two new oxepine-containing alkaloids (<b>1</b> and <b>2</b>), two new 4-aryl-quinolin-2-one alkaloids (<b>3</b> and <b>4</b>), and four new prenylated xanthones (<b>5</b>–<b>8</b>) from the deep-sea-derived fungus <i>Aspergillus versicolor</i> SCSIO 05879. Extensive NMR spectroscopic analysis, quantum mechanical calculations, and X-ray single-crystal diffraction were used to elucidate their structures, including their absolute configurations. Versicoloids A and B, versicone A, and cottoquinazoline A showed antifungal activities against three phytopathogenic fungi. The antifungal activities of these bioactive compounds strongly depend on the fungal species. Especially versicoloids A and B showed strong fungicidal effect (MIC of 1.6 μg/mL) against <i>Colletotrichum acutatum</i>, compared with that of the positive control cycloheximide (MIC of 6.4 μg/mL). The results of antifungal experiments indicated that versicoloids A and B may be regarded as candidate agents of antifungal agrochemicals

Tetramic acid derivatives and polyphenols from sponge-derived fungus and their biological evaluation

<div><p>Fifteen compounds, including two tetramic acid derivatives, penicillenol A₁ (<b>1</b>) and penicillenol A₂ (<b>2</b>), six polyphenols containing both phenolic bisabolane sesquiterpenoid and diphenyl ether units, expansols A–F (<b>3</b>–<b>8</b>), together with six phenolic bisabolane sesquiterpenoids (<b>9</b>–<b>14</b>) and diorcinol (<b>15</b>), were isolated from the fermentation broth of the marine-derived fungus ZSDS1-F11 isolated from the sponge <i>Phakellia fusca</i> Thiele collected in the Yongxing island of Xisha. Their structures were elucidated mainly by using extensive NMR spectroscopic and mass spectrometric analyses. Compounds <b>3</b>–<b>5</b>, <b>7</b> and <b>8</b> showed potent COX-1 inhibitory activity with IC₅₀ values of 5.3, 16.2, 30.2, 41.0 and 56.8 μM, respectively. Meanwhile, compounds <b>3</b>–<b>8</b> showed potent COX-2 inhibitory activity with IC₅₀ values of 3.1, 5.6, 3.0, 5.1, 3.2 and 3.7 μM, respectively. In addition, compound <b>1</b> exhibited antituberculosis activity with 96.1% inhibition at concentration of 10 μM.</p></div

Chrysamides A–C, Three Dimeric Nitrophenyl <i>trans</i>-Epoxyamides Produced by the Deep-Sea-Derived Fungus <i>Penicillium chrysogenum</i> SCSIO41001

Three dimeric nitrophenyl <i>trans</i>-epoxyamides, chrysamides A–C (<b>1</b>–<b>3</b>), were obtained from the deep-sea-derived fungus <i>Penicillium chrysogenum</i> SCSIO41001. Their structures were characterized by spectroscopic analysis, electronic circular dichroism computations, and X-ray single-crystal diffraction analysis. Notably, compound <b>1</b> possesses a novel centrosymmetric dimer skeleton featuring an unprecedented 7-oxa-2,5-diazabicyclo[2.2.1]­heptane ring system, which represents the first example of dimeric nitrophenyl <i>trans</i>-epoxyamide in nature. Compound <b>3</b> suppresses the production of proinflammatory cytokine interleukin-17. A possible biosynthetic pathway of <b>1</b>–<b>3</b> was proposed

Antituberculosis compounds from a deep-sea-derived fungus <i>Aspergillus</i> sp. SCSIO Ind09F01

<p>Eleven diketopiperazine and fumiquinazoline alkaloids (<b>1–11</b>) together with a tetracyclic triterpenoid helvolic acid (<b>12</b>) were obtained from the cultures of a deep-sea derived fungus <i>Aspergillus</i> sp. SCSIO Ind09F01. The structures of these compounds (<b>1</b>–<b>12</b>) were determined mainly by the extensive NMR, ESIMS spectra data and by comparison with previously described compounds. Besides, anti-tuberculosis, cytotoxic, antibacterial, COX-2 inhibitory and antiviral activities of these compounds were evaluated. Gliotoxin (<b>3</b>), 12,13-dihydroxy-fumitremorgin C (<b>11</b>) and helvolic acid (<b>12</b>) exhibited very strong anti-tuberculosis activity towards <i>Mycobacterium tuberculosis</i> with the prominent MIC₅₀ values of <0.03, 2.41 and 0.894 μM, respectively, which was here reported for the first time. Meanwhile gliotoxin also displayed significant selective cytotoxicities against K562, A549 and Huh-7 cell lines with the IC₅₀ values of 0.191, 0.015 and 95.4 μM, respectively.</p