5 research outputs found
Rhodium-Catalyzed Difunctionalization of Alkenes Using Cyclic 1,3-Dicarbonyl-Derived Iodonium Ylides
Herein, we introduce an iodonium ylide strategy to achieve
novel
α-alkylation of cyclic 1,3-dicarbonyls through harnessing C(sp3)–Rh species generated from 5-exo-trig cyclization to provide rapid access to molecular hybridization
of medically important isoindolin-1-ones and cyclic 1,3-dicarbonyls
from readily available substrates. This approach features mild conditions,
good yield, excellent functional group tolerance, and the simultaneous
formation of two new chemical bonds and one stereogenic center. Moreover,
the hydroxyl group of resulting product provides a good handle for
downstream transformations. Importantly, we also demonstrate this
strategy can be achieved in a one-pot manner. A C(sp3)–Rh
complex was prepared and proved to be the key intermediate
Xylaolide A, a new lactone from the fungus Xylariaceae sp. DPZ-SY43
<div><p>Chemical investigation of the fungus Xylariaceae sp. DPZ-SY43 has led to the isolation of a new compound, xylaolide A (<b>1</b>) together with three known compounds (<b>2</b>–<b>4</b>). The structures were established by analysing the spectroscopic data. Compound <b>1</b> was evaluated for its cytotoxicity.</p></div
Penixanthones A and B, two new xanthone derivatives from fungus <i>Penicillium</i> sp. SYFz-1 derived of mangrove soil sample
<p>Two new xanthone derivatives, penixanthones A (<b>1</b>) and B (<b>2</b>), together with three known compounds, aspenicillide (<b>3</b>), 1,5-dihydroxy-3-methoxy-7-methyl-anthracene-9,10-dione (<b>4</b>) and 1,2-indandiol (<b>5</b>), were isolated from the ethyl acetate extract of a culture of the fungus <i>Penicillium</i> sp. SYFz-1, which was separated from a mangrove soil sample. The structures of these compounds were elucidated by spectroscopic methods including NMR and mass spectrometry. The absolute configurations of penixanthones A (1) and B (2) were determined on the basis of electronic circular dichroism (ECD) data analysis.</p
Isochromophilones A–F, Cytotoxic Chloroazaphilones from the Marine Mangrove Endophytic Fungus <i>Diaporthe</i> sp. SCSIO 41011
Six new highly oxygenated chloroazaphilone
derivatives, isochromophilones
A–F (<b>1</b>–<b>6</b>), were obtained from
the mangrove-derived fungus <i>Diaporthe</i> sp. SCSIO 41011,
together with six known analogues (<b>7</b>–<b>12</b>). The structures of <b>1</b>–<b>6</b> including
absolute configurations were determined by detailed NMR, MS spectroscopic
analyses, and electronic circular dichroism spectra. Compounds <b>1</b> and <b>2</b> represent the first reported azaphilones
lacking a carbonyl group at C-6. Compound <b>8</b> exhibited
cytotoxic activities against three renal carcinoma cell lines, ACHN,
OS-RC-2, and 786-O cells, with IC<sub>50</sub> values ranging from
3.0 to 4.4 μM, and <b>4</b> showed activity against 786-O
cells with an IC<sub>50</sub> of 8.9 μM. Further studies indicated
that <b>4</b> induced apoptosis in 786-O cells in a dose- and
time-dependent manner
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 MIC<sub>50</sub> 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 IC<sub>50</sub> values of 0.191, 0.015 and 95.4 μM, respectively.</p