Total Synthesis of (±)-Phomoidride D

Described herein is a synthetic strategy for the total synthesis of (±)‐phomoidride D. This highly efficient and stereoselective approach provides rapid assembly of the carbocyclic core by way of a tandem phenolic oxidation/intramolecular Diels–Alder cycloaddition. A subsequent SmI2‐mediated cyclization cascade delivers an isotwistane intermediate poised for a Wharton fragmentation that unveils the requisite bicyclo[4.3.1]decene skeleton and sets the stage for synthesis completion

Asymmetric Total Synthesis of Neoxaline

A first asymmetric total synthesis and determination of the absolute configuration of neoxaline has been accomplished through the highly stereoselective introduction of a reverse prenyl group to create a quaternary carbon stereocenter using (−)-3a-hydroxyfuroindoline as a building block, construction of the indoline spiroaminal via cautious stepwise oxidations with cyclizations from the indoline, assembly of (<i>Z</i>)-dehydrohistidine, and photoisomerization of unnatural (<i>Z</i>)-neoxaline to the natural (<i>E</i>)-neoxaline as the key steps

Anti-steatosis compounds from leaves of <i>Mallotus furetianus</i>

<p>There is no drug administration-approved therapy for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). In this study, eight compounds, gallic acid (<b>1</b>), methyl gallate (<b>2</b>), corilagin (<b>3</b>), 3,4,8,9,10-pentahydroxydibenzo[<i>b,d</i>]pyran-6-one (<b>4</b>), repandinin B (<b>5</b>), (Z)-3-hexenyl-β-D-glucopyranoside (<b>6</b>), (+)-lyoniresinol-3α-O-α-L-rhamnopyranoside (<b>7</b>) and mallophenol A (<b>8</b>) were isolated from the active fractions of <i>Mallotus furetianus</i>. Three compounds, (<b>6, 7</b> and <b>8</b>) revealed potent anti-steatosis activity in the oleic acid (OA)-induced steatosis cell model, with the minimum effective concentration of 0.05 (<b>6</b>), 0.0005 (<b>7</b>) and 0.0005 (<b>8</b>) μg/mL, which were much lower than the control compound, fibrate (72.4 μg/mL).</p

Synthesis of Bisdesmosidic Oleanolic Acid Saponins via a Glycosylation-Deprotection Sequence under Continuous Microfluidic/Batch Conditions

We report the first synthesis of a series of bisdesmosidic oleanolic acid saponins using microflow reactor Comet X-01 via a continuous flow glycosylation-batch deprotection sequence. The main results of this study can be summarized as follows: (1) The microfluidic glycosylation of oleanolic acid at C-28 was achieved in quantitative yield and was applied to the synthesis of six C-28-monoglycosidic saponins. (2) The microfluidic glycosylation of oleanolic acid at C-3 was achieved in good yield without orthoester byproduct formation and was applied to the synthesis of three bisdesmosidic saponins. (3) The continuous synthesis of saponins via a microfluidic glycosylation-batch deprotection sequence was achieved in four steps involving two purifications. Thus, the continuous microfluidic glycosylation-deprotection process is expected to be suitable for the preparation of a library of bisdesmosidic oleanolic acid saponins for in vivo pharmacological studies

Total synthesis of (±)-phomoidride D: A 22 year odyssey

Recent efforts in our labs. have culminated in a completed synthesis of the phomoidride D via a strategy that evolved over a 22-yr period. The evolution of this strategies will be discussed

Total synthesis of (±)-phomoidride D: A 22 year odyssey

Recent efforts in our labs. have culminated in a completed synthesis of the phomoidride D via a strategy that evolved over a 22-yr period. The evolution of this strategies will be discussed

Aogacillins A and B Produced by <i>Simplicillium</i> sp. FKI-5985: New Circumventors of Arbekacin Resistance in MRSA

Aogacillins A and B, capable of overcoming arbekacin resistance in methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), were isolated from a culture broth of <i>Simplicillium</i> sp. FKI-5985. Their structures were elucidated by NMR spectroscopic studies and ECD analyses. The aogacillins possessed a novel carbon skeleton, including a β-keto-γ-methyliden-δ-lactone ring connected to a 2-ethyl-6-methylcyclohexane ring by spiro conjugation

Toward the Synthesis of Phomoidride D

An efficient and highly stereoselective approach toward the phomoidride family of natural products is described. The carbocyclic core structure was assembled using a tandem phenolic oxidation/Diels–Alder cycloaddition and a tandem 5-<i>exo</i>-<i>trig</i>/5-<i>exo</i>-<i>trig</i> radical cyclization to deliver an isotwistane intermediate that, upon a late-stage xanthate-initiated Grob fragmentation, furnishes the requisite bicyclo[4.3.1]­decene

Phellilane L, Sesquiterpene Metabolite of <i>Phellinus linteus</i>: Isolation, Structure Elucidation, and Asymmetric Total Synthesis

A new cyclopropane-containing sesquiterpenoid, phellilane L (<b>1</b>), was isolated from the medicinal mushroom <i>Phellinus linteus</i> (“Meshimakobu” in Japanese), a member of the Hymenochaetaceae family and a well-known fungus that is widely used in East Asia. The planar structure of <b>1</b> was determined on the basis of spectroscopic analysis. The authors achieved the first total synthesis of <b>1</b>. Our protecting group-free synthesis features a highly stereoselective one-pot synthesis involving an intermolecular alkylation/cyclization/lactonization strategy for construction of the key cyclopropane-γ-lactone intermediate. Additionally, our synthesis determined the absolute configuration of phellilane L (<b>1</b>)