scholarly journals Tom J. Mabry's Natural Products Chemistry Program: 1960–2007

2007 ◽  
Vol 2 (10) ◽  
pp. 1934578X0700201
Author(s):  
Lalita M. Calabria ◽  
Tom J. Mabry
Keyword(s):  
Biological Sciences ◽  
Developmental Biology ◽  
Natural Products ◽  
Faculty Member ◽  
Natural Product ◽  
University Of Texas ◽  
Natural Products Chemistry ◽  
University Of Zurich ◽  
The University ◽  
Natural Product Chemist

This paper presents an overview of Dr. Mabry's accomplishments in his career as a natural product chemist, first at the University of Zürich as a post-doctoral fellow, and from 1962, as a faculty member at the University of Texas at Austin in the Department of Botany until the late 1990s, when the Biological Sciences programs at UT-Austin were completely reorganized. From then until his retirement in 2006, he was a member of the Molecular Cell and Developmental Biology faculty.

C–O Ring-Containing Natural Products: Cyanolide A (Krische), Bisabosqual A (Parker), Iso-Eriobrucinol A (Hsung), Trichodermatide A (Hiroya), Batrachotoxin Core (Du Bois)

2017 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Radical Cyclization ◽  
Ethyl Vinyl ◽  
University Of Texas ◽  
Iridium Catalysis ◽  
University Of Wisconsin ◽  
Bisabosqual A ◽  
The University ◽  
Very High

Michael J. Krische at the University of Texas at Austin developed (Angew. Chem. Int. Ed. 2013, 52, 4470) a total synthesis of cyanolide A 7 in only seven steps, a sequence so short it is shown here in its entirety. Diol 1 was subjected to enantioselective cat­alytic bisallylation under iridium catalysis to furnish 2 with very high levels of ste­reocontrol. Cross metathesis using ruthenium catalyst 3 first with ethyl vinyl ketone and then with ethylene resulted in the production of pyran 4. Glycosylation of 4 with phenylthioglycoside 5, stereoselective reduction of the ketone function, and oxidative cleavage of the olefin then furnished the carboxylic acid 6. Finally, dimerization of 6 with 2-methyl-6-nitrobenzoic anhydride (MBNA) yielded cyanolide A. Kathlyn A. Parker at Stony Brook University reported (J. Am. Chem. Soc. 2013, 135, 582) a tandem radical cyclization strategy for the total synthesis of bisabosqual A 11. The key substrate 9 was prepared in three steps from the diester 8. Treatment of 9 with tri-s-butylborane and TTMS in the presence of air induced the tandem 5-exo, 6-exo radical cyclization to produce the complete core 10 of the natural product as a mixture of diastereomers, which could be equilibrated. Some further redox maneu­vers then led to bisabosqual A. Richard P. Hsung at the University of Wisconsin, Madison disclosed (Org. Lett. 2013, 15, 3130) a very brief synthesis of iso-eriobrucinol A and related isomers using a unique cascade sequence. First, phloroglucinol 12 and citral 13 were condensed using piperidine and acetic anhydride. The product of this operation was the tetracy­clic cyclobutane 14, the result of an oxa-[3+3] annulation followed by a stepwise, cat­ionic [2+2] cycloaddition. Treatment of 14 with methyl propiolate in the presence of catalytic indium(III) chloride under microwave irradiation furnished iso-eriobrucinol A, as well as the isomeric natural product iso-eriobrucinol B. A concise approach to trichodermatide A 19 was developed (Angew. Chem. Int. Ed. 2013, 52, 3546) by Kou Hiroya at Musashino University. Aldehyde 16, which was syn­thesized from L-tartaric acid, was condensed with 1,3-cyclohexanedione in the presence of piperidine, resulting in diketone 17.

Latest Applications of the Diels-Alder Reaction in the Synthesis of Natural Products (2017-2020)

Synthesis ◽  
2021 ◽  
Author(s):  
Markus Kalesse ◽  
Aamer Saeed ◽  
Alexandru Sara ◽  
Um-e Farwa
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Building Blocks ◽  
Alder Reaction ◽  
Diels Alder ◽  
High Rank ◽  
Total Syntheses ◽  
Diels Alder Reaction ◽  
Natural Product Chemist

The Diels-Alder reaction has long established its high rank in the toolbox of any natural product chemist. The tremendous toleration of building blocks of various complexity and derivatization degree, as well as the enablement of furnishing six-membered rings with well-defined stereochemistry represents its main features and advantages. In recent years, many total syntheses of natural products relied at some point on the use of a [4+2]-cycloaddition step. Among classic approaches, several modifications of the Diels-Alder reaction, such as hetero-Diels-Alder reactions, dehydro-Diels-Alder reactions or domino-Diels-Alder reactions have been employed to extend the scope in the synthesis of natural products. Our review covers the application of the Diels-Alder reaction in natural product syntheses from 2017 to 2020, as well as selected methodologies which were inspired by, or could be used to access natural products.

C–O Containing Natural Products

2015 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Biological Activities ◽  
Max Planck ◽  
Penicillium Species ◽  
Antimitotic Agent ◽  
Berkelic Acid ◽  
Metal Catalyzed ◽  
The University

It is thought that the pseudopterane class of diterpenoid natural products, of which 11-gorgiacerol is a member, arises biosynthetically by a photo-ring contraction of the related furanocembranes. Johann Mulzer at the University of Vienna has applied (Org. Lett. 2012, 14, 2834) this logic to realize the total synthesis of 11-gorgiacerol. Ringclosing metathesis of the butenolide 1 using the Grubbs second generation catalyst produced the tricycle 2. When irradiated, 2 undergoes a 1,3-rearrangement to furnish the natural product in good yield. Whether this rearrangement is concerted, or occurs stepwise via a diradical intermediate, is not known. Although ring-closing metathesis has become a reliable method for macrocycle construction, its use here to set what then becomes an extracyclic olefin is notable. Berkelic acid is produced by an extremophile bacterium penicillium species that lives in the toxic waters of an abandoned copper mine, and this natural product has been found to possess some very intriguing biological activities. Not surprisingly, berkelic acid has attracted significant attention from synthetic chemists, including Francisco J. Fañanás of Universidad de Oviedo in Spain, who has developed (Angew. Chem. Int. Ed. 2012, 51, 4930) a scalable, protecting-group free total synthesis. The key step in this route is the remarkable silver(I)-catalyzed coupling of alkyne 3 and aldehyde 4 to produce, after hydrogenation, the structural core 5 of (–)-berkelic acid on a gram scale. Some tools from the field of organocatalysis have been brought to bear (Angew. Chem. Int. Ed. 2012, 51, 5735) on a new total synthesis of the macrolide (+)-dactylolide by Hyoungsu Kim of Ajou University in Korea and Jiyong Hong of Duke University. The bridging tetrahydropyranyl ring is fashioned by way of an intramolecular 1,6-oxa conjugate addition of dienal 6 to produce 8 under catalysis by the secondary amine 7. Following some synthetic manipulations, the macrocyclic ring 12 is subsequently forged by an NHC-catalyzed oxidative macrolactonization using the carbene catalyst 10 and diphenoquinone 11 as the oxidant. A new approach to the nanomolar antimitotic agent spirastrellolide F methyl ester has been reported (Angew. Chem. Int. Ed. 2012, 51, 8739) by Alois Fürstner of the Max-Planck-Institut, Mülheim. Two elegant metal-catalyzed processes form the key basis of this strategy.

scholarly journals High Performance Computing Prediction of Potential Natural Product Inhibitors of SARS-CoV-2 Key Targets

2020 ◽  
Author(s):  
Kendall Byler ◽  
Joseph Landman ◽  
Jerome Baudry
Keyword(s):  
Natural Products ◽  
Virtual Screening ◽  
High Performance Computing ◽  
Natural Product ◽  
High Performance ◽  
Spike Protein ◽  
Main Protease ◽  
The Common ◽  
The University ◽  
Performance Computing

This work describes using a supercomputer to perform virtual screening of natural products and natural products derivatives against several conformations of 3 proteins of SARS-CoC-2 : papain-like protease, main protease and spike protein. We analyze the common chemical features of the top molecules predicted to bind and describe the pharmacophores responsible for The University of Ala predicted binding.

Fungal Metabolites as Pharmaceuticals

2014 ◽  
Vol 67 (6) ◽  
pp. 827 ◽  
Author(s):  
Andrew M. Beekman ◽  
Russell A. Barrow
Keyword(s):  
Natural Products ◽  
New Zealand ◽  
Natural Product ◽  
Medicinal Chemistry ◽  
Fungal Metabolites ◽  
Natural Products Chemistry

Natural products, their derivatives or compounds based on natural product leads constitute ~50 % of clinically used pharmaceuticals. This review highlights pharmaceuticals currently used in Australia and New Zealand that have their origins in fungal metabolites, discussing the natural products chemistry and medicinal chemistry leading to their application as pharmaceuticals.

Alkene and Alkyne Metathesis: (+)-Anamarine (Sabitha), ( ± )-Pseudotabersonine (Martin), Lactimidomycin (Fürstner)

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Indian Institute ◽  
Alkyne Metathesis ◽  
Max Planck ◽  
Ring Closing Metathesis ◽  
University Of Texas ◽  
Ru Catalyst ◽  
Cross Metathesis ◽  
University Of Zurich ◽  
Indian Institute Of Science ◽  
The University

Masato Matsugi of Meijo University showed (J. Org. Chem. 2010, 75, 7905) that over five iterations, the fluorous-tagged Ru catalyst 1b was readily recovered and reused for the cyclization of 2 to 3. Hengquan Yang of Shanxi University reported (Chem. Commun. 2010, 46, 8659) that the Hoveyda catalyst 1a encapsulated in mesoporous SBA-1 could also be reused several times. Jean-Marie Basset of KAUST Catalysis Center, Régis M. Gauvin of Université Lille, and Mostafa Taoufik of Université Lyon 1 described (Chem. Commun. 2010, 46, 8944) a W catalyst on silica that was also active for alkene metathesis. Reto Dorta of the University of Zurich, exploring several alternatives, found (J. Am. Chem. Soc. 2010, 132, 15179) that only 4c cyclized cleanly to 5. Karol Grela of the Polish Academy of Sciences showed (Synlett 2010, 2931) that 3-nitropropene (not illustrated) participated in cross-metathesis when catalyst 1c was used. Shawn K. Collins of the Université de Montré al complexed (J. Am. Chem. Soc. 2010, 132, 12790) 6 with a quinolinium salt to direct paracyclophane formation. Min Shi of the Shanghai Institute of Organic Chemistry incorporated (Org. Lett. 2010, 12, 4462) the cyclopropene 8 in cross-metathesis, to give 10. A. Srikrishna of the Indian Institute of Science (Bangalore) constructed (Synlett 2010, 3015) the cyclooctenone 12 by ring-closing metathesis. LuAnne McNulty of Butler University established (J. Org. Chem. 2010, 75, 6001) that a cyclic boronic half acid 15, prepared by ring-closing metathesis, coupled with an iodoalkene 16 to deliver the diene 17 with high geometric control. Gowravaram Sabitha of the Indian Institute of Chemical Technology, Hyderabad, en route to (+)-anamarine 21, observed (Tetrahedron Lett. 2010, 51, 5736) that the tetraacetate 18b would not participate in cross-metathesis. Fortunately, 18a , an earlier intermediate in the synthesis, worked well. Stephen F. Martin of the University of Texas prepared (Org. Lett. 2010, 12, 3622) (±)-pseudotabersonine 24 by way of a spectacular metathesis that converted 22 to 23. Ring-closing alkyne metathesis was a key step in the total synthesis of lactimidomycin 27 reported (J. Am. Chem. Soc. 2010, 132, 14064) by Alois Fürstner of the Max-Planck- Institut Mülheim.

The 1-MeV Electron Microscope Installation at the University of Colorado

1973 ◽  
Vol 31 ◽  
pp. 8-9 ◽  
Author(s):  
Mircea Fotino
Keyword(s):  
Electron Microscopy ◽  
Developmental Biology ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
National Institutes Of Health ◽  
Experimental Program ◽  
University Of Colorado ◽  
Transmission Electron ◽  
The University ◽  
Research Resources

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.

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