scholarly journals Total Synthesis of 4-Acetyl-1,3-Dihydroimidazo[4,5-c]Pyridin-2-One, a New Microbial Metabolite from a Streptomyces Species

2009 ◽  
Vol 4 (7) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Tobias Bender ◽  
Paultheo von Zezschwitz
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Secondary Metabolite ◽  
Pyridine Derivative ◽  
Stille Reaction ◽  
Streptomyces Species ◽  
Streptomyces Sp ◽  
Microbial Metabolite

The structure of a new secondary metabolite from Streptomyces sp. was determined as 4-acetyl-1,3-dihydroimidazo[4,5-c]pyridin-2-one by synthesis of the natural product itself and of the regioisomeric 7-acetylimidazo[4,5-b]pyridine derivative. The former compound was prepared, in 28% overall yield, in a sequence of nitration, reduction, condensation, and Stille reaction of 4-aminopyridine, while the regioisomer was obtained in 5% overall yield by amination, nitration, reduction, condensation, and oxidation of 4-ethylpyridine.

Total synthesis of (–)-pateamine A, a novel immunosuppressive agent from Mycale sp

2004 ◽  
Vol 82 (2) ◽  
pp. 353-365 ◽  
Author(s):  
Gerald Pattenden ◽  
Douglas J Critcher ◽  
Modesto Remuiñán
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Marine Sponge ◽  
Coupling Reaction ◽  
Immunosuppressive Agent ◽  
Side Chain ◽  
Amino Ester ◽  
Stille Reaction ◽  
Amino Esters ◽  
Pateamine A

A convergent synthesis of the unique thiazole-containing polyene bis-lactone pateamine A (1) isolated from the marine sponge Mycale sp is described. The synthesis features the ubiquitous Stille sp2–sp2 coupling reaction to elaborate the E,Z-diene macrolide core 23 and the all-E polyenamine side chain in the natural product. It also highlights the scope for enantiopure sulfinimine intermediates in the synthesis of chiral β-amino ester moieties in complex structures.Key words: pateamine A, immunosuppressive agent from marine sponge Mycale sp, total synthesis, novel 19-membered bis-lactone, thiazole metabolite, polyenamine, Stille reaction, sulfinimines, chiral β-amino esters.

scholarly journals Discovery of Novel Glycerolated Quinazolinones from Streptomyces sp. MBT27

2018 ◽  
Author(s):  
Nataliia Machushynets ◽  
Changsheng Wu ◽  
Somayah S. Elsayed ◽  
Thomas Hankemeier ◽  
Gilles P. van Wezel
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Secondary Metabolite ◽  
Anthranilic Acid ◽  
Growth Conditions ◽  
Secondary Metabolite Production ◽  
Streptomyces Sp ◽  
Metabolite Production ◽  
Bioactive Natural Products ◽  
Interesting Family

AbstractActinobacteria are a major source of novel bioactive natural products. A challenge in the screening of these microorganisms lies in finding the favorable growth conditions for secondary metabolite production and dereplication of known molecules. Here, we report that Streptomyces sp. MBT27 produces 4-quinazolinone alkaloids in response to elevated levels of glycerol, whereby quinazolinones A (1) and B (2) form a new sub-class of this interesting family of natural products. Global Natural Product Social molecular networking (GNPS) resulted in a quinazolinone-related network that included anthranilic acid (3), anthranilamide (4), 4(3H)-quinazolinone (5) and 2,2-dimethyl-1,2-dihydroquinazolin-4(3H)-one (6). Actinomycins D (7) and X2 (8) were also identified in the extracts of Streptomyces sp. MBT27. The induction of quinazolinone production by glycerol combined with biosynthetic insights provide evidence that glycerol is integrated into the chemical scaffold. The unprecedented 1,4-dioxepane ring that is spiro-fused into the quinazolinone backbone, is most likely formed by intermolecular etherification of two units of glycerol. Our work underlines the importance of varying the growth conditions for the discovery of novel natural products and for understanding their biosynthesis.

First Total Synthesis of 27-deoxylyngbyabellin A

Synthesis ◽  
2021 ◽  
Author(s):  
Yang Zhang ◽  
Yi Liu ◽  
Yuguo Du
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Secondary Metabolite ◽  
Building Block ◽  
Aldol Reaction ◽  
Cascade Reaction ◽  
Hydroxy Ester ◽  
Marine Cyanobacteria ◽  
One Pot ◽  
Key Steps

In this study, we documented the first total synthesis of marine cyanobacteria secondary metabolite 27-deoxylyngbyabellin A in 10 linear steps with 9.7% overall yield. Key steps entailed (1) one-pot cascade reaction of (S)-2-(benzyloxy)-3-methylbutanoic acid and Boc-Ile-Thz-OMe with the building block β-azido disulfide 7 to access the critical thiazole units 3 and 4, (2) chiral oxazaborolidinone-mediated asymmetry aldol reaction to construct (S)-β-hydroxy ester 5, and (3) DPPA-mediated macrolactamization of linear precursor 2 to achieve the natural product 27-deoxylyngbyabellin A.

Progress Toward The Total Synthesis Of The Marine Natural Product Karlotoxin 5

Planta Medica ◽  
2013 ◽  
Vol 79 (10) ◽  
Author(s):  
M Albadry ◽  
Y Zou ◽  
Y Takahashi ◽  
A Waters ◽  
M Hossein ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Marine Natural Product

Total Synthesis of the Antitumor Depsipeptide FE399 and its S-Benzyl Derivative: A Macrolactamization Approach

2020 ◽  
Author(s):  
Takayuki Tonoi ◽  
Miyuki Ikeda ◽  
Teruyuki Sato ◽  
Ryo Kawahara ◽  
Takatsugu Murata ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Total Synthesis ◽  
Natural Product ◽  
Condensation Reaction ◽  
Practical Method ◽  
Equilibrium Mixture ◽  
Conformational Isomers ◽  
Single Isomer

<div>An efficient and practical method for the synthesis of (9R,14R,17R)-FE399, a novel antitumor bicyclic depsipeptide, was developed. A 2-methyl-6-nitrobenzoic anhydride (MNBA)-mediated dehydration condensation reaction was effectively employed for the formation of the 16-membered macrocyclic depsipeptide moiety of FE399. FE399 was found to exist as an inseparable equilibrium mixture of conformational isomers; the mixture was quantitatively transformed into the corresponding S-benzyl product and isolated as a single isomer. Thus, we could confirm that the molecular structure of FE399 obtained by this method is identical to that of the natural product.</div>

A One-Pot Chemoenzymatic Synthesis of (2S,4R)-4-Methylproline Enables the First Total Synthesis of Antiviral Lipopeptide Cavinafungin B

2018 ◽  
Author(s):  
Christian R. Zwick ◽  
Hans Renata
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Complex Molecule ◽  
Molecular Target ◽  
Chemoenzymatic Synthesis ◽  
General Strategy ◽  
One Pot

We report an efficient ten-step synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (Rink-Boc-ATG-resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner.This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

Convergent Total Synthesis of Principinol D, a Rearranged Kaurane Diterpenoid

2019 ◽  
Author(s):  
Timothy Newhouse ◽  
Aneta Turlik ◽  
Yifeng Chen ◽  
Anthony Scruse
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Late Stage ◽  
Membered Ring ◽  
Entry Point ◽  
Ketone Reduction ◽  
Coupling Approach

<div> <p>The total synthesis of principinol D, a rearranged kaurane diterpenoid, is reported. This grayanane natural product is constructed via a convergent fragment coupling approach, wherein the central 7-membered ring is synthesized at a late stage. The bicyclo[3.2.1]octane fragment is accessed by a Ni-catalyzed α-vinylation reaction. Strategic reductions include a diastereoselective SmI<sub>2</sub>-mediated ketone reduction with PhSH and a new protocol for selective ester reduction in the presence of ketones. The convergent strategy reported herein may be an entry point to the larger class of kaurane diterpenoids.</p> </div>

A Short Synthesis of (+)-Brefeldin C via Enantioselective Radical Hydroalkynylation

2019 ◽  
Author(s):  
Lars Gnägi ◽  
Severin Vital Martz ◽  
Daniel Meyer ◽  
Robin Marc Schärer ◽  
Philippe Renaud
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Oxidation State ◽  
Single Step ◽  
Radical Process ◽  
Target Molecule ◽  
Short Synthesis ◽  
The One

<div><div><div><div><p>A very concise total synthesis of (+)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentane stereocenters in a single step. The use of a furan substituent allows to achieve a high trans diastereoselectivity during the radical process and it contains the four carbon atoms C1–C4 of the natural product in an oxidation state closely related to the one of the target molecule. The eight-step synthesis require six product purifications and it provides (+)-brefeldin C in 18% overall yield.</p></div></div></div></div>

Identification of the kinanthraquinone biosynthetic gene cluster by expression of an atypical response regulator

2021 ◽  
Vol 85 (3) ◽  
pp. 714-721
Author(s):  
Risa Takao ◽  
Katsuyuki Sakai ◽  
Hiroyuki Koshino ◽  
Hiroyuki Osada ◽  
Shunji Takahashi
Keyword(s):  
Heterologous Expression ◽  
Gene Cluster ◽  
Secondary Metabolite ◽  
Response Regulator ◽  
Bac Library ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Gene Organization ◽  
Biosynthetic Gene ◽  
Streptomyces Sp

ABSTRACT Recent advances in genome sequencing have revealed a variety of secondary metabolite biosynthetic gene clusters in actinomycetes. Understanding the biosynthetic mechanism controlling secondary metabolite production is important for utilizing these gene clusters. In this study, we focused on the kinanthraquinone biosynthetic gene cluster, which has not been identified yet in Streptomyces sp. SN-593. Based on chemical structure, 5 type II polyketide synthase gene clusters were listed from the genome sequence of Streptomyces sp. SN-593. Among them, a candidate gene cluster was selected by comparing the gene organization with grincamycin, which is synthesized through an intermediate similar to kinanthraquinone. We initially utilized a BAC library for subcloning the kiq gene cluster, performed heterologous expression in Streptomyces lividans TK23, and identified the production of kinanthraquinone and kinanthraquinone B. We also found that heterologous expression of kiqA, which belongs to the DNA-binding response regulator OmpR family, dramatically enhanced the production of kinanthraquinones.

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