scholarly journals Pre-fractionated Microbial Samples – The Second Generation Natural Products Library at Wyeth

Molecules ◽  
2008 ◽  
Vol 13 (6) ◽  
pp. 1406-1426 ◽  
Author(s):  
Melissa Wagenaar
Synlett ◽  
2020 ◽  
Vol 31 (04) ◽  
pp. 327-333 ◽  
Author(s):  
Jesper L. Kristensen ◽  
Sebastian Clementson ◽  
Mikkel Jessing ◽  
Paulo J. Vital

Erythrina alkaloids were identified at the end of the 19th century and today, more than 100 members of the erythrinane family have been isolated. They are characterized by a unique tetracyclic, α-tertiary spiroamine scaffold. Herein we detail our efforts towards the development of a divergent enantioselective synthesis of (+)-dihydro-β-erythroidine (DHβE) – one of the most prominent members of this intriguing family of natural products.1 Introduction2 Synthetic Strategy2.1 First Generation2.2 Second Generation2.3 Third Generation2.3.1 Radical Endgame2.3.2 Completion of the Total Synthesis3 Conclusion


Author(s):  
Takayoshi Awakawa ◽  
Lena Barra ◽  
Ikuro Abe

Abstract Sulfonamides and sulfamates are a group of organosulfur compounds that contain the signature sulfamoyl structural motif. These compounds were initially only known as synthetic antibacterial drugs but were later also discovered as natural products. Eight highly potent examples have been isolated from actinomycetes to date, illustrating the large biosynthetic repertoire of this bacterial genus. For the biosynthesis of these compounds, several distinct and unique biosynthetic machineries have been discovered, capable to generate the unique S-N bond. For the creation of novel, second generation natural products by biosynthetic engineering efforts, a detailed understanding of the underlying enzyme machinery towards potent structural motifs is crucial. In this review, we aim to summarize the current state of knowledge on sulfonamide and sulfamate biosynthesis. A detailed discussion for the secondary sulfamate ascamycin, the tertiary sulfonamide sulfadixiamycin A, and the secondary sulfonamide SB-203208 is provided and their bioactivities and mode of actions are discussed.


2016 ◽  
Vol 52 (85) ◽  
pp. 12638-12641 ◽  
Author(s):  
Xiao-Bo Ding ◽  
Daniel P. Furkert ◽  
Margaret A. Brimble

The heronapyrroles are a family of antibiotic natural products containing the rare 2-nitropyrrole motif.


Author(s):  
Paola Tirello ◽  
Marchesini Enrico ◽  
Pamela Gherardo ◽  
Damiano Raniero ◽  
Filippo Rossetto ◽  
...  

The American leafhopper Erasmoneura vulnerata, detected in Europe in early 2000s, has recently become a pest in North-Italian vineyards. Issues were recorded in organic and conventional vine-yards despite the application of insecticides devoted to the control of other pests. Erasmoneura vulnerata completes three generations, and the second generation is frequently associated to large populations. The selection of appropriate active ingredients and the timing of their application is crucial for effective pest control. Field trials were carried out in North-eastern Italy, using a randomized design, to evaluate the impact of insecticides applied against other grapevine leafhoppers on E. vulnerata populations. The beginning of the second generation was selected as best timing for insecticide application. For a number of natural products, two applications were planned. Among the selected insecticides, the most effective were acetamiprid, flupyradifurone and lamb-da-cyhalothrin. Regarding natural products, the most effective was kaolin that could represent an alternative to pyrethrins in organic vineyards. The identification of pest threshold levels and the evaluation of side effects of the most effective insecticides on key natural enemies occurring in vineyards are required


2019 ◽  
Author(s):  
Yu Kawamata ◽  
Julien Vantourout ◽  
David P. Hickey ◽  
Peng Bai ◽  
Longrui Chen ◽  
...  

<div> <div> <div> <p>C–N cross-coupling is one of the most valuable and widespread transformations in organic synthesis. Largely dominated by Pd- and Cu-based catalytic systems, it has proven to be a staple transformation for those in both academia and industry. The current study presents the development and mechanistic understanding of an electrochemically driven, Ni-catalyzed method for achieving this reaction of high strategic importance. Through a series of electrochemical, computational, kinetic, and empirical experiments the key mechanistic features of this reaction have been unraveled, leading to a second generation set of conditions that is applicable to a broad range of aryl halides and amine nucleophiles, including complex examples on oligopeptides, medicinally-relevant heterocycles, natural products, and sugars. Full disclosure of the current limitations as well as procedures for both batch and flow scale-ups (100 gram) are also described. </p> </div> </div> </div>


2006 ◽  
Vol 14 (8) ◽  
pp. 2810-2815 ◽  
Author(s):  
Helmer Søhoel ◽  
Anne-Marie Lund Jensen ◽  
Jesper V. Møller ◽  
Poul Nissen ◽  
Samuel R. Denmeade ◽  
...  

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 85
Author(s):  
Paola Tirello ◽  
Enrico Marchesini ◽  
Pamela Gherardo ◽  
Damiano Raniero ◽  
Filippo Rossetto ◽  
...  

The American leafhopper Erasmoneura vulnerata, detected in Europe in the early 2000s, has recently become a pest in North-Italian vineyards. Infestations were recorded in organic and conventional vineyards despite the application of insecticides targeting other pests. Erasmoneura vulnerata completes three generations per year, and the second generation is frequently associated with large populations. The selection of appropriate active ingredients and the timing of their application is crucial for effective pest control. Field trials were carried out in Northeastern Italy, using a randomized design, to evaluate the impact of insecticides applied against other grapevine leafhoppers on E. vulnerata populations. The beginning of the second generation was selected as the best time for insecticide application. For natural products, two applications were planned. Among the selected insecticides, the most effective were acetamiprid, flupyradifurone and lambda-cyhalothrin. Regarding natural products, the most effective was kaolin which could represent an alternative to pyrethrins in organic vineyards. The identification of pest threshold levels and the evaluation of side effects of the most effective insecticides on key natural enemies occurring in vineyards are required.


2019 ◽  
Author(s):  
Yu Kawamata ◽  
Julien Vantourout ◽  
David P. Hickey ◽  
Peng Bai ◽  
Longrui Chen ◽  
...  

<div> <div> <div> <p>C–N cross-coupling is one of the most valuable and widespread transformations in organic synthesis. Largely dominated by Pd- and Cu-based catalytic systems, it has proven to be a staple transformation for those in both academia and industry. The current study presents the development and mechanistic understanding of an electrochemically driven, Ni-catalyzed method for achieving this reaction of high strategic importance. Through a series of electrochemical, computational, kinetic, and empirical experiments the key mechanistic features of this reaction have been unraveled, leading to a second generation set of conditions that is applicable to a broad range of aryl halides and amine nucleophiles, including complex examples on oligopeptides, medicinally-relevant heterocycles, natural products, and sugars. Full disclosure of the current limitations as well as procedures for both batch and flow scale-ups (100 gram) are also described. </p> </div> </div> </div>


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