An efficient synthesis of δ-(L-α-aminoadipyl)-L-seryl-D-valine (LLD ASV), a naturally occuring tripeptide from the fermentation of Penicillium chrysogenum

1988 ◽  
Vol 53 (11) ◽  
pp. 2854-2856
Author(s):  
Bogdan Liberek ◽  
Regina Kasprzykowska

The synthesis of δ-(L-α-aminoadipyl)-L-seryl-D-valine (LLD ASV), a naturally occuring congener of the well known tripeptide δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine (LLD ACV) which is the linear precursor of isopenicillin N, penicillin N, cephalosporin C is described. An efficient method for producing the requisite α-monobenzyl ester of N-benzyloxycarbonyl-L-homoglutamic acid for subsequent condesation at the side chain δ-carboxy group is presented.

2014 ◽  
Vol 662 ◽  
pp. 59-62
Author(s):  
Shan Shan Gong ◽  
Qi Sun

A facile and efficient method for the synthesis ofP1,P3-dizidovudine-5′,5′-triphosphate has been developed. The coupling of zidovudine diphosphate with zidovudine phosphoropiperidate based on the DCI activation of P-N bond afforded the desired product in good yield.


2014 ◽  
Vol 50 (99) ◽  
pp. 15760-15763 ◽  
Author(s):  
Huanhuan Li ◽  
Yang Wang ◽  
Kai Yuan ◽  
Ye Tao ◽  
Runfeng Chen ◽  
...  

The rhodium-catalyzed synthesis of phenazasilines from readily achievable biarylhydrosilanes is presented. This highly efficient method offers opportunities for preparing π-extended phenazasilines with enhanced optoelectronic properties for device applications in organic electronics.


1987 ◽  
Vol 65 (1) ◽  
pp. 189-190 ◽  
Author(s):  
Michel Girard ◽  
David B. Moir ◽  
John W. ApSimon

The title compound 1 was prepared in 13% overall yield starting from the commercially available and inexpensive 3,5-dimethoxybenzoic acid (4). The n-pentyl side chain was elaborated from cross-coupling reactions between halides.


Synthesis ◽  
2018 ◽  
Vol 50 (12) ◽  
pp. 2416-2422 ◽  
Author(s):  
Man-Su Tu ◽  
Guang-Jian Mei ◽  
Feng Shi ◽  
Si-Jia Liu ◽  
Xiao-Li Jiang ◽  
...  

An efficient approach for the synthesis of chromene derivatives from vinyl o-quinone methides was established via a Brønsted acid catalyzed electrocyclization. By using this methodology, a series of structurally diversified chromenes was synthesized in a highly atom-economic and environmentally benign manner with generally good to excellent yields (up to 98% yield). This reaction will not only provide an efficient method for the construction of chromene scaffolds, but also enrich the research area of o-quinone methides.


2006 ◽  
Vol 73 (3) ◽  
pp. 962-970 ◽  
Author(s):  
Danielle Janus ◽  
Birgit Hoff ◽  
Eckhard Hofmann ◽  
Ulrich K�ck

ABSTRACT In filamentous fungi, RNA silencing is an attractive alternative to disruption experiments for the functional analysis of genes. We adapted the gene encoding the autofluorescent DsRed protein as a reporter to monitor the silencing process in fungal transformants. Using the cephalosporin C producer Acremonium chrysogenum, strains showing a high level of expression of the DsRed gene were constructed, resulting in red fungal colonies. Transfer of a hairpin-expressing vector carrying fragments of the DsRed gene allowed efficient silencing of DsRed expression. Monitoring of this process by Northern hybridization, real-time PCR quantification, and spectrofluorometric measurement of the DsRed protein confirmed that downregulation of gene expression can be observed at different expression levels. The usefulness of the DsRed silencing system was demonstrated by investigating cosilencing of DsRed together with pcbC, encoding the isopenicillin N synthase, an enzyme involved in cephalosporin C biosynthesis. Downregulation of pcbC can be detected easily by a bioassay measuring the antibiotic activity of individual strains. In addition, the presence of the isopenicillin N synthase was investigated by Western blot hybridization. All transformants having a colorless phenotype showed simultaneous downregulation of the pcbC gene, albeit at different levels. The RNA-silencing system presented here should be a powerful genetic tool for strain improvement and genome-wide analysis of this biotechnologically important filamentous fungus.


Synlett ◽  
2019 ◽  
Vol 30 (20) ◽  
pp. 2273-2278 ◽  
Author(s):  
Piroska Gyárfás ◽  
János Gerencsér ◽  
Warren S. Wade ◽  
László Ürögdi ◽  
Zoltán Novák ◽  
...  

An efficient method for nucleophilic aromatic substitution on 7-azaindoles has been developed. The reaction is facilitated by the unique dual influence of SEM as both protecting and activating group, permitting mild conditions and short reaction times that are compatible with sensitive functional groups. The method is suitable for the synthesis of a broad range of products, most notably ethers.


RSC Advances ◽  
2014 ◽  
Vol 4 (46) ◽  
pp. 24001-24006 ◽  
Author(s):  
Kommuri Shekarrao ◽  
Partha Pratim Kaishap ◽  
Venkateshwarlu Saddanapu ◽  
Anthony Addlagatta ◽  
Sanjib Gogoi ◽  
...  

An efficient method was developed for the synthesis of pyrazole fused heterocycles via the palladium-catalyzed solvent free reaction of β-halovinyl/aryl aldehydes and 3-aminopyrazoles/5-aminopyrazoles under microwave irradiation in good yields.


2015 ◽  
Vol 1083 ◽  
pp. 51-54 ◽  
Author(s):  
Wen Qian Zheng ◽  
Mei Xia Du ◽  
Feng Feng ◽  
Guo Lin Chen ◽  
Min Liao ◽  
...  

The mono-(6-p-toluenesulfonyl)-β-cyclodextrin was firstly synthesized fast and efficiently by adopting ultrasound assisted method in alkaline water solution. The reaction time was only 40 min but with the yield of 31.1% under ultrasound condition. Compared with the conventional synthetic methods, the proposed novel method could shorten the reaction time and improve the yield. It is a simple, rapid and efficient method.


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