Total synthesis and absolute configuration of the natural dipeptide .gamma.-glutamylmarasmine

Broek, L. A. G. M. Van Den; Breuer, M.; Liskamp, Rob M. J.; Ottenheijm, H. C. J.

doi:10.1021/jo00384a024

Cited by 25 publications

(16 citation statements)

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“…Initial attempts to convert the trimethylsilylethyl ester 17 into the corresponding carboxylic acid with fluoride sources failed,6 but this transformation could be performed with trifluoroacetic acid in CH 2 Cl 2 to afford the desired keto acid 18 in high yield without affecting the methyl ester (Scheme ) 13. With compound 18 in hand, we were prepared to attempt the second key step, that is a formal ketene/ketone‐[2+2]‐intramolecular cycloaddition using the protocol by Romo et al.…”

Section: Methodsmentioning

confidence: 99%

Polymer‐Templated Perylene‐Probe Noncovalent Self‐Assembly: A New Strategy for Label‐Free Ultrasensitive Fluorescence Turn‐On Biosensing

Wang

Chen

Jiao

et al. 2013

Chemistry A European J

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A new label-free fluorescence turn-on strategy for highly sensitive biosensing has been developed. A negatively charged perylene probe was synthesized. Polycations could induce aggregation of the perylene probe through noncovalent interactions and the fluorescence of the probe's monomer was efficiently quenched. Upon addition of a single-stranded nucleic acid, competitive binding of the negatively charged nucleic acid (a polyanion) to the cationic polymer resulted in the release of a monomer and thus a turn-on fluorescence signal was detected. Without the use of any amplification techniques, a detection limit of 2 pM DNA was obtained. Based on these results, an assay strategy for the highly sensitive detection of alkaline phosphatase (ALP) activity has been demonstrated. λ Exonuclease (λ exo) could degrade 5'-phosphorylated single-stranded DNA. However, when the DNA sample was treated with ALP, the phosphate functional group was removed by ALP and it could no longer be degraded by λ exo. Binding of the DNA to the perylene probe-polycation complex resulted in a turn-on fluorescence signal, which could be used for sensing of ALP. The method is highly sensitive, a limit of detection as low as 0.02 mU mL(-1) ALP was obtained. Our method is simple, convenient, highly sensitive, and inexpensive.

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Section: Methodsmentioning

confidence: 99%

Polymer‐Templated Perylene‐Probe Noncovalent Self‐Assembly: A New Strategy for Label‐Free Ultrasensitive Fluorescence Turn‐On Biosensing

Wang

Chen

Jiao

et al. 2013

Chemistry A European J

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“…was shown to be c-glutamylmarasmine and the absolute configuration of the sulfur in this peptide 31 (R 5 glutamyl) was (S). 76 A diastereoisomer of marasmine itself, with (R) chirality at sulfur, occurs in fruit of the tree, Scorodocarpus borneensis (''wood garlic''). 77 Sparsomycin 32 from Streptomyces sparsogenes var.…”

Section: C-glutamylcysteine Sulfoxides and Related Compoundsmentioning

confidence: 99%

Role of sulfur chirality in the chemical processes of biology

2005

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Chiral structures profoundly influence chemical and biological processes. While chiral carbon biomolecules have received much attention, chirality is also possible in certain sulfur compounds; just as with carbon, there can be differences in the physiological behavior of chiral sulfur compounds. For instance, one drug enantiomer, Nexium (esomeprazole, a chiral sulfoxide), is used for its superior clinical properties as a proton pump inhibitor over the racemic mixture, Prilosec (Losec, omeprazole). This critical review introduces sulfur stereochemistry and nomenclature, and provides a comprehensive approach to chiral sulfur compounds and their enzymatic reactions in general and secondary metabolism. The major structural types of biological interest are sulfonium salts, sulfoxides, and sulfoximines. (103 references).

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“…However, the TMSE-ester of ketoacid 34 could be removed selectively from compound 33 using trifluoroacetic acid in methylene chloride. 16 …”

Section: Resultsmentioning

confidence: 99%

Total Syntheses of the Monoterpene Indole Alkaloids (±)-Alstilobanine A and E and (±)-Angustilodine

Feng¹,

Majireck

Weinreb³

2013

J. Org. Chem.

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A synthetic strategy has been developed culminating in stereoselective total syntheses of the small class of unusual monoterpenoid indole alkaloids exemplified by alstilobanine A (3) and E (2) and angustilodine (1). A pivotal step includes a novel intermolecular Michael-type addition of an indole ester dianion to a piperidine-derived nitrosoalkene to form the C15, C16 bond of the alkaloids. In addition, an application of the Romo protocol for effecting a stereoselective intramolecular nucleophile-assisted aldol-lactonization was employed, leading to a β-lactone incorporating the requisite cis-fused 2-azadecalin moiety and also setting the C15, C19, C20 relative stereochemistry of the metabolites. It was then possible to stereoselectively effect an aldolization of a dianion derived from this indole ester β-lactone intermediate with formaldehyde to introduce the requisite C16 hydroxymethyl group. Further manipulations of the system ultimately led to the three alkaloids in racemic form.

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Total synthesis and absolute configuration of the natural dipeptide .gamma.-glutamylmarasmine

Cited by 25 publications

References 0 publications

Polymer‐Templated Perylene‐Probe Noncovalent Self‐Assembly: A New Strategy for Label‐Free Ultrasensitive Fluorescence Turn‐On Biosensing

Polymer‐Templated Perylene‐Probe Noncovalent Self‐Assembly: A New Strategy for Label‐Free Ultrasensitive Fluorescence Turn‐On Biosensing

Role of sulfur chirality in the chemical processes of biology

Total Syntheses of the Monoterpene Indole Alkaloids (±)-Alstilobanine A and E and (±)-Angustilodine

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