ChemInform Abstract: Carbon-Carbon Bond Formation via a Tandem Cationic 2-aza-Cope Rearrangement-Lewis Acid Promoted Petasis Reaction.

info:eu-repo/semantics/publishe

Carbon-carbon bond formation via a tandem cationic 2-aza-Cope rearrangement - Lewis acid promoted Petasis reaction.

info:eu-repo/semantics/publishe

ChemInform Abstract: Carbon-Carbon Bond Formation via a Tandem Cationic 2-aza-Cope Rearrangement-Lewis Acid Promoted Petasis Reaction

info:eu-repo/semantics/publishe

Cleromyrine I, a new cyclohexapeptide from clerodendrum myricoides

A cyclic hexapeptide was isolated from Clerodendrum myricoides. The amino acid composition was determined by chiral chromatography. The sequence c(Ala-Gly-Pro-Ile-Val-Phe). A proposal for the conformation is given. © 1989.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

A combinatorial approach to the structure elucidation of a pyoverdine siderophore produced by a Pseudomonas putida isolate and the use of pyoverdine as a taxonomic marker for typing P-putida subspecies

The structure of a pyoverdine produced by Pseudomonas putida, W15Oct28, was elucidated by combining mass spectrometric methods and bioinformatics by the analysis of non-ribosomal peptide synthetase genes present in the newly sequenced genome. The only form of pyoverdine produced by P. putida W15Oct28 is characterized to contain alpha-ketoglutaric acid as acyl side chain, a dihydropyoverdine chromophore, and a 12 amino acid peptide chain. The peptide chain is unique among all pyoverdines produced by Pseudomonas subspecies strains. It was characterized as -l-Asp-l-Ala-d-AOHOrn-l-Thr-Gly-c[l-Thr(O-)-l-Hse-d-Hya-l-Ser-l-Orn-l-Hse-l-Ser-O-]. The chemical formula and the detected and calculated molecular weight of this pyoverdine are: C65H93N17O32, detected mass 1624.6404 Da, calculated mass 1624.6245. Additionally, pyoverdine structures from both literature reports and bioinformatics prediction of the genome sequenced P. putida strains are summarized allowing us to propose a scheme based on pyoverdines structures as tool for the phylogeny of P. putida. This study shows the strength of the combination of in silico analysis together with analytical data and literature mining in determining the structure of secondary metabolites such as peptidic siderophores

Identification of ethylsuccinylcarnitine present in some human urines.

Ethylsuccinylcarnitine, a previously undescribed acylcarnitine, was identified in urines obtained from 81% of adult volunteers. Its chemical structure was obtained by 1H nuclear magnetic resonance spectroscopy of the urinary purified compound and confirmed by its chemical synthesis. Its urinary excretion followed a circadian rhythm with a maximum occurring between 8 p.m. and 1 a.m. Excretion of this compound was enhanced after a load of L-carnitine and in this case, total 24-h urinary excretion may raise up to about 75 microM. It was observed that the day after adryamicine treatment, the compound was no more excreted. This molecule was absent or in trace amounts in urines obtained from few adults as well as in urines obtained from young subjects. In the positive urines, we detected an unknown organic acid whose excretion was almost parallel to that of ethylsuccinylcarnitine