148404-92-6Relevant articles and documents
Divalent Transition-Metal-Ion Stress Induces Prodigiosin Biosynthesis in Streptomyces coelicolor M145: Formation of Coeligiosins
Morgenstern, Anne,Paetz, Christian,Behrend, Anne,Spiteller, Dieter
, p. 6027 - 6032 (2015)
The bacterium Streptomyces coelicolor M145 reacts to transition-metal-ion stress with myriad growth responses, leading to different phenotypes. In particular, in the presence of Co2+ ions (0.7mM) S. coelicolor consistently produced a red phenotype. This phenotype, when compared to the wild type, differed strongly in its production of volatile compounds as well as high molecular weight secondary metabolites. LC-MS analysis revealed that in the red phenotype the production of the prodigiosins, undecylprodigiosin and streptorubin B, was strongly induced and, in addition, several intense signals appeared in the LC-MS chromatogram. Using LC-MS/MS and NMR spectroscopy, two new prodigiosin derivatives were identified, that is, coeligiosin A and B, which contained an additional undecylpyrrolyl side chain attached to the central carbon of the tripyrrole ring system of undecylprodigiosin or streptorubin B. This example demonstrates that environmental factors such as heavy metal ion stress can not only induce the production of otherwise not observed metabolites from so called sleeping genes but alter the products from well-studied biosynthetic pathways. Under stress: Stress caused by many divalent transition metal ions can lead to the formation of diverse phenotypes in Streptomyces coelicolor M145. The red phenotype overproduces prodigiosins and novel prodigiosin derivatives, coeligiosins.
Unimolecular Reactions of Ionized Alkanes
Wendelboe, Jens. F.,Bowen, Richard D.,Williams Dudley H.
, p. 2333 - 2339 (1981)
The unimolecular reactions of several CnH2n+2+. radical cations are discussed in terms of species involving an incipient carbonium ion coordinated to a radical.These species can be formed by stretching the appropriate bond in the ionized alkane.Subsequent isomerization of the incipient carbonium ion can give rise to rearranged structures in which a 1,2-alkyl shift has effectively occurred.By means of such mechanisms, much of the previously reported data concerning decomposition of ionized n-butane can be explained; in particular, the results of 2H-labeling studies can be interpreted.In addition, new labeling data are reported for ionized n-pentane and isopentane; the results indicate that both 1,2-methyl and 1,2-ethyl shifts precede or accompany dissociation of these C5H12+. species.Previously published 13C- and 2H-labeling data on ionized n-heptane are also considered; these results can be uderstood in terms of competing 1,2-methyl, -ethyl, and -propyl shifts.
Chain hydrocarbon substituted isoindoline -1, 3 - diketone PDE4 inhibitor and medicinal use thereof
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Paragraph 0267-0268; 0273-0274, (2021/10/27)
The invention relates to a compound shown I and a racemate thereof. A stereoisomer, a tautomer, an isotope label, a solvate, a polymorph, an ester, a prodrug or a pharmaceutically acceptable salt thereof, and a preparation method thereof, and a medical use thereof, the structure of said formula I being as follows.
Topological study of mechanistic diversity in conjugated fatty acid biosynthesis
Bhar, Palash,Reed, Darwin W.,Covello, Patrick S.,Buist, Peter H.
supporting information; experimental part, p. 6686 - 6690 (2012/08/27)
Variations on an oxidative theme: The precision with which FAD2-type desaturases carry out C-H activation reactions on flexible lipidic substrates is astonishing. The conformational space available within the active site of these enzymes has been explored using deuterium-labeled substrates, and evidence for a novel quasi-eclipsed conformer has been uncovered. The scheme shows some prototypical substrate conformations. Copyright
Synthesis and use of probes to investigate the cryptoregiochemistry of the first animal acetylenase
Abad, Jose-Luis,Rodriguez, Sergio,Camps, Francisco,Fabrias, Gemma
, p. 7558 - 7564 (2007/10/03)
(Chemical Equation Presented) Thaumetopoea pityocampa pheromone glands contain an unusual Δ11 acetylenase that produces an alkynoic fatty acid intermediate in the sex pheromone biosynthetic pathway of this species. In this article, we describe
Structure-property correlations in model compounds of oligomer liquid crystals
Sasanuma, Yuji,Ono, Tetsushi,Kuroda, Yoshihiko,Miyazaki, Emi,Hikino, Ken,Arou, Jun,Nakata, Kohji,Inaba, Hideaki,Tozaki, Ken-Ichi,Hayashi, Hideko,Yamaguchi, Kentaro
, p. 13163 - 13176 (2007/10/03)
Structure-property correlations of the following model compounds for oligomer liquid crystals (LCs) have been investigated: monomers, C 6H5O(CH2)xCH3 (x = 4 and 5); dimers, C6H5O
Facile Preparation of Perdeuteriated Intermediates for the Synthesis of Chain Labelled Thermotropic Liquid Crystals
Lipinski, K.,Lipinska, T.,Suszko-Purzycka, A.,Rykowski, A.
, p. 667 - 672 (2007/10/02)
The preparation of perdeuteriated analogues of carboxylic acids, alcohols and alkyl bromides which have general formula CnD2n+1X (X = COOD, OD, Br; n=3,5,7,8) for use in liquid crystals research is described.Key words: perdeuteriated carboxylic acids, alcohols, alkyl bromides, liquid crystals.
Pseudo One-Step Cleavage of C-C Bonds in the Decomposition of Ionized Carboxyclic Acids. Radical Like Reactions in Mass Spectrometry
Weiske, Thomas,Schwarz, Helmut
, p. 323 - 347 (2007/10/02)
Metastable molecular ions of hexanoic acid (1) decompose unimolecularly to C2H5. and protonated methacrylic acid (5-H+)(92percent rel. abund.).Investigation of the mechanism reveals that 1) the branched cation radical 11 must be regarded as the essential intermediate in the course of the rearrangement/dissociation reaction and 2) the process commences with intramolecular hydrogen transfer from either C-3 or C-5 to the ionized carbonyl oxygen ("hidden" hydrogen migration).Hydrogen transfer from C-4, which would correspond to the well-known McLafferty rearrangement, is of no importance in the C2H5.-elimination from 1.The same conclusion applies for various alternative mechanisms, as for example a SRi type reaction, 1 -> 2-H+.The gas phase chemistry of the cation radical of 1, and in particular the hydrogen exchange processes between the methylene groups C-2/C-3 and C-5/C-6, is in surprisingly close correspondence to the chemistry of free alkyl radicals. - The syntheses of various 13C and 2H-labelled model compounds are described.
The Synthesis of Specifically and Selectively Deuteriated 4,4'-Bisalkoxyazoxybenzene Derivatives
Boden, Neville,Bushby, Richard J.,Clark, Leslie D.
, p. 543 - 551 (2007/10/02)
In connection with deuterium n.m.r. studies of molecular motion in liquid crystals we have developed a number of methods for the synthesis of selectively deuteriated 4,4'-bisalkoxyazoxybenzenes.This paper is concerned with (i) the labelling of specific methylene segments of the alkoxy-chains, (ii) the labelling of the aromatic nucleus, and (iii) the selective enrichment of the deuterium content of one alkoxy-chain relative to the other.Our studies of the n.m.r. spectra of these liquid crystals have shown that there is not (as has sometimes been supposed) a monotonic decrease in C-D quadrupole splitting in passing from the oxygen to the CD3 end of the alkoxy-chain.In -PAA (p-azoxyanisole) we have also shown that the smaller splitting is associated with the CD3O group nearest to the NO end of azoxy-group.Whereas the photorearrangement of azoxy-compounds is normally regiospecific, the photorearrangement of PAA selectively deuteriated in one methoxy-group is unusual in that it leads to isotopically scrambled products.
