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Simon-Colin C.,French Research Institute for Exploitation of the Sea | Gouin C.,French Research Institute for Exploitation of the Sea | Lemechko P.,French Research Institute for Exploitation of the Sea | Lemechko P.,CNRS East Paris Institute of Chemistry and Materials Science | And 2 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences

A new gas chromatography-mass spectrometry (GC-MS) method for the localization of double bond in monounsaturated 3-hydroxyalkenoic acids monomers has been developed. A three steps derivation assay was used including a methanolysis, then acetylation and dimethyldisulfide (DMDS) addition to alkene groups. Electron impact GC-MS analysis of such derivatives offers characteristic fragments allowing the unambiguous determination of double bond position in side chain. This novel method is well-suited for the routine analysis of poly-beta-hydroxyalkanoates (PHAs), and was used to characterize monounsaturated monomers in both 3-hydroxyalkenoic acids standards as well as in mcl-PHAs and poly(3-hydroxyoctanoate-. co-3-hydroxyundecenoate) (PHOU) produced by bacterial strain . Pseudomonas guezennei from glucose or a mixture of sodium octanoate plus 10-undecenoic acid, respectively. © 2012 . Source

Delaye P.-O.,CNRS Institute of Molecular Chemistry - Reims | Lameiras P.,CNRS Institute of Molecular Chemistry - Reims | Kervarec N.,Service Communications de RMN RPE | Mirand C.,CNRS Institute of Molecular Chemistry - Reims | Berber H.,CNRS Institute of Molecular Chemistry - Reims
Journal of Organic Chemistry

An improved enantioselective total synthesis of (?)-linderol A has been achieved via a five-step reaction with a 21% overall yield, starting from phloroacetophenone and (?)-α-phellandrene, two commercially available reagents. In the diastereoselective epoxidation step, the analysis of the two endocyclic epoxide intermediates reveals a hindered sp2?sp 3 rotation, which results in rotational diastereoisomers. © 2010 American Chemical Society. Source

Roger B.,Societe Phytotagante | Jeannot V.,Societe Phytotagante | Fernandez X.,CNRS Institute of Chemistry | Cerantola S.,Service Communications de RMN RPE | Chahboun J.,Societe Phytotagante
Phytochemical Analysis

Introduction Iris resinoid obtained from Iris germanica or Iris pallida rhizomes is widely used in the perfume industry but its chemical composition has not yet been reported. Nevertheless, very active compounds have been identified in iris rhizomes including iridals and isoflavones. Objective In this first study concerning iris resinoid composition, flavonoids were qualitatively and quantitatively investigated in I. germanica and I. pallida resinoids. Methodology Resinoids were first fractionated by reverse-phase flash chromatography in order to obtain fractions containing all isoflavones. These fractions were analysed by HPLC-DAD (diode array detector) and the fractions containing isoflavones were analysed by HPLC-QTOF (quadrupole time of flight)-MS. Then, the main isoflavones were isolated and identified by NMR and high-resolution mass spectroscopy (HRMS). Finally, total and individual isoflavones were quantified by HPLC-DAD at 265 nm using an external calibration method with irigenin as the external standard. Results Eight isoflavones were identified in both resinoids (irigenin, iristectorigenin A, nigricin, nigricanin, irisflorentin, iriskumaonin methyl ether, irilone, iriflogenin), one isoflavone only was identified in I. germanica resinoid (irisolidone), whereas one isoflavone (8-hydroxyirigenin), one isoflavanone (2,3-dihydroirigenin) and one benzophenone (2,6,4'-trihydroxy-4-methoxybenzophenone) only were identified in I. pallida resinoid. Isoflavones were quantified in I. germanica and I. pallida resinoids at 180 ± 1.6 mg/g and 120 ± 3.3 mg/g respectively. Conclusion The study shows that I. germanica and I. pallida resinoids are rich in flavonoids and that these two Iris species can be distinguished by simply analysing the polyphenol fraction. Copyright © 2011 John Wiley & Sons, Ltd. Source

Simon-Colin C.,French Research Institute for Exploitation of the Sea | Gouin C.,French Research Institute for Exploitation of the Sea | Lemechko P.,French Research Institute for Exploitation of the Sea | Lemechko P.,CNRS East Paris Institute of Chemistry and Materials Science | And 4 more authors.
International Journal of Biological Macromolecules

The biosynthesis of medium chain length poly(3-hydroxyalkanoates) mcl PHAs by Pseudomonas guezennei using glucose, sodium octanoate, and 10-undecenoic acid as sole or mixed carbon sources was investigated. Chemical composition of polyesters was analyzed by GCMS and NMR. The copolyester produced by P. guezennei from glucose mainly consisted of 3-hydroxyoctanoate and 3-hydroxydecanoate, and the presence of 3-hydroxydodec-5-enoate was demonstrated. Using sodium octanoate as the sole nutrient, the microorganism produced a poly(3-hydroxyoctanoate) (PHO) polymer containing up to 94mol% 3-hydroxyoctanoate. Biosynthesis of poly[(3-hydroxyoctanoate)-co-(3-hydroxyundecenoate)] (PHOU) copolymers bearing terminal reactive double bonds on its side chains with unsaturation degree ranging from 8.8% to 78.2% was obtained by tuning the ratio of sodium octanoate/10-undecenoic acid in the medium. Thermal analysis indicated semi-crystalline polymers with melting temperatures (Tm) ranging from 46 to 55°C, fusion enthalpy (ΔH) comprised between 3 and 35J/g and glass transition temperature (Tg) from -36 to -44°C, except for the highly amorphous 78.2% unsaturated PHOU with a low Tg (-50°C). Molecular weights determined by GPC ranged from 119000 and 530000g/mol. The biosynthesis of natural polyesters with controlled ratio of vinyl-terminated side chains is of great interest for further chemical modifications. © 2012 Elsevier B.V. Source

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