616-01-3Relevant articles and documents
Synthesis of 14C-labeled FAD-C44
Bieniarz, Christopher,Ramakrishna, Kornepati V.,Kelly, Terence P.
, p. 243 - 250 (2000)
Synthesis of 14C-labeled FAD-C44 1 at the tertiary carbon by the dimerization of 14C labeled erucic acid 2 is described. Labeling at the C-14 position of erucic acid is achieved by a convergent approach involving the Wittig coupling
Programmable Assembly of Peptide Amphiphile via Noncovalent-to-Covalent Bond Conversion
Sato, Kohei,Ji, Wei,Palmer, Liam C.,Weber, Benjamin,Barz, Matthias,Stupp, Samuel I.
, p. 8995 - 9000 (2017)
Controlling the number of monomers in a supramolecular polymer has been a great challenge in programmable self-assembly of organic molecules. One approach has been to make use of frustrated growth of the supramolecular assembly by tuning the balance of attractive and repulsive intermolecular forces. We report here on the use of covalent bond formation among monomers, compensating for intermolecular electrostatic repulsion, as a mechanism to control the length of a supramolecular nanofiber formed by self-assembly of peptide amphiphiles. Circular dichroism spectroscopy in combination with dynamic light scattering, size-exclusion chromatography, and transmittance electron microscope analyses revealed that hydrogen bonds between peptides were reinforced by covalent bond formation, enabling the fiber elongation. To examine these materials for their potential biomedical applications, cytotoxicity of nanofibers against C2C12 premyoblast cells was tested. We demonstrated that cell viability increased with an increase in fiber length, presumably because of the suppressed disruption of cell membranes by the fiber end-caps.
Membrane-interacting properties of the functionalised fatty acid moiety of muraymycin antibiotics
Ries, Oliver,Carnarius, Christian,Steinem, Claudia,Ducho, Christian
, p. 879 - 886 (2015)
Functional insights into bioactive natural products with medicinal potential are often hindered by their structural complexity. We herein report a simplified model system to investigate the functional significance of a structural motif of biologically potent muraymycin antibiotics of the A-series. These compounds have a highly unusual ω-guanidinylated fatty acid moiety, which has been proposed to mediate membrane penetration, thus enabling the interaction of A-series muraymycins with their intracellular target MraY. Our assay was based on a synthetic conjugate of this fatty acid structure with a negatively charged fluorophore lacking membrane permeability. Using this conjugate, immobilised giant unilamellar lipid vesicles and confocal laser scanning fluorescence microscopy, we demonstrated that the attachment of the ω-N-hydroxy-guanidinyl fatty acid unit led to an enhanced uptake of the fluorophore into the vesicles. This represents the first experimental evidence of this unusual structural motif's functional relevance for the parent natural product, which may support the future design of novel muraymycin analogues.
Structural and solubility parameter correlations of gelation abilities for dihydroxylated derivatives of long-Chain, naturally occurring fatty acids
Zhang, Mohan,Selvakumar, Sermadurai,Zhang, Xinran,Sibi, Mukund P.,Weiss, Richard G.
supporting information, p. 8530 - 8543 (2015/06/02)
Creating structure-property correlations at different distance scales is one of the important challenges to the rational design of molecular gelators. Here, a series of dihydroxylated derivatives of long-chain fatty acids, derived from three naturally occurring molecules - oleic, erucic and ricinoleic acids - are investigated as gelators of a wide variety of liquids. Conclusions about what constitutes a more (or less!) efficient gelator are based upon analyses of a variety of thermal, structural, molecular modeling, and rheological results. Correlations between the manner of molecular packing in the neat solid or gel states of the gelators and Hansen solubility data from the liquids leads to the conclusion that diol stereochemistry, the number of carbon atoms separating the two hydroxyl groups, and the length of the alkanoic chains are the most important structural parameters controlling efficiency of gel formation for these gelators. Some of the diol gelators are as efficient or even more efficient than the well-known, excellent gelator, (R)-12-hydroxystearic acid; others are much worse. The ability to form extensive intermolecular H-bonding networks along the alkyl chains appears to play a key role in promoting fiber growth and, thus, gelation. In toto, the results demonstrate how the efficiency of gelation can be modulated by very small structural changes and also suggest how other structural modifications may be exploited to create efficient gelators.
Fe-catalyzed one-pot oxidative cleavage of unsaturated fatty acids into aldehydes with hydrogen peroxide and sodium periodate
Spannring, Peter,Yazerski, Vital,Bruijnincx, Pieter C. A.,Weckhuysen, Bert M.,Klein Gebbink, Robertus J. M.
, p. 15012 - 15018 (2013/11/06)
A one-pot method has been developed for the oxidative cleavage of internal alkenes into aldehydes by using 0.5mol % of the nonheme iron complex [Fe(OTf)2(mix-bpbp)] (bpbp=N,N'-bis(2-picolyl)-2,2'-bipyrrolidine) as catalyst and 1.5equivalents of hydrogen peroxide and 1equivalent of sodium periodate as oxidants. A mixture of diastereomers of the chiral bpbp ligand can be used, thereby omitting the need for resolution of its optically active components. The cleavage reaction can be performed in one pot within 20h and under ambient conditions. Addition of water after the epoxidation, acidification and subsequent pH neutralization are crucial to perform the epoxidation, hydrolysis, and subsequent diol cleavage in one pot. High aldehyde yields can be obtained for the cleavage of internal aliphatic double bonds with cis and trans configuration (86-98 %) and unsaturated fatty acids and esters (69-96 %). Good aldehyde yields are obtained in reactions of trisubstituted and terminal alkenes (62-63 %). The products can be easily isolated by a simple extraction step with an organic solvent. The presented protocol involves a lower catalyst loading than conventional methods based on Ru or Os. Also, hydrogen peroxide can be used as the oxidant in this case, which is often disproportionated by second- and third-row metals. By using only mild oxidants, overoxidation of the aldehyde to the carboxylic acid is prevented. Copyright
Synthesis of N-alkyl-N-hydroxyguanidines: A comparative study using different protecting group strategies
Ries, Oliver,Ochmann, Anne,Ducho, Christian
, p. 2357 - 2368 (2011/09/20)
Representing a prime example of the interesting structures found in natural products, the N-alkyl-N-hydroxyguanidine moiety has so far only found limited attention in synthetic organic chemistry. Our studies on Streptomyces-produced muraymycin nucleoside
Erucic acid, a cheap source of synthetic pheromones
Subbaraman, A S,Mithran, S,Mamdapur, V R
, p. 865 - 866 (2007/10/02)
Easily accessible starting materials, viz. aleuritic acid, tetrahydrofurfuryl alcohol, propargyl alcohol and undecenoic acid have earlier been used by us for the synthesis of a large number of insect pheromones.We now report that erucic acid (1), a major component of mustard oil, is yet another cheap starting material for the synthesis of pheromones (Ia and Ib) of sugarcane internode moth, Chilo sacchariphagus and mascalure (II), the pheromone of housefly, Musca domestica.
