Polyélectrolytes optiquement actifs à hydrophobie variable, 1. Copolymères amide‐acide acryliques obtenus par hydrolyse contrǒlée des (±), (+) et (−) poly[N‐(sec‐butyl)‐N‐méthyl‐acrylamides]

Braud, Christian; Vert, Michel

doi:10.1002/macp.1974.021750307

Cited by 19 publications

(6 citation statements)

References 12 publications

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“…Type 0 poly(L-malate) had been previously chemically synthesized and characterized (Vert & Lenz, 1979; Braud et al, 1982Braud et al, , 1985Braud & Vert, 1983;Guerin et al, 1986;Ohuchi, 1985). A sample was obtained from Dr. Vert, Rouen.…”

Section: Resultsmentioning

confidence: 99%

An unusual polyanion from Physarum polycephalum that inhibits homologous DNA-polymerase .alpha. in vitro

Fischer¹,

Erdmann²,

Holler³

1989

Biochemistry

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From extracts of microplasmodia of Physarum polycephalum and their culture medium, an unusual substance was isolated which inhibited homologous DNA polymerase alpha of this slime mold but not beta-like DNA polymerase and not heterologous DNA polymerases. Analysis, especially NMR spectroscopy, revealed the major component to be an anionic polyester of L-malic acid and the inhibition to be due to poly(L-malate) in binding reversibly to DNA polymerase alpha. The mode of inhibition is competitive with substrate DNA and follows an inhibition constant Ki = 10 ng/mL. Inhibition is reversed in the presence of spermine, spermidine, poly(ethylene imine), and calf thymus histone H1. According to its ester nature, the inhibitor is slightly labile at neutral and instable at acid and alkaline conditions. Its largest size corresponds to a molecular mass of 40-50 kDa, but the bulk of the material after purification has lower molecular masses. The inhibitory activity depends on the polymer size and has a minimal size requirement.

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Section: Resultsmentioning

confidence: 99%

An unusual polyanion from Physarum polycephalum that inhibits homologous DNA-polymerase .alpha. in vitro

Fischer¹,

Erdmann²,

Holler³

1989

Biochemistry

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“…PMLA is readily water-soluble and is hydrolyzed very fast in aqueous environment, unless special precautions are taken. The hydrolysis of synthetic PMLA has been extensively studied by Braud and Vert . Blocking the carboxylic side groups of PMLA has been a strategy conveniently used to modify its properties and simultaneously to slow hydrolysis.…”

Section: Introductionmentioning

confidence: 99%

Thermal Decomposition of Fungal Poly(β,l-malic acid) and Poly(β,l-malate)s

et al. 2006

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The thermal decomposition of poly(beta,l-malic acid), poly(alpha-methyl beta,l-malate), and ionic complexes of the polyacid with alkyltrimethylammonium salts was studied by TGA, GPC, and FTIR and NMR spectroscopy. It was found that poly(beta,l-malic acid) depolymerized above 200 degrees C by an unzipping mechanism with generation of fumaric acid which is then partially converted in a mixture of maleic acid and anhydride. On the contrary, random scission of the main chain was found to happen in the thermal decomposition of poly(alpha-methyl beta,l-malate). On the other hand, ionic poly(beta,l-malate)s degraded through a well defined three-stage process, the first one being depolymerization of the poly(malate) main chain along with decomposition of the ionic complex. Decomposition of the previously generated alkyltrimethylammonium salts followed by unspecific cracking of the resulting nitrogenated compounds happened at higher temperatures. Mechanisms partially explaining the decomposition processes of the three studied systems were proposed according to collected data.

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“…The molecular composition of the PMLABeH copolymers is characterized by the presence of benzylated malic acid units in the polymer chain. To assess the effect of the benzyl ester function on the degradation of the copolymers, the data were compared with those for the PMLA homopolymer, provided from previous studies [20,21]. Prior to making such a comparison it should be mentioned that an exact comparis9n of the degradation data from different experiments is not possible due to effects from different experimental conditions on the degradation rate.…”

Section: Resultsmentioning

confidence: 99%

Nanospheres prepared from poly(?-malic acid) benzyl ester copolymers: evidence for their in vitro degradation

Stolnik

Garnett

Davies

et al. 1996

J Mater Sci: Mater Med

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The in vitro degradation of nanospheres perpared from three benzyl ester derivatives of poly (13-malic acid) containing 80, 90 and 100% of benzylated malic acid units was studied. The progressive decrease in the molecular weight of the copolymers was observed as the nanospheres degraded, demonstrating that the degradation under the experimental conditions occurred by a simple hydrolytic cleavage of the ester bond between the monomeric units. The degradation was slow, with the weight average molecular weight decreasing to about 70% of the initial value in 5 months for all the nanosphere systems. A comparison of degradation rates for benzyl ester copolymers with the degradation rate of poly (13-malic acid) homopolymer demonstrated a decreased degradation rate of benzylated copolymers which suggests that the introduction of a pendent benzyl ester function in proximity to the ester bond in the main chain, reduces the rate of the bond cleavage. No significant difference in the degradation behaviour of highly benzylated copolymers, containing 90 and 80% of benzylated malic acid units, and fully benzylated polymer could be detected to prove an autocatalytic role on degradation of the free pendent carboxyl group in the former two copolymers.

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Polyélectrolytes optiquement actifs à hydrophobie variable, 1. Copolymères amide‐acide acryliques obtenus par hydrolyse contrǒlée des (±), (+) et (−) poly[N‐(sec‐butyl)‐N‐méthyl‐acrylamides]

Cited by 19 publications

References 12 publications

An unusual polyanion from Physarum polycephalum that inhibits homologous DNA-polymerase .alpha. in vitro

An unusual polyanion from Physarum polycephalum that inhibits homologous DNA-polymerase .alpha. in vitro

Thermal Decomposition of Fungal Poly(β,l-malic acid) and Poly(β,l-malate)s

Nanospheres prepared from poly(?-malic acid) benzyl ester copolymers: evidence for their in vitro degradation

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