Acétolyse d'une diazocétone derivée d'octose: synthése d'une N-acétyllincosamine protégée, de ses epiméres en c-6 et c-7, et d'une 3-oxétanone á chane latérale glucidique

The acetolysis with anhydrous acetic acid of the diazoketone 1, prepared from potassium 1,2:3,4-di-O-isopropylidene-α-D-galacturonate, gave ketoacetates having the D-glycero (3)and L-glycero (5)configuration at C-7, together with the 3-oxetanone 7, a product of pyranose-ring opening. Starting from the ketoacetates 3 and 5, the lincosamine derivative, 6-acetamido-6,8-dideoxy-1,2:,4-di-O-isopropylidene -α-D-erythro-D-galacto-octopyranose (8), and its three diastereoisomers at C-6 and C-7 (9, 10, and 11) were obtained by oximation, reduction, and N-acetylation.

Résumé

L'acétolyse par l'acide acétique anhydre de la diazocétone 1 dérivée du 1,2:3,4-di-O-isopropylidéne-α-D-galacturonate de potassium, donne les céto-acétates deconfiguration D-glycéro (3) et L-glycéro (5) sur C-7, ainsi que la 3-oxétanone 7 qui résulte de l'ouverture du cycle pyranosique. A partir des céto-acétates 3 et 5, on a obtenu, par oximation, réduction et N-acétylation, le dérivé de la lincosamine, 6-acétamido-6,8-didésoxy-1,2:3,4-di-O-isopropylidéne-α-D-érythro-D-galacto-octo-pyranose (8), et ses trois diastéréoisoméres en C-6 et C-7 (9, 10 et 11).     

Biosynthèse de cellulose bactérienne à pertir de glycérol sélectivement deutérié en position 1, 2, ou 3: Etude par résonance magnétique nucléaire

Glycerol specifically deuterated at C-1, C-2, or C-3 was prepared and used for the biosynthesis of bacterial cellulose with Acetobacter xylinum.The material obtained were converted into glucitol hexaacetate and analyzed by 250-MHz nuclear magnetic resonance and mass spectrometry. The spectra indicated that the protons of the C-3 position of the starting glycerol were incorporated as substituents of the C-6 and C-1 positions of the cellulose. Similarly, protons of the C-2 and C-5 positions of the cellulose came essentially from water and the protons bonded at the C-3 and C-4 positions of the cellulose from protons bonded to C-1 of the starting glycerol.     

Sur la stéréospécificité de la ribonucléoside-diphosphate-réductase: préparation de désoxyribonucléosides pyrimidiques deutérés

Methyl 2-deoxy-3,5,6-tri-O-p-nitrobenzoyl- -ribo-hexofuranoside was converted into the glycosyl halide which was then condensed with 2,4-bis(trimethylsilyloxy)-pyrimidine in the presence of mercuric chloride to give, after alkaline methanolysis, 1-(2-deoxy-β- -ribo-hexofuranosyl)uracil, in a yield too low for the reaction to be applied to deuterated compounds. Methyl 2-deoxy- -allofuranoside-2-d was degraded into methyl 2-deoxy- -arabinofuranoside-2-d. Its di-p-nitrobenzoate was converted into the glycosyl halide which was coupled with 2,4-bis(trimethylsilyloxy)-pyrimidine to give, after alkaline hydrolysis, deuterated deoxyuridine. Thiationammonolysis of a mixture of the 3′,5′-di-p-nitrobenzoates of the latter compound and its anomer gave the corresponding deoxycytidines. Comparison of the n.m.r. spectra of these compounds to that of deuterated deoxycytidine, prepared by the enzymic reduction of cytidine 5′-pyrophosphate with the Escherichia coli system in the presence of deuterium oxide confirmed that the substitution of a hydroxyl group by a hydrogen atom proceeds with retention of configuration.     

Réponses électroantennographiques de deux parasitoïdes Ichneumonidés,Diadromus pulchellus et D. collaris,aux odeurs de végétaux,du phytophage-hôte Acrolepiopsis assectella et du partenaire sexuel

Résumé Chez Diadromus pulchellus WSM et D. collaris Gr., Hyménoptères Ichneumonidés parasitoïdes spécialistes des nymphes d'A. assectella lépidoptère inféodé aux Allium, des EAG sont enregistrés en réponse à l'odeur du poireau sain ou attaqué par les larves du phytophage, odeurs actives par ailleurs sur leur comportement locomoteur (cinèses). Le thiosulfinate de dipropyle (Ti-P₂) très spécifique et abondant dans les Allium, et instable, est le mieux perçu par les deux parasitoïdes mais n'a aucun effet locomoteur chez D. pulchellus contrairement aux disulfures et thiosulfonates, plus stables et moins spécifiques. Les propriétés de l'acétate d'éthyle, actif sur l'antenne des deux parasitoïdes, et sur la locomotion de D. pulchellus expliqueraient en partie les activités biologiques du poireau attaqué sur ces parasitoïdes. Des EAG sont aussi obtenus chez les deux espèces avec l'odeur du chou et de composés soufrés plus ou moins spécifiques des Crucifères. Le thiocyanate de méthyle (TCN-M), le plus actif sur l'antenne et seul efficace sur le comportement locomoteur (de D. pulchellus), expliquerait en partie l'installation reconnue de D. collaris sur Plutella maculipennis spécialiste des Crucifères et rend celle de D. pulchelles vraisemblable.L'odeur des larves de dernier stade d'A. assectella est seule efficace sur l'antenne et la locomotion des femelles de D. pulchellus. Les mâles de ce dernier réagissent (EAG, locomotion) à des odeurs de cocons de l'hôte et particulièrement à ceux occupés par une femelle de leur espèce.     

Étude du mécanisme d'établissement des liaisons glutaraldéhyde-protéines

Commercial aqueous 25 per cent glutaraldehyde solutions contain no stable derivative of this aldehyde, but compounds of variable molecular weight which easily revert to glutaraldehyde. The effect of pH on the reaction of glutaraldehyde with amino acids and on the stability of the products under acid conditions, shows the importance of the structure modification of the dialdehyde which occurs when pH increases, and even leads to precipitation in highly alkaline solutions. This precipitate results from aldol condensation of glutaraldehyde molecules. It contains aldehyd groups conjugated with ethylenic double bonds. Such a structure reacts with amino groups to give an imino bond, stabilized by resonance with the ethylenic bond, and does not undergo Michael-type addition reactions.Therefore, glutaraldehyde does not react with proteins under its free form, but as an unsaturated polymer, which gives imino bonds stabilized by conjugation.     

ACTION D'UN CHIMIO-STÉRILISANT,LA THIOURÉE,SUR MUSCA DOMESTICA ADULTE

Résumé La thiourée incorporée à l'alimentation des imagos de Musca domestica entraîne une diminution de la fécondité et de la fertilité qui croît avec la concentration. La dose de 1% provoque une réduction de la ponte de 63% et du pourcentage de nymphose de 14%. Dans les croisements où un des sexes seulement est traité, la réduction de fécondité est supérieure si les femelles sont traitées (51%) plutôt que les mâles (29 et 21%). En outre le produit s'avère plus efficace lorsqu'il est incorporé à du sucre plutôt qu'à du lait. Une modification du rythme de la ponte est observée quand les deux sexes sont traités. Il ne semble pas y avoir de récupération de la fertilité avec le temps. Enfin la toxicité du produit est plus élevée pour les mâles que pour les femelles.

---

Summary When thiourea is incorporated into the diet of adult Musca domestica, the fecundity of crosses decreases with increasing doses. The decrease is about 40%, 52%, 56%, 63%, 69% and 77% respectively for concentrations of 0.25%, 0.50%, 0,75%, 1.0%, 1.5% and for a saturated solution. The decrease varies for a given concentration depending on the direction of the parental cross. The females are more sensitive than the males; at a dose of 1%, when a male parent has been treated, the decrease in fecundity of the female is only 20–29%, compared with up to 56% in crosses where the female parent has been treated. When both sexes have been treated fecundity decreases by 72–84% depending on the type of food given. In fact, the thiourea appears to be more effective when it is incorporated in milk rather than in sugar.Fertility is likewise reduced; the percentage of eggs hatching and larvae emerging decrease from 25 to 50% according to the type of cross made. The larvae are less affected than the eggs and it seems that the thiourea has more effect on the eggs than on larval development. Full fertility is apparently not regained.The rhythm of laying is similarly modified in cases where the two sexes have been treated. Fewer eggs are laid at the beginning of the cycle than at the end; 72% and 42% of the eggs are laid at the end of the cycle in crosses made from individuals fed on sugar and milk respectively.The toxicity of the substance varies according to the sex. The males are more sensitive than the females and their longevity is likewise more affected than that of the females.

     

Solubilisation et caractérisation d'une glycoprotéine : fucosyl-transférase cérébrale

1. A glycoprotein: fucosyl-transferase activity was demonstrated in sheep cerebral cortex, using desialylated fetuin as exogenous acceptor and detergent Trition X 100 for solubilization.

2. Addition of Triton X 100 to the membrane suspension gave first an activation then a solubilization of the cerebral fucosyl-transferase.

3. Hydrophobic chromatography was investigated for purification of the enzyme. Binding was effective using alkyl-agarose chromatographic columns with two or more than two atoms of carbon, but elution was only possible with ethyl and butyl-agarose.

4. Combination of subcellular fractionation and hydrophobic chromatography on ethylagarose led to a 30 fold purification.

5. After ethyl-agarose chromatography, some properties of fucosyl-transferase were studied: the optimal temperature was 25°C. The optimum pH was about neutrality. Light activation was observed with Mn²⁺ concentration below 1 mM.

6. Homogeneity was tested using Ultrogel chromatography, polyacrylamide gel electrophoresis and ultracentrifugation.

7. It was concluded that ethyl-agarose hydrophobic chromatography easily bind a few solubilized proteins (about 20 per cent of the ST supernatant). When elution was performed, these proteins, including fucosyl-transferase, were released from ethyl-agarose columns as a stable aggregate, only dissociated with lower ionic strength.

Ethyl-agarose fraction (eluted with KCl 120 mM) showed homogeneity:

— with Ultrogel AcA 22 chromatography (Mw = 300.000).

— with polyacrylamide gel electrophoresis without S.D.S.

— with the analytical ultracentrifugo giving Mw = 280.000; S₂₀ = 10.

But after dialysis overnight against a buffer without KCl, ultracentrifugation technics showed no homogeneity. Futhermore, SDS gel electrophoresis gave more than four bands.     

ÉTUDE DE LA TEMPÉRATURE CORPORELLE DE LA BLATTE, À TEMPÉRATURE AMBIANTE VARIABLE

Résumé La température interne d'un insecte dictyoptère femelle, Blaberus craniifer Burm., est détectée par une thermistance disposée dans la cavité incubatrice de l'animal. Sa température ambiante est soumise à une variation périodique de faible amplitude. Ce protocole expérimental permet de préciser les phénomènes d'adaptation thermique d'un poïkilotherme.

---

Summary The thermal adaptation of Blaberus craniifer (Insecta Dictyoptera) was studied. The body-temperature measurements were made on the animal kept in a regulated box. Simultaneously we recorded the temperature of a similar box as a control. Both boxes were submitted to a pseudosinusoidal variation of temperature of low amplitude.The analysis of the curves obtained shows that variation of the body temperature is dephased and damped in comparison with the control box temperature. When the animal is previously killed the dephasing decreases and the damping increases.An increase of thermal inertia in the living insect is also observed.

     

Préparation et dosage immunonéphélémétrique du fibrinogène de lapin

Pure rabbit fibrinogen was prepared by a method involving two ammonium sulfate precipitations, one 2 M phosphate buffer precipitation, one DEAE cellulose chromatography and lastly one Sepharose 6 B chromatography. The aminoacid composition was determined and an immunonephelemetric assay was proposed. This assay allowed an accurate determination of fibrinogen concentration in a rabbit with inflammatory reaction.     

Upslope movements and large scale expansions: the taxonomy and biogeography of the Coenonympha arcania –C. d arwiniana –C. gardetta butterfly species complex

Sibling species groups are suitable models for the understanding of inter‐ and intraspecific processes in taxonomy and biogeography. We analysed 262 individuals from the Alps of the Coenonympha arcania/gardetta species complex by allozyme electrophoresis. These taxa showed high variance amongst populations (F_ST: 0.391) and strong intertaxon genetic differentiation (F_CT: 0.376). Although morphologically similar, Coenonympha gardetta and Coenonympha arcania clearly differ in their genetic characteristics; the morphologically intermediate taxa Coenonympha darwiniana darwiniana and Coenonympha darwiniana macromma are genetically well distinguished from each other and the two other taxa. Coenonympha arcania and C. d. macromma most probably share a common ancestor and evolved by cladogenesis, whereas the taxonomic situation of C. d. darwiniana is still unresolved: This taxon might be the result of hybridization between C. arcania and C. gardetta or it might have a common ancestor together with C. gardetta. We suggest species rank for all four taxa. The distribution of genetic diversity of these populations and the differentiation amongst populations suggest rather different biogeographical scenarios: C. arcania most probably is of Mediterranean origin with postglacial range expansion northwards; C. gardetta survived the last ice age in peripheral refugia of the Alps and has spread all over this high mountain system in the postglacial; C. darwiniana and C. macromma survived the Würm in geographic proximity to their actual distribution areas and only have performed moderate uphill translocations during postglacial warming. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 890–904.     

Conséquences du traitement préalable par le précocène 2 sur les réponses du criquet migrateur,Locusta migratoria, à un apport en hormone juvénile exogène

Un apport unique de 10 g d'hormone juvénile 1, réalisé chez des criquets du dernier stade larvaire à corpora allata intacts ou préalablement soumis à une application de precocène 2, provoque, à la mue suivante, l'apparition d'individus dont les caractéristiques sont intermédiaires entre celles du dernier stade larvaire et celles de l'imago. Cependant, les criquets traités par le précocène 2 présentent des variations phénotypiques plus prononcées, se traduisant par un maintien accru des caractéristiques larvaires. Les études ultrastructurales montrent que les corpora allata dégénèrent rapidement sous l'action des 400 g de précocène 2.

---

Summary In fifth instar locusts, with intact corpora allata or previously subjected to precocene 2 action, a single injection of 10 g juvenile hormone 1 leads, at the next molt, to the appearance of individuals displaying characters ranging from the typical larval to the typical imaginal ones. But, unexpectedly, the phenotypic variations are more marked in the precocene 2 treated locusts, and are typified by an increased retention of larval characters. Electron microscopic studies indicate that the use of 400 g of precocene 2 rapidly leads to the degeneration of the corpora allata.