Alcaloides d'Alstonia lanceolifera

From the aerial parts of Alstonia lanceolifera six alkaloids were isolated and identified: O-trimethoxycinnamoylvincamajine, O-trimethoxy-cinnamoyl-10-methoxyvincamajine, O-trimethoxycinnamoyl-10-hydroxyvincamajine, O-trimethoxybenzoylhydroxyvincamajine, 10-methoxyvincamajine, N(a)-methyl-10-methoxyakuammidine. These alkaloids are new compounds, except for the first. The position of aromatic substituents was determined by study of the Nuclear Overhauser Effect (N.O.E.) in the NMR spectra.     

Composes halogenes d'une algue rouge,Falkenbergia rufolanosa tetrasporophyte d' Asparagopsis armata

Water extraction of fresh Falkenbergia rufolanosa followed by water-ether partition, yielded halomethanes, polyhalo ethyl and methyl acetates and especially polyhalo acetones. It is the first example of polyhalo compounds extracted from a tetrasporophyte in the Bonnemaisoniaceae.     

Note preliminaire concernant la decouverte d'une faune et d'une flore du niveau de Ronzon dans l'Oligocene inferieur du Bassin d'Aquitaine

The new locality of Ruch (Gironde), from a lateral facies of the “Calcaire de Castillon” formation has yielded an important flora and fauna. From the biostratigraphic point of view the mammalian fauna allows to show that Ruch is contemporaneous of the reference locality of Ronzon (Auvergne).     

Trietrpenoides d'Agauria salicifolia

3-acetylmorolic acid, 3-acetylmoradiol, 3-acetylmoraldehyde, taraxerol, taraxerone, sitosterol and agauriasterone, an isomer of nor-31-lanosterone, have been isolated from the methanolic extract of the bark of Agauria salicifolia.     

Alcoxyhalogenation d'acides gras acetyleniques vrais ou disubstitues

Reaction of t-butyl hypobromite (HBBT) with true or disubstituted acetylenic fatty acids leads to the formation of gemdimethoxy gemdibromides, resulting from the addition of two mol of HBBT upon each mol of substrate. Neither digemmethoxybromide nor vinylic methoxybromide, resulting from the addition of only one mol of HBBT, are formed.If the triple bond is a terminal one, only the Markovnikov addition compound is formed but if the triple bond is located in the middle of the chain, the both possible isomers are present.     

Du probleme de l'origine des Dinosauriens d'apres les donneesde l'ichnologie du Trias

With the data of the osteological paleontology and these of the ichnology, the authors attempt to restore the biotopes where lived the trackmakers, biotopes which have favoured in the Triassic the evolution and the expansion of the Archosaurs, the specialized Reptiles in the easy and rapid locomotion. They pointed out that the chirotheroid footprints cannot be attributed at all events to the Pseudosuchians and they come to the conclusion that Dinosaurs and Pseudosuchians, as separated groups, are appeared as early as the lower Triassic.     

Epistreptophyllum (Hexacorallaire Jurassique), genre colonialou solitaire? examen d'un matériel nouveau d'Israel

Epistreptophyllum, a rather common coral in the Middle and Late Jurassic of Europe and Asia, is generally regarded as solitary. Some specimens collected in Late Callovian beds of the northern Negev, Israel, show genuine branching which would suggest a colonial habit for this genus. Eventual convergence between the genera Epistreptophyllum, Haplaraea and Diplaraea is presumed.     

Winwaloeusia,genre nouveau d'Acritarche du Devonien

Any Acritarchs that previously were included in the genus Veryhachium (DEUNFF 1954) are transferred in the new genus Winwaloeusia.     

Sur les conditions de gisement de l'ichthyofaune oligocene d'Aix-en-Provence (Bouches-du-Rhone): Essai de definition d'un modele paleoecologique et paleogeographique

The study of the fossil fishes preserved in 19 successive fossiliferous beds sampled while excavating in the city ofAix-en-Provence permits the elaboration of a sedimentary model for the Oligocene gypsiferous marls. These seem to have been deposited on a coastal plain, in continental waters characterized by a fluctuating, very low, salt-content.     

Composes phenoliques du latex d'Hevea brasiliensis: aglycones

The latex of Hevea brasiliensis; clone PR 107, contains from 160 to 1100 μg total phenolics per ml. This wide variability is associated with season, tapping system and application or not of a stimulant (Ethrel). The following aglycones have been identified in hydrolysed extracts: vanillic, salicyclic, syringic, gentisic, p- and m-hydroxybenzoic and protocatechuic acids; scopoletin, aesculetin and coumarin; ferulic, sinapic, caffeic, o- and p-coumaric acids; quercetin and kaempferol; tyrosine and dihydroxyphenylalanine. Flavans and condensed tannins are also present in latex.     

Premiere decouverte d'une faune de petits mammiferes dans le Paleogene du bassin d'Aurillac (Cantal): Implications stratigraphiques

The so-called “série carbonatée” of Aurillac-Arpajon basin is generally ascribed to the upper Oligocene; a newlydiscovered micrommalian fauna shows that the basis of this sequence is really older and at least of a middle oligocene age.     

Regulation d'activité de l'α-Amylase à différentes températures d'adaptation et en fonction de l'ablation des pédoncules oculaires et du stade de mue chez Palaemon serratus

The influence of thermal acclimatisation of the shrimp Palaemon serratus on the specific activity of α-amylase and the soluble proteins of the hepato pancreas show the presence of a metabolic compensation kinetic within this organ. The kinetic properties of partially purified α-amylase show that 2 sites are able to fix starch in the absence of NaCl but only 1 site when NaCl is present. The importance of conformational changes of the enzyme is shown by examining its regulatory properties according to the different temperatures of adaptation, and to the removal of eyestalks and the molt cycle. During these changes there are no qualitative variations in α-amylase isoenzymes.     

Isoenzymes de l'anhydrase carbonique d'un poisson euryhalin: Variations en relation avec l'osmoregulation

A chemical study of carbonic anhydrase (EC 4.2.1.1) from the red blood cells and the gills of an euryhaline fish (Anguilla anguilla) is presented. Animals adapted to fresh water were compared to those adapted to sea water.The physicochemical constants of the various molecular forms isolated by chromatograhy and isoelectric focusing were determined; isoeleletric pH, molecular weight, and the K_m and V/E of the enzyme dehydration activity were compared.In both red cells and gills of fish adapted in either media various forms were isolated, characterized by different enzymatic kinetics (high- and low-activity forms) but having the same molecular weight (27 250). Some isoenzymes isolated from the gills differed significantly from those isolated from the red cells.Adaptation to fresh water or sea water is accompanied by modifications in the distribution of yhe isoenzymes in both red cells and gills: adaptation to sea water is characterized by a shift of the molecular forms towards an isoelectric pH higher than pH = 6.The role of these enzymes is discussed under both a physiological and biochemical point of view in relation to the electrolyte exchange across fish gill. The origin of the different molecular forms of the carbonic anhydrase is discussed in relation to the prevailing theories on this subject.     

Alcaloïdes d'Ochrosia miana: Ochromianine et Ochromianoxine

The structure of ochromianine and ochromianoxine two new alkaloids isolated from the barks of Ochrosia miana are deduced from spectral analysis.