POST-LUMINESCENCE DES CHLOROPLASTES INTACTS ET ALTERES PAR DENATURATION PARTIELLE: ETUDE EXPERIMENTALE, INTERPRETATION THEORIQUE ET CALCUL D'ENERGIES D'ACTIVATION

Abstract— The authors have studied the temperature effect on the luminescence of spinach chloroplast suspension after illumination at 675 nm.
The decay of the luminescence has been followed at constant temperature (from 0°C to 40°C) or after sudden temperature jumps (0°C ≤Δ T ≤ 47°C).
They have compared the results obtained with intact chloroplasts and those after mild thermal denaturation.
From these experimentally found values they have calculated the activation energies related to the radiative and non-radiative ways of disappearence of the entity which is at the origin of the luminescence.
On the basis of the values found for these energies (0·9 eV and 0·43 eV respectively), the authors evolve the hypothesis that this entity may be an electron self-trapped in the chloroplast structure (small polaron).     

ETUDE PAR RESONANCE PARAMAGNETIQUE ELECTRONIQUE DE LA PHOTOSENSIBILISATION DES ACIDES AMINES PAR LA PROFLAVINE

Abstract— –The photosensitization of amino acids by proflavine is studied using the technique of electron spin resonance spectroscopy. The analysis of the line shape as a function of the incident microwave power (both in the presence and absence of oxygen) and the dependence of the numbers of free radicals on the intensity of the incident light allow one to suggest that two types of radicals are formed. One is formed by a biphotonic process, the nature of the radicals being the same as in the case of ionising radiation, while the other is probably the RO₂ radical formed as a result of photodynamic action.     

OXAZOLIDONES ET DIOXOLONNES DU GERMANIUM (IV) ET (II) DU PHOSPHORE (III), DE L'ARSENIC (III) ET DU SOUFRE

Abstract

Diffèrents modes de synthèse d'oxazolidones 1.2.4-7 et de dioxolonnes 8-11 germaniées sont décrites.

La stabilité thermique de germadioxolonnes a été étudiée. La décomposition procède d'un méchanisme du type (2 + 2 + 1), avec ouverture du cycle et formation de germylène.

La réactivité chimique des oxazolidones et dioxolonnes germaniées a été étudité. Des réactions d'échange avec des dérives organominéraux dichlorés conduit facilement et avec de bons rendements aux derives isologues, phosphorés(III). arseniés(III), soufrés. ou germaniés(IV). La réaction d'échange entre une dioxolonne germaniée et le dichlorogermylène nous a permis d'obtenir un nouveau germylène fonctionnel cyclique stable 20 qui a été caractérisé par spectrographie (RMN ¹H. masse).

Different synthetic ways for germaoxazolidones 1.2.4-7 or dioxolonnes 8-11 have been described.

The thermal stability of germadioxolonnes has been studied. Decomposition occurs by a [2 + 2 + 1] ring opening with formation of germylene.

The chemical reactivity of germaoxazolidones or dioxolonnes has been studied. Exchange reactions with dihalogenated covalent compounds occur readily lcading to phosphorus(III). arsenic(III). sulphur or germanium(IV) analogs.

From dichlorogermylene, new stable fonctionnal cyclic germylene 20 is obtained and characterized.     

SEPARATION ET CARACTERISATION SPECTROSCOPIQUE DU MONOMERE ET DES POLYMERES DE LA C. PHYCOCYANINE.*

Abstract— Monomer, trimer and hexamer states of C. Phycocyanin chromophore protein have been isolated. Owing to a very slow approach to equilibrium mixing, it has been possible to estimate the number of each type of the two chromophores ‘s’; and ‘f’ present, using a fluoros-cence polorization method. It is found that there is one s chromophore and one f chromophore per protein monomer of molecular weight 30,000, a value in agreement with the monomer mol. wt. determined by Berns et al and by thermodynamic measurements in this laboratory. Absorption and fluorescence spectra of hexamer and monomer solutions have been compared. The hexamer solution shows greater fluorescence than the monomer solution, a phenomenon that may be attributable to a change in environment of chromophore following polymerization, with consequent change of fluorescence yield of each chromophore type and/or variation in energy transfer between them.     

ETUDE PAR FLUORESCENCE DE BASES DE SCHIFF DU PYRIDOXAL, COMPARAISON AVEC LA L ASPARTATE-AMINOTRANSFERASE

Abstract— –Absorption and emission spectra of Schiff bases of pyridoxal-HCI or pyridoxal-5-phosphate with L-valine, n -butylamine or N-α-acetyl-L-lysine-N-methylamide have been studied as a function of pH. We can write the complete ionization diagram and equilibria. The results of Martell[6] are confirmed: the forms analogous to the coenzyme in aspartate aminotransferase, which absorb at 410 nm and 360 nm (or 340 nm for the Schiff base with n-butyl-amine) have the phenol OH ionized; the imine nitrogen is protonated for species absorbing at 410nm (in the enzyme: inactive form and complex with aminoacid) and unprotonated for species absorbing at 360 nm (in the enzyme, active form). Their fluorescence wavelengths are respectively 500 nm and 430 nm. Protonation of the pyridine nitrogen of these forms does not shift the absorption band; the fluorescence intensity is 20-fold greater for the N-protonated forms.
The real pK of the imine nitrogen is 8.5 ±0.8 for species with pyridine N-protonated or 10.4 for the non-protonated forms. The observed pK 6.3 in the enzyme can be explained if the imine nitrogen is hydrogen bonded to an amino-acid side chain of the protein: lysine, tyrosine, serine, sulfhydryl.
The quantum yield of the coenzyme fluorescence in the enzyme has been compared to that of the analogous Schiff base (absorbing at the same wavelength). According to the results, we cannot deduce whether the pyridine nitrogen is protonated in pyridoxal form of the enzyme.
If it is protonated, as in the pyridoxamine form, the coenzyme environment is not the same in the two forms. If the pyridine nitrogen is unprotonated in the pyridoxal form and protonated in the pyridoxamine form, the environment of the coenzyme is the same in these two forms of the enzyme.     

TELOMERISATION PAR CATALYSE REDOX IX ADDITION DE TELOGENES PHOSPHORES SUR DES COMPOSES POSSEDANT DEUX DOUBLES LIAISONS NON CONJUGUEES

Abstract

The synthesis of telechelic oligomers with phosphorated end groups was realized by redox catalysis telomerization reaction by addition of phosphorated telogens containing a trichloromethyl group on monomers with two non-conjugated double bonds.

Nous effectuons la synthèse d'oligoméres téléchéliques à extrémités phosphorées en additionnant au moyen de la réaction de télomerisation par catalyse Redox des télogènes phosphorés renfernant le groupement trichlorométhyle, sur des monomères à deux doubles liaisons non conjuguées.     

ETUDE STRUCTURALE DU(N,N-DIMETHYLAMINOCARBONYL-l-METHOXYCARBONYL-2-ETHENYL(Z))-2-OXO-2-TETRAMETHYL- 4,4,5,5-DIOXAPHOSPHOLANE-1,3,2. PHENOMENE DE PREFIGURATION A L'ETAT SOLIDE D'UN INTERMEDIAIRE REACTIONNEL PENTACOORDINE

Abstract

Phosphonate 2 is obtained by hydrolysis of the spirophosphorane 1. IR. ¹H and ³¹P NMR spectra confirm the phosphonate structure. However, one question remains about the relative position of the amide group and ester function relative to the phosphonate group. We resolved this difficulty through X-ray crystallography of 2.

Phosphonate 2 structure shows a slightly distorted figure of the spirophosphorane 1 of which it comes from. This observation is quite astonishing because of the many possible carbonyl positions of the new ester function. We can reasonably rationalize this phenomenon as the prefiguration of a pentacoordinated chemical intermediate which permits to explain easily the opposite reaction for the P_IV → P_v way. So, phosphonate 2 structure is in between two pentacoordinate structures.     

SYNTHESE DE DERIVES DU THIOPHENE SUBSTITUES EN POSITION 2 ET 5

Abstract

Six new potentially active drugs derivatives of 2.5-disubstituted thiophene are synthesized by a multistep procedure based on the reactivity of a sulfur carbanions: compounds 2, 3, 4 and 8 are symmetrical, substituted by identical functional groups, and compounds 10, 14 are non symmetrical.     

AGREGATION DES CHLOROPHYLLES IN VITRO-II. PHOTODECOLORATION DE LA CHLOROPHYLLE a ADSORBEE SUR DES PARTICULES DE LIPOPROTEINES EXTRAITES DU LAIT

Abstract— Chlorophyll a (chl a ) adsorbed on milk proteins or lipoproteins has absorption maxima at 437 ± 1 nm and 671 ± 1 nm, whatever its concentration. A 750-nm-absorbing form appears when (chl/proteins) > 2 × 10^-2 mg chl/mg proteins, in the case of lipoproteins; or 4.5 × 10^-3 mg chl/mg proteins, in the case of proteins. In both cases, the apparent molar extinction coefficient at 671 nm is the same (3 × 10⁴ liter mole^-1 cm^-1) at the highest (chl/proteins) ratio for which no 750 nm absorbancy appears. It is shown that adsorbed chl a undergoes irreversible (in the present conditions) photo-oxidation by light in the presence of oxygen. The reaction is second order, with similar rate constants for chl a adsorbed to proteins or to lipoproteins.     

2-二乙氨基-3-(4''''-甲氧基苯甲酰基)-2-硫-1,3,2-氧氮磷杂环戊烷晶体结构研究

取代2-硫-1,3,2-氧氮磷杂环戊烷衍生物多为具有生物活性的含磷杂环化合物。其中,某些可作为杀虫剂、杀螨剂、阻化剂、抗病毒及抗肿瘤活性剂等等。文献报导了系列此类化合物的合成方法,为了进一步探讨环状含氧氮磷杂化合物的生物活性与结构的关系,本文报导标题化合物的晶体结构。     

PHOTOBIOLOGIE DU MESOCOTYLE D'AVOINE–IV. SPECTRES D'ACTION ET EFFICACITE QUANTIQUE DE LA LUMIERE

Abstract— The wavelengths most active in influencing the growth of segments of oat mesocotyl are 435 nm (blue), 665 nm (red) and 730 nm (far red). Using a high-energy source (1.5 × 10¹⁸ quanta/cm²), an inhibition in all areas of the spectrum except the far red was obtained. The efficiency of the different radiations was studied: blue light is the most active, red and far red have about the same efficiency; green is a thousand times less active. The effect induced by blue light cannot be directly attributed to phytochrome, because the wavelength of maximum effect does not correspond with that of maximum absorption of the pigment (there is 55 nm difference); also, blue light is more active than the red radiation.     

PHOTOCHIMIE DES ACIDES AMINES AROMATIQUES EN SOLUTION - I. dl-PHENYLALANINE, dl-TYROSINE ET l-DOPA

Abstract— The action of ultraviolet radiation on dl -phenyldanine, dl -tyrosine and l -dopa has been studied in dilute aqueous solutions (10^-2M–5 × 10^-3M). Irradiation was performed in nitrogen or in air, at a wavelength of 254nm. The photoproducts of low molecular weight (amino acids, carboxylic acids, amines) were isolated either by chromatography on an ion exchange column or by thin-layer chromatography and identified mainly by ultraviolet absorption and staining with ninhydrin. The isolation of photopolymers was carried out by chromatography on a Biogel column; identification of these photoproducts was mainly achieved by ultraviolet and infrared spectroscopy. With phenylalanine, which is the most photosensitive amino acid, the principal reaction results in splitting of the side chain, giving alanine, glycine, and four other amine compounds whose structure has not been determined. In air, additional minor products resulting from photooxydation are obtained: ortho, meta and paratyrosine. Traces of phenylethylamine were isolated after irradiation in an inert atmosphere. The polymers produced under air and nitrogen are similar. They probably result from rearrangement of aromatic radicals formed by splitting of the side chain. Tyrosine and dopa, irradiated in air, yield mainly melanin; before polymerization, tyrosine is first converted into dopa. In a inert atmosphere, these aromatic aminoacids also polymerize, giving monophenolic and biphenolic compounds with structure close to that of melanin. The biphenolic polymer (thus obtained from dopa) shows the properties of a leuco derivative of melanin. The monophenolic polymer can be converted into melanin by the combined action of oxygen and ultraviolet radiation. Other reactions give only minor products: parahydroxy-phenyllactic acid and 3,4-dihydroxyphenyllactic acid by deamination-hydroxylation of tyrosine and dopa (in air): meta and paratyrosine by dehydroxylation of dopa, either in air or in nitrogen.     

PHOSPHORYL TO CARBONYL MIGRATION OF AMINO GROUPS IN MIXED ANHYDRIDES. REACTIVITY AND CRYSTAL STRUCTURE OF N-METHYL-2-BENZOYLOXY-2-OXO-1,3,2-OXAZAPHOSPHORINANE

Abstract

Cyclic mixed anhydride, N-methyl-2-benzoyloxy-2-oxo-1,3,2-oxazaphosphorinane (1a) has been synthesised and the rate of its fragmentation involving nitrogen migration from phosphorus to carbonyl carbon has been measured. (1a) was found to be ca. 60 times less reactive than the non-cyclic, O-methyl-N,N-dimethyl analogue. The crystal and molecular structure of (1a) has been determined using x-ray diffraction. Pna2₁, a=22.229(6), b=7.597(2), c=7.210(2) Å; V=1217.6(6) ų. Final R=3.08% for 1037 reflections with I(rel) > 2[sgrave]I(rel) and 157 parameters. The observed conformation of the molecule of (1a) is very different from that required for the fragmentation to occur; in order to achieve the geometry postulated for the transition state significant rotations about the P[sbnd]O and O[sbnd]C bonds would be necessary and steric hindrance by the 4,6-axial hydrogens would be expected.     

卟啉化合物的研究 ⅩⅢ.取代四苯基卟啉蒽醌化合物的合成和光谱性质研究

本文报道了一组取代四苯基卟啉蒽醌化合物的合成和光谱性质研究,并根据波谱数据和各化合物荧光猝灭程度的不同,讨论了化合物的结构以及取代基,卟啉和蒽醌之间的距离对分子内电子传递产生影响的内在因素。     

ETUDE EN SPECTROMETRIE DE MASSE DE PHOSPHONATES ENYNIQUES ET DE β-CETOPHOSPHONATES-γ, δ-ETHYLENIQUES

The mass spectrometric study of acetylenic dialkylphosphonates (I) and of γ, δ-éthylenic-β-ketophosphonates (II) is characterised by rearrangement processes of the phosphorylated group and cleavage of the phosphorus-carbon bond. The fragmentation patterns of compounds II were identical to those found for I by loss of water.     

Dialkyltriazaniumsalze, 1. Mitt.: Die Umsetzung von 2-Dialkylamino-1,3,2-dioxaphospholanen und 2-Dialkylamino-1,3,2-dioxaphosphorinan mit Chloramin in Gegenwart von Ammoniak

Zusammenfassung 2-Dialkylamino-1,3,2-dioxaphospholane und-phosphorinane reagieren mit Chloramin in Gegenwart von Ammoniak zu Dialkyltriazaniumchloriden und polymeren Phosphorverbindungen. Es ist dies bis jetzt die einzige Reaktion, bei der die Chloraminierung eines Dialkylaminophosphins nicht am Phosphor, sondern am Stickstoff stattfindet und Dialkyltriazaniumchloride in guter Ausbeute gebildet werden. Als erster Reaktionsschritt wird eine Spaltung der P-N-Bindung durch Chloramin angenommen. Die entstandenen Spaltprodukte, 2-Chlorphospholan und Dialkylhydrazin, reagieren mit Chloramin/Ammoniak weiter zu den gen. Endprodukten.

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2-Dialkylamino-1,3,2-dioxaphospholanes and-phosphorinanes react with chloroamine and ammonia yielding dialkyltriazanium chlorides and a polymeric phosphorus compound. This is the first chloroamination reaction where chloroamine reacting with a dialkyl aminophosphine apparently attacks the nitrogen and not the phosphorus atom yielding dialkylhydrazine and 2-chlorophospholane. These compounds then react with chloroamine and ammonia to give dialkyltriazanium chloride and a phosphorus compound of polymeric character.

     

Three-dimensional structures of phosphorus-containing heterocycles. Communication 34. 2-Phenoxy-2-oxo-1,3,2-oxathiaphosphorinanes

Conclusions According to the data from the¹H NMR spectra, the dipole moments, and the Kerr effect, the preferred conformation of 2-aroxy-2-oxy-1,3,2-oxathiaphosphorinanes is a chair conformation with an axial orientation of the aroxy grouping and a gauche orientation of the aryl group relative to the P=O bond on the side of the cyclic oxygen atom. In the investigated compounds the p- conjugation is disrupted, as evidenced by the orthogonal orientation of the unshared pair of p electrons of the exocyclic oxygen atom and the orbitals of the benzene ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 570–575, March, 1985.     

Novel heterocycles. 2. Synthesis of the 1,3,2-benzodiazaphosphorin ring system

A series of 1,3-disubstituted-2,3-dihydro-1,3,2-benzodiazaphosphorin-4(1H)one 2-oxides was prepared by a method involving the treatment of an appropriate anthranilamide with phosphorus trichloride. Tricyclic diazaphosphorins 24 and 28 were also prepared. Some spectral data of the products are also discussed.