Contribution à la phytochimie du genre Gentiana,XIX. Identification de nouveaux C-glucosides flavoniques dans Gentiana pyrenaicaL

Phytochemistry of genus Gentiana, XIX: Identification of new C-glycosylflavones in Gentiana pyrenaica L . Five flavone C-glucosides [6-C-β-D -glucopyranosyl-tricine ( 1 ) or isopyrenine; 7-O-β-D -glucopyranosyl-6-C-β-D -glucopyranosyltricine ( 2 ) or isopyrenine-7-O-glucoside; isoscoparine-7-O-glucoside ( 3 ); 7-O-β-D -glucopyranosyl-6-C-β-D -glucopyranosylacacetine ( 4 ) and isovitexine-7-O-glucoside ( 5 ) or saponarine] as well as the flavonol glucoside isoquercitrine ( 9 ) have been isolated chromatographically, using polyamide and cellulose columns, from the aerial parts of Gentiana pyrenaica L . 1 and 2 are new compounds and the first glycoflavones trisubstituted on cycle B. Compound 4 is also encountered for the first time in nature.     

A New Xanthone Diglucoside from Swertia perennisL.

A new xanthone diglucoside (1) has been isolated from the aerial parts of Swertia perennis L. (Gentianaceae) by means of column chromatography on polyamide, followed by preparative TLC. on silica gel. From UV. and NMR. data, its structure has been established as 1,3-di-β-D -glucopyranosyl-7,8-dihydroxyxanthone or norswertianine-1,3-diglucoside.     

Etude des composés flavoniques et xanthoniques dans les feuilles de Gentiana ciliataL

Study of the flavonic and xanthonic compounds in the leaves of Gentiana ciliata L . Fifteen 1,3,7,8-oxygenated xanthones ( 1 – 15 ) were isolated from the leaves of Gentiana ciliata L. (genus Gentianopsis). Among these were six new glycosides: glucosyl-1-decussatin 6 , glucosyl-1-gentiacaulein ( 8 ), primeverosyl-8-isogentiacaulein ( 9 ), glucosyl-3-isogentiacaulein ( 10 ), glucosyl-1-swertianin ( 12 ) and primeverosyl-7-swertianin ( 13 ). Three known flavone C-glucosides were also found ( 16 – 18 ).     

Synthese de nouveaux acides sulfoniques et de sila-sultones ethyleniques

The sulfonation of 1-sila-3-clopentenes and corresponding silabicyclohexanes by CISO₃SiMe₃ leads to novel ethylenic silasultones which are hydrolyzed to their sulfonic acids. Depending upon the degree of substitution of the double bond or cyclopropane ring, a competition may occur between the usually observed C-Si bond cleavage and the until now more rarely observed CH cleavage. An interpretation of these results is proposed.     

Contribution à la phytochimie du genre Gentiana. XXV. Etude des composés flavoniques et xanthoniques dans les feuilles de Gentiana X marcailhouana RY. Nouveaux cinnamoyl-C-glucosides flavoniques

Phytochemistry of genus Gentiana XXV: Study of the flavonic and xanthonic compounds in leaves of Gentiana X marcailhouana RY . New cinnamoyl-C-glucosyl-flavones Nine flavonic compounds: isoorientin ( 1 ), isovitexin ( 2 ), isoorientin-4′-O-β-D -glucoside ( 3 ), isovitexin-4′-O-β-D -glucoside ( 4 ), luteolin-7-O-β-D -glucoside ( 5 ), trans-cafeoyl-2′′-isoorientin ( 6 ), trans-feruloyl-2′′-isoorientin ( 7 ), trans-p-coumaroyl-2′′-isoorientin ( 8 ), p-O-β-D -glucosyl-trans-cafeoyl-2′′-isoorientin ( 9 ) and three xanthones: gentioside ( 10 ), isogentisine ( 11 ), mangiferin ( 12 ), have been identified from leaves of Gentiana X marcailhouana RY . Compounds 8 and 9 were described for the first time. The cyclitol L -(+)-bornesitol ( 13 ) has been also isolated.     

Enzymes immobilisees—IV : Les vanacryls et leur emploi dans la preparation de nouveaux derives insolubles de la trypsine

Treatment of methacrylyl chloride with vanillin gave the corresponding ester 1 which was polymerized (or co-polymerized with allylic alcohol), to give various polyaldehydes, called vanacryls. These polymers were successfully used for immobilizing trypsin according to the probable scheme: PolCHO + H₂NEnz → PolCHNEnz.     

Synthese et application de nouveaux sulfures a chaine perfluoree

Metallation of thiols R_FC₂H₄SH followed by alkylation with iodides R′_FC₂H₄I leads either to symmetrical or to unsymmetrical sulphides R_FC₂H₄SC₂H₄R′_F (with R_F=R′_F or R_F ≠ R′_F). All compounds obtained are good solvents of gases (particularly O₂, CO, CO₂, N₂).This property allows their application as biological carriers of dissolved gases.     

Contribution à la phytochimie du genre Gentiana. XXII. Identification de nouveaux O-glucosides de la mangiférine dans Gentiana asclepiadeaL.

Phytochemistry of genus Gentiana. XXII. Identification of new O-glucosides of mangiferin in Gentiana asclepiadea L. Two new O-glucosides of mangiferin (mangiferin-7-O-β-D -glucoside ( 1 ) and mangiferin-6-O-β-D -glucoside ( 2 )) have been isolated from the leaves of Gentiana asclepiadea L . This is the first full structure elucidation of naturally occurring O-glucosides of C-glucosylxanthones. The known C-glucosylflavone, saponarin ( 5 ) was also identified.     

Contribution à la phytochimie de genre Gentiana. XXIV.. Nouveaux C-glycosides flavoniques dans les feuilles de Gentiana asclepiadeaL.

Phytochemistry of genus Gentiana, XXIV. New C-glycosylflavones from the leaves of Gentiana asclepiadea L. p-Hydroxybenzoyl-2″-isoorientin-4′-O-β-D-glucoside ( 1 ) was isolated from the leaves of Gentiana asclepiadea L. by means of column chromatography. This is the first occurrence in nature of a p-hydroxybenzoate of isoorientin. p-Hydroxybenzoyl-2″-isoorientin ( 2 ) was also shown to be present in the same plant.     

Synthèse et ouverture d'oxiranes précurseurs de nouveaux arylo β-amino alcools dans les conditions de catalyse par transfert de phase

Novel derivatives of β-amino alcohols have been prepared by reaction of primary amines with oxirane derivatives. The synthesis of epoxide by o-alkylation of substituted phenols with epibromhydrin under solvent-free solid–liquid phase-transfer catalysis conditions has been described.     

Contribution à la phytochimie du genre Gentiana. X. Etude des composés flavoniques et xanthoniques dans les feuilles de Gentiana vernaL.

One new ( 1 ) and one previously identified ( 2 ) flavone-C-glycosides were isolated from leaves of Gentiana verna L . by means of column chromatography. The columns used were polyamid and cellulose. The structure of the new compound was established as iso-orientin-2″-O-glucoside by means of UV. and NMR. spectrosocpy. The known compound was shown to be isoorientin-4′-O-glucoside.     

Evolution structurale de nouveaux germanates et silicates de type wadéïte et de structure apparentée

The crystal structure of 12 new silicates and germanates with the general formulas: A₂BSi₃O₉ (A = K, Rb; B = Ti, Sn) and A₂BGe₃O₉ (A = K, Rb, Cs, Tl; B = Ti, Sn) were determined. Silicates and germanates Cs₂BGe₃O₉ (B = Ti, Sn) and Tl₂TiGe₃O₉ belong to wadéïte type structure. Nonplanar cyclic Ge₃O₉ rings are present in germanates A₂BGe₃O₉ (A = K, Rb; B = Ti, Sn) and Tl₂SnGe₃O₉. Structural evolution of these compounds is discussed.     

Sur de nouveaux germanates et silicates de type bénitoïte

Five new “benitoïte” type germanates: ATaGe₃O₉ (A = K, Rb, Tl), RbNbGe₃O₉, and the silicate BaSnSi₃O₉ were synthesized. Solid solutions A(Ta_1−xNb_x) Ge₃O₉, ATa(Ge_3−ySi_y)O₉ (A = K, Rb, Tl) and BaSn(Ge_3−ySi_y)O₉ were also studied. Positions of atoms in the hexagonal cell were determined from intensity of X-ray powder diffraction patterns.     

Nombre de transport et conductivite cationique dans les oxydes de calcium et de strontium

The cationic transference numbers have been determined for alkaline earth oxides using sample linear expansion measurements coupled with coulometric titration.Single crystal CaO has been studied in the temperature range 1200–1450°C, under oxygen partial pressures varying from 1 to 10^?5 atm. Under air, t_Ca at 1300°C is close to 0.02.Polycrystalline samples of SrO, under air, were tested from 1100°C to 1350°C, and showed a t_Sr value of 0.012 at 1300°C.The total conductivity of CaO was measured to obtain a value for the cationic conductivity. This value is compared with the data obtained from the self diffusion coefficient of Ca in CaO.     

Synthèse de flavones et de xanthones dans la série du benzo[4,5]thiophène

We describe the first synthesis of 2-arylbenzo[4,5]thieno-[2,3-b]pyran-4-one and of 2-arylbenzo [4,5] thieno [3,2-b] pyran-4-one, from benzo [4,5] thiophene and we have extended these cyclizations to obtain the heterocyclic analogs of the xanthones.     

Contribution à la phytochimie du genre Gentiana IX. Etude de composés flavoniques et xanthoniques dans les feuilles de gentiana CampestrisL. 1ère communication

Two new xanthone-O-glycoside, the 1,3,5-trihydroxy-xanthone-8-O-β-D -glucopyranoside ( 3 ), the 1,5-dihydroxy-3-methoxyxanthone-8-O-β-D -glucopyranoside ( 4 ), have been isolated from the leaves of Gentiana campestris L . by means of column chromatography on polyamid. Two known xanthones ( 1 , 2 ) which are respectively the aglycones of 3 and 4 and a flavone: iso-orientine ( 5 ) have also been isolated and identified.