Jean Favre-Bonvin

Les iridoïdes et séco-iridoïdes: Répartition, structure, propriétés, biosynthèse

Resume 80 composes rencontres a letat naturel ont ete classes suivant leur structure: monoterpenes methylcyclopentanoides, iridoides proprement dits, seco-iridoides. Pour chacun deux sont indiquees la repartition chez les vegetaux, la structure et la stereochimie (si elle est elucidee). Un tableau taxinomique groupe les familles et genres de plantes a iridoides. Les proprietes generales de ces composes, leur recherche chez les vegetaux et leur action biologique sont brievement decrites. Les experiences effectuees sur leur biosynthese sont mentionnees: de lacide mevalonique aux iridoides et seco-iridoides, de la loganine aux seco-iridoides et aux alcaloides indoliques.

Mycosporins from Ascochyta pisi, Cladosporium herbarum and Septoria nodorum

Abstract The chemical structure of the mycosporin isolated from Ascochyta pisi, Cladosporium herbarum and Septoria nodorum was established as mycosporin-2 glucoside.

Highly oxygenated flavones from Mentha piperita

Abstract Six highly oxygenated flavones have been isolated from the leaves of Mentha piperita . Five known compounds, 5-hydroxy-6,7,8,4′-tetramethoxyflavone, 5,4′-dihydroxy-6,7,8-trimethoxyflavone, 5,3′-dihydroxy-6,7,8,4′-tetramethoxyflavone, 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavone and 5,3′,4′-trihydroxy-6,7,8-trimethoxyflavone, are reported for the first time in the genus Mentha . The sixth compound has been identified as 5,6-dihydroxy-7,8,3′,4′-tetramethoxyflavone by UV, NMR and mass spectra.

Le fomentariol: Nouvelle benzotropolone isolée de Fomes fomentarius

Abstract The brown—red colour of the external layer of Fomes, fomentarius is basically due to three compounds. The main constituent, fomentariol, has the structure 7,4′-di(3-hydroxy-1-propenyl)-purpurogallin.

Herpetrione, lignoide trimere isole d'herpetospermum caudigerum

Resume The title compound, a new trimer of coniferyl alcohol, has been isolated from defatted seeds of Herpetospermum caudigerum Wall. (Cucubitaceae). Its structure was elucidated by spectroscopic means as rel -( 7′S , 8′S , 7″S , 8″S -4,9,4′,4″-tetrahydroxy-5,5′,5″-trimethoxy-7-oxo-8.3′,7′.0.9″,8′.8″,9′.0.7″-lignoid.

True structure of triumboidin, a flavone glycoside from Triumfetta rhomboidea

Abstract The structure of triumboidin isolated from Triumfetta rhomboidea as scutellarein 7- O - l -arabinorhamnoside is inconsistent with the spectral data. Its true structure has been established as scutellarein 6-xyloside 7-rhamnoside. 1 H and 13 C NMR and FAB-MS data for scutellarein 7- O -α- l -rhamnoside have also been provided.

Herpepentol, nouveau lignoide pentamere isole d'Herpetospermum caudigerum wall.

Abstract The title compound, a new pentamer of coniferyl alcohol has been isolated from seeds of Herpetospermum caudigerum Wall. (Cucurbitaceae). Its structure was established by spectroscopic means as 4,9,9′,9″,9″′,4″″-hexahydroxy-5,5′,5″,5″′,5″″-pentamethoxy-7.0.4′,8.3′,7′.0.4″,8′.3″,7″.0.4 8″.3″′,7″′.0.9″″,8″8′.″″--lignoid.

Open and ring forms of mycosporin-2 from the ascomycete Gnomonia leptostyla

Abstract The three reproductive forms of Gnomonia leptostyla synthesize mycosporin-2 ring and open forms. The chemical structures were determined from NMR and MS data.

Structural revision of the flavone majoranin from Majorana hortensis

Abstract Majoranin isolated from Majorana hortensis and characterized earlier as 5,7,4′-trihydroxy-6,8,3′-trimethoxyflavone was found to be different from sudachitin of the same structure. Its true structure has been established as 5,6,4′-trihydroxy-7,8,3′-trimethoxyflavone (thymonin) by spectral data and direct comparison.

Structure de l'herpetotriol, sesquilignane trimere de l'alcool coniferylique, isole d'herpetospermum caudigerum wall.

Resume herpetotriol, a new lignan isolated from Herpetospermum caudigerum , has the structure of a trimer, ( 2 ), of coniferyl alcohol.