Jean Teste

Composés bromés de Rytiphlea tinctoria (Rhodophyceae)

Abstract Four aromatic bromo compounds have been isolated from the ethanolic extract of Rytiphlea tinctoria after treatment with diazomethane: 2,4-dibromo-1,3,5-trimethoxy-benzene,5,6,3′,5′-tetrabromo-3,4,2′,4′,6′-pentamethoxydiphenylmethane, 5,6-dibromo-3,4-dimethoxy-benzyl alcohol and its ethyl ether. In addition to sterols, amino acids, this extract also contains quinonoid bromo-pigments which could play a role in photosensitisation of chlorophylls, a role normally taken by the phycobilins, in other Rhodophyceae.

Phenols bromes d'une algue rouge, Halopytis incurvus: Acides carboxyliques

Abstract Extracts of Halopytis incurvus yielded, after methylation, the esters of 3,5-dibromo-4-methoxy-phenylacetic acid and 2-methoxy-3-(3′,5′-dibromo-4′-methoxyphenyl)acrylic acid.

Seasonal chemical evolution of the alga Cystoseira elegans

Abstract Among the Mediterranean algae belonging to the family Cystoseiraceae analysed for diterpenic compounds, only Cystoseira elegans contains eleganolone, epoxy-eleganolone and elegandiol, as does the Atlantic alga Bifurcaria bifurcata . Surprisingly, for the seasonal Cystoseira elegans , these compounds are present only at the beginning of growth of the alga during Spring and they disappear in the Summer yielding important seasonal variation data for diterpenoids, and also for sterols, alginic acid,mannitol and cellulose.

Phenols bromes des algues rouges: Cyclotribromoveratrylene, nouveau derive obtenu au cours de l'extraction de Halopytis pinastroïdes

Abstract Cyclotribromoveratrylene has been isolated from an ethanolic extract of fresh Halopytis pinastroides , after treatment with diazomethane. This new

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

Abstract 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.

The occurrence of C28 sterols in red algae

Abstract Lenormandia prolifera and Amansia glomerata contain large amounts of 24-methylenecholesterol. These two algae belong to the Amansia group of Rhodomelaceae as do Rytiphloea tinctoria and Vidalia volubilis, which are already known to be able to alkylate sterols at C-24. Halopythis pinastroides is an exception in the Amansia group, no C-28 sterols being present in this alga.

Effet de l'acide gibberellique (GA3) sur la croissance d'Asparagopsis armata (Rhodophycées, Bonnemaisoniales) en culture

Abstract Effect of gibberellic acid (GA3) on the growth of Asparagopsis armata in culture.—The gibberellic acid (GA3) stimulates the growth of the Asparagopsis armata in culture. This effect was observed by adding doses of 6,5X10−5M or 6,5X10−7M of this acid in Von Stosch medium.