Louis Piovetti

Meroditerpenoids and derivatives from the brown alga Cystoseira baccata and their antifouling properties

The brown alga Cystoseira baccata harvested along the Atlantic coasts of Morocco yielded seven new meroditerpenoids (1-4) and derivatives (5-7), whose chemical structures were elucidated mainly by 2D NMR and mass spectrometry. Surprisingly, for all these compounds, which possess a bicyclo[4.3.0]nonane ring system, a trans fusion of the bicyclic system was deduced by stereochemical studies even though such compounds isolated from Cystoseira species are known to have a typical cis orientation for the bridgehead methyls. The antifouling and antibacterial activities of compounds 1-5 and 7 were evaluated, as well as their toxicity toward nontarget species. Compounds 4, 5, and 7 showed antifouling activities against growth of microalgae, macroalgal settlement, and mussel phenoloxidase activity, while being nontoxic to larvae of sea urchins and oysters.

Diterpenoids from the Mediterranean Brown Alga Dictyota sp. Evaluated as Antifouling Substances against a Marine Bacterial Biofilm

Four new cyclized diterpenes, one xenicane (1) and three dolabellanes (2-4), were isolated, along with seven previously reported metabolites [3beta-hydroxydilophol (5), dictyols E (6) and C (7), hydroxycrenulide (8), 9-acetoxy-15-hydroxy-1,6-dollabelladiene (9), hydroxyacetyldictyolal (10), and fucoxanthin], from a Mediterranean species of Dictyota sp. collected in Le Brusc Lagoon (French Mediterranean coast). Their structures, as well as their relative configurations, were determined through extensive spectrometric (IR, HRESIMS, 1D and 2D NMR) data analysis and molecular modeling studies and by comparison with those reported in literature. Some of the isolated metabolites were evaluated for their antiadhesion activity against a marine bacterial biofilm (Pseudoalteromonas sp. D41).

A novel acyclic diterpene from the brown alga bifurcaria bifurcata

Abstract A novel epoxy-diterpene identified as 7,8-epoxy-1-hydroxy-13-keto-3,7,11,15-tetramethylhexadeca-2 E ,5 E ,10 E ,-14-tetraene was isolated from Bifurcaria bifurcata , a brown alga belonging to the family Cystoseiraceae, in which eleganolone, epoxy-eleganolone and eleganediol have previously been isolated.

An extract from the brown alga Bifurcaria bifurcata induces irreversible arrest of cell proliferation in a non-small-cell bronchopulmonary carcinoma line

In this study, the antiproliferative activity of a crude extract isolated from Bifurcaria bifurcata (Velley) Ross, a common marine brown alga of the Atlantic shores of Europe, was investigated. Its antiproliferative effect on asynchronous cells of a human non-small-cell bronchopulmonary carcinoma line (NSCLC-N6), particularly chemo-resistant, was expected in vitro. Cell growth appeared to be inhibited in the G1 phase of the cell cycle, and kinetic studies in pretreated cells showed that this growth arrest was irreversible. These events are related to a terminal differentiation induction.

Volatile constituents of Cupressus dupreziana and the sesquiterpenes of Cupressus sempervirens

Abstract Analysis of wood essential oil of Cupressus dupreziana revealed 26 components: 13 monoterpenes and 13 sesquiterpenes. The main components were carv

Monoterpenes et sesquiterpenes oxygenes de Cupressus dupreziana

Resume Twelve oxygenated mono- and sesquiterpenes have been isolated from the heartwood extractives of Cupressus dupreziana. Six of them are new compounds with p-menthane, alaskane and 1,7-diepicedrane skeletons. Structures were determined by spectral methods. The chemotaxonomic significance of these findings are discussed.

Les sesquiterpenes de Cupressus dupreziana

Abstract Heartwood extractives of C. dupreziana were investigated. Carvacrol methyl ether, cedrol and α-cedrene are present, together with sesquiterpene hydrocarbons. A comparison is made with those found in C. sempervirens and other Cupressus species.

Volatile constituents of the leaves of Cupressus dupreziana and Cupressus sempervirens

Abstract The essential oils of the leaves of Cupressus dupreziana and Cupressus sempervirens were compared. The composition of the hydrocarbon fraction showed a great similarity between the two species.

Dosage des acides et aldéhydes phénoliques par chromatographie liquide haute-performance: analyse comparative des sols de haute montagne et de leur végétation

Abstract Analysis of phenolic acids and aldehydes by high-performance liquid chromatography: a comparative analysis of high mountain soils and their vegetation. A method is described for the analysis of phenolic acids and aldehydes by reversed-phase high-performance liquid chromatography with a ternary isocratic elution system. It is applied to the separation and the estimation of phenolic compounds issued from: (1) pyrenean soils at high altitude (Pyrenees-Orientales, France, 2500 m), and (2) the main plant growing there. Phenolic extracts of soil and plant are isolated exactly in the same way by the procedure described.

Diterpene composition of Cupressus dupreziana and Cupressus sempervirens

Abstract The heartwood of Cupressus dupreziana and C. sempervirens were shown to contain similar mixtures of diterpenes.