Chemical composition of laurencia obtusa extract and isolation of a new C15-acetogenin

A new C15-acetogenin, sagonenyne (20), exhibiting an unusual single tetrahydropyran ring was isolated from an ethyl acetate extract of Laurencia obtusa collected on the Corsican coastline. Its structure was established by detailed NMR spectroscopic analysis, mass spectrometry, and comparison with literature data. Twenty-three known compounds were identified in the same extract by means of column chromatography steps, using a (13)C-NMR computer aided method developed in our laboratory. In addition to sesquiterpenes, which represent the main chemical class of this extract, diterpenes, sterols, and C15-acetogenins were identified. The crude extract was submitted to a cytotoxicity assay and was particularly active against THP-1 cells, a human leukemia monocytic cell line.info:eu-repo/semantics/publishedVersio

Etude de la composition chimique d'huiles essentielles et d'extraits de menthe de Corse et de Kumquats

This study has two objectives, on one hand, contributes to diversify the offer especially in the domain of Plant Perfume Aromatic and Medicine in Corsica by characterising chemical composition of their essential oil and extract. On the other hand, it's to contribute to develop an analytical method for complex natural mixtures based on using 13C NMR spectroscopy without preliminary isolation of components. Analysis of chemical compositions of essential oils (EO) and extracts (micro-wave assisted and hydrolate) of mints growing wild in Corsica and five species from the gender Fortunella has been done by combination of GC(RI), GC/MS and 13C NMR. EO from M. aquatica, M. pulegium and M. suaveolens ssp. suaveolens possesses chemical compositions widely reported in the literature. In contrary, EO from M. suaveolens ssp. suaveolens from the piperitenone chemotype (73.5 %) appears original. In the same way, EO and hydrolate extract (HE) from the insularis subspecies, an endemic species of Corsica and Sardinia, posses an original chemical composition characterized by the association of pulegone (respectively 44.4 and 14.8 %) and cis-cis-p-menthenolide (respectively 27.3 and 67.3 %), a p-menthane -methylene--butyrolactone described for the first time as a natural product. If botanical differentiation of both sub-species (suaveolens and insularis) is a complex task., the occurrence (ssp. insularis) and the lack (ssp. suaveolens) of cis-cis-p-menthenolide in EO permits to deduce the belonging to each subspecies. The chemical composition of their essential oils may be considered as an additional tool to the authentification of botanically close subspecies. EO of fruits from the gender Fortunella are close to EO from the gender Citrus characterized by high contents of limonene (> 90%).EO, HE and Microwave assisted Extract (ME) of leaves from the gender Fortunella posses a sesquiterpen rich chemical composition (germacrene D and -elemol). 13C NMR has shown to be a powerful tool to identify unusual compounds like germacra-1(10),5-dien-4-ol, amorph-4-en-10-ol, amorph-4-en-10-ol and trans-guai-6-en-10-ol which added originalities to EO, HE and ME. Determination of chemical composition of EO from fruits, EO and ME from leaves from five species from Fortunella permits to differentiate each species only by their quantitative variation.Les travaux présentés dans ce mémoire contribuent d'une part, à la diversification de l'offre PPAM en région Corse en caractérisant les plantes par l'étude détaillée de la composition chimique des huiles essentielles et d'extraits et d'autre part, au développement de la RMN du 13C en tant qu'outil d'analyse des mélanges complexes naturels. Ainsi, nous avons étudié par CPG (IR), CPG-SM et RMN du 13C la composition chimique d'huiles essentielles et d'extraits (hydrolat et micro-ondes) obtenus à partir de quatre espèces de menthe poussant à l'état spontané en Corse ainsi que de cinq espèces du genre Fortunella cultivés à la station INRA-GEQA de San Ghjulianu. La majorité des huiles essentielles de M. aquatica, M. pulegium et M. suaveolens ssp. suaveolens possèdent des compositions chimiques fréquemment décrites dans la littérature. En revanche, certaines huiles essentielles de M. suaveolens ssp. suaveolens présentent une composition jamais décrite, caractérisée par la présence majoritaire de la pipériténone (73,5 %). De la même manière, les huiles essentielles et extraits d'hydrolat de la sous-espèce insularis, endémique corso-sarde, possèdent des compositions chimiques originales, caractérisées par d'importantes teneurs en pulégone (respectivement 44,4 et 14,8 %) mais surtout en cis-cis-p-menthénolide (respectivement 27,3 et 67,3 %). Cette lactone p-menthanique, possédant le motif -méthylene--butyrolactone, n'avait jamais été identifiée à partir d'une source naturelle. Si la différenciation botanique des deux sous-espèces M. suaveolens ssp. suaveolens et ssp. insularis apparait délicate, la prise en compte du critère présence (ssp. insularis)/absence (ssp. suaveolens) de la cis-cis-p-menthénolide, constitue un outil fiable pour la détermination de la sous espèce. Les huiles essentielles de fruits du genre Fortunella présentent des similitudes avec celles du genre Citrus avec des teneurs en limonène voisines de 90%. Par contre, les d'huiles essentielles et extraits (hydrolat et micro-ondes) de feuilles de Fortunella japonica présentent des compositions chimiques, très originales caractérisés par des fortes teneurs en sesquiterpènes. Le germacrène D et le -élémol sont les composés majoritaires. L'utilisation de la RMN du 13C nous a permis d'identifier de nombreux sesquiterpènes oxygénés peu communs tels que le germacra-1(10),5-dièn-4-ol, l'amorph-4-èn-10-ol, l'amorph-4-èn-10-ol et le trans-guai-6-èn-10-ol. L'étude des huiles essentielles de fruits et de feuilles ainsi que des extraits micro-ondes de cinq espèces du genre Fortunella (F. japonica, F. margarita, F. obovata, F. crassifolia et F. hindsii) montre que seules des variations quantitatives peuvent permettre de différencier ces espèces

Integrated Analysis by GC(RI), GC-MS and 13C NMR of Fortunella japonica Leaf Volatiles Obtained by Hydrodistillation, Microwave- assisted Hydrodistillation and Hydrolate Extraction

International audiencewas investigated by combination of chromatographic (GC, CC) and spectroscopic techniques (GC-MS, 13C NMR). F. japonica essential oil and extracts are complex mixtures of 28-60 compounds being mainly oxygenated sesquiterpenes. The EO composition was dominated by germacrene D (14.9% bêta-elemol (9.1%), cis-guai-6-en-10bêta-ol (6.3%),bêta-eudesmol (5.5%), and delta-elemene (5.2%). Limonene was the unique monoterpene identified at appreciable amount (7.1%). The extract obtained by microwave assisted hydrodistillation contained as main components:bêta-elemol (12.4%), germacrene D (9.9%), cis-guai-6-en- 10bêta-ol (9.0%),bêta-eudesmol (8.2%), germacra-1(10),5-dien-4bêta-ol (7.1%) and bêta-eudesmol (6.4%). Finally, the highest content of oxygenated sesquiterpenes (near 92%) was found in the hydrolate extract displaying cryptomeridiol (23.3%, but totally absent in the EO and ME),bêta-eudesmol (20.6%) and alpha-eudesmol (10.7%). Combined analysis by chromatographic and spectroscopic techniques appeared useful for identification of various sesquiterpenols bearing a tertiaryalcohol function

Snyderol derivatives from Laurencia obtusa collected in Corsica

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Integrated Analysis by GC(RI), GC-MS and 13C NMR ofFortunella japonica Leaf Volatiles Obtained by Hydrodistillation,Microwave- assisted Hydrodistillation and Hydrolate Extraction

International audiencewas investigated by combination of chromatographic (GC, CC) and spectroscopic techniques (GC-MS, 13C NMR). F. japonica essential oil and extracts arecomplex mixtures of 28-60 compounds being mainly oxygenated sesquiterpenes. The EO composition was dominated by germacrene D (14.9%), -elemol(9.1%), cis-guai-6-en-10-ol (6.3%), -eudesmol (5.5%), and -elemene (5.2%). Limonene was the unique monoterpene identified at appreciable amount(7.1%). The extract obtained by microwave assisted hydrodistillation contained as main components: -elemol (12.4%), germacrene D (9.9%), cis-guai-6-en-10-ol (9.0%), -eudesmol (8.2%), germacra-1(10),5-dien-4-ol (7.1%) and -eudesmol (6.4%). Finally, the highest content of oxygenated sesquiterpenes(near 92%) was found in the hydrolate extract displaying cryptomeridiol (23.3%, but totally absent in the EO and ME), -eudesmol (20.6%) and-eudesmol(10.7%). Combined analysis by chromatographic and spectroscopic techniques appeared useful for identification of various sesquiterpenols bearing a tertiaryalcohol function

Halogenated C15 Acetogenin Analogues of Obtusallene III from aLaurenciella sp. Collected in Corsica

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Integrated Analysis by GC(RI), GC-MS and 13C NMR of Fortunella japonica Leaf Volatiles Obtained by Hydrodistillation, Microwave- assisted Hydrodistillation and Hydrolate Extraction

International audiencewas investigated by combination of chromatographic (GC, CC) and spectroscopic techniques (GC-MS, 13C NMR). F. japonica essential oil and extracts are complex mixtures of 28-60 compounds being mainly oxygenated sesquiterpenes. The EO composition was dominated by germacrene D (14.9% bêta-elemol (9.1%), cis-guai-6-en-10bêta-ol (6.3%),bêta-eudesmol (5.5%), and delta-elemene (5.2%). Limonene was the unique monoterpene identified at appreciable amount (7.1%). The extract obtained by microwave assisted hydrodistillation contained as main components:bêta-elemol (12.4%), germacrene D (9.9%), cis-guai-6-en- 10bêta-ol (9.0%),bêta-eudesmol (8.2%), germacra-1(10),5-dien-4bêta-ol (7.1%) and bêta-eudesmol (6.4%). Finally, the highest content of oxygenated sesquiterpenes (near 92%) was found in the hydrolate extract displaying cryptomeridiol (23.3%, but totally absent in the EO and ME),bêta-eudesmol (20.6%) and alpha-eudesmol (10.7%). Combined analysis by chromatographic and spectroscopic techniques appeared useful for identification of various sesquiterpenols bearing a tertiaryalcohol function

New Metabolites Isolated from a Laurencia obtusa Population Collected in Corsica

The chemical investigation of an ethyl acetate extract (EtOAc) obtained from Laurencia obtusa, collected in Corsica, allowed for the identification of three new compounds (1, 2, and 4) and six known compounds. Compounds 1 to 4 were isolated and fully characterized by a detailed spectroscopic analysis. Compounds 1 and 2 are two C15-acetogenins sharing the same ring system: a tetrahydropyran linked by a methylene to a tetrahydrofuran ring. Compound 1 exhibits a bromoallene unit whereas compound 2 possesses an uncommon α-bromo-α,β-unsaturated aldehyde terminal unit. Compound 4 is the first diterpene exhibiting a 19(4 → 3)abeo-labdane skeleton isolated from a Laurencia species. Isolation of concinndiol (compound 3) together with compound 4 suggests a common biosynthetic origin. Additionally, five known compounds, namely sagonenyne, laurene, α-bromocuparene, microcladallene A, and β-snyderol were identified in chromatographic fractions by NMR analysis using a computerized method that was developed in our laboratory

Corrosion Inhibition of C38 Steel in 1M HCl Media by Alkaloidic Extract from Xylopia frutescens Amazonian Tree

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Chemical Composition of the Fruit Oils of Five Fortunella Species Grown in the Same Pedoclimatic Conditions in Corsica (France)

International audienceFruit oil from five species of kumquat (Fortunella japonica, F. margarita, F. crassifolia, F. obovata, and F. hindsii) grown in the same pedoclimatic conditions have been analyzed by a combination of chromatographic and spectroscopic techniques. The compositions of the five fruit oils were strongly dominated by limonene (84.2-96.3%). Other components present with appreciable contents were myrcene (1.3-12.9%) and germacrene D (0.3-2.4%)