Jacqueline Smadja

Deterioration of edible oils during food processing by ultrasound.

During food emulsification and processing of sunflower oil (most used edible oil), a metallic and rancid odour has been detected only for insonated oil and foods. Some off-flavour compounds (hexanal and hept-2-enal) resulting from the sono-degradation of sunflower oil have been identified. A wide variety of analytical techniques (GC determination of fatty acids, UV spectroscopy, free fatty acids and GC/MS) were used to follow the quality of insonated sunflower oil and emulsion. Different edible oils (olive, sunflower, soybean, em leader ) show significant changes in their composition (chemical and flavour) due to ultrasound treatment.

Antioxidant polyphenol-rich extracts from the medicinal plants Antirhea borbonica, Doratoxylon apetalum and Gouania mauritiana protect 3T3-L1 preadipocytes against H2O2, TNFα and LPS inflammatory mediators by regulating the expression of superoxide dismutase and NF-κB genes

BackgroundAdipose cells responsible for fat storage are the targets of reactive oxygen species (ROS) like H2O2 and pro-inflammatory agents including TNFα and LPS. Such mediators contribute to oxidative stress and alter inflammatory processes in adipose tissue, leading to insulin resistance during obesity. Thus, the identification of natural compounds such as plant polyphenols able to increase the antioxidant and anti-inflammatory capacity of the body is of high interest. We aimed to evaluate the biological properties of polyphenol-rich extracts from the medicinal plants A. borbonica, D. apetalum and G. mauritiana on preadipocytes exposed to H2O2, TNFα or LPS mediators.MethodsMedicinal plant extracts were analysed for their polyphenol contents by Folin-Ciocalteu and UPLC-ESI-MS methods as well as for their free radical-scavenging activities by DPPH and ORAC assays. To assess the ability of polyphenol-rich extracts to protect 3T3-L1 preadipocytes against H2O2, TNFα or LPS mediators, several parameters including cell viability (MTT and LDH assays), ROS production (DCFH-DA test), IL-6 and MCP-1 secretion (ELISA) were evaluated. Moreover, the expression of superoxide dismutase, catalase and NF-κB genes was explored (RT-QPCR).ResultsAll medicinal plants exhibited high levels of polyphenols with free radical-scavenging capacities. Flavonoids such as quercetin, kaempferol, epicatechin and procyanidins, and phenolic acids derived from caffeic acid including chlorogenic acid, were detected. Polyphenol-rich plant extracts did not exert a cytotoxic effect on preadipocytes but protected them against H2O2 anti-proliferative action. Importantly, they down-regulated ROS production and the secretion of IL-6 and MCP-1 pro-inflammatory markers induced by H2O2, TNFα and LPS mediators. Such a protective action was associated with an increase in superoxide dismutase antioxidant enzyme gene expression and a decrease in mRNA levels of NF-κB pro-inflammatory transcription factor.ConclusionThis study highlights that antioxidant strategies based on polyphenols derived from medicinal plants tested could contribute to regulate adipose tissue redox status and immune process, and thus participate to the improvement of obesity-related oxidative stress and inflammation.

Tigliane diterpenes from Croton mauritianus as inhibitors of chikungunya virus replication

A bioassay-guided purification of an EtOAc extract of the leaves of Croton mauritianus using a chikungunya virus-cell-based assay led to the isolation of 12-O-decanoylphorbol-13-acetate (1) and the new 12-O-decanoyl-7-hydroperoxy-phorbol-5-ene-13-acetate (2), along with loliolide, vomifoliol, dehydrovomifoliol, annuionone D and bluemol C. The planar structure and the relative configuration of compound 2 were elucidated based on spectroscopic analysis, including 1D- and 2D-NMR experiments, mass spectrometry, and comparison with literature data. Compounds 1 and 2 inhibited chikungunya virus-induced cell death in cell culture with EC50s of 2.4±0.3 and 4.0±0.8 μM, respectively.

Isolation and Characterization of α,β-Unsaturated γ-Lactono-Hydrazides from Streptomyces sp.

Two novel α,β-unsaturated γ-lactono-hydrazides, geralcin A (2) and geralcin B (3), were isolated from Streptomyces sp. LMA-545. This unusual scaffold consists of the condensation of alkyl-hydrazide with an α,β-unsaturated γ-lactone, 3-(5-oxo-2H-furan-4-yl)propanoic acid (1), which was isolated from the same broth culture. Amberlite XAD-16 solid-phase extraction was used during the cultivation step, and the trapped compounds (1-3) were eluted from the resin with methanol. The structures were elucidated using (1)H, (13)C, and (15)N NMR spectroscopic analysis and high-resolution mass spectrometry. Geralcin B (3) was cytotoxic against MDA231 breast cancer cells with an IC(50) of 5 μM.

24-O-Ethylmanoalide, a Manoalide-related Sesterterpene from the Marine sponge Luffariella cf. variabilis

A new manoalide-related sesterterpene, 24-O-ethylmanoalide (3), was isolated from the Indian Ocean sponge Luffariella cf. variabilis, together with the known compounds manoalide (1), seco-manoalide, manoalide monoacetate and 24-O-methyl-manoalide (2). The structure of compound 3 was elucidated by interpretation of its spectroscopic data.

Solvent-free microwave extraction : an innovative tool for rapid extraction of essential oil from aromatic herbs and spices.

A relatively simple apparatus is described for extracting essential oils from aromatic plant material by atmospheric solvent-free microwave extraction (SFME) without the addition of any solvent or water. Isolation and concentration of volatile compounds were performed by a single stage. The product solutions of volatile compounds were directly analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The essential oils from aromatic herbs (basil, crispate mint, thyme) and spices (ajowan, cumin, star anise) extracted by SFME for 30 minutes and 1 hour, were similar to those obtained by conventional hydro-distillation (HD) for (respectively) 4 and 8 hours. Substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes hydrocarbons are present in the essential oils of the aromatic plants extracted by SFME in comparison with HD. Solvent-free microwave extraction is clearly advantageous to conventional distillation in terms of rapidity, efficiency, cleanliness, substantial saving of energy, and is environmentally friendly.

Composition of the Essential Oil of the Endemic Psiadia arguta Pers. (Voigt) from Mauritius

Abstract The composition of the water-distilled essential oil of Psiadia arguta (Pers.) Voigt, an endemic plant species belonging to the Asteraceae family from Mauritius, was determined by GC/MS on a polar and non-polar columns. Thirty-one constituents have been identified with isoeugenol (56.5%) and isoeugenyl acetate (5.6%) as the major constituents.

Cyclopropane-containing sterols in the marine sponge Petrosia spheroı̈da

Abstract The sterols of the sponge Petrosia spheroida collected in the Indian Ocean, were isolated by liquid chromatography and reverse-phase HPLC. Sterols were characterized by GC, GC–MS and in some cases by 1H- and 13C-NMR. P. spheroida contained seven Δ5-unsaturated steroids with various C8–C10 side chains including petrosterol and 23,24-dihydrocalysterol, two cyclopropane-containing sterols. Chemotaxonomic considerations about the genus Petrosia are discussed.

Volatile Compounds from Melicope obscura

To evaluate the interpopulation variability of volatile compounds in Melicope obscura, four samples representing four populations were collected all over the distribution area of the species in Reunion Island (Indian Ocean). The samples were extracted by hydrodistillation, and analyzed using GC/FID and GC/MS techniques. The study revealed that, in the four essential oils obtained, oxygenated sesquiterpenes were one of the major chemical classes (9.2–35.2%), mainly consisting of a new compound, (+)‐6‐ethenyl‐2‐hydroxy‐6,10‐dimethylundeca‐2,9‐dien‐4‐one (1), called melicopenol (8.6–30.1%). The compound was isolated by column chromatography and identified by spectral analyses including 1D‐ and 2D‐NMR.

Synthesis of sesquiterpene alcohols from calarene and thujopsene

Oxidation and reduction reactions on two sesquiterpene hydrocarbons, calarene 1 and thujopsene 7, have been investigated in order to produce inexpensive fragrances for perfumery. Oxidation using m-chloroperbenzoic acid gave epoxides, ketones and unsaturated alcohols with a fair selectivity. Reduction reactions with LiAlH4 and LiEt3BH of the epoxidized and ketonic compounds gave sesquiterpenic alcohols in good yields. The structures of these compounds have been determined from concerted application of two-dimensional NMR techniques. Odour analysis of these derivatives should permit the selection of novel fragrance materials for perfumers. #1997 by John Wiley & Sons, Ltd.