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A molecular network investigation of Psiloxylon mauritianum leaf extracts from five different specimens led to the detection of a diversity of flavonoids, triterpenes, and phloroglucinols. Some compounds from these molecular classes are reported to target fever-linked symptoms (antioxidant, antiviral, anti-inflammatory, and antibacterial activities) and may explain the plant's success as a local traditional remedy. The phytochemical study of one extract allowed the isolation and characterization of an original seco-ring-A lupane structurally similar to the anti-inflammatory betulinic acid, 11 known triterpenes, 2 flavonoids, and a chalcone. Antiviral assays highlighted the in vitro anti-Zika activity of corosolic and betulinic acids found in the plant. Some interesting structure–activity relationships could be drawn between the new compound and the known active triterpenes. [ABSTRACT FROM AUTHOR]

Les huiles de graines de quatre Cucurbitacées tropicales de l’île de la Réunion, provenant respectivement de deux variétés de l’espèce Lagenaria leucaritha (calebasses bouteille et la gale) et de deux espèces du genre Luffa (pipangailles lisse et à côtes), ont été analysées aussi bien pour la fraction saponifiable que pour la fraction insaponifiable. L’étude de la fraction saponifiable a été consacrée, d’une part, à la détermination de la composition quantitative et qualitative en acides gras des différentes huiles dont les résultats ont fait l’objet d’une publication antérieure [1] et, d’autre part, à celle de leurs triacylglycérols. Une comparaison des compositions en acides gras des deux genres étudiés a permis de mettre en évidence les spécificités propres à chaque genre. Les genres Lagenaria et Luffa, présentant une composition en acides gras qualitativement similaire, contiennent ainsi les AG couramment rencontrés dans le règne végétal, à savoir les acides palmitique, stéarique, oléique et linoléique. Ce dernier est, par ailleurs, l’acide gras majoritaire avec des teneurs supérieures à 50%. La présence de cet acide gras essentiel confère ainsi à ces huiles de bonnes propriétés diététiques et nutritionnelles. Au sein du genre Lagenaria, les huiles des graines des variétés bouteille et la gale se caractérisent par leur teneur élevée en acide linoléique (71,5% pour la variété bouteille, et 81,5% pour la variété la gale). Les huiles de Lagenaria leucaritha sont du type palmitique-linoléique car ces deux acides gras représentent quantitativement plus de 85% des AG totaux. Contrairement à ces deux huiles, celles du genre Luffa se différencient, d’une part, par une teneur moindre en acide linoléique avec 55,3% pour l’espèce Luffa acutangula et 51,2% pour l’espèce Luffa cylindrica. D’autre part, elles sont du type palmitique-oléique-linoléique puisque ces trois acides gras représentent 90% des AG totaux. Afin de compléter l’étude de la fraction saponifiable de ces quatre huiles, la détermination de la composition qualitative et quantitative en triacylglycérols a été réalisée et les résultats ont été comparés à ceux obtenus à partir de Cucurbitacées d’origine tempérée appartenant aux genres Cucurbita et Cucumis [2].

Casearia coriacea Vent., an endemic plant from the Mascarene Islands, was investigated following its antiplasmodial potentialities highlighted during a previous screening. Three clerodane diterpene compounds were isolated and identified as being responsible for the antiplasmodial activity of the leaves of the plant: caseamembrin T (1), corybulosin I (2), and isocaseamembrin E (3), which exhibited half maximal inhibitory concentrations (IC50) of 0.25 to 0.51 µg/mL. These compounds were tested on two other parasites, Leishmania mexicana mexicana and Trypanosoma brucei brucei, to identify possible selectivity in one of them. Although these products possess both antileishmanial and antitrypanosomal properties, they displayed selectivity for the malaria parasite, with a selectivity index between 6 and 12 regarding antitrypanosomal activity and between 25 and 100 regarding antileishmanial activity. These compounds were tested on three cell lines, breast cancer cells MDA-MB-231, pulmonary adenocarcinoma cells A549, and pancreatic carcinoma cells PANC-1, to evaluate their selectivity towards Plasmodium. This has not enabled us to establish selectivity for Plasmodium, but has revealed the promising activity of compounds 1–3 (IC50 < 2 µg/mL), particularly against pancreatic carcinoma cells (IC50 < 1 µg/mL). The toxicity of the main compound, caseamembrin T (1), was then evaluated on zebrafish embryos to extend our cytotoxicity study to normal, non-cancerous cells. This highlighted the non-negligible toxicity of caseamembrin T (1). [ABSTRACT FROM AUTHOR]

The lipid extract of the marine sponge Luffariella cf. variabilis from Mayotte (Indian Ocean) has proven to be an extraordinarily rich source of a wide variety of unusual steroids belonging to the 5[alpha],8[alpha]-epidioxy sterol family. Ten epidioxy sterols have been identified: 5[alpha],8[alpha] -epidioxycholesta-6,22-dien-3[beta]-ol, 5[alpha],8[alpha] -epidioxycholest-6-en-3[beta]-ol, 5[alpha], 8[alpha]-epidioxy-24([zeta])-methylcholesta-6,22-dien-3[beta]-ol, 5[alpha],8[alpha]-epidioxy-24(S)-methylcholest-6-en-3[beta]-ol and its epimer (24R), 5[alpha],8[alpha]-epidioxy-24(S)-ethylcholesta-6, 22-dien-3[beta]-ol and its epimer (24R), 5[alpha],8[alpha] -epidioxy-24([S])-ethylcholest-6-en3[beta]-ol and its epimer (24R), along with 5[alpha],8[alpha]-epidioxy-24([zeta]) -methylcholesta-6,9(11),22-trien-3[beta]-ol. Their structures were determined by nuclear magnetic resonance ([sup.1]H, [sup.13]C) and electron impact mass spectrometry. The mixture of the 10 steroids showed inhibitive activity against the human T-cell leukemia/lymphotropic virus type I (HTLV-I) and also displayed cytotoxic activity against the human breast cancer cell line (MCF[sub.7]WT). Key words: Luffariella cf. variabilis, marine sponge, 5[alpha], 8[alpha]-epidioxy sterols, antitumor and antiviral activities.

Background: Adipose 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. Methods: Medicinal 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). Results: All 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. Conclusion: This 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. [ABSTRACT FROM AUTHOR]

The conventional hydrodistillation method (HD) has been compared with three different variants of the microwave-assisted hydrodistillation technique (MADH), on Lavandula angustifolia flowers, both in terms of oil yield and effects on the glandular trichome morpho-structure. The amount and composition of essential oil extracted in 4 h by HD was similar to that obtained in only 20 min by MADH and even lower than that extracted with a steam variant (MASD) of MADH itself. Histo-cytochemical investigations and scanning electron microscopy showed that glandular trichome, after 4 h of HD, appeared swollen, with a deeply wrinkled surface and empty of essential oil, however maintaining the integrity of their cuticle. Many oil droplets were stuck to the outside of the trichome cuticle, sometimes arranged in large aggregates. After 20 min of MADH or MASD, trichomes appeared empty as well, but also particularly disrupted, or at least with holes in their head cuticle. Oil droplets were present outside the glands and in the inter-rib regions of the flower calyx, except in the case of MASD. After this extraction method, neither oil droplets nor other lipid staining were present in the samples, confirming the effectiveness of this particular MADH technique. These investigations suggest that the rapidity of MADH and MASD in extracting essential oil is mainly due to the collapse of trichome structure and the consequent direct release of its content, without which it has to slowly permeate through membranes and cuticle, as in the case of HD. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Petitgrain essential oils of Citrus latifolia Tanaka (two varieties, Lime Tahiti and Lime de Perse) and Citrus limon (L.) Burm.f. (three varieties, Meyer, Eureka, Doux), Family Rutaceae, from Reunion Island (Indian Ocean) have been analysed by GC-MS. Some major components found on Supelcowax column are β-pinene, sabinene, limonene, citronellal, linalool, neral, geranial and neryl acetate, in different amounts according to variety. The chemical composition of each variety is responsible for the typical olfactory notes. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The essential oils of two scented geranium ( Pelargonium spp.) cultivars grown on Reunion Island were investigated by GC-MS. The specific odour attributes of each single constituent were correlated with the olfactory impression of the two essential oils. The scent of the essential oil extracted from the well-known rose-scented geranium cultivar, Pelargonium cv. Rosé, is based on the rosy, fruity, minty and faintly citrusy aromas of the main components, citronellol (21.9%), geraniol (18.3%), linalool (16.0%), citronellyl formate (11.6%) and isomenthone (7.6%), accompanied by minor compounds of olfactory significance, including geranyl formate (4.0%), nerol (1.7%), geranyl tiglate (1.6%) and neryl propanoate (1.5%) in particular. The volatile constituents of the essential oil of a second geranium cultivar ( Pelargonium sp.) are dominated by monoterpene hydrocarbons, of which the most abundant is p-cymene (35.8%). This oil possesses a very unusual, although very pleasant, 'citrusy-peppery-spicy' and herbaceous scent, somewhat pungent, which is rather reminiscent of thyme. Chemotaxonomic considerations about the genus Pelargonium are also discussed. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Dodonea viscosa (L.) Jacq from Reunion Island (Indian Ocean) was investigated for its leaf essential oil composition. The plant was extracted by hydrodistillation and its essential oil analysed by gas chromatography coupled to mass spectrometry. This study revealed that oxygenated nor-diterpenes and diterpenes were one of the major chemical classes (> 50%) mainly consisting of three modified cyclopropylclerodanes containing a bicyclo[5.4.0]undecane ring system: one new furanoid norditerpene, dodovisate C, and two furanoid diterpenes, the known methyl dodovisate A and the new methyl iso-dodovisate A. These three compounds were isolated by liquid chromatography and their structures established on the basis of spectroscopic studies. The absolute configuration of dodovisate C was elucidated through a joint experimental and theoretical (B3LYP/6-311+G(d,p)) electronic circular dichroism study. The relative configurations of methyl dodovisate A and methyl iso-dodovisate A were determined using linear regressions of theoretical chemical shifts versus experimental values with the (B3LYP/6-311+G(d,p)) method. [ABSTRACT FROM AUTHOR]

Indigofera is the third-largest genus in the family of Fabaceae, with approximately 750 species. It is distributed across all tropical regions. Indigofera species are widely employed in traditional medicine all around the world, against many ailments. Thus, based on these medicinal properties, various investigations have been undertaken in order to appraise the pharmacological activities and the chemical composition of these species. A recent paper provides a summary of the phytochemistry and pharmacology of the genus Indigofera. Consequently, this review is a continuation of this previous study by updating some data and adding information about the phylogeny and traditional uses of the genus. To provide an overview of the phylogeny, traditional uses, phytochemistry, pharmacology and toxicity of the genus Indigofera , and to identify the remaining gaps and thus supply a basis for further investigations. A review of the literature was performed by consulting scientific databases such as 'ScienceDirect', 'PubMed', 'Google Scholar' and 'SpringerLink' and using the keyword Indigofera. Over 60 Indigofera species are reported in traditional medicine. The uses depend on the country and the species, but similarities have been noticed. Indeed, treatments of gastrointestinal disorders, inflammatory conditions and pain, skin ailments, and respiratory and infectious diseases are recurring. Phytochemical studies have led to the identification of more than 200 compounds, notably flavonoids and terpenoids. Many pharmacological activities have been demonstrated, particularly antimicrobial, cytotoxic and anti-inflammatory activities, and thus allowed to assert most of the traditional uses of the genus. Some active compounds have been isolated and have shown remarkable therapeutic potential, like the alkaloid indirubin, which is currently being clinically trialed. The data on the genus Indigofera are extensive, but gaps still remain. Indeed, some promising species have not been assessed for their phytochemistry and/or pharmacology and thus remain unexplored. Moreover, relatively few active compounds have been isolated and tested for their biological activity, and studies to explain their mechanism of action are nearly inexistent. Furthermore, some pharmacological studies have inappropriate methodologies that make the results difficult to interpret. Consequently, further in-depth and relevant research is required to supplement the knowledge on this wide-ranging genus and to confirm its reported therapeutic potential. Image 1 [ABSTRACT FROM AUTHOR]

Abstract N -myristoylation (Myr) is an eukaryotic N -terminal co- or post-translational protein modification in which the enzyme N -myristoyltransferase (NMT) transfers a fatty acid (C14:0) to the N -terminal glycine residues of several cellular key proteins. Depending on the cellular context, NMT may serve as a molecular target in anticancer or anti-infectious therapy, and drugs that inhibit this enzyme may be useful in the treatment of cancer or infectious diseases. As part of an on-going project to identify natural Homo sapiens N -myristoyltransferase 1 inhibitors (HsNMT1), two ellagitannins, punicalagin (1) and isoterchebulin (2), along with eschweilenol C (3) and ellagic acid (4) were isolated from the bark of Terminalia bentzoë (L.) L. f. subsp. bentzoë. Their structures were determined by means of spectroscopic analyses and comparison with literature data. Punicalagin (1) and isoterchebulin (2) showed significant inhibitory activity towards HsNMT1, and also against Plasmodium falciparum NMT (PfNMT) both in vitro and in cellulo , opening alternative paths for new NMT inhibitors development. This is the first report identifying natural products from a botanical source as inhibitors of HsNMT and PfNMT. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Adipose 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., Methods: Medicinal 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)., Results: All 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., Conclusion: This 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.

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.

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-methylmanoalide (2). The structure of compound 3 was elucidated by interpretation of its spectroscopic data.

Polyphenol content and free radical scavenging capacity of seven kinds of sugar manufacturing products (A sugars, clear juices, syrups, massecuite, and A, B, and C molasses) were studied. Seventy-two samples were collected at different stages of the process during two sugar harvests from a local sugar factory (Bois-Rouge, La Réunion). The total phenolic content of sugar products was determined according to the Folin-Ciocalteu assay. Polyphenols of sugar products were extracted with ethyl acetate and quantified by LC-UV-ESI-MS during all of the process. ABTS and DPPH assays were applied to aqueous solution of sugar products, which exhibited interesting free radical scavenging activity. Comparatively, ethyl acetate extracts exhibited higher antioxidant activity. Multivariate analyses (principal component analysis and canonical discriminant analysis) demonstrated a significant correlation between polyphenols and antioxidant activity. Moreover, it was observed that the sugar process results in an increase of the phenolic content and the free radical scavenging capacity of the different products. These products and especially molasses proved to be a rich source of natural antioxidants and may represent an interesting alternative to synthetic food antioxidants.

Seven cane brown sugars (four from La Réunion, two from Mauritius, and one from France) were investigated for their polyphenol content and volatile composition in relation to their free radical scavenging capacity determined by ABTS and DPPH assays. The thin layer coated on the sugar crystal was extracted by Soxhlet extractor with dichloromethane. The volatile compounds of brown sugars were studied by GC-MS, and 43 compounds were identified. The total phenolic content of brown sugars was determined according to the Folin-Ciocalteu method. Phenolic compounds were quantified in the brown sugar extracts by LC-UV-ESI-MS. Brown sugar aqueous solutions exhibited weak free radical scavenging activity in the DPPH assay and higher antioxidant activity in the ABTS assay at relatively high concentration. The brown sugar extracts showed interesting free radical scavenging properties despite the low concentration of phenolic and volatile compounds. Sugar is a common foodstuff traditionally used for its sweetening properties, which might be accompanied by antioxidant properties arising from molecules (polyphenols, Maillard products) other than sucrose of the cane brown sugars.