Sabine Montaut

Glucoraphasatin: Chemistry, occurrence, and biological properties

Glucoraphasatin is an atypical glucosinolate mainly found in Raphanus sativus roots and sprouts. This review focuses on the chemistry, the occurrence, and the biological properties of glucoraphasatin.

An overview on neuroprotective effects of isothiocyanates for the treatment of neurodegenerative diseases

The discovery of new natural compounds with pharmacological properties is a field of interest widely growing, especially for the management of neurodegenerative diseases. As no pharmacological treatment is available to prevent the development of these disorders, dietary intake of foods or plant-based extracts with antioxidant properties might have beneficial effects on human health and improve brain functions. Isothiocyanates (ITCs), derived from the hydrolysis of the corresponding glucosinolates (GLs), mainly found in Brassica vegetables (Brassicaceae) and, to a lesser extent, in Moringaceae plants, have demonstrated to exert neuroprotective properties. Specifically, strong evidences suggest that antioxidant effects may be ascribed mainly to their peculiar ability to activate the Nrf2/ARE pathway, but alternative mechanisms of action have also been suggested. This review summarizes the current knowledge about the neuroprotective effects of ITCs in counteracting oxidative stress as well as inflammatory and apoptotic mechanisms, using in vitro and in vivo models of acute and chronic neurodegenerative disease. Therefore, ITCs could be regarded as a promising source of alternative medicine for the prevention and/or treatment of neurodegenerative diseases.

Updated glucosinolate profile of Dithyrea wislizenii.

Fruit extracts of Dithyrea wislizenii were analyzed for desulfoglucosinolates and intact glucosinolates using HPLC-APCI-MS and HPLC-ESI-MS, respectively. 2-Propenylglucosinolate (sinigrin) was shown to be present in the extracts. 6-Methylsulfanylhexyl- (glucolesquerellin 9), 6-methylsulfinylhexyl- (glucohesperin 10), 7-methylsulfanylheptyl- (11), and 5-methylsulfanylpentylglucosinolate (glucoberteroin 12) were isolated from the extracts and characterized by NMR and MS data. 7-Methoxyglucobrassicin was not detected in D. wislizenii extracts.

Profile and quantification of glucosinolates in Pentadiplandra brazzeana Baillon

Glucosinolates (GLs) present in root, seed, and leaf extracts of Pentadiplandra brazzeana Baillon were characterized and quantified according to the ISO 9167-1 method based on the HPLC analysis of desulfo-GLs. The analyses were complemented by GC-MS analyses of the isothiocyanates (ITCs) generated from GL degradation by myrosinase. Glucotropaeolin (1a), glucolimnanthin (2a), and glucoaubrietin (3a) were shown to be present in the root extract, whereas the seed mainly contained 3a. 3,4-Dimethoxybenzyl GL (4a), glucobrassicin (5a) and traces of 1a were detected in the leaf extract. The products were fully characterized as their desulfo-counterparts by spectroscopic techniques.

Glucosinolate Profiling and Antimicrobial Screening of Aurinia leucadea (Brassicaceae)

Glucosinolates (GLs) were characterized in various aerial parts (stems, leaves, and flowers) of Aurinia leucadea (Guss.) C. Koch and quantified according to the ISO 9167‐1 official method based on the HPLC analysis of desulfoglucosinolates. Eight GLs, i.e., glucoraphanin (GRA), glucoalyssin (GAL; 1), gluconapin (GNA; 2), glucocochlearin (GCC), glucobrassicanapin (GBN; 3), glucotropaeolin (GTL), glucoerucin (GER), and glucoberteroin (GBE) were identified. The total GL contents were 57.1, 37.8, and 81.3 μmol/g dry weight in the stems, leaves, and flowers, respectively. The major GL detected in all parts of the plant was 2, followed by 1 and 3. GC/MS Analysis of the volatile fractions extracted from the aerial parts of fresh plant material either by hydrodistillation or CH2Cl2 extraction showed that these fractions mostly contained isothiocyanates (ITCs). The main ITCs were but‐3‐enyl‐ (55.6–71.8%), pent‐4‐enyl‐ (7.6–15.3%), and 5‐(methylsulfinyl)pentyl ITC (0–9.5%), originating from the corresponding GLs 2, 3, and 1, respectively. The antimicrobial activity of the volatile samples was investigated by determining inhibition zones with the disk‐diffusion method and minimal inhibitory concentrations (MIC) with the microdilution method. They were found to inhibit a wide range of bacteria and fungi, with MIC values of 2.0–32.0 μg/ml, indicating their promising antimicrobial potential, especially against the fungi Candida albicans and Rhizopus stolonifer as well as against the clinically important pathogen Pseudomonas aeruginosa.

Phytochemical constituents of Cardamine diphylla

From the methanol extract of the Cardamine diphylla rhizome, methylethyl- (1), 2-methylbutyl- (2), 3-methylpentyl- (4), 3-indolylmethyl- (5), 1-methoxy-3-indolylmethyl- (6), 4-methoxy-3-indolylmeth...

Synthesis, identification and chemical features of high-purity trimethylselenonium iodide

High-purity (99.8%±1.1) trimethylselenonium iodide (TMSeI) was synthesized from dimethyl selenide and methyl iodide. Its chemical structure was confirmed using the spectroscopic methods of nuclear magnetic resonance, Fourier transform infrared and electrospray ionization-mass spectrometry. Some thermodynamic properties of the pure TMSeI were studied with differential scanning calorimetry, and its decomposition point and entropy were determined to be 157.7 °C and 100.7 kJ mol−1, respectively. The chromatographic and UV absorption behavior of the trimethylselenonium cation was also studied and the photochemical and chemical stability of TMSe+ and its decomposition products under varying microwave digestion conditions were examined. Some peculiar, yet interesting chemical properties on the stability of the compound were revealed. This is the first time that the chemical properties of this compound are comprehensively studied by various techniques and from different angles. The high purity of the synthesized compound allows it to be used as a primary standard compound in analytical method development and in basic and environmentally related studies.

Stability of benzylic-type isothiocyanates in hydrodistillation-mimicking conditions.

Pentadiplandra brazzeana Baillon (Pentadiplandraceae) is known to contain benzyl-, 3-methoxybenzyl-, 4-methoxybenzyl-, 3,4-dimethoxybenzyl-, and indole-type glucosinolates, and the essential oil obtained from its roots is mainly constituted of benzyl isothiocyanate and benzyl cyanide. In a previous study by the authors, it was surmised that partial hydrolytic degradation of 4-methoxybenzyl isothiocyanate, one major expected compound, occurred during the hydrodistillation process of essential oil preparation. To probe this hypothesis, a selection of diversely substituted benzylic-type isothiocyanates was submitted to standard hydrodistillation-mimicking conditions. After extraction with dichloromethane, the reaction mixtures were analyzed using GC-MS. The aqueous phases resulting from liquid-liquid extraction were analyzed by HPLC and GC-MS. 2-Methoxybenzyl, 4-methoxybenzyl, 3,4-dimethoxybenzyl, and 3,4,5-trimethoxybenzyl isothiocyanates underwent conversion into 2-methoxybenzyl, 4-methoxybenzyl, 3,4-dimethoxybenzyl, and 3,4,5-trimethoxybenzyl alcohols, respectively, whereas benzyl, 3-methoxybenzyl, and 4-chlorobenzyl isothiocyanates were converted into the corresponding benzylamines.

Glucosinolate Diversity in Bretschneidera sinensis of Chinese Origin.

The glucosinolate (GL) profile in several plant parts (leaf, branch, bark, root, and fruit) of Bretschneidera sinensis from three geographical regions of the Peoples Republic of China was established for the first time by HPLC. During this investigation, benzyl GL (1), 4-hydroxybenzyl GL (2), 2-hydroxy-2-methylpropyl GL (3), and 4-methoxybenzyl GL (4) were identified. In addition, one new GL, 3-hydroxy-4-methoxybenzyl GL (5), was isolated in a minor amount from the fruit and characterized by spectroscopic data interpretation. Furthermore, traces of 4-hydroxy-3-methoxyphenylacetonitrile were detected by GC-MS analysis in the fruits, thus confirming the presence of the regioisomeric 4-hydroxy-3-methoxybenzyl GL (6). GLs 1-5 were also quantified for the first time by HPLC in the various plant organs.

Review on Cardamine diphylla (Michx.) A. wood (Brassicaceae): ethnobotany and glucosinolate chemistry.

ETHNOPHARMACOLOGICAL RELEVANCE Cardamine diphylla (Michx.) A. Wood, commonly called toothwort, is a spring perennial herb belonging to the Brassicaceae family. This endemic plant of Eastern North America has been widely used by multiple American First Nations (i.e. indigenous people of North America) for food and medicine for centuries. APPROACH AND METHODS The aim of the review is to describe the botany, ethnopharmacology, phytochemistry, and bioactivity of Cardamine diphylla. The review covers literature on Cardamine diphylla, and the alternative name Dentaria diphylla, from English and French language sources. RESULTS Multiple traditional uses of Cardamine diphylla by American First Nations are well documented. Initial health studies showed that the tested concentrations of the extract were not toxic against brine shrimp larvae and the same extract had a weak free-radical scavenging activity. However, bioactive compounds in the form of aliphatic and indole glucosinolates and some indole alkaloids have been isolated from this plant. Ecological research regarding Cardamine diphylla-insect interactions (such as feeding and oviposition) is also available in the literature. CONCLUSIONS The wide range of traditional uses by multiple American First Nations suggests that the antibacterial, antiviral, immunostimulant, analgesic, antipyretic, and anti-inflammatory activities of this plant should be explored in in vitro and in vivo tests. Traditional modes of preparation of the plant suggest that some of the medicinal properties could certainly be attributed to glucosinolate degradation products (i.e. isothiocyanates), but a clear assignment of active molecules and mechanisms of action remain to be elucidated. The presence of glucosinolates indicates that the plant could be probed for cancer chemopreventive properties. Overall, the review shows that more investigation is necessary to determine the possible benefits of Cardamine diphylla extracts to pharmaceutical companies as a nutraceutic specialty phytotherapeutic agent against respiratory (cold and sore throat) or gastrointestinal problems.