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The last decades have shown a spectacular and partially unexplained rise in the prevalence of autism spectrum disorders (ASD). This rise in ASD seems to parallel changes in the dietary composition of fatty acids. This change is marked by the replacement of cholesterol by omega-6 (n-6) fatty acids in many of our food products, resulting in a drastically increased ratio of omega-6/omega-3 (n-6/n-3). In this context, we review the available knowledge on the putative role of fatty acids in neurodevelopment and describe how disturbances in n-6/n-3 ratios may contribute to the emergence of ASDs. Both clinical and experimental research is discussed. We argue that a change in the ratio of n-6/n-3, especially during early life, may induce developmental changes in brain connectivity, synaptogenesis, cognition and behavior that are directly related to ASD., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objective: In the oligoarticular subgroup of juvenile idiopathic arthritis, a strong association has been found with the expression of human leukocyte antigen class II molecules HLA-DQA1 *0401-DQB1*0402 and DQA1*0501-DQB1*0301, whereas DQA1*0501-DQB1*0201 is neutral and DQA1 *0201-DQB1*0201 protective. A presentation of different peptides by these DQ alleles would support their role in the disease process., Methods: Using a synthetic nonapeptide library, a peptide binding motif was determined for the associated DQA1*0501-DQB1*0301 molecule and compared to the neutral and the protective DQ molecules., Results: A differential motif for the three molecules could be deduced, suggesting that peptides preferentially binding to the associated vs. the neutral/protective DQ-molecules are mutually exclusive., Conclusion: These results imply a role for differential peptide presentation in the pathogenesis of oligoarthritic JIA. The search for peptides initiating the disease process might be facilitated which could then lead to therapeutical interventions.

(2R)-alpha-(beta-D-Glucopyranosyloxy)-4-hydroxybenzeneacetonitrile (taxiphyllin) dihydrate, C(14)H(17)NO(7) x 2H(2)O, is a naturally occurring cyanogenetic glycoside which has been isolated from Henriettella fascicularis (Sw.) C. Wright (Melastomataceae). Its structure is stabilized by a wealth of intermolecular O-H...O and O-H...N hydrogen bonds spun into a three-dimensional network. Further stabilization arises from an intramolecular O-H...O bond and weak intermolecular C-H...O interactions. The very anisotropic growth speeds of the basal pinacoids from methanol mirror a certain structural inhomogeneity.

A new isoflavone, 4',5,7-trihydroxy-6,8-dimethylisoflavone (1), and a new sesterterpenoic acid (2), together with five known compounds, lichexanthone (3), (-)-pinoresinol (4), betulinic acid, palmitic acid, and beta-sitosterol, were isolated from a dichloromethane extract of the branches of Henriettella fascicularis. Their structures were established by extensive spectroscopic methods. An attempt to determine the absolute stereochemistry of (2E,6S)-6-[(1R,5Z,3aS,9R,10Z,12aR)-1,2,3,3a,4,7,8,9,12,12a-decahydro-9-hydroxy-3a,6,10-trimethylcyclopentanocycloundecen-1-yl]-2-methylhept-2-enoic acid (2) was performed by single-crystal X-ray analysis, using Cu Kalpha radiation. Compound 1 showed significant competitive binding to estrogen receptor beta and moderate antiestrogenic activity with cultured Ishikawa cells.

The hydroalcoholic extract of Tinnevelli senna is widely used as a laxative phytomedicine. In order to improve the knowledge of the chemical composition of this extract, LC/MS and LC/MS(n) studies were performed, allowing the on-line identification of most of the known constituents, i. e., flavonoids, anthraquinones and the typical dianthronic sennosides. However, the identity of four compounds could not be ascertained on-line under the given LC/MS conditions. These substances were isolated and their structures elucidated as kaempferol, the naphthalene derivative tinnevellin 8-glucoside and two new carboxylated benzophenone glucosides.

The terpenoid constituents of Targionia lorbeeriana grown in vivo and in vitro were compared. The analysis of the dichloromethane extract was performed by HPLC-UV and by HPLC-MS. The obtained results revealed that the sesquiterpene lactones isolated from the dichloromethane extract of the wild Targionia lorbeeriana were also produced by the liverwort in in vitro cultures, in the same relative amounts. The composition of essential oils was evaluated by GC and GC-MS. Both, the yield and diversity of the essential oil obtained from wild growing T. lorbeeriana gametophytes were higher than those growing in vitro. Although, a significant number of compounds produced in vivo were maintained in vitro, a considerable number of other ones were not detected. Instead, under in vitro conditions, some new compounds were found which do not accumulate under wild conditions.

A total of 78 different extracts from 20 medicinal plants belonging to 14 plant families from Mali were tested for their antifungal, larvicidal, molluscicidal, antioxidant and radical scavenging activities. Dichloromethane, methanol, water and ethanol extracts were used. TLC autobiography for antifungal activity was run with Cladosporium cucumerinum and Candida albicans. Extracts were also tested on the larvae of the mosquitoes Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Molluscicidal activities were established with the snails Biomphalaria glabrata, Biomphalaria pfeifferi and Bulinus truncatus. beta-Carotene and DPPH solutions sprayed on TLC plates were used for antioxidant and radical scavenging assays. Of the extracts investigated, 20% were antioxidant and radical scavengers, 19% fungicidal, 30% were larvicidal and 11% were molluscicidal. Three of the plant extracts, from Cussonia barteri (Araliaceae), Glinus oppositifolius (Aïzoaceae) and Lannea velutina (Anacardiaceae) gave positive responses in all four tests., (Copyright 2001 John Wiley & Sons, Ltd.)

Two minor saponins obtained from the methanolic extract of the leaves of Ilex paraguariensis have been characterised by 13C-NMR, 1H-NMR, API-MS and chemical hydrolysis as oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)-(28-->1)- beta-D-glucopyranosyl ester (guaiacin B) and oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-(alpha-L-rhamnopyranosyl- (1-->2))-alpha-L-arabinopyranosyl)-(28-->1)-beta-D-glucopyranosyl ester (nudicaucin C). Both are isomeric forms of the known matesaponins 1 (MSP 1) and 2 (MSP 2) and differ only by the nature of the aglycone: they have oleanolic acid instead of ursolic acid, as found in the matesaponins. These minor saponins have not been fully separated from their major isomers MSP 1 and 2 and were characterised by in-mixture NMR analysis, LC-MS and LC-MSn experiments.

In order to discover new bioactive compounds from plant sources which could become new leads or new drugs, extracts should be simultaneously evaluated by chemical screening and by various biological or pharmacological targets. Chemical screening using hyphenated techniques such as LC/UV and LC/MS, and more recently LC/NMR, quickly provides ample structural information, leading in many cases to the identification of compounds. This allows researchers to distinguish between known compounds (dereplication) and new molecules directly from crude plant extracts. Thus, the tedious isolation of known compounds can be avoided, and a targeted isolation of constituents presenting novel or unusual spectroscopic features can be undertaken. In parallel, extracts are also subjected to various bioassays that should be simple, reproducible, and rapid. This approach will be illustrated by the search for new molluscicidal, antioxidant, and antifungal compounds from tropical plants.

Rapid detection of biologically active natural products plays a key role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biological assays and HPLC analysis with various detection methods are used. Techniques such as HPLC coupled to UV photodiode array detection (LC/DAD-UV) and to mass spectrometry (LC/MS or LC/MS/MS) provide numerous on-line structural data on the metabolites prior to isolation. The recent introduction of HPLC coupled to nuclear magnetic resonance (LC/NMR) represents a powerful complement to LC/UV/MS screening. Various plant species belonging to the Gentianaceae and Leguminosae have been analysed by LC/UV, LC/MS, LC/MS/MS and LC/NMR. These hyphenated techniques allow a rapid structural determination of known plant constituents with only a minute amount of plant material. Simple bioautographic assays such as those used for screening antifungal constituents can also be performed on-line directly by collecting HPLC peaks and measuring the activity against the fungi of interest. These bioassays permit a rapid localisation of the bioactive natural products. With such a combined approach, the time consuming isolation of common natural products is avoided and an efficient targeted isolation of compounds presenting interesting spectroscopical or biological features is performed. Several representative applications of the use of LC/MS and LC/NMR for the dereplication and identification of antifungal constituents are presented in the present paper.

A new antifungal and radical scavenging 2-hydroxyflavanone, named mosloflavanone, was isolated from the dichloromethane extract of Mosla soochouensis together with the known mosloflavone and moslosooflavone. Structures were established by spectroscopic and chemical methods, as well as X-ray crystallography.