Elemental analysis of 3,4-methylenedioxymethamphetamine (MDMA): A tool to determine the synthesis method and trace links.

The elemental composition of 3,4-methylenedioxymethamphetamine (MDMA) powders and tablets was determined. The objective was the identification of the synthesis method and application of the elemental profile in comparative analysis. The developed analytical method comprised the digestion of a sample followed by quantitative analysis with inductive coupled plasma mass spectrometry (ICP-MS) and inductive coupled plasma atomic emission spectroscopy (ICP-AES). The sample collection consisted of a unique set of MDMA powders (57) from illicit production sites and MDMA tablets (97) taken from large seizures (over 500 tablets) in the Netherlands. The production method of MDMA could be determined for 89 of the 97 tablets. In 84 cases reductive amination using Pt as the catalyst was used, in four cases reductive amination using NaBH(4) or a similar reducing agent was employed and one mixed sample (Pt and B) was found. None of the MDMA tablets were assigned to the aluminium amalgam method. Using the elemental profile, 13 links were identified within the 97 MDMA tablets using cluster analysis based on Pearson correlations. Of these links 10 were corroborated by additional analyses.

Attraction of Phytoseiulus persimilis (Acari: Phytoseiidae) towards volatiles from various Tetranychus urticae-infested plant species.

Plants infested with the spider mite Tetranychus urticae Koch, may indirectly defend themselves by releasing volatiles that attract the predatory mite Phytoseiulus persimilis Athias-Henriot. Several plants from different plant families that varied in the level of spider mite acceptance were tested in an olfactometer. The predatory mites were significantly attracted to the spider mite-infested leaves of all test plant species. No differences in attractiveness of the infested plant leaves were found for predatory mites reared on spider mites on the different test plants or on lima bean. Thus, experience with the spider mite-induced plant volatiles did not affect the predatory mites. Jasmonic acid was applied to ginkgo leaves to induce a mimic of a spider mite-induced volatile blend, because the spider mites did not survive when incubated on ginkgo. The volatile blend induced in ginkgo by jasmonic acid was slightly attractive to predatory mites. Plants with a high degree of direct defence were thought to invest less in indirect defence than plants with a low degree of direct defence. However, plants that had a strong direct defence such as ginkgo and sweet pepper, did emit induced volatiles that attracted the predatory mite. This indicates that a combination of direct and indirect defence is to some extent compatible in plant species.

Molecular basis of glycoalkaloid induced membrane disruption.

In this study the interaction between the glycoalkaloids alpha-chaconine, alpha-solanine and alpha-tomatine and sterols in model membranes was analysed systematically using techniques like membrane leakage, binding experiments, detergent extraction, electron microscopy, NMR and molecular modelling. The most important properties for sterols to interact with glycoalkaloids turned out to be a planer ring structure and a 3 beta-OH group, whereas for alpha-chaconine the 5-6 double bond and the 10-methyl group were also of importance. The importance of sugar-sugar interactions was illustrated by the high synergistic effect between alpha-chaconine and alpha-solanine, the leakage enhancing effect of glycolipids, and the almost complete loss of activity after deleting one or more mono-saccharides from the glycoalkaloids. The formed complexes which were resistant against detergent extraction existed of glycoalkaloid/sterol in a 1:1 ratio and formed tubular structures (alpha-chaconine) with an inner monolayer of phospholipids, whereas with alpha-tomatine also spherical structures were formed. Based on the results a molecular model for glycoalkaloid induced membrane disruption is presented.