Coumarin-based octopamine phototriggers and their effects on an insect octopamine receptor

We have developed and characterized efficient caged compounds of the neurotransmitter octopamine. For derivatization, we introduced [6-bromo-8-(diethylaminomethyl)-7-hydroxycoumarin-4-yl]methoxycarbonyl (DBHCMOC) and {6-bromo-7-hydroxy-8-[(piperazin-1-yl)methyl]coumarin-4-yl}methoxycarbonyl (PBHCMOC) moieties as novel photo-removable protecting groups. The caged compounds were functionally inactive when applied to heterologously expressed octopamine receptors (AmOctα1R). Upon irradiation with UV-visible or IR light, bioactive octopamine was released and evoked Ca2+ signals in AmOctα1R-expressing cells. The pronounced water solubility of compounds 2-4 in particular holds great promise for these substances as excellent phototriggers of this important neurotransmitter.     

Gas chromatographic triglyceride profiling of milk fat; comparison of packed and short metal capillary columns

 The quantitative aspects of triglyceride profiling of milk fat by capillary column gas chromatography (GC) were investigated. Fifty samples of pure Austrian milk fat were tested as described in Annex III of the European Community (EC) Commission regulation no. 454/95 by using a packed as well as a short metal capillary column. Capillary GC was equivalent to the packed column in terms of analytical precision (relative standard deviation of repeated injections). All samples tested fulfilled the purity criteria (S-values), irrespective of the chromatographic technique used. Nevertheless, the S-values obtained by capillary GC deviated to some extent from those of the packed column. The differences exceeded the value for reproducibility laid down in Annex III, EC regulation no. 454/95 in 18 of 50 cases. As a consequence, the equivalency of capillary GC for determining the purity of milk fat according to EC regulation no. 454/95 should be re-assessed. Received: 4 April 1997 / Revised version: 26 June 1997     

Large-scale patterning of gold nanopillars in a porous anodic alumina template by replicating gold structures on a titanium barrier

Gold nanopillars are grown in patterns inside a porous anodic alumina template. On selected positions, defined by a gold "seed" pattern, gold is electroplated into the pores, while a barrier layer underneath the porous template blocks the deposition on the rest of the surface. Large-scale arrays of free-standing nanopillar islands are obtained after selective etching of the alumina template.     

Low-intensity Husbandry as a Cost-efficient Way to Preserve Dry Grasslands

Abstract

Dry grasslands represent unique ecosystems that are known for high biodiversity. Land use changes have led to a decline in Europe. Shrub encroachment is a major problem in incorrectly or unmanaged areas, and affects not only flora and fauna but also leads to changes in the appearance of the landscape. Our study was conducted on the island of Hiddensee, north-east Germany, where today dry grasslands are endangered by shrub encroachment. We analysed the current land use under consideration of farming costs as well as current agricultural subsidies. Our results show that revenues of low-intensity cattle husbandry only account for 61% of total costs and that farming becomes profitable only with subsidies. Our study illustrates that goats can be a cost-efficient solution for areas with high shrub cover in contrast to manual clearing. The maintenance of dry grasslands is therefore more cost-efficient with grazing animals than with technical-manual labour.     

Hochdruckflüssigchromatographische Untersuchung von Vanille-CO2-Hochdruckextrakten

HPLC has been used for the determination of vanillin,p-hydroxybenzaldehyde, vanillic acid,p-hydroxybenzoic acid, ethyl vanillin, piperonal and coumarin in CO₂ extracts and alcoholic extracts of vanilla beans. Ethyl vanillin, piperonal and coumarin were found in none of the samples. By measuring vanillin,p-hydroxybenzaldehyde, vanillic acid andp-hydroxybenzoic acid a great difference between the amount and the ratio of these main components of the usual alcoholic vanilla extracts and the CO₂ vanilla extracts was shown. The present requirements for vanilla extracts and products containing vanilla extracts refer only to the composition of alcoholic extracts for which, in contrast to CO₂ vanilla extracts, many studies have been published. The critical examination of products containing CO₂ vanilla extracts by using the ratios of vanilla compounds found in the present literature could lead to erroneous complaints. For the purpose of estimating the influence of the extraction solvent on the yield of vanillin, one sample of vanilla beans of each provenance was extracted besides the CO₂ extraction also with the solvents ethanol-water according to the method for a single-fold extract and with the solvents dichloromethane and hexane. In all three cases dichloromethane was found to be the best solvent. Furthermore, the ethanol-water extraction tended to give 6–22% more vanillin than the CO₂ extraction. To achieve unequivocal results, the examination of more samples is necessary.     

Characterization of Amount and Quality of Tucuman Kernel Oil as a Potential Biomass

Amazonian tucuman (Astrocaryum aculeatum) fruit pulp is consumed directly without heat treatment, and is appreciated in the region of Manaus, Amazonas State, Brazil. The kernel is discarded after pulp removal, resulting in costs related to waste management. This study aimed to perform an estimate on the annual amount of kernels generated by commercialization of tucuman fruit in six markets in Manaus by monthly application of questionnaires to merchants. The yield of edible pulp and kernels were assessed, as well as the yield and characteristics of kernel oil. Fruits consisted of pulp (26% fresh weight) and the coproduct is mainly pyrene (70%), comprising a hard woody endocarp (61%) and an oily kernel (39% dry weight). Kernel oil yield ranged from 28% to 45%. The generated coproducts were estimated as 272 t/y (fresh weight) and approximately 6–10 t/y of lauric oil could be obtained. The main fatty acids were lauric—12:0 (52.3–57.5%) and myristic—14:0 (23.4–27.1%), presenting a similar profile to other lauric oils such as coconut, palm kernel, and babassu oils. Oxidative stability ranged from 20 to 44 hours, which is considered high compared to other lauric oils. The recovery of this coproduct will improve the sustainability of the tucuman chain, providing a new product of Amazonian biodiversity and reducing the environmental impact.     

The enhanced growth of multi-walled carbon nanotubes using an atmospheric pressure plasma jet

The growth of multi-walled carbon nanotube (MWCNT) forests was investigated using an atmospheric pressure plasma jet (APPJ) system with a mixture of helium and acetylene gases. The MWCNT forests grown on Fe catalyst were compared with those grown on Ni. The growth of MWCNT forests using Fe as the catalyst was better than the growth of MWCNT forests using Ni. The MWCNT forests grown using Fe catalyst and with a plasma power of 30 W were about 17 ± 9% taller than for the plasma off. We were unable to grow MWCNTs using Ni catalyst with the plasma power off; but curly MWCNTs were grown using Ni catalyst if the plasma power was 30 W. It is found that MWCNT growth is enhanced using an APPJ. The height of the forests produced using this APPJ system was also better than that reported by other researchers using either CVD or PECVD systems.