Artificial Neural Networks and the Study of the Psychoactivity of Cannabinoid Compounds

Cannabinoid compounds have widely been employed because of its medicinal and psychotropic properties. These compounds are isolated from Cannabis sativa (or marijuana) and are used in several medical treatments, such as glaucoma, nausea associated to chemotherapy, pain and many other situations. More recently, its use as appetite stimulant has been indicated in patients with cachexia or AIDS. In this work, the influence of several molecular descriptors on the psychoactivity of 50 cannabinoid compounds is analyzed aiming one obtain a model able to predict the psychoactivity of new cannabinoids. For this purpose, initially, the selection of descriptors was carried out using the Fisher`s weight, the correlation matrix among the calculated variables and principal component analysis. From these analyses, the following descriptors have been considered more relevant: E(LUMO) (energy of the lowest unoccupied molecular orbital), Log P (logarithm of the partition coefficient), VC4 (volume of the substituent at the C4 position) and LP1 (Lovasz-Pelikan index, a molecular branching index). To follow, two neural network models were used to construct a more adequate model for classifying new cannabinoid compounds. The first model employed was multi-layer perceptrons, with algorithm back-propagation, and the second model used was the Kohonen network. The results obtained from both networks were compared and showed that both techniques presented a high percentage of correctness to discriminate psychoactive and psychoinactive compounds. However, the Kohonen network was superior to multi-layer perceptrons.

EVALUATION OF THE INTERACTION OF NUTRIENTS IN THE ZINC APPLICATION IN SEEDS OF THE RICE

The efficient fertilizer use contend micronutrient depends, also, of the interactions that occur with some nutrients. The objective was to study the interaction of zinc with the excessively nutrient ones in function of the application of different doses and sources of Zn saw seed in the culture of the rice. The experiment was carried through in conditions of vegetation house, in the FCAV/Unesp. The used experimental delineation was entirely cazualized, with three repetitions. The treatments had been five doses: 0; 1,0; 2,0; 4,0 and 8,0 g of Zn for kg of seed; e two zinc sources; sulphate of zinc (22% of Zn) and zinc oxide (50% of Zn). The experimental unit was a translucent polyethylene tray, filled with 5 washed thick sand, where 50 seeds of rice had been sown (to var. Caiapo). To the 30 days after the sowing, effected the cut of the plants, separating them in aerial part and roots. From the results of the dry substance and text of nutrients of the aerial part and root of the rice, the accumulation of the nutrients in the respective agencies of the plants was calculated. Becoming fullfilled it variance analysis and the when necessary unfoldings. It had effect of the interactions in distinguishing way between root and aerial part of rice, with regard to the doses and sources.

Storage proteins and cell wall mobilisation in seeds of Sesbania virgata (Cav.) Pers. (Leguminosae)

The endosperm of seeds of Sesbania virgata (Cav.) Pers. accumulates galactomannan as a cell wall storage polysaccharide. It is hydrolysed by three enzymes, one of them being alpha-galactosidase. A great amount of protein bodies is found in the cytoplasm of endospermic cells, which are thought to play the major role as a nitrogen reserve in this seed. The present work aimed at understanding how the production of enzymes that degrade storage compounds is controlled. We performed experiments with addition of inhibitors of transcription (actinomycin-d and alpha-amanitin) and translation (cycloheximide) during and after germination. In order to follow the performance of storage mobilisation, we measured fresh mass, protein contents and alpha-galactosidase activity. All the inhibitors tested had little effect on seed germination and seedling development. Actinomycin-d and cycloheximide provoked a slight inhibition of the storage protein degradation and concomitantly lead to an elevation of the alpha-galactosidase activity. Although alpha-amanitin showed some effect on seedling development at latter stages, it presented the former effect and did not change galactomannan degradation performance. Our data suggest that some of the proteases may be synthesised de novo, whereas alpha-galactosidase seems to be present in the endosperm cells probably as an inactive polypeptide in the protein bodies, being probably activated by proteolysis when the latter organelle is disassembled. These evidences suggest the existence of a connection between storage proteins and carbohydrates mobilisation in seeds of S. virgata, which would play a role by assuring a balanced afflux of the carbon and nitrogen to the seedling development.

Characterisation, immunolocalisation and antifungal activity of a lipid transfer protein from chili pepper (Capsicum annuum) seeds with novel alpha-amylase inhibitory properties

Lipid transfer proteins (LTPs) were thus named because they facilitate the transfer of lipids between membranes in vitro. This study was triggered by the characterization of a 9-kDa LTP from Capsicum annuum seeds that we call Ca-LTP(1). Ca-LTP(1) was repurified, and in the last chromatographic purification step, propanol was used as the solvent in place of acetonitrile to maintain the protein`s biological activity. Bidimensional electrophoresis of the 9-kDa band, which corresponds to the purified Ca-LTP(1), showed the presence of three isoforms with isoelectric points (pIs) of 6.0, 8.5 and 9.5. Circular dichroism (CD) analysis suggested a predominance of alpha-helices, as expected for the structure of an LTP family member. LTPs immunorelated to Ca-LTP(1) from C. annuum were also detected by western blotting in exudates released from C. annuum seeds and also in other Capsicum species. The tissue and subcellular localization of Ca-LTP(1) indicated that it was mainly localized within dense vesicles. In addition, isolated Ca-LTP(1) exhibited antifungal activity against Colletotrichum lindemunthianum, and especially against Candida tropicalis, causing several morphological changes to the cells including the formation of pseudohyphae. Ca-LTP(1) also caused the yeast plasma membrane to be permeable to the dye SYTOX green, as verified by fluorescence microscopy. We also found that Ca-LTP(1) is able to inhibit mammalian alpha-amylase activity in vitro.

GRASSIUS: A Platform for Comparative Regulatory Genomics across the Grasses

Transcription factors (TFs) are major players in gene regulatory networks and interactions between TFs and their target genes furnish spatiotemporal patterns of gene expression. Establishing the architecture of regulatory networks requires gathering information on TFs, their targets in the genome, and the corresponding binding sites. We have developed GRASSIUS (Grass Regulatory Information Services) as a knowledge-based Web resource that integrates information on TFs and gene promoters across the grasses. In its initial implementation, GRASSIUS consists of two separate, yet linked, databases. GrassTFDB holds information on TFs from maize (Zea mays), sorghum (Sorghum bicolor), sugarcane (Saccharum spp.), and rice (Oryza sativa). TFs are classified into families and phylogenetic relationships begin to uncover orthologous relationships among the participating species. This database also provides a centralized clearinghouse for TF synonyms in the grasses. GrassTFDB is linked to the grass TFome collection, which provides clones in recombination-based vectors corresponding to full-length open reading frames for a growing number of grass TFs. GrassPROMDB contains promoter and cis-regulatory element information for those grass species and genes for which enough data are available. The integration of GrassTFDB and GrassPROMDB will be accomplished through GrassRegNet as a first step in representing the architecture of grass regulatory networks. GRASSIUS can be accessed from www.grassius.org.

Heterogeneous photocatalytic degradation of acid dyes in aqueous TiO2 suspensions: Kinetics and toxicity

This work assesses the photocatalytic (TiO2/UV) degradation of a simulated acid dye bath (Yellow 3, Red 51, Blue 74, and auxiliary chemicals). Color and phytotoxicity removal were monitored by spectrophotometry and lettuce (Lactuca sativa) seeds as the test organism, respectively. Mineralization was determined by DOC analyses. Photocatalytic, photolytic, and adsorption experiments were performed, showing that adsorption was negligible. After 240 minutes of irradiation, it was achieved 96% and 78% of color removal with photocatalysis and photolysis, respectively. 37% of mineralization occurred with photocatalysis only. The dye bath was rendered completely non-toxic after 60 minutes of photocatalytic treatment; the same result was only achieved with photolysis after 90 minutes. A kinetic model composed of two first-order in series reactions was used. The first photocatalytic decolorization rate constant was k(1) = 0.062 min(-1) and the second k(2) = 0.0043 min(-1), approximately two times greater than the photolytic ones.