Antioxidant activities of polyphenols extracted from Perilla frutescens varieties

Various cultivars of Perilla frutescens (L.) (var. crispa and var. frutescens) Britt. were harvested in China and Japan. They were easily differentiated on the basis of their foliage color, that varied from red to green. Water extracts of dried plants were investigated for their antioxidant activity (AA) and their polyphenolic compounds compared. Among them, cinnamic acid derivatives (coumaroyl tartaric acid, caffeic acid and rosmarinic acid), flavonoids (apigenin 7-O-caffeoylglucoside, scutellarein 7-Odiglucuronide, luteolin 7-O-diglucuronide, apigenin 7-O-diglucuronide, luteolin 7-Oglucuronide, and scutellarein 7-O-glucuronide) and anthocyanins (mainly cis-shisonin, shisonin, malonylshisonin and cyanidin 3-O-(E)-caffeoylglucoside-5-O-malonylglucoside) were quantified. AA assays are based on the inhibition of the free radical 2,2-diphenyl-1- picrylhydrazyl (DPPH). The DPPH radical scavenging activity was calculated as Trolox® [(±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid] equivalent antioxidant capacity (TEAC). The mean amount of total phenolics of the water extracts (4-29 ?mol/100 mL) and the TEAC value calculated (23-167 ?mol TE/100 mL) confirmed the high antioxidant activity of these leaf water extracts. These results were highly correlated within some o-dihydroxylated polyphenolic compounds and AA. (Résumé d'auteur

Deep sequencing of the Mexican avocado transcriptome, an ancient angiosperm with a high content of fatty acids

Background: Avocado (Persea americana) is an economically important tropical fruit considered to be a good source of fatty acids. Despite its importance, the molecular and cellular characterization of biochemical and developmental processes in avocado is limited due to the lack of transcriptome and genomic information. Results: The transcriptomes of seeds, roots, stems, leaves, aerial buds and flowers were determined using different sequencing platforms. Additionally, the transcriptomes of three different stages of fruit ripening (pre-climacteric, climacteric and post-climacteric) were also analyzed. The analysis of the RNAseqatlas presented here reveals strong differences in gene expression patterns between different organs, especially between root and flower, but also reveals similarities among the gene expression patterns in other organs, such as stem, leaves and aerial buds (vegetative organs) or seed and fruit (storage organs). Important regulators, functional categories, and differentially expressed genes involved in avocado fruit ripening were identified. Additionally, to demonstrate the utility of the avocado gene expression atlas, we investigated the expression patterns of genes implicated in fatty acid metabolism and fruit ripening. Conclusions: A description of transcriptomic changes occurring during fruit ripening was obtained in Mexican avocado, contributing to a dynamic view of the expression patterns of genes involved in fatty acid biosynthesis and the fruit ripening process

Analyse conformationnelle et structure électronique d’acétates d’énols

L’analyse conformationnelle de trois acétates d’énols (acétate de vinyle 1, acétate de cis propényle 2 et acétate d’isopropényle 3) a été effectuée en utilisant la méthode CNDO/2.Les conformations les plus stables de 1 et 2, correspondent à la forme plane où l’oxygène carboxylique est en cis avec l’enchaînement vinylique et le carbone vinylique terminal en trans par rapport au groupement acétate. La conformation la plus stable de 3 correspond à une forme gauche.Le calcul du moment dipolaire moyen pour les composés X et 3 est en bon accord avec les résultats expérimentaux

Phosphates d’énols

La méthode CNDO/2 a été employée pour calculer les conformations d’équilibre de neuf phosphates d’énols diméthyliques. Les résultats sont discutés en tenant compte des données expérimentales antérieures. Les conformations les plus stables sont gauches (angle dièdre P — O — C = C compris entre 80 et 120°)

Phosphates d’énols

Les moments dipolaires d’une série de quatorze phosphates énoliques ont été déterminés. Les valeurs trouvées sont relativement constantes et voisines de 3 D. Les calculs effectués en utilisant la méthode CNDO/2 sont en désaccord avec l'expérience. De meilleurs résultats sont obtenus en utilisant les paramètres de SANTRY pour l’atome de phosphore