Physiological characterization of Jasmine flower (Jasminum sambac) senescence during storage

The aim of this work was to identify metabolic differences and hormonal profiles in jasmine flower (Jasminum sambac) and to investigate the possibility that experimental promotion of retardation of the senescence of jasmine flower may mediated by abscisic acid (ABA) and phenolic content. Determinations of ABA and phenols were made in flower senescing under different conditions using two different packaging materials such as polyethylene (PE) and polypropylene (PP) of 200 gauge micron thickness with no ventilation. Pre-treatment of 4 % boric acid for jasmine flowers was selected. Abscisic acid levels in petals also increased during senescence 91.27 pmol g-1, but much less in boric acid-treated jasmine flower 34.16 pmol g-1. However, the lowest content of total phenolics was measured in buds and partially opened flowers 50.90 μg/g but highest in fully opened 61.80 μg/g on the fourth day of storage, respectively. It was concluded that boric acid prevented the early rise in ethylene production and considerably improved jasmine flower shelf-life

Influence of seed polymer coating with Zn and Fe nanoparticles on storage potential of pigeonpea seeds under ambient conditions

Present laboratory experiment was conducted with an objective to know the effect of seed polymer coat-ing with Zn and Fe nanoparticles (NPs) in comparison to their bulk forms on storage potential of pigeonpea seeds. Results revealed that seed polymer coating with Zn and Fe NPs had significant effect on storability of pigeonpea seeds. Among the treatments Zn NPs at 750 ppm was found to be superior in all the studied parameters viz., seed germination (96.00, 88.67 and 81.67 %), seedling length (25.67, 22.57 and 18.60 cm), seedling dry weight (85, 81.45 and 78. 45 mg), field emergence (89.67, 77.67 and 63.33 %), seedling vigour index (2556, 2001 and 1519), alpha amylase and dehydrogenase enzymes activities at 0, 6 and 10 months, respectively and it was statistically on par with Zn NPs at 500 ppm and Fe NPs at 500 ppm. The nanoparticles treatment didn’t affect the seed moisture content (%) and insect infestation (%), however the significant difference was observed between polymer coated and uncoated seeds. In over all, the results of the study demonstrated the possibility of application Nanotechnology in Seed Science Research

Seed polymer coating with Zn and Fe nanoparticles: An innovative seed quality enhancement technique in pigeonpea

A laboratory study was undertaken to know the effect of seed polymer coating with Zn and Fe nanoparticles (NPs) at different concentration (10, 25, 50, 100, 250, 500, 750 and 1000 ppm) in pigeonpea at Department of Seed Science and Technology, UAS, Raichur. Among the treatments seed polymer coating with Zn NPs at 750 ppm recorded significantly higher seed germination (96.00 %), seedling length (26.63 cm), seedling dry weight (85.00 mg), speed of germination (32.95), field emergence (89.67 %), seedling vigour index (2556), dehydrogenase activity (0.975 OD value) and ?-amylase activity (25.67 mm) and lowest abnormal seedlings (2.50 %) over their bulk forms and control followed by Fe and Zn NPs at 500 ppm. However, in contrast to beneficial effects, these NPs also shown inhibitory effect on germination and seedling growth at higher concentration (nano Zn >750 ppm and nano Fe > 500 ppm). Hence, from the results it is concluded that Zn NPs at 750 ppm can be used to enhance quality of the pigeonpea seeds

Phytochemical analysis, antioxidant and anti-inflammatory activity of leaves and bark of Ceropegia rollae Hemadri

The purpose of the present study is to evaluate in vitro antioxidant activity and anti-inflammatory activity of methanolic extract of the leaves and the bark of the plant Ceropegia rollae Hemadri. The antioxidant activity of the both leaves and bark extract was studied using FRAP and DPPH method. The in vitro anti-inflammatory activity and phytochemical characterization were carried using known protocols. The various phytochemical components such as total phenolics and flavonoids were determined. The plant Ceropegia rollae also contains tannis and ascorbic acid. This is related to the antioxidant activity of the plant Ceropegia rollae extract. The leaves shows good antioxidant and anti-inflammatory activity as compared to the bark. These can be used as natural antioxidant and anti-inflammatory agents

GaSbBi alloys and heterostructures: fabrication and properties

International audienceDilute bismuth (Bi) III-V alloys have recently attracted great attention, due to their properties of band-gap reduction and spin-orbit splitting. The incorporation of Bi into antimonide based III-V semiconductors is very attractive for the development of new optoelectronic devices working in the mid-infrared range (2-5 µm). However, due to its large size, Bi does not readily incorporate into III-V alloys and the epitaxy of III-V dilute bismides is thus very challenging. This book chapter presents the most recent developments in the epitaxy and characterization of GaSbBi alloys and heterostructures

Deciphering the origin of cooperative catalysis by dirhodium acetate and chiral spiro phosphoric acid in an asymmetric amination reaction

The mechanism of asymmetric amination of diazo-acetate by tert-butyl carbamate catalyzed by dirhodium tetra(trifluoro)acetate and chiral SPINOL-phosphoric acid is examined using DFT (M06 and B3LYP) computations. A cooperative participation of both catalysts is noticed in the stereo-controlling transition state of the reaction

Asymmetric Cooperative Catalysis in a Three-Component Reaction: Mechanism and Origin of Enantio- and Diastereoselectivities

Mechanistic insights gained through density functional theory (DFT M06 and B3LYP) computations on a three-component cooperative asymmetric catalytic reaction between a diazo ester, a carbamate, and an imine, catalyzed by dirhodium acetate and chiral phosphoric acid (Brønsted acid), are presented. The addition of the dirhodium-bound enol to the imine yielding an α,β-diamino ester is energetically more preferred over a potentially competitive protonation of the same enol leading to an α-amino ester

Insights on the Origin of Regiodivergence in the Parallel Kinetic Resolution of <i>rac</i>-Aziridines Using a Chiral Lanthanum–Yttrium Bimetallic Catalyst

Parallel kinetic resolution of racemic mixtures is an important method used in asymmetric synthesis of chiral compounds. In a recent example, a <i>rac</i>-<i>cis</i>-2,3-substituted chiral <i>N</i>-benzoyl aziridine was reacted with dimethyl malonate, in the presence of a La–Y heterobimetallic chiral BINAM Schiff base (L) catalyst, to form enantiomerically pure (ee > 98%) γ-amino acid derivatives through a ring-opening reaction in near-quantitative yields from both the enantiomers (∼48%). High regio- and enantioselectivities even with a <i>rac</i>-aziridine, having C2 and C3 substituents as similar as ethyl and <i>n</i>-propyl. Through a comprehensive computational investigation, we delineate the origin of regio-divergent and enantioselective formation of γ-amino ester derivatives. The Gibbs free energy of the transition state for the ring-opening at the propyl substituted C2 carbon leading to 3-benzamidoheptan-4-yl malonate is found to be 7.2 kcal/mol lower than that at the ethyl substituted C3 carbon in the case of (2<i>R</i>,3<i>S</i>)-aziridine. A reversal of the regio-chemical preference for its enantiomeric (2<i>S</i>,3<i>R</i>)-aziridine is noted where the ring-opening occurs at the ethyl substituted C3 carbon. The La–Y catalyst is found to initially “recognize” both the enantiomers of the <i>rac</i>-aziridine rather indiscriminately. The activation barriers for the most-preferred ring-opening for each enantiomer are found to be closely similar, suggesting that both enantiomers would react. The high regio-selectivity in the addition of lanthanum-bound malonate to the aziridine anchored onto the yttrium center is due to a unique geometric disposition of the aziridine in the stereocontrolling ring-opening transition state. The lowest-energy ring-opening transition state for each enantiomer of aziridine exhibited very similar geometries, while notable geometric distortions is identified in the malonate addition to less-preferred site of the same enantiomer