Synthesis and Evaluation of New Phytotoxic Fluorinated Chalcones as Photosystem II and Seedling Growth Inhibitors.

The development of novel phytotoxic compounds has been an important aim of weed control research. In this study, we synthesized fluorinated chalcone derivatives featuring both electron-donating and electron-withdrawing groups. These compounds were evaluated both as inhibitors of the photosystem II (PSII) electron chain as well as inhibitors of the germination and seedling growth of Amaranthus plants.

R132 expresses antimicrobial genes and produces metabolites that modulate immune system.

Unlabelled: Actinobacteria is a phylum composed of aerobic, Gram-positive, and filamentous bacteria with a broad spectrum of biological activity, including antioxidant, antitumor, and antibiotic. The crude extract of R132 was fractionated on a C18 silica column and the isolated compound was identified by H and C nuclear magnetic resonance as 3-(phenylprop-2-enoic acid), also known as -cinnamic acid. Antimicrobial activity against human pathogens was assayed in vitro (disk-diffusion qualitative test) and in vivo using larvae (RT-qPCR).

Rational Design, Synthesis and Evaluation of Indole Nitrogen Hybrids as Photosystem II Inhibitors.

We report the synthesis of twelve indole derivatives bearing nitro or amide groups via Fischer indole methodology followed by reduction/acetylation and amidation reactions. After thorough characterization, these indoles were subjected to a number of studies in order to evaluate their bioactive potential as photosynthesis and plant growth inhibitors. Firstly, these molecular hybrids were evaluated as photosystem II (PSII) inhibitors through chlorophyll a (Chl a) fluorescence measurement.

Chemical profile of the parotoid gland secretion of the Amazonian toad (Rhinella margaritifera).

The secreted poisonin bufonids (Anura: Bufonidae) include proteins, biogenic amines, toxic bufadienolides and alkaloids. The chemical composition of the methanolic extract of parotoid gland secretions by the Amazonian toad Rhinella margaritifera was evaluated in a UFLC-DAD-micrOTOF system. Of the twenty three compounds found in the methanolic extract, eighteen were identified by the mass/charge ratio as: five arginine diacids, six bufagenins (telocinobufagin, marinobufagin, bufotalin, cinobufotalin, bufalin and cinobufagin), six bufotoxins, and an alkaloid (dehydrobufotenin).

Comparative study of the chemical profile of the parotoid gland secretions from Rhaebo guttatus from different regions of the Brazilian Amazon.

Amphibian cutaneous secretion has great potential for bioprospection and is a great tool in the development of bioproducts. Thus, the objective of the present work was to evaluate the comparative study of the chemical profile parotoid gland secretions from Rhaebo guttatus collected in two distinct regions of the Brazilian Amazon. For this, the chemical composition of six methanolic extracts of this species were analyzed by Liquid Chromatography in UV and MS Detection Ultra-Chromatography Systems (UFLC-DAD-micrOTOF).

Synthesis and evaluation of indole derivatives as photosynthesis and plant growth inhibitors.

Indole derivatives were synthetized based on the Fischer indole methodology using different phenyl hydrazine hydrochlorides and either cyclohexanone or 2-butanone. The pre- and post-emergent herbicidal activities were evaluated against Ipomoea grandifolia. A carbazole, 6-chloro-2,3,4,9-tetrahydro-1H-carbazole (3b), decreased the PIabs parameter by 32% and increased the cross-section related parameters, indicating the inactivation of the reaction center on photosystem II.

Measuring dielectric properties for microwave-assisted extraction of essential oils using single-mode and multimode reactors.

The dielectric properties of , sp., and were investigated as a function of frequency and temperature, using dry plant matter and its mixtures with water at different concentrations. This was followed by the extraction of essential oils performed with microwave heating in single-mode and multimode cavities with a variable power 6.

Measurement of Dielectric Properties and Microwave-Assisted Homogeneous Acid-Catalyzed Transesterification in a Monomode Reactor.

Microwave heating technology is dependent on the dielectric properties of the materials being processed. The dielectric properties of H2SO4, H3PO4, ClSO3H, and H3CSO3H were investigated in this study using a vector network analyzer in an open-ended coaxial probe method at various temperatures. Phosphoric and sulfuric acids presented higher loss tangents in the frequency range 0.