Chemical Composition and Metabolomic Analysis of Amaranthus cruentus Grains Harvested at Different Stages

This study aimed at investigating the impact of early versus normal grain harvesting on the chemical composition and secondary metabolites of Amaranthus cruentus species grown in South Africa. Mature harvested grain had higher (p < 0.05) DM, CF, NDF and ADF content compared to prematurely harvested grain. There were no significant (p > 0.05) differences between CP, ADL and GE of premature and mature harvested grains. Mature harvesting resulted in higher grain Ca, P, Mg and K content. Essential amino acids spectrum and content remained similar regardless of maturity at harvest. The grains displayed an ample amount of unsaturated fatty acids; the highest percentage was linoleic acid: 38.75% and 39.74% in premature and mature grains, respectively. β-Tocotrienol was detected at 5.92 and 9.67 mg/kg in premature and mature grains, respectively. The lowest was δ-tocotrienol which was 0.01 and 0.54 mg/kg in premature and mature grains, respectively. Mature harvested grain had a higher secondary metabolite content compared to premature harvested grains. The results suggest that mature harvested Amaranthus cruentus grain contain more minerals and phytochemicals that have health benefits for human and livestock immunity and gut function, which ultimately improves performance. This study concludes that A. cruentus grown in South Africa is a potential alternative cereal to major conventional cereals.     

Conditions for S′-formation in an Al-Cu-Mg alloy

DSC-measurements show in a simple and convincing manner that the precipitation of the metastableS-phase in an Al-2.1% Cu-1.3% Mg alloy is enhanced in the presence of lattice defects (dislocation loops, helices, dislocations), but is little influenced by pre-existing GPB-zones.

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Zusammenfassung DSC-Untersuchungen zeigen auf einfache und überzeugende Weise, da\ die Bildung der metastabilen S-Phase in einer Al-Cu-Mg-Legierung (Al-2.1%, Cu 1.3 %Mg) in Gegenwart von Gitterdefekten (Versetzungsringe, Wendeln, Versetzungen) gesteigert, aber durch vorherige GPB-Zonen nur wenig beeinflu\t wird.

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We are greatly indebted to Centre de Recherches de Voreppe S. A. for the preparation of the alloy.     

60, 90 and 250 MHz 1H NMR spectra of sultams and sultones

The high-field ¹H NMR spectra of 1,3-propanesultams (2), 2,4-butanesultams (3) and 2,4-dimethyl-1,3-butadienesultams (6) are reported. Comparison of 2,3 and 6 with 1,3-propanesultone (1) and 2,4-dimethyl-1,3-butadienesultone (5) reveals that the paramagnetic shift induced by the NH group is smaller than that induced by oxygen. NMR spectra at lower temperature show coupling effects with the NH proton. A half-chair conformation was deduced for 2,4-butanesultam from coupling constants and from a conformational analysis based on the R values, but a chair-chair interconversion could not be detected in the temperature range between 210 and 330 K. An unambiguous assignment was carried out for the methyl signals in the spectrum of 5 by homodecoupling experiments.     

Evidence for GP-zone formation in an Al-3% Zn alloy

The presence of small GP-zones in an Al-3 wt% Zn solid solution aged at temperatures below 80° is inferred from calorimetric reversion studies, although this composition lies outside the miscibility gap of the accepted phase diagram. The size of the zones is about 1 to 1.5 nm, as measured by high resolution electron microscopy.We are greatly indebted to the research staff in the electron microscopy laboratory of C.E.N.G. (Grenoble, France) for the use of a high resolution electron microscope.     

Environmentally friendly synthesis of Ag/SiO2 nanoparticles using Thymus kotschyanus extract and its application as a green catalyst for synthesis of spirooxindoles

Today, plant extracts based on synthetic procedures have drawn consideration over conventional methods like physical and chemical procedures to synthesize nanomaterials. Green synthesis of nanomaterials has become an area of interest because of numerous advantages such as non-hazardous, economical, and feasible methods with a variety of applications in biomedicine, nanotechnology and nano-optoelectronics and as catalysts for various organic transformations. In this research, silver nanoparticles were deposited on the surface of nano-silica spheres by an in-situ reduction of Ag⁺ ions using an aqueous extract of Thymus kotschyanus aerial parts as a natural reducing and a capping agent. The result recorded from ultraviolet–visible (UV–Vis) spectrometer, Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS) and X-ray powder diffraction supports the biosynthesis and characterization of Ag/SiO₂ nanoparticles. The results indicated that the average size of Ag/SiO₂ nanoparticles is 25–60 nm. The Ag/SiO₂ nanoparticles act as an environmentally friendly heterogeneous catalyst in the synthesis of spirooxindoles via the three-component condensation reaction of isatins, activated methylene reagents, and 1,3-dicarbonyl compounds in aqueous media, and the desired products were obtained with yields ranging from 90 to 98%. The catalyst can be recovered easily and used repetitively without significant loss of catalytic activity.

Graphical abstract

     

A synthetic route to 11-(1H-pyrrol-1-yl)-11H-indeno[1,2-b]quinoxaline derivatives exploiting a three-component coupling strategy under microwave irradiation

11H-Indeno[1,2-b]quinoxalin-11-ones generated in situ from ninhydrin and various 1,2-phenylenediamines, catalysed by montmorillonite K10 under microwave irradiation, condense with 4-hydroxyproline to produce 11-(1H-pyrrol-1-yl)-11H-indeno[1,2-b]quinoxaline derivatives in good yields.     

The Complexation of Lanthanides by AZO-β-Diketones Stability Constants

The stability constants of the complexes between the trivalent lanthanide series of cations and series of azo-β-diketone ligands are reported. The measurements were conducted at 30° at an ionic strength of zero, in 100% methanol. The relation between the overall stability constant (log β₂) and atomic number of the lanthanide elements, shows a buffer zone at the gadolinium area. The relation between (log β₂) and the basicity of the studied ligands (ΣpK's) are also, discussed. The overall stability values obtained reflected a great affinity of the organic ligands for chelation with lanthanide ions.     

Syntheses of New Isocephems and Isodethiaoxacephems as Antimicrobial Agents

The cis-configurated isocephem 26 as well as isodethiaoxacephems 21 and 33 were synthesized (Schemes 4 and 5). The key step involves chlorination of the corresponding carbanions of 23, 18 , and 31 with CF₃SO₂Cl followed by internal alkylation. β-Lactams 3, 21, 26 , and 33 were found to possess biological activity against several pathogenic microorganisms in vitro. Electronic activation of the lactam moiety in isodethiaoxacephem 33 remarkably enhanced its biological activity.     

On the Synthesis of 3-Acetyl-1-aryl-1,4,5,6-tetrahydro-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazepin-7-ones by Reaction of Nitrilimines with 3-Aminopropanoic Acid

Summary. Nitrilimines were prepared from N-arylhydrazono chlorides and reacted with -alanine yielding the corresponding amidrazones, which were treated with 1,1-carbonyldiimidazole in THF affording the hitherto unknown 3-acetyl-1-aryl-1,4,5,6-tetrahydro-1,2,4-triazepin-7-ones.