Characterization of volatile and non-volatile fractions of spices using evolved gas analysis and multi-shot analytical pyrolysis

In the present work, evolved gas analysis-mass spectrometry (EGA-MS) and analytical pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) were used to characterize both the volatile and non-volatile fractions of six commercially available spices. Analysis of spices is usually performed through the study of their headspace composition by solid phase microextraction (SPME). In this new approach, EGA-MS was used to establish thermal degradation regions, and Py-GC/MS was used to obtain compositional information on each region separately using double-shot pyrolysis. This study demonstrates that EGA-MS and Py-GC/MS provide the same advantages of solid-phase micro extraction and increase the range of detectable products by performing high-temperature desorption and degradation of the non-volatile fraction of spices. Our approach provided both qualitative and semi-quantitative data that could be used in the future to improve authentication studies by considering the results not only of headspace composition, but also on the pyrolytic behavior of the lignocellulosic matrix

HPLC-DAD and HPLC-ESI-MS-MS profiles of hydroalcoholic extracts of Chamaemelum nobile and Mentha pulegium, and study of their antihemolytic activity against AAPH-induced hemolysis

Chamaemelum nobile and Mentha pulegium are two herbs used in traditional medicine throughout the world, including Algeria. The present research aimed to study the phenolic composition of C. nobile (CN) and M. pulegium (MP) hydroalcoholic extracts, as well as their antioxidant and antihemolytic effects in AAPH-induced hemolysis on human erythrocytes. Colorimetric estimation of total polyphenols, total flavonoids, flavones and flavonols and condensed tannins showed that CN was richer in total flavonoids, flavones and flavonols and condensed tannins than MP, while MP was richer in total polyphenols. A total of 46 compounds were found using HPLC/DAD and HPLC/ESI-MS-MS analysis, of which 39 were identified. All these identified compounds are divided into five structural groups; phenolic acids, quinic acid esters, flavonoids, caffeic acid oligomers and fatty acids. For the CN, 27 compounds were identified. In contrast, for the MP, only 18 compounds were identified. Both extracts showed good antioxidant activity in vitro. The IC50 for DPPH radical scavenging activity were 19.98 +/- 0.91 mu g/mL for MP and 52.77 +/- 1.53 mu g/mL for CN. The MP had a reducing power of 223.74 +/- 1.08 mg ascorbic acid equivalent/g extract, while CN's was 130.65 +/- 1.69 mg Asc E/g. Both extracts were also significantly effective and in a dose-dependent manner in reducing AAPH-induced oxidative damage on erythrocyte membranes with IC50s of 127.48 +/- 3.14 mu g/mL for CN and 129.52 +/- 2.15 mu g/mL for MP. Lipid peroxidation induced by AAPH and estimated by MDA levels revealed that both extracts significantly reduced MDA levels at doses of 200 and 300 mu g/mL, particularly MP. Our findings provide evidence that C. nobile and M. pulegium have a considerable protective effect on the erythrocyte membrane against free radicals generated by AAPH. (C) 2022 SAAB. Published by Elsevier B.V. All rights reserved

Corrigendum to "Never boring: Non-invasive palaeoproteomics of mummified human skin" [J. Archaeol. Sci. (2020) 105145]

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Human dispersal and plant processing in the Pacific 55 000–50 000 years ago

The dynamics of our species’ dispersal into the Pacific remains intensely debated. The authors present archaeological investigations in the Raja Ampat Islands, north-west of New Guinea, that provide the earliest known evidence for humans arriving in the Pacific more than 55 000–50 000 years ago. Seafaring simulations demonstrate that a northern equatorial route into New Guinea via the Raja Ampat Islands was a viable dispersal corridor to Sahul at this time. Analysis of faunal remains and a resin artefact further indicates that exploitation of both rainforest and marine resources, rather than a purely maritime specialisation, was important for the adaptive success of Pacific peoples

Interferon-γ-producing immature myeloid cells confer protection against severe invasive group A Streptococcus infections

Cytokine-activated neutrophils are known to be essential for protection against group A Streptococcus infections. However, during severe invasive group A Streptococcus infections that are accompanied by neutropenia, it remains unclear which factors are protective against such infections, and which cell population is the source of them. Here we show that mice infected with severe invasive group A Streptococcus isolates, but not with non-invasive group A Streptococcus isolates, exhibit high concentrations of plasma interferon-γ during the early stage of infection. Interferon-γ is necessary to protect mice, and is produced by a novel population of granulocyte–macrophage colony-stimulating factor-dependent immature myeloid cells with ring-shaped nuclei. These interferon-γ-producing immature myeloid cells express monocyte and granulocyte markers, and also produce nitric oxide. The adoptive transfer of interferon-γ-producing immature myeloid cells ameliorates infection in wild-type and interferon-γ-deficient mice. Our results indicate that interferon-γ-producing immature myeloid cells have a protective role during the early stage of severe invasive group A Streptococcus infections

Pyrolysate composition and silylation efficiency in analytical pyrolysis of glucans as a function of pyrolysis time

The pyrolytic behaviour of two oligosaccharides – cellobiose and cellohexose – was studied using reactive pyrolysis-GC/MS with in situ hexamethyldisilazane derivatisation. Pyrolysis was conducted in a sealed vessel at various times ranging from 0.2 to 60 min. Semi-quantitative calculations were carried out on integrated peak areas to obtain information on derivatisation efficiency and composition of the pyrolysate as a function of pyrolysis time. The results were compared with a previous work by us in which glucose and cellulose were studied with the same procedure. The relative areas of anhydrosugars were found to decrease with the increase of the degree of polymerisation of the substrate, while the derivatisation efficiency showed an opposite trend. The results were explained by considering the role of both the sealed environment and water molecules freed during the pyrolysis process. We hypothesised that higher amounts of water were released from glucans with low degrees of polymerization, hindering both secondary pyrolysis reactions and derivatisation efficiency. Glucans with high degrees of polymerization, on the contrary, showed high signals of secondary pyrolysis products, consistent with a lower amount of water and the formation of a liquid phase