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Simultaneous component analysis as an interesting preliminary data analysis method in GC-MS – an example of headspace screening of Polish grasses

Wróbel-Szkolak Joanna, Cwener Anna, Pietraś Rafał, Komsta Łukasz

Acta Chromatographica

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2024

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Vol. 36, no. 1

52--58

EN

70 species of grasses family (Poaceae), coming from genera: Agrostis, Alopecurus, Anthoxanthum, Apera, Arrhenatherum, Avena, Brachypodium, Briza, Bromus, Calamagrostis, Corynephorus, Cynosurus, Dactylis, Danthonia, Deschampsia, Digitaria, Echinochloa, Elymus, Eragrostis, Festuca, Glyceria, Helictotrichon, Hierochloe, Holcus, Hordeum, Koeleria, Leymus, Lolium, Milium, Molinia, Nardus, Panicum, Phalaris, Phleum, Phragmites, Poa, Saccharum and Setaria, collected mostly from natural stands in Poland during 2020 season, were subjected to GC-MS fingerprinting of headspace volatile fraction above dried material. Obtained mass spectrometry data were analyzed by means of principal component analysis (PCA) and hierarchical cluster analysis (HCA). Five species: Glyceria maxima (Hartm.) Holmb., Lolium multiflorum Lam., Hordeum jubatum L., Bromus tectorum L. and Bromus secalinus L. were identified as outliers, which is consistent with our earlier analysis by thin layer chromatography. These species deserve further look and their outliance is orthogonal to coumarin content, which was independently observed for odorant species of grasses.

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Characterization of lacosamide metabolites by UHPLC–ESI–HRMS method

Gawlik Maciej, Skibiński Robert, Komsta Łukasz

Acta Chromatographica

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2020

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Vol. 32, no. 2

107--116

EN

In this study, the in vitro phase I metabolism of lacosamide was characterized with the use of ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry (quadrupole time-of-flight). The use of two metabolism simulation techniques (photocatalysis and human liver microsomes) allowed the characterization of a polar metabolite of parent compound, not yet described. The experiment with the participation of HLM gave the ability to describe the full liver metabolic pathway of lacosamide. It has been proven that this molecule undergoes deacetylation, demethylation, and during liver tissue metabolism. Photocatalysis with the use of a TiO2 catalyst was proved to be a complementary technique in mimicking in vitro drug metabolism.

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Military Training Areas and Vegetation – the Effect of Explosion Craters on Species Diversity along a Moisture Gradient

Krawczyk Rafał, Zubel Robert, Komsta Łukasz

Polish Journal of Ecology

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2019

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Vol. 67, nr 3

194--205

EN

Military training areas, where ecosystems are shaped under a complex disturbance regime, are recognized to be favourable pieces of land for maintaining high biological diversity. Our study focused on explosion craters – a small-scale disturbance type of high severity, and their effect on species diversity including vascular plants, bryophytes and lichens. The research was carried out on an active military training area in Nowa Dęba (SE Poland). The examined vegetation represented open communities on nutrient-poor soils with a wide range of soil moisture conditions. We compared 76 pairs of vegetation samples, each pair consisting of a crater and a closely located control plot of the same size. Out of 135 species recorded (72 vascular plants, 33 mosses, 9 liverworts, 22 lichens), 37 were found only in craters, while 19 occurred only in control plots. Both, species number and diversity were significantly higher for craters than controls. In general, the positive effect of cratering on all studied groups rises from dry to wet habitats. The highest increase of diversity was observed in relation to bryophytes in the moist habitats. Moreover, craters within habitats of higher moisture turned out to be more resistant to alien colonization and at the same time were characterized by significantly higher number of red-listed species compared to the control plots. Differences in species composition between craters and undisturbed plots were most visible in moderately moist habitats. We found several species with a strong preference for craters, and the plants of the highest indicative value are Atrichum tenellum and Dicranella cerviculata.