2D FTIR correlation spectroscopy and EPR analysis of Urtica dioica leaves from areas of different environmental pollution

Air pollution in the places of Betula pendula growth and development changes the physicochemical properties and the main allergen content of its pollen

Pollen allergy becomes an increasing problem for humans, especially in the regions, where the air pollution level increases due to the traffic and urbanization. These factors may also affect the physiological activity of plants, causing changes in pollen allergenicity. The aim of the study was to estimate the influence of air pollutants on the chemical composition of birch pollen and the secondary structures of the Bet v1 protein. The research was conducted in seven locations in Malopolska region, South of Poland of a different pollution level. We have found slight fluctuations in the values of parameters describing the photosynthetic light reactions, similar spectra of leaf reflectance and the negligible differences in the discrimination values of the δ13C carbon isotope were found. The obtained results show a minor effect of a degree of pollution on the physiological condition B. pendula specimen. On the other hand, mean Bet v1 concentration measured in pollen samples collected in Kraków was significantly higher than in less polluted places (p = .03886), while FT-Raman spectra showed the most distinct variations in the wavenumbers characteristic of proteins. Pollen collected at sites of the increased NOx and PM concentration, show the highest percentage values of potential aggregated forms and antiparallel β-sheets in the expense of α-helix, presenting a substantial impact on chemical compounds of pollen, Bet v1 concentration and on formation of the secondary structure of proteins, what can influence their functions.

Characterization of nettle leaves (Urtica dioica) as a novel source of protease for clotting dromedary milk by non-destructive methods

This study investigates the valorization of the nettle leaves (Urtica dioica) as a novel source of a protease for clotting dromedary milk. The aim of this work is to study the effect of extracting pH on the enzymatic activity of nettle leaves extracts. The extraction was achieved in phosphate citrate buffer at different pH values (from 3 to 6.5) and the obtained extracts were used to coagulate dromedary milk. The characterization of the obtained extracts was carried out using non-destructive methods namely FT-MIR, fluorescence spectroscopy and turbiscan instrument. The extract prepared at pH = 4 had the highest proteolytic activity. The fluorescence and turbiscan measurements revealed a substantial effect of the pH value on chlorophyll residues extraction and stability, respectively. At an acidic environment (pH range of 3 - 4), the enzymatic extracts were unstable (with turbiscan stability index (TSI) values ~ 20), while at a nearly neutral pH value (pH range of 5 - 6.5), they were found to be more stable as indicated by the low TSI values ~ 1. The maximum milk-clotting activity (MCA) (0.021 U/mL) was obtained for the extracts prepared at pH = 4.

Nitrogen influenced biomolecular changes on Physalis L. species studied using 2DCOS spectral analysis coupled with chemometric and Receiver operation characteristics analysis

The determination of the molecular composition of plant leaves is essential to assist in nutritional management, whether for cultivated or non-cultivated species. In this sense, the study aimed to apply FTIR technique in combination with chemometrics and ROC analysis for the evaluation of changes in compositional of plant leaves of Physalis angulata and Physalis peruviana due to nitrogen fertilization treatments. Both species were grown under different doses of nitrogen (0, 200, 400, and 600 Kg ha^-1) and leaf samples were evaluated using ATR-FTIR. Our results demonstrate that the spectra of both species were influenced by the nitrogen doses. The computed band area from the lipid/amide, lipid/carbohydrates, degree of esterification and calcium oxalate shows nitrogen fertilization due to 400 Kg ha^-1 of N treatment is more effective for a better quality of yield. 2D correlation spectral analysis (2DCOS) reveals cellulose and pectin begins changes followed by amide of proteins due to nitrogen treatment in P. peruviana samples. The P. angulata plants shows hemicellulose changes predominating followed by proteins and polysaccharides. The obtained principle component analysis plot and loading values show the Physalis species samples distinctly separated from control with protein and carbohydrates are predominant in influencing separation among them. Receiver operation characteristic analysis shows a higher value of area under the curve reflecting better reliability of the experiments carried out. Hierarchical cluster analysis shows closed separation for a similar group on dissimilarity scale. Thus the use of 2DCOS coupled with chemometrics helps to identify changes in the composition of leaves of physalis species due to nitrogen doses, constituting a fast and precise measuring for the suitable management of this fertilization.