Perceptions of change in the environment caused by the COVID-19 pandemic: Implications for environmental policy.

COVID-19 lockdown measures have impacted the environment with both positive and negative effects. However, how human populations have perceived such changes in the natural environment and how they may have changed their daily habits have not been yet thoroughly evaluated. The objectives of this work were to investigate (1) the social perception of the environmental changes produced by the COVID-19 pandemic lockdown and the derived change in habits in relation to i) waste management, energy saving, and sustainable consumption, ii) mobility, iii) social inequalities, iv) generation of noise, v) utilization of natural spaces, and, vi) human population perception towards the future, and (2) the associations of these potential new habits with various socio-demographic variables. First, a SWOT analysis identified strengths (S), weaknesses (W), opportunities (O), and threats (T) generated by the pandemic lockdown measures. Second, a survey based on the aspects of the SWOT was administered among 2370 adults from 37 countries during the period from February to September 2021. We found that the short-term positive impacts on the natural environment were generally well recognized. In contrast, longer-term negative effects arise, but they were often not reported by the survey participants, such as greater production of plastic waste derived from health safety measures, and the increase in e-commerce use, which can displace small storefront businesses. We were able to capture a mismatch between perceptions and the reported data related to visits to natural areas, and generation of waste. We found that age and country of residence were major contributors in shaping the survey participants ´answers, which highlights the importance of government management strategies to address current and future environmental problems. Enhanced positive perceptions of the environment and ecosystems, combined with the understanding that livelihood sustainability, needs to be prioritized and would reinforce environmental protection policies to create greener cities. Moreover, new sustainable jobs in combination with more sustainable human habits represent an opportunity to reinforce environmental policy.

High-resolution structural profile of hylaseptin-4: Aggregation, membrane topology and pH dependence of overall membrane binding process.

Hylaseptin-4 (HSP-4, GIGDILKNLAKAAGKAALHAVGESL-NH2) is an antimicrobial peptide originally isolated from Hypsiboas punctatus tree frog. The peptide has been chemically synthetized for structural investigations by CD and NMR spectroscopies. CD experiments reveal the high helical content of HSP-4 in biomimetic media. Interestingly, the aggregation process seems to occur at high peptide concentrations either in aqueous solution or in presence of biomimetic membranes, indicating an increase in the propensity of the peptide for adopting a helical conformation. High-resolution NMR structures determined in presence of DPC-d38 micelles show a highly ordered α-helix from amino acid residues I2 to S24 and a smooth bend near G14. A large separation between hydrophobic and hydrophilic residues occurs up to the A16 residue, from which a shift in the amphipathicity is noticed. Oriented solid-state NMR spectroscopy show a roughly parallel orientation of the helical structure along the POPC lipid bilayer surface, with an insertion of the hydrophobic N-terminus into the bilayer core. Moreover, a noticeable pH dependence of the aggregation process in both aqueous and in biomimetic membrane environments is attributed to a single histidine residue (H19). The protonation degree of the imidazole side-chain might help in modulating the peptide-peptide or peptide-lipid interactions. Finally, molecular dynamics simulations confirm the orientation and preferential helical conformation and in addition, show that HSP-4 tends to self-aggregate in order to stabilize its active conformation in aqueous or phospholipid bilayer environments.

Constituents from stem barks of Luehea ochrophylla Mart and evaluation of their antiparasitic, antimicrobial, and antioxidant activities.

Luehea species are found in almost all Central and South American countries. The present work describes the phytochemical study, isolation, and structural characterisation of friedelin, ß-friedelinol, lupeol, pseudotaraxasterol, ß-sitosterol, betulinic acid, taraxasterol, (-)-epicatechin, ß-sitosterol-3-O-ß-d-glucopyranoside, and (+)-epicatechin-(4ß→8)-epicatechin from stem barks of Luehea ochrophylla Mart. The structural identification of the isolated compounds was mainly performed by NMR analyses and comparison with the data from literature. These compounds were isolated for the first time in the genus Luehea, except ß-sitosterol glucopyranoside, (-)-epicatechin, and lupeol. Hexane extract (HE) and dichloromethane (DF) and ethyl acetate (AF) fractions exhibited antiparasitic activity against amastigote (intracellular) and trypomastigote culture forms of Trypanosoma cruzi. The ethanol extract (EE), DF, and ethanol fraction (EF) exhibited considerable antifungal activity against Candida albicans. Moreover, extracts and fractions exhibited significant percentage of capture free radicals of 2,2-diphenyl-picrylhydrazyl (DPPH) when compared to the standard of ascorbic acid.

Constituents of Brosimum potabile.

The ethanolic extract from the stem of Brosimum potabile afforded (-)-centrolobin (1), isolated for the first time in this genus. The identification of this compound included COSY and NOESY two-dimensional NMR data.