Phytochemicals containing biologically active polyphenols as an effective agent against Covid-19-inducing coronavirus.

The outbreak of Covid-19 disease caused by SARS-CoV-19, along with the lack of targeted medicaments and vaccines, forced the scientific world to search for new antiviral formulations. In this review, we describe the current knowledge about plant extracts containing polyphenols that inhibit Covid-19. Many plant-derived natural compounds (polyphenols) might provide a starting point for the research on the use of plant extracts in coronavirus treatment and prevention. Antivirus polyphenolic drugs can inhibit coronavirus enzymes, which are essential for virus replication and infection. This group of natural substances (betulinic acid, indigo, aloeemodine, luteolin, and quinomethyl triterpenoids, quercitin or gallates) is a potential key to designing antiviral therapies for inhibiting viral proteases. The known pharmacophore structures of bioactive substances can be useful in the elaboration of new anti-Covid-19 formulations. The benefit of using preparations containing phytochemicals is their high safety for patients and no side effects.

Remote-control of the enantiomeric supramolecular recognition mediated by chiral azobenzenes bound to human serum albumin.

Three novel tyrosine-conjugated azobenzene molecules were designed and their ability to target a natural chiral host matrix (human serum albumin, HSA) was investigated. We found that the interplay between the spatial configuration of the chiral substituents and the change in local symmetry resulting from the photoisomerization process strongly affects the optical activity of the bound photochromes. In particular, the different signal amplification obtained upon binding of the photoswitches to the biopolymer enables obtaining a chirooptical system tunable over a wide range of wavelengths.

Effective control of the intrinsic DNA morphology by photosensitive polyamines.

Non-viral vectors for gene therapy such as DNA-cationic probe complexes offer important bio-safety advantages over viral approaches, due to their reduced pathogenicity, immunogenicity and cytotoxicity. In the present study we examine two polycationic water-soluble azobenzene derivatives (bis-Azo-2N and bis-Azo-3N) containing different linear unsubstituted polyamine moieties and we demonstrate the ability of such photochromes to destabilize the intrinsic B-DNA secondary structure in a concentration-dependent manner. Furthermore, through a detailed series of biophysical experiments, varying the photochrome conformation, temperature, salt and DNA concentration, we provide a detailed insight into the azobenzene-DNA binding pathway (Ka: bis-Azo-2N(trans)-DNA = 5.3 ± 0.3 × 104 M-1, Ka: bis-Azo-2N(cis)-DNA = 2.6 ± 0.2 × 104 M-1, Ka: bis-Azo-3N(trans)-DNA = 7.1 ± 0.4 × 104 M-1 and Ka: bis-Azo-3N(cis)-DNA = 5.1 ± 0.4 × 104 M-1) establishing the versatility of such materials as promising candidates for use in non-viral gene delivery systems.

Using metabolomics to monitor kidney transplantation patients by means of clustering to spot anomalous patient behavior.

BACKGROUND: NMR spectroscopy-based metabolomics is a system approach used to investigate the metabolic profile of biological fluids with multivariate data analysis tools. The aim of this study was to examine the kidney graft recovery process noninvasively through the examinations of urine samples using (1)H NMR spectroscopy combined with chemometric tools. METHODS: Urine samples were treated as the source of metabolites reflecting the pathological and clinical conditions of patients with transplanted kidneys. We observed 15 subjects (9 males and 6 females) during the graft recovery process and initial days thereafter. The patients provided at least 9 samples each, applying advanced statistical methods of analysis: Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis PLS-DA). RESULTS: The PCA model (for all subjects exp. var. PC1 13.96% and PC2 9.88%) allowed us to clearly designate 3 stages of recovery: initially the kidney is not working; in the second stage, it regains functions, and the third stage includes follow-up during hospitalization. PCA analysis of a single patient follows graft recovery based on biochemical (metabolites) information, assigning the appropriate recuperation stage. CONCLUSIONS: NMR spectroscopy together with chemometric analysis allow monitoring of kidney graft recovery to identify patients who are not progressing within the normal range.

Coordination of heavy metals by dithiothreitol, a commonly used thiol group protectant.

D,L-Dithiothreitol (DTT), known also as Cleland reagent, is a thiol group protectant, used commonly in peptide and protein chemistry. Therefore, it is often added at high concentrations in preparations of proteins relevant to heavy metal biochemistry. The coordination of five of these metal ions, Zn(II), Cd(II), Pb(II), Ni(II) and Cu(I) to DTT was studied by means of potentiometric titrations, and UV-Vis and NMR spectroscopies. It was found that DTT forms specific and very stable polymeric and monomeric complexes with all of these metal ions, using both of its sulfur donors. The quantitative description of these complexes in solution and the solid state provides the basis for predictions of interference from DTT in studies of metal ion binding of thiol-containing biomolecules.

Copper complexes of glycyl-histidyl-lysine and two of its synthetic analogues: chemical behaviour and biological activity.

Copper complex formation equilibria of glycyl-L-histidyl-L-lysine (Gly-His-Lys, GHK) and of two synthetic analogues, where the histidine residue was replaced with a synthetic amino acid (L-spinacine or L-1,2,3,4-tetrahydro-isoquinoline-3-carboxylic acid), have been carefully investigated using different experimental techniques: potentiometry, solution calorimetry, UV-VIS spectrophotometry, circular dichroism and electron paramagnetic resonance spectroscopies. All the ligands formed complexes having different stoichiometries and stabilities; evidence for the formation of binuclear species is also shown. The structures of the main complexes are discussed. It is suggested that the lateral lysine amino group participates in complex formation, but only at alkaline pH values: at physiological pH this group is protonated and available for possible interactions with cellular receptors. The above tripeptides have been tested for their enzymatic stability in human serum: the synthetic compounds showed no significant degradation for at least 3 h. Finally, their activity as growth factor has been studied in vitro. The two synthetic analogues showed an activity comparable to or even higher than that of GHK, thus suggesting their possible use as additives in cell culture media, even in the presence of serum. Relevant information on the GHK action mechanism as cell growth factor has been obtained: the formation of copper complexes, driven by the first (Gly) residue, appears necessary while the second residue (His) does not appear to play a specific role; the presence of the free side chain of the third residue (Lys) appears to be of fundamental importance.