Benzenesulfonamide derivatives as Vibrio cholerae carbonic anhydrases inhibitors: a computational-aided insight in the structural rigidity-activity relationships.

Vibrio cholerae causes life-threatening infections in low-income countries due to the rise of antibacterial resistance. Innovative pharmacological targets have been investigated and carbonic anhydrases (CAs, EC: 4.2.1.1) encoded by V. cholerae (VchCAs) emerged as a valuable option. Recently, we developed a large library of para- and meta-benzenesulfonamides characterised by moieties with a different flexibility degree as CAs inhibitors. Stopped flow-based enzymatic assays showed strong inhibition of VchαCA for this library, while lower affinity was detected against the other isoforms. In particular, cyclic urea 9c emerged for a nanomolar inhibition of VchαCA (KI = 4.7 nM) and high selectivity with respect to human isoenzymes (SI≥ 90). Computational studies revealed the influence of moiety flexibility on inhibitory activity and isoform selectivity and allowed accurate SARs. However, although VchCAs are involved in the bacterium virulence and not in its survival, we evaluated the antibacterial activity of such compounds, resulting in no direct activity.

Synthesis, characterization, molecular docking and network pharmacology of bioactive metallic sulfonamide-isatin ligands against promising drug targets

• Synthesis of new Sulfonamide-isatin based scaffolds to incorporate first row metals. • Molecular docking to find a best docking pocket for COVID-19 protein. • Online network pharmacology to find a best target for Alzheimer and carbonic anhydrase-II related gene targets. • Characterization with most promising analytical techniques and DFT based studies. • In vitro enzyme inhibition and antimicrobial profiling of new compounds. A series of sulfonamide and isatin based Schiff bases, (S1) and (S2), and their metal (Co2+, Ni2+, Cu2+ and Zn2+) complexes (1)-(8) were synthesized and characterized by spectroscopic (UV, IR, MS, 1H and 13C-NMR), elemental, magnetic and physical techniques. The non-electrolytic character of Co2+, Ni2+, and Zn2+ compounds and electrolytic nature of Cu2+ was established by their conductance studies. The energies of Frontier Molecular Orbitals (FMOs) were also used to explore various global and quantum chemical qualities. To find the activity and molecular targets in curing Alzheimer's Disease (AD) and Carbonic Anhydrase II (CA-II) inhibition, Network Pharmacology modeling was used. The prospective targets were predicted using the Swiss Target PredictionR online facility. The Gene CardsR database has been used to find genes linked to AD and CA-II. We also conducted Gene OntologyR (GO) analysis on the intersecting genes targets on active targets of synthesized compounds by DAVID (Database for Annotation, Visualization and Integrated Discovery) Bioinformatics Services using the CytoscapeR program. The in vitro enzyme inhibition assays were done against protease, amylase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) while their antimicrobial studies were performed against pathogenic bacterial and fungal species. The antioxidant values, evaluated as 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing assay power (FRAP) (%) ranged between 51.0±0.11-68.1±0.11% with IC 50 ranging 146.84-196.08 µL/mol. [Display omitted] [ FROM AUTHOR]

Gustatory and Saliva Secretory Dysfunctions in COVID-19 Patients with Zinc Deficiency.

Given the ever-progressing studies on coronavirus disease 2019 (COVID-19), it is critical to update our knowledge about COVID-19 symptomatology and pathophysiology. In the present narrative review, oral symptoms were overviewed using the latest data and their pathogenesis was hypothetically speculated. PubMed, LitCovid, ProQuest, and Google Scholar were searched for relevant studies from 1 April 2021 with a cutoff date of 31 January 2022. The literature search indicated that gustatory dysfunction and saliva secretory dysfunction are prevalent in COVID-19 patients and both dysfunctions persist after recovery from the disease, suggesting the pathogenic mechanism common to these cooccurring symptoms. COVID-19 patients are characterized by hypozincemia, in which zinc is possibly redistributed from blood to the liver at the expense of zinc in other tissues. If COVID-19 induces intracellular zinc deficiency, the activity of zinc-metalloenzyme carbonic anhydrase localized in taste buds and salivary glands may be influenced to adversely affect gustatory and saliva secretory functions. Zinc-binding metallothioneins and zinc transporters, which cooperatively control cellular zinc homeostasis, are expressed in oral tissues participating in taste and saliva secretion. Their expression dysregulation associated with COVID-19-induced zinc deficiency may have some effect on oral functions. Zinc supplementation is expected to improve oral symptoms in COVID-19 patients.

Is carbonic anhydrase inhibition useful as a complementary therapy of Covid-19 infection?

The ongoing Covid-19 is a contagious disease, and it is characterised by different symptoms such as fever, cough, and shortness of breath. Rising concerns about Covid-19 have severely affected the healthcare system in all countries as the Covid-19 outbreak has developed at a rapid rate all around the globe. Intriguing, a clinically used drug, acetazolamide (a specific inhibitor of carbonic anhydrase, CA, EC 4.2.1.1), is used to treat high-altitude pulmonary oedema (HAPE), showing a high degree of clinical similarities with the pulmonary disease caused by Covid-19. In this context, this preliminary study aims to provide insights into some factors affecting the Covid-19 patients, such as hypoxaemia, hypoxia as well as the blood CA activity. We hypothesise that patients with Covid-19 problems could show a dysregulated acid-base status influenced by CA activity. These preliminary results suggest that the use of CA inhibitors as a pharmacological treatment for Covid-19 may be beneficial.

Chemical kinetics of the development of coronaviral infection in the human body: Critical conditions, toxicity mechanisms, "thermoheliox", and "thermovaccination".

Kinetic modeling of the behavior of complex chemical and biochemical systems is an effective approach to study of the mechanisms of the process. A kinetic model of coronaviral infection development with a description of the dynamic behavior of the main variables, including the concentration of viral particles, affected cells, and pathogenic microflora, is proposed. Changes in the concentration of hydrogen ions in the lungs and the pH -dependence of carbonic anhydrase activity (a key breathing enzyme) are critical. A significant result is the demonstration of an acute bifurcation transition that determines life or system collapse. This transition is connected with exponential growth of concentrations of the process participants and with functioning of the key enzyme carbonic anhydrase in development of toxic effects. Physical and chemical interpretations of the therapeutic effects of the body temperature rise and the potential therapeutic effect of "thermoheliox" (respiration with a thermolized mixture of helium and oxygen) are given. The phenomenon of "thermovaccination" is predicted, which involves stimulation of the immune response by "thermoheliox".