SARS-CoV-2 E-PROTEIN VIROPORIN INHIBITOR BIT225 ACTIVE IN hACE2 TRANSGENIC MICE

Background: The CoV-2 envelope (E) protein plays an important role in virus assembly, budding, immunopathogenesis and disease severity. E protein has ion channel activity, is located in Golgi and ER membranes of infected cells and is associated with inflammasome activation and immune dysregulation. Here we report that BIT225, an investigational HIV clinical compound, inhibits E ion channel activity and prevents body weight loss and mortality and reduces inflammation in lethally infected K18-hACE2 transgenic mice. BIT225 efficacy was observed when dosing was initiated before or 24 h or 48 h after infection. Method(s): SARS-CoV-2 E protein ion channel activity and Xenopus TMEM16A were measured in Xenopus oocytes. K18-hACE2 transgenic mice were infected intranasally with 104 pfu SARS CoV 2 (US-WA1/2020) and dosed orally twice daily with BIT225 for up to 12 Days. Dosing was initiated 12 h pre-infection or 24 h or 48 h post-infection. Disease parameters measured were survival, body weight, viral RNA by qPCR and infectious virus titre (plaque assay) in lung tissue homogenates and serum. In addition, levels of pro-inflammatory cytokines (IL-6, IL-1alpha, IL-1beta, TNFalpha & TGFbeta, MCP-1) were measured in lung and serum samples. Result(s): BIT225 inhibited ion channel activity of E-protein, but not that of TMEM16A in Xenopus oocytes. BIT225 dosed at 300mg/kg BID for 12 days starting 12 h pre-infection completely prevented body weight loss and mortality in SARS-CoV-2 infected K18 mice (n=12), while all vehicle-dosed animals reached a mortality endpoint by day 9 across two studies (n=12). Figure 1 shows results from a time of addition study: When treatment with BIT225 started at 24 h post-infection, body weight loss and mortality was also prevented (100% survival, n=5). In the group of mice where treatment started at 48 h after infection, body weight loss and mortality were prevented in 4 of 5 mice. Treatment efficacy was associated with significant reduction in lung viral load (3.5 log10), virus titer (4000 pfu/ml) and lung and serum cytokine levels. Conclusion(s): BIT225 is an inhibitor of SARS-CoV-2 E-protein viroporin activity. In the K18 model BIT225 protected mice from weight loss and death, inhibited virus replication and reduced inflammation. These effects were noted when treatment with BIT225 was initiated before or 24-48 hours after infection and validate viroporin E as a viable antiviral target and support the clinical study of BIT225 in treatment of SARS-CoV-2.

In silico investigation of the therapeutic and prophylactic potential of medicinal substances bearing guanidine moieties against COVID-19.

The current viral pandemic, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), creates health, mental, economic, and other serious challenges that are better to say global crisis. Despite the existence of successful vaccines, the possible mutations which can lead to the born of novel and possibly more dangerous variants of the virus as well as the absence of definitive treatment for this potentially fatal multiple-organ infection in critically ill patients make us keep searching. Theoretically targeting human and viral receptors and enzymes via molecular docking and dynamics simulations can be considered a wise, rational, and efficient way to develop therapeutic agents against COVID-19. In this way, The RNA-dependent RNA polymerase (RdRP), main protease, and spike glycoprotein of SARS-CoV-2 as well as the human angiotensin-converting enzyme 2 receptor and transmembrane serine protease 2 are the most discussed and studied targets that play essential roles in the viral life and infection cycle. In the current in silico investigation, the guanidine functionality containing drugs and medicinal substances such as metformin, famotidine, neuraminidase inhibitors, antimalarial medications, anticancer drug imatinib, CGP compounds, and human serine protease inhibitor camostat were studied against the above-mentioned therapeutic targets and most of them (especially imatinib) have revealed an incredible spectrum of free docking scores and MD results. The current in silico investigation that its novel perspective of view is corroborated by the different experimental and clinical evaluations, confirms that the guanidine moiety can be considered as a missing promising pharmacophore in drug design and development approaches against SARS-CoV-2. Considering the chemical potency of this polyamine group in chemical interaction creation, the observed outcomes in this virtual screening were not surprising. On the other hand, the guanidine functional group has unique physico-chemical properties such as basicity that can make the target cells intracellular pH undesirable for the virus entry, uncoating, and cytosolic lifecycle. According to the obtained results in the current study that are interestingly confirmed by the previously reported efficacy of some the guanidine carrying drugs in COVID-19, guanidine as a potential multi-target anti-SARS-CoV-2 functional scaffold deserves further comprehensive investigations. Supplementary Information: The online version contains supplementary material available at 10.1007/s11696-022-02528-y.

Efficacy Validation of SARS-CoV-2-Inactivation and Viral Genome Stability in Saliva by a Guanidine Hydrochloride and Surfactant-Based Virus Lysis/Transport Buffer.

To enhance biosafety and reliability in SARS-CoV-2 molecular diagnosis, virus lysis/transport buffers should inactivate the virus and preserve viral RNA under various conditions. Herein, we evaluated the SARS-CoV-2-inactivating activity of guanidine hydrochloride (GuHCl)- and surfactant (hexadecyltrimethylammonium chloride (Hexa-DTMC))-based buffer, Prep Buffer A, (Precision System Science Co., Ltd., Matsudo, Japan) and its efficacy in maintaining the stability of viral RNA at different temperatures using the traditional real-time one-step RT-PCR and geneLEAD VIII sample-to-result platform. Although Prep Buffer A successfully inactivated SARS-CoV-2 in solutions with high and low organic substance loading, there was considerable viral genome degradation at 35 °C compared with that at 4 °C. The individual roles of GuHCl and Hexa-DTMC in virus inactivation and virus genome stability at 35 °C were clarified. Hexa-DTMC alone (0.384%), but not 1.5 M GuHCl alone, exhibited considerable virucidal activity, suggesting that it was essential for potently inactivating SARS-CoV-2 using Prep Buffer A. GuHCl and Hexa-DTMC individually reduced the viral copy numbers to the same degree as Prep Buffer A. Although both components inhibited RNase activity, Hexa-DTMC, but not GuHCl, directly destroyed naked viral RNA. Our findings suggest that samples collected in Prep Buffer A should be stored at 4 °C when RT-PCR will not be performed for several days.

Effects of Ozone on the thermal decomposition behavior of Guanidine Nitrate

The deterioration of chemicals contained in safety devices is an important issue because such devices must be ready for emergencies and should remain functional for a long period of time, even when exposed to degrading environments. In this study, we focused on the influence of ozone disinfection on chemicals present in safety devices as ozone can be used for virus inactivation in compartments housing these devices. Specifically, we conducted accelerated deterioration tests to evaluate the effects of ozone exposure on guanidine nitrate (GN).Under the experimental conditions of this study, ozone-containing water deteriorated GN, whereas no change was observed in GN exposed to dry ozone. The ion chromatography (IC) analysis of the deteriorated product suggested that GN decomposed into nitrate ions, while capillary electrophoresis (CE) revealed a transformation of guanidine ions into ammonium ions. These results imply that GN deterioration produces ammonium nitrate. Additionally, ultraviolet-visible spectroscopy revealed the reaction products between GN and ozone, which were considered electrically neutral because of their absence in the results of IC and CE analyses.In a differential accelerating rate calorimeter, decomposition started at a lower temperature for the deteriorated GN than for the pristine sample. This indicates that the deterioration products affected the thermal decomposition behavior of GN. This change in exothermic and pressure-release behavior is considered to have an impact on the performance of pyrotechnics using GN.

Antiseptic drugs and disinfectants with experience of the second year of COVID-19 pandemic-related side effects

This review covers publications during the period January 2021 to December 2021 on adverse reactions to antiseptic drugs and disinfectants. Specific agents discussed are alcohols (ethanol, isopropanol), aldehydes (formaldehyde), ethylene oxide, guanidines (chlorhexidine, polyhexamethylene guanidine, and polyhexamethylene biguanidine), benzalkonium compounds, triclosan, povidone-iodine, and sodium hypochlorite. No new data were identified for glutaraldehyde, cetrimide, tosylchloramide, triclocarban, and phenolic compounds. The use of antiseptic drugs and disinfectants has increased considerably since 2020 in various medical and occupational settings, in commerce and gastronomy, as well as in the home, due to their antiviral properties against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the still ongoing Coronavirus Disease 2019 (COVID-19) pandemic. Irritant effects on the respiratory system, the skin and eyes were the most common adverse reaction, while the widespread and occasionally excessive use led to increased reports of poisonings as well as of oral misuse of disinfectants, sometimes associated with serious outcomes such as death from methanol intoxication. Eye exposures in children caused by inadvertent exposures due to unsupervised dispensers in public spaces were pointed out as being specifically problematic. Side effects in the eye may also occur in the general population by improper and unprotected use of UV lamps. The need to improve the safe use of disinfectant devices was pointed out in general.

METASTATIC BLADDER PARAGANGLIOMA WITH UNDERLYING SHDB MUTATION

Introduction Phaeochromocytoma and paraganglioma (PPGL) are rare tumors with up to 40% associated with inherited germline mutations. SHDB mutation is associated with an increased risk of metastasis. Case A 36-year-old male presented with hypertensive emergency. He was diagnosed to have a bladder paraganglioma at age 32 when he presented with hypertensive crisis. Ga-68 DOTANOC PET/CT scan then showed a localized 4.7 x 5.3 cm bladder paraganglioma and he underwent complete surgical resection with resolution of his symptoms. Genetic testing done showed SHDB, deletion (exon 1), heterogenous pathogenic variant. He remained asymptomatic and was lost to follow-up due to COVID-19 until his recent admission. During this admission, he had labile blood pressure with symptoms of palpitations and lethargy. He was found to have a 4.3x elevated urine normetanephrine (1639 ug/day, N<374.7). Metanephrine and 3-methoxytyramine levels were normal. His blood pressure was controlled with phenoxybenzamine 20 mg TDS (1 mg/kg), telmisartan 40 mg OM and carvedilol 25 mg BD with improvement in his symptoms. Subsequent anatomical imaging with CT and functional imaging with Ga-68 DOTATATE showed a small recurrence at the bladder wall with metastatic lesions at the left sacral ala measuring 4.5 x 5.1 cm, and multiple lytic lesions over the spine, ribs and also the left acetabulum with the highest uptake of Ga-68 DOTATATE at the C2 vertebra (SUV max 93). He is now planned for peptide receptor radionuclide therapy (PRRT). SHDB mutation is associated with a higher risk of metastatic disease which has remained unexplained. Treatment for metastatic disease include surgical resection where possible, targeted therapy such as PRRT, meta-iodobenzylguanidine (MIBG) therapy, radiotherapy and also systemic therapy such as chemotherapy and tyrosine kinase inhibitors. Conclusion Patients with PPGL, especially those with SHDB mutation, require monitoring at regular intervals to screen and detect metastasis to reduce mortality and morbidity.

Investigating the structure-activity relationship of marine polycyclic batzelladine alkaloids as promising inhibitors for SARS-CoV-2 main protease (Mpro).

Over a span of two years ago, since the emergence of the first case of the novel coronavirus (SARS-CoV-2) in China, the pandemic has crossed borders causing serious health emergencies, immense economic crisis and impacting the daily life worldwide. Despite the discovery of numerous forms of precautionary vaccines along with other recently approved orally available drugs, yet effective antiviral therapeutics are necessarily needed to hunt this virus and its variants. Historically, naturally occurring chemicals have always been considered the primary source of beneficial medications. Considering the SARS-CoV-2 main protease (Mpro) as the duplicate key element of the viral cycle and its main target, in this paper, an extensive virtual screening for a focused chemical library of 15 batzelladine marine alkaloids, was virtually examined against SARS-CoV-2 main protease (Mpro) using an integrated set of modern computational tools including molecular docking (MDock), molecule dynamic (MD) simulations and structure-activity relationships (SARs) as well. The molecular docking predictions had disclosed four promising compounds including batzelladines H-I (8-9) and batzelladines F-G (6-7), respectively according to their prominent ligand-protein energy scores and relevant binding affinities with the (Mpro) pocket residues. The best two chemical hits, batzelladines H-I (8-9) were further investigated thermodynamically though studying their MD simulations at 100 ns, where they showed excellent stability within the accommodated (Mpro) pocket. Moreover, SARs studies imply the crucial roles of the fused tricyclic guanidinic moieties, its degree of unsaturation, position of the N-OH functionality and the length of the side chain as a spacer linking between two active sites, which disclosed fundamental structural and pharmacophoric features for efficient protein-ligand interaction. Such interesting findings are greatly highlighting further in vitro/vivo examinations regarding those marine natural products (MNPs) and their synthetic equivalents as promising antivirals.

COVID-19 pneumonia in a child. A surprise finding

Background: Coronavirus disease 19 (COVID-19) tends to be milder in children, but severe cases have been reported. We described a case report of a toddler admitted to our department with additional findings, highlighting the importance of assessing the patient as a whole. Case Presentation: A previously healthy, 15-month-year-old girl presented with fever and dry cough for 10 days, respiratory distress and PCR SARS-CoV-2 was positive. At admission, she presented with hypoxemia (SpO2 89-90% in room air), global retraction and bilateral bronchospasm. She was treated with bronchodilators, methylprednisolone, remdesivir and also amoxicillin/clavulanic acid. Her complete blood count revealed leucocytosis 16,160x109/L, 41% lymphocytes, C-reactive protein 57,9 mg/L, procalcitonin 0,13 ng/mL, sedimentation rate 44 mm/h, ferritin 218,4 ng/mL. Chest computed tomography (CT) scan revealed bilateral peripheral areas of ground glass, coexisting consolidation areas at inferior lobes but also revealed a 6 cm supra-renal mass. Abdominal ultrasound and CT confirmed an heterogeneous right supra-renal gland mass of 5,5cm along the greatest diameter with diffuse calcifications, evolving the inferior vena cava and the renal vascular pedicle, no signs of liver, bone, cutaneous or ganglionic metastization. These features were suggestive of neuroblastoma in stage L2. Vanillylmandelic acid, normetanephrine/creatinine ratio and metanephrine/creatinine ratio were elevated. The metaiodobenzylguanidine (Mibg) scan showed a localized disease. The total excision of the tumour mass was performed, and the histology confirmed neuroblastoma with no N-myc oncogene amplification, nor other bad prognosis chromosomal abnormalities. She is currently under oncological surveillance, with no signs of recurrence. Learning Points Discussion: Neuroblastoma is the most common extracranial solid tumour of childhood. It is known for its broad spectrum of clinical behaviour and outcome. In this case, although this toddler was admitted due to COVID-19 pneumonia, it allowed to identify a localized tumour, perform excision and due to the favourable biology tumour, she has a very good chances of being cured and free of disease.

Filling in the Gaps in Metformin Biodegradation: a New Enzyme and a Metabolic Pathway for Guanylurea.

The widely prescribed pharmaceutical metformin and its main metabolite, guanylurea, are currently two of the most common contaminants in surface and wastewater. Guanylurea often accumulates and is poorly, if at all, biodegraded in wastewater treatment plants. This study describes Pseudomonas mendocina strain GU, isolated from a municipal wastewater treatment plant, using guanylurea as its sole nitrogen source. The genome was sequenced with 36-fold coverage and mined to identify guanylurea degradation genes. The gene encoding the enzyme initiating guanylurea metabolism was expressed, and the enzyme was purified and characterized. Guanylurea hydrolase, a newly described enzyme, was shown to transform guanylurea to one equivalent (each) of ammonia and guanidine. Guanidine also supports growth as a sole nitrogen source. Cell yields from growth on limiting concentrations of guanylurea revealed that metabolism releases all four nitrogen atoms. Genes encoding complete metabolic transformation were identified bioinformatically, defining the pathway as follows: guanylurea to guanidine to carboxyguanidine to allophanate to ammonia and carbon dioxide. The first enzyme, guanylurea hydrolase, is a member of the isochorismatase-like hydrolase protein family, which includes biuret hydrolase and triuret hydrolase. Although homologs, the three enzymes show distinct substrate specificities. Pairwise sequence comparisons and the use of sequence similarity networks allowed fine structure discrimination between the three homologous enzymes and provided insights into the evolutionary origins of guanylurea hydrolase.IMPORTANCE Metformin is a pharmaceutical most prescribed for type 2 diabetes and is now being examined for potential benefits to COVID-19 patients. People taking the drug pass it largely unchanged, and it subsequently enters wastewater treatment plants. Metformin has been known to be metabolized to guanylurea. The levels of guanylurea often exceed that of metformin, leading to the former being considered a "dead-end" metabolite. Metformin and guanylurea are water pollutants of emerging concern, as they persist to reach nontarget aquatic life and humans, the latter if it remains in treated water. The present study has identified a Pseudomonas mendocina strain that completely degrades guanylurea. The genome was sequenced, and the genes involved in guanylurea metabolism were identified in three widely separated genomic regions. This knowledge advances the idea that guanylurea is not a dead-end product and will allow for bioinformatic identification of the relevant genes in wastewater treatment plant microbiomes and other environments subjected to metagenomic sequencing.

Comprehensive Virtual Screening of the Antiviral Potentialities of Marine Polycyclic Guanidine Alkaloids against SARS-CoV-2 (COVID-19).

The huge global expansion of the COVID-19 pandemic caused by the novel SARS-corona virus-2 is an extraordinary public health emergency. The unavailability of specific treatment against SARS-CoV-2 infection necessitates the focus of all scientists in this direction. The reported antiviral activities of guanidine alkaloids encouraged us to run a comprehensive in silico binding affinity of fifteen guanidine alkaloids against five different proteins of SARS-CoV-2, which we investigated. The investigated proteins are COVID-19 main protease (Mpro) (PDB ID: 6lu7), spike glycoprotein (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17), and a non-structural protein (nsp10) (PDB ID: 6W4H). The binding energies for all tested compounds indicated promising binding affinities. A noticeable superiority for the pentacyclic alkaloids particularly, crambescidin 786 (5) and crambescidin 826 (13) has been observed. Compound 5 exhibited very good binding affinities against Mpro (ΔG = -8.05 kcal/mol), nucleocapsid phosphoprotein (ΔG = -6.49 kcal/mol), and nsp10 (ΔG = -9.06 kcal/mol). Compound 13 showed promising binding affinities against Mpro (ΔG = -7.99 kcal/mol), spike glycoproteins (ΔG = -6.95 kcal/mol), and nucleocapsid phosphoprotein (ΔG = -8.01 kcal/mol). Such promising activities might be attributed to the long ω-fatty acid chain, which may play a vital role in binding within the active sites. The correlation of c Log P with free binding energies has been calculated. Furthermore, the SAR of the active compounds has been clarified. The Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) studies were carried out in silico for the 15 compounds; most examined compounds showed optimal to good range levels of ADMET aqueous solubility, intestinal absorption and being unable to pass blood brain barrier (BBB), non-inhibitors of CYP2D6, non-hepatotoxic, and bind plasma protein with a percentage less than 90%. The toxicity of the tested compounds was screened in silico against five models (FDA rodent carcinogenicity, carcinogenic potency TD50, rat maximum tolerated dose, rat oral LD50, and rat chronic lowest observed adverse effect level (LOAEL)). All compounds showed expected low toxicity against the tested models. Molecular dynamic (MD) simulations were also carried out to confirm the stable binding interactions of the most promising compounds, 5 and 13, with their targets. In conclusion, the examined 15 alkaloids specially 5 and 13 showed promising docking, ADMET, toxicity and MD results which open the door for further investigations for them against SARS-CoV-2.