Exploring the Benzazoles Derivatives as Pharmacophores for AChE, BACE1, and as Anti-Aß Aggregation to Find Multitarget Compounds against Alzheimer's Disease.

Despite the great effort that has gone into developing new molecules as multitarget compounds to treat Alzheimer's disease (AD), none of these have been approved to treat this disease. Therefore, it will be interesting to determine whether benzazoles such as benzimidazole, benzoxazole, and benzothiazole, employed as pharmacophores, could act as multitarget drugs. AD is a multifactorial disease in which several pharmacological targets have been identified-some are involved with amyloid beta (Aß) production, such as beta secretase (BACE1) and beta amyloid aggregation, while others are involved with the cholinergic system as acetylcholinesterase (AChE) and butirylcholinesterase (BChE) and nicotinic and muscarinic receptors, as well as the hyperphosphorylation of microtubule-associated protein (tau). In this review, we describe the in silico and in vitro evaluation of benzazoles on three important targets in AD: AChE, BACE1, and Aß. Benzothiazoles and benzimidazoles could be the best benzazoles to act as multitarget drugs for AD because they have been widely evaluated as AChE inhibitors, forming π-π interactions with W286, W86, Y72, and F338, as well as in the AChE gorge and catalytic site. In addition, the sulfur atom from benzothiazol interacts with S286 and the aromatic ring from W84, with these compounds having an IC50 value in the µM range. Also, benzimidazoles and benzothiazoles can inhibit Aß aggregation. However, even though benzazoles have not been widely evaluated on BACE1, benzimidazoles evaluated in vitro showed an IC50 value in the nM range. Therefore, important chemical modifications could be considered to improve multitarget benzazoles' activity, such as substitutions in the aromatic ring with electron withdrawal at position five, or a linker 3 or 4 carbons in length, which would allow for better interaction with targets.

A Novel Compound from the Phenylsulfonylpiperazine Class: Evaluation of In Vitro Activity on Luminal Breast Cancer Cells.

Breast cancer (BC) is the most common cancer in women, and is characterized by its histological and molecular heterogeneity. Luminal BC is an estrogen receptor-positive subtype, with varied clinical courses. Although BC patients are eligible for hormone therapy, both early and late relapses still occur, and thus there is a demand for new cytotoxic and selective treatment strategies for these patients. In the present study, inspired by the structure of phenylsulfonylpiperazine, a series of 20 derivatives were tested in bioassays against MCF7, MDA-MB-231 and MDA-MB-453 BC cells to discover new hit compounds. After 48 h of treatment, 12 derivatives impaired cell viability and presented significant IC50 values against at least one of the tumor lineages. Overall, the luminal BC cell line MCF7 was more sensitive to treatments. Compound 3, (4-(1H-tetrazol-1-yl)phenyl)(4-((4-chlorophenyl)sulfonyl)piperazin-1-yl)methanone, was the most promising, with IC50 = 4.48 µM and selective index (SI) = 35.6 in MCF7 cells. Compound 3 also presented significant antimigratory and antiproliferative activities against luminal BC cells, possibly by affecting the expression of genes involved in the epithelial-mesenchymal transition mechanism, upregulating E-Cadherin transcripts (CDH1). Our findings suggest that phenylsulfonylpiperazine derivatives are potential candidates for the development of new therapies, especially those targeting luminal BC.

Exploring Quinazoline Nitro-Derivatives as Potential Antichagasic Agents: Synthesis and In Vitro Evaluation.

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease in humans. The current antichagasic drugs nifurtimox and benznidazole have inconveniences of toxicity; therefore, the search for alternative therapeutic strategies is necessary. The present study reports the synthesis, drug-likeness predictions, and in vitro anti-trypanosome activity of a series of 14 quinazoline 2,4,6-triamine derivatives. All compounds were tested against T. cruzi (epimastigotes and trypomastigotes) and in HFF1 human foreskin fibroblasts. The bioassays showed that compounds 2-4 containing nitrobenzoyl substituents at 6-position of the quinazoline 2,4,6-triamine nucleus were the most potent on its antiprotozoal activity. The effect was observed at 24 h and it was preserved for at least 5 days. Also, compounds 2-4 were not toxic to the human control cells, showing high selectivity index. The quinazoline nitro derivatives have potential use as antichagasic agents.

Synthesis of Hybrid Molecules with Imidazole-1,3,4-thiadiazole Core and Evaluation of Biological Activity on Trypanosoma cruzi and Leishmania donovani.

The aim of this work was to obtain and evaluate, as antiprotozoals, new derivatives of benzoate imidazo-1,3,4-thiadiazole 18-23 based on the concepts of molecular repositioning and hybridization. In the design of these compounds, two important pharmacophoric subunits of the fexnidazole prototype were used: metronidazole was used as a repositioning molecule, p-aminobenzoic acid was incorporated as a bridge group, and 1,3,4-thiadiazole group was incorporated as a second pharmacophore, which at position 5 has an aromatic group with different substituents incorporated. The final six compounds were obtained through a five-step linear route with moderate to good yields. The biological results demonstrated the potential of this new class of compounds, since three of them 19-21 showed inhibitory activity on proliferation, in the order of 50%, in the in vitro assay against epimastigotes of T. cruzi (Strain Y sensitive to nifurtimox and benznidazole) and promastigotes of L. donovani, at a single concentration of 50 µM.

Structure-Aided Computational Design of Triazole-Based Targeted Covalent Inhibitors of Cruzipain.

Cruzipain (CZP), the major cysteine protease present in T. cruzi, the ethiological agent of Chagas disease, has attracted particular attention as a therapeutic target for the development of targeted covalent inhibitors (TCI). The vast chemical space associated with the enormous molecular diversity feasible to explore by means of modern synthetic approaches allows the design of CZP inhibitors capable of exhibiting not only an efficient enzyme inhibition but also an adequate translation to anti-T. cruzi activity. In this work, a computer-aided design strategy was developed to combinatorially construct and screen large libraries of 1,4-disubstituted 1,2,3-triazole analogues, further identifying a selected set of candidates for advancement towards synthetic and biological activity evaluation stages. In this way, a virtual molecular library comprising more than 75 thousand diverse and synthetically feasible analogues was studied by means of molecular docking and molecular dynamic simulations in the search of potential TCI of CZP, guiding the synthetic efforts towards a subset of 48 candidates. These were synthesized by applying a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) centered synthetic scheme, resulting in moderate to good yields and leading to the identification of 12 hits selectively inhibiting CZP activity with IC50 in the low micromolar range. Furthermore, four triazole derivatives showed good anti-T. cruzi inhibition when studied at 50 µM; and Ald-6 excelled for its high antitrypanocidal activity and low cytotoxicity, exhibiting complete in vitro biological activity translation from CZP to T. cruzi. Overall, not only Ald-6 merits further advancement to preclinical in vivo studies, but these findings also shed light on a valuable chemical space where molecular diversity might be explored in the search for efficient triazole-based antichagasic agents.

Effects of Arborvitae (Thuja plicata) Essential Oil on Cervical Cancer Cells: Insights into Molecular Mechanisms.

AIMS: This study aimed to assess the effects of AEO in an in vitro model of cell lines derived from cervical cancer-namely, HeLa and SiHa-by screening for AEO's cytotoxic properties and examining its influence on the modulation of gene expression. BACKGROUND: Cervical cancer stands as a prevalent global health concern, affecting millions of women worldwide. The current treatment modalities encompass surgery, radiation, and chemotherapy, but significant limitations and adverse effects constrain their effectiveness. Therefore, exploring novel treatments that offer enhanced efficacy and reduced side effects is imperative. Arborvitae essential oil, extracted from Thuja Plicata, has garnered attention for its antimicrobial, anti-inflammatory, immunomodulatory, and tissue-remodeling properties; however, its potential in treating cervical cancer remains uncharted. OBJECTIVE: The objective of this study was to delve into the molecular mechanisms induced by arborvitae essential oil in order to learn about its anticancer effects on cervical cancer cell lines. METHODS: The methods used in this study were assessments of cell viability using WST-1 and annexin V- propidium iodide, mRNA sequencing, and subsequent bioinformatics analysis. RESULTS: The findings unveiled a dose-dependent cytotoxic effect of arborvitae essential oil on both HeLa and SiHa cell lines. Minor effects were observed only at very low doses in the HaCaT non-tumorigenic human keratinocyte cells. RNA-Seq bioinformatics analysis revealed the regulatory impact of arborvitae essential oil on genes enriched in the following pathways: proteasome, adherens junctions, nucleocytoplasmic transport, cell cycle, proteoglycans in cancer, protein processing in the endoplasmic reticulum, ribosome, spliceosome, mitophagy, cellular senescence, and viral carcinogenesis, among others, in both cell lines. It is worth noting that the ribosome and spliceosome KEGG pathways are the most significantly enriched pathways in HeLa and SiHa cells. CONCLUSION: Arborvitae essential oil shows potential as a cytotoxic and antiproliferative agent against cervical cancer cells, exerting its cytotoxic properties by regulating many KEGG pathways.

Synthesis of Chalcones, Screening In silico and In vitro and Evaluation of Helicobacter pylori Adhesion by Molecular Docking.

AIMS: We synthetized 10 hydroxylated and methoxylated chalcones and evaluated them targeting MMP-9 inhibition, looking for the rate of adhesion of H. pylori in gastric cells, and then, reduction of the inflammatory response as alternative therapeutic agents for controlling the infection. BACKGROUND: Helicobacter pylori is a Gram-negative bacterium that chronically infects the human stomach, a risk factor for the development of inflammatory gastrointestinal diseases, including cancer, and is classified as a group I carcinogen. It is estimated that it infects around 45% of the global population and that the persistence of the infection is related to the adhesion of the bacteria in the gastric epithelium. The progression of gastric lesions to cancer is connected to the activation of the NF-κB and MAPK pathways, especially in cagA+ strains, which are related to increased expression of MMP-9. The activation of these metalloproteinases (MMPs) contributes to the adhesion of the bacterium in gastric cells and the evolving stages of cancer, such as enabling metastasis. Due to the increasing resistance to the current therapy protocols, the search for alternative targets and candidate molecules is necessary. In this way, controlling adhesion seems to be a suitable option since it is a crucial step in the installation of the bacterium in the gastric environment. OBJECTIVE: Synthetize ten hydroxylated and methoxylated chalcones. Assess their anti-H. pylori potential, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Evaluate their cytotoxicity in AGS cells and selectivity with L-929 cells. Analyze the results and correlate them with in silico predictions to evaluate potential anti-adhesive properties for the chalcones against H. pylori. METHODS: The chalcones were synthetized by Claisen-Schmidt condensation using Ba(OH)2 or LiOH as catalysts. Predictive in silico assays in PASS Online, tanimoto similarity, ADME properties and molecular docking in MMP-9 (PDB code: 6ESM) were performed. The in vitro assays carried out were the cell viability in gastric adenocarcinoma cells (AGS) and fibroblasts (L-929) by the MMT method and anti-H. pylori, by the broth microdilution method, through the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). RESULTS: Ten chalcones were synthesized through Claisen-Schimdt condensation with yields of 10 to 52% and characterized by 1H and 13C nuclear magnetic resonance (NMR) and mass spectrometry (MS). in silico data revealed the possibility of anti-H. pylori, anti-inflammatory, and MMP-9 inhibition for the chalcones. Chalcone 9 showed the best growth inhibition values for MIC and MBC, at 1 µg/mL and 2 µg/mL, respectively. Chalcones 14 and 15 likewise demonstrated excellent inhibitory results, being 2 µg/mL for both MIC and MBC. Additionally, 15 had the best MMP-9 inhibition score. Despite not corroborating the in silico findings, chalcones 10, 13, and 18 showed good cytotoxicity and the best selectivity indices. CONCLUSION: All compounds exhibited strong activity against H. pylori, specially 15. The predicted MMP-9 inhibition by molecular docking added to the reasonable SI and CI50 values for 15 and the satisfactory reduction in the rate of survival of the bacteria, reveals that it may be acting synergically to reduce the inflammatory response and the possibilities for developing a tumor by inhibiting both bacteria and malignant cells.

(Dimethylamino)methylene hydantoins as building blocks in the synthesis of oxoaplysinopsins and parabanic acids with antifungal activity.

A short, efficient, and stereoselective methodology is described for the synthesis of 5-((dimethylamino)methylene)hydantoins and their conversion into oxoaplysinopsins and parabanic acids. A highly convergent one-pot, two-step reaction between methyl N-arylglycinates, isocyanates, and DMFDMA under microwave irradiation provided the corresponding (dimethylamino)methylene hydantoins as a single E-stereoisomer in high overall yields. The synthesis of (S)-1-(1-phenylethyl) chiral hydantoins, which undergo a stereoselective addition of acetic anhydride, aza-heterocycles, and amines, received special attention. The reaction with indole delivered a series of novel oxoaplysinopsins. Meanwhile, parabanic acids were prepared by a new approach, treating (dimethylamino)methylene hydantoins with mCPBA to generate the oxidative fragmentation of the exocyclic methylene. The antifungal evaluation of the prepared products was carried out on a series of Candida spp., finding potent growth inhibition. According to previous docking studies, this activity is probably due to the inhibitory interaction of the derivatives with the active site of the fungal HMGR enzyme.

Repurposing antiparasitic N,N'-aliphatic diamine derivatives as promising antimycobacterial agents.

In previous studies, we demonstrated the potent activity of a library of 25 N,N'-disubstituted diamines (NNDDA) toward Trypanosomatid and Apicomplexa parasites. Considering the structure similarity between this collection and SQ109, an antituberculosis compound, and its compelling antiparasitic properties, we aimed to repurpose this library for tuberculosis treatment. We assayed this collection against Mycobacterium tuberculosis H37Rv and M. avium, obtaining several compounds with MIC values below 10 µM. The most active analogs were also evaluated against M. smegmatis, a non-pathogenic species, and the non-tuberculosis mycobacteria M. abscessus, M. kansasii, and M. fortuitum. 3c stands out as the lead mycobacterial compound of the collection, with potent activity against M. tuberculosis (minimal inhibitory concentration [MIC] = 3.4 µM) and moderate activity against M. smegmatis, M. kansasii, and M. fortuitum (all with MIC values of 26.8 µM). To unravel the mechanism of action, we employed the web-based platform Polypharmacology Browser 2 (PPB2), obtaining carbonic anhydrases as potential drug targets. Nevertheless, none of the compounds displayed experimental inhibition. In summary, our study confirms the validity of the repurposing approach and underscores the antimycobacterial potential of NNDDA compounds, especially the analog 3c, setting a stepping stone for further studies.

Synthesis, Biological Activity, and Molecular-Docking Studies of New Brassinosteroid Analogs.

Much work has been dedicated to the quest to determine the structure-activity relationship in synthetic brassinosteroid (BR) analogs. Recently, it has been reported that analogs with phenyl or benzoate groups in the alkyl chain present activities comparable to those shown by natural BRs, depending on the nature of the substituent in the aromatic ring. However, as it is well known that the activity depends on the structure of the whole molecule, in this work, we have synthesized a series of compounds with the same substituted benzoate in the alkyl chain and a hydroxyl group at C3. The main goal was to compare the activities with analogs with -OH at C2 and C3. Additionally, a molecular-docking study and molecular dynamics simulations were performed to establish a correlation between the experimental and theoretical results. The synthesis of eight new BR analogs was described. All the analogs were fully characterized by spectroscopical methods. The bioactivity of these analogs was assessed using the rice lamina inclination test (RLIT) and the inhibition of the root and hypocotyl elongation of Arabidopsis thaliana. The results of the RLIT indicate that at the lowest tested concentration (1 × 10-8 M), in the BR analogs in which the aromatic ring was substituted at the para position with methoxy, the I and CN substituents were more active than brassinolide (50-72%) and 2-3 times more active than those analogs in which the substituent group was F, Cl or Br atoms. However, at the highest concentrations, brassinolide was the most active compound, and the structure-activity relationship changed. On the other hand, the results of the A. thaliana root sensitivity assay show that brassinolide and the analogs with I and CN as substituents on the benzoyl group were the most active compounds. These results are in line with those obtained via the RLIT. A comparison of these results with those obtained for similar analogs that had a hydroxyl group at C2 indicates the importance of considering the whole structure. The molecular-docking results indicate that all the analogs adopted a brassinolide-like orientation, while the stabilizing effect of the benzoate group on the interactions with the receptor complex provided energy binding values ranging between -10.17 and -13.17 kcal mol-1, where the analog with a nitrile group was the compound that achieved better contact with the amino acids present in the active site.

A one-pot five component reaction for the synthesis of tetrazol-benzofuran hybrids and their inhibitory activity against Mucor lusitanicus.

A synthetic strategy for obtaining a new series of 1,5-disubstituted tetrazole-benzofuran hybrid systems via a one-pot five-component reaction is described. This process involves a Ugi-azide multicomponent reaction coupled to an intramolecular cyclization catalyzed by Pd/Cu, resulting in low to moderate yields from 21 to 67%. This protocol allowed the synthesis of highly substituted benzofurans at the 2-position through an operationally simple process under mild reaction conditions and with high bond forming efficiency due to the formation of six new bonds (two C-C, two C-N, one N-N, and one C-O). Besides, to evaluate the antifungal activity of 1,5-disubstituted tetrazole-benzofurans 9a-n, in vitro studies against Mucor lusitanicus were performed, finding that compound 9b exhibits bioactivity comparable to the commercial antifungal drug Amphotericin B. These results suggest potential for use in controlling mucormycosis infections in animal models, highlighting the importance of these findings given the limited antifungal drug options and high mortality rates associated with this infection.

Synthesis and anti-ureolitic activity of Biginelli adducts derived from formylphenyl boronic acids.

Urease is a metalloenzyme that contains two Ni(II) ions in its active site and catalyzes the hydrolysis of urea into ammonia and carbon dioxide. The development of effective urease inhibitors is crucial not only for mitigating nitrogen losses in agriculture but also for offering an alternative treatment against infections caused by resistant pathogens that utilize urease as a virulence factor. This study focuses on synthesizing and investigating the urease inhibition potential of Biginelli Adducts bearing a boric acid group. An unsubstituted or hydroxy-substituted boronic group in the Biginelli adducts structure enhances the urease inhibitory activity. Biophysical and kinetics studies revealed that the best Biginelli adduct (4e; IC50 = 132 ± 12 µmol/L) is a mixed inhibitor with higher affinity to the urease active site over an allosteric one. Docking studies confirm the interactions of 4e with residues essential for urease activity and demonstrate its potential to coordinate with the nickel atoms through the oxygen atoms of carbonyl or boronic acid groups. Overall, the Biginelli adduct 4e shows great potential as an additive for developing enhanced efficiency fertilizers and/or for medical applications.

Metal(triphenylphosphine)-atovaquone Complexes: Synthesis, Antimalarial Activity, and Suppression of Heme Detoxification.

To ascertain the bioinorganic chemistry of metals conjugated with quinones, the complexes [Ag(ATV)(PPh3)2] (1), [Au(ATV)(PPh3)]·2H2O (2), and [Cu(ATV)(PPh3)2] (3) were synthesized by the coordination of the antimalarial naphthoquinone atovaquone (ATV) to the starting materials [Ag(PPh3)2]NO3, [Au(PPh3)Cl], and [Cu(PPh3)2NO3], respectively. These complexes were characterized by analytical and spectroscopical techniques. X-ray diffraction of single crystals precisely confirmed the coordination mode of ATV to the metals, which was monodentate or bidentate, depending on the metal center. Both coordination modes showed high stability in the solid state and in solution. All three complexes showed negative log D values at pH 5, but at pH 7.4, while complex 2 continued to have a negative log D value, complexes 1 and 3 displayed positive values, indicating a more hydrophilic character. ATV and complexes 1-3 could bind to ferriprotoporphyrin IX (FePPIX); however, only complexes 1-3 could inhibit ß-hematin crystal formation. Phenotype-based activity revealed that all three metal complexes are able to inhibit the growth of P. falciparum with potency and selectivity comparable to those of ATV, while the starting materials lack this activity. The outcomes of this chemical design may provide significant insights into structure-activity relationships for the development of new antimalarial agents.

New Smoothened ligands based on the purine scaffold as potential agents for treating pancreatic cancer.

Aberrant activation of the Hedgehog (Hh) signalling pathway has been associated with the development and progression of pancreatic cancer. For this reason, blockade of Hh pathway by inhibitors targeting the G protein-coupled receptor Smoothened (SMO) has been considered as a therapeutic target for the treatment of this cancer. In our previous work, we obtained a new SMO ligand based on a purine scaffold (compound I), which showed interesting antitumor activity in several cancer cell lines. In this work, we report the design and synthesis of 17 new purine derivatives, some of which showed high cytotoxic effect on Mia-PaCa-2 (Hh-dependent pancreatic cancer cell lines) and low toxicity on non-neoplastic HEK-293 cells compared with gemcitabine, such as 8f, 8g and 8h (IC50 = 4.56, 4.11 and 3.08 µM, respectively). Two of these purines also showed their ability to bind to SMO through NanoBRET assays (pKi = 5.17 for 8f and 5.01 for 8h), with higher affinities to compound I (pKi = 1.51). In addition, docking studies provided insight the purine substitution pattern is related to the affinity on SMO. Finally, studies of Hh inhibition for selected purines, using a transcriptional functional assay based on luciferase activity in NIH3T3 Shh-Light II cells, demonstrated that 8g reduced GLI activity with a IC50 = 6.4 µM as well as diminished the expression of Hh target genes in two specific Hh-dependent cell models, Med1 cells and Ptch1-/- mouse embryonic fibroblasts. Therefore, our results provide a platform for the design of SMO ligands that could be potential selective cytotoxic agents for the treatment of pancreatic cancer.

1H-1,2,3-triazol-1,4-naphthoquinone Derivatives: Novel Inhibitors Targeting Pyocyanin Biosynthesis for P. Aeruginosa Infection Treatment Advances.

BACKGROUND: This study investigates the potential of eleven 1H-1,2,3-triazol-1,4-naphthoquinone conjugates as virulence factor inhibitors (like Pyocyanin) and their affinity for PhzM, a crucial enzyme for Pyocyanin biosynthesis in Pseudomonas aeruginosa infections. METHODS: A straightforward synthetic pathway enabled the production of these compounds, which were characterized and structurally confirmed through spectroscopic analyses. Evaluation of their impact on PhzM thermal stability identified promising candidates for PhzM binders. RESULTS: Concentration-response behavior elucidated their binding affinity, revealing them as the first reported micromolar affinity ligands for PhzM. Structure-activity relationship analysis emphasized the role of specific molecular moieties in binding affinity modulation, paving the way for future advanced inhibitors' development. CONCLUSION: These findings highlight the potential of naphthoquinone-triazole derivatives as leads for novel therapeutics against P. aeruginosa infections.

Evaluation of Thiazolidine Derivatives with Potential Anti-ZIKV Activity.

OBJECTIVE: In this study, we have synthesized 19 Thiazolidine (TZD) derivatives to investigate their potential anti-ZIKV effects. METHODS: Nineteen thiazolidine derivatives were synthesized and evaluated for their cytotoxicity and antiviral activity against the ZIKA virus. RESULTS: Among them, six demonstrated remarkable selectivity against the ZIKV virus, exhibiting IC50 values of <5µM, and the other compounds did not demonstrate selectivity for the virus. Interestingly, several derivatives effectively suppressed the replication of ZIKV RNA copies, with derivatives significantly reducing ZIKV mRNA levels at 24 hours post-infection (hpi). Notably, two derivatives (ZKC-4 and -9) stood out by demonstrating a protective effect against ZIKV cell entry. Informed by computational analysis of binding affinity and intermolecular interactions within the NS5 domain's N-7 and O'2 positions, ZKC-4 and FT-39 displayed the highest predicted affinities. Intriguingly, ZKC-4 and ZKC-9 derivatives exhibited the most favorable predicted binding affinities for the ZIKV-E binding site. CONCLUSION: The significance of TZDs as potent antiviral agents is underscored by these findings, suggesting that exploring TZD derivatives holds promise for advancing antiviral therapeutic strategies.

Design, synthesis, docking studies and bioactivity evaluation of 1,2,3-triazole eugenol derivatives.

Aim: The design, synthesis, docking studies and evaluation of the in vitro antifungal and cytotoxic properties of eugenol (EUG) containing 1,2,3-triazole derivatives are reported. Most of the derivatives have not been reported.Materials & methods: The EUG derivatives were synthesized, molecular docked and tested for their antifungal activity.Results: The compounds showed potent antifungal activity against Trichophyton rubrum, associated with dermatophytosis. Compounds 2a and 2i exhibited promising results, with 2a being four-times more potent than EUG. The binding mode prediction was similar to itraconazole in the lanosterol-14-α-demethylase wild-type and G73E mutant binding sites. Additionally, the pharmacokinetic profile prediction suggests good gastrointestinal absorption and potential oral administration.Conclusion: Compound 2a is a promising antifungal agent against dermatophytosis caused by T. rubrum.

[Box: see text].

Cytotoxic and Anti-HSV-1 Effects of Caulerpin Derivatives.

Marine organisms represent a potential source of secondary metabolites with various therapeutic properties. However, the pharmaceutical industry still needs to explore the algological resource. The species Caulerpa lamouroux Forssk presents confirmed biological activities associated with its major compound caulerpin, such as antinociceptive, spasmolytic, antiviral, antimicrobial, insecticidal, and cytotoxic. Considering that caulerpin is still limited, such as low solubility or chemical instability, it was subjected to a structural modifications test to establish which molecular regions could accept structural modification and to elucidate the cytotoxic bioactive structure in Vero cells (African green monkey kidney cells, Cercopithecus aethiops; ATCC, Manassas, VA, USA) and antiviral to Herpes simplex virus type 1. Substitution reactions in the N-indolic position with mono- and di-substituted alkyl, benzyl, allyl, propargyl, and ethyl acetate groups were performed, in addition to conversion to their acidic derivatives. The obtained analogs were submitted to cytotoxicity and antiviral activity screening against Herpes simplex virus type 1 by the tetrazolium microculture method. From the semi-synthesis, 14 analogs were obtained, and 12 are new. The cytotoxicity assay showed that caulerpin acid and N-ethyl-substituted acid presented cytotoxic concentrations referring to 50% of the maximum effect of 1035.0 µM and 1004.0 µM, respectively, values significantly higher than caulerpin. The antiviral screening of the analogs revealed that the N-substituted acids with methyl and ethyl groups inhibited Herpes simplex virus type 1-induced cytotoxicity by levels similar to the positive control acyclovir.

Synthesis, in vitro and in silico evaluation of gallamide and selenogallamide derivatives as inhibitors of the SARS-CoV-2 main protease.

The present work reports the inhibitory effect of amides derived from gallic acid (gallamides) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro), along with cytotoxicity evaluation and molecular docking studies. In addition to gallamides, other relevant compounds were also synthesized and evaluated against Mpro, making a total of 25 compounds. Eight compounds presented solubility issues during the inhibitory assay and one showed no inhibitory activity. Compounds 3a, 3b, and 3f showed the highest enzymatic inhibition with IC50 = 0.26 ± 0.19 µM, 0.80 ± 0.38 µM, and 2.87 ± 1.17 µM, respectively. Selenogallamide 6a exhibited IC50 values of 5.42 ± 2.89 µM and a comparison with its nonselenylated congener 3c shows that the insertion of the chalcogen moiety improved the inhibitory capacity of the compound by approximately 10 times. Regarding the cellular toxicity in THP-1 and Vero cells, compounds 3e and 3g, showed moderate cytotoxicity in Vero cells, while for THP-1 both were nontoxic, with CC50 > 150 µM. Derivative 3d showed moderate cytotoxicity against both cell lines, whereas 6d was moderatly toxic to THP-1. Other compounds analyzed do not induce substantial cellular toxicity at the concentrations tested. The molecular docking results for compounds 3a, 3b, and 3f show that hydrogen bonding interactions involving the hydroxyl groups (OH) of the gallate moiety are relevant, as well as the carbonyl group.

Simplified Method for Kinetic and Thermodynamic Screening of Cardiotonic Steroids through the K+-Dependent Phosphatase Activity of Na+/K+-ATPase with Chromogenic pNPP Substrate.

The antitumor effect of cardiotonic steroids (CTS) has stimulated the search for new methods to evaluate both kinetic and thermodynamic aspects of their binding to Na+/K+-ATPase (IUBMB Enzyme Nomenclature). We propose a real-time assay based on a chromogenic substrate for phosphatase activity (pNPPase activity), using only two concentrations with an inhibitory progression curve, to obtain the association rate (kon ), dissociation rate (koff ), and equilibrium (Ki ) constants of CTS for the structure-kinetics relationship in drug screening. We show that changing conditions (from ATPase to pNPPase activity) resulted in an increase of Ki of the cardenolides digitoxigenin, essentially due to a reduction of kon In contrast, the Ki of the structurally related bufadienolide bufalin increased much less due to the reduction of its koff partially compensating the decrease of its kon When evaluating the kinetics of 15 natural and semisynthetic CTS, we observed that both kon and koff correlated with Ki (Spearman test), suggesting that differences in potency depend on variations of both kon and koff A rhamnose in C3 of the steroidal nucleus enhanced the inhibitory potency by a reduction of koff rather than an increase of kon Raising the temperature did not alter the koff of digitoxin, generating a ΔH‡ (koff ) of -10.4 ± 4.3 kJ/mol, suggesting a complex dissociation mechanism. Based on a simple and inexpensive methodology, we determined the values of kon , koff , and Ki of the CTS and provided original kinetics and thermodynamics differences between CTS that could help the design of new compounds. SIGNIFICANCE STATEMENT: This study describes a fast, simple, and cost-effective method for the measurement of phosphatase pNPPase activity enabling structure-kinetics relationships of Na+/K+-ATPase inhibitors, which are important compounds due to their antitumor effect and endogenous role. Using 15 compounds, some of them original, this study was able to delineate the kinetics and/or thermodynamics differences due to the type of sugar and lactone ring present in the steroid structure.