Modest Inhibitory Activity Research Articles

Targeting Alzheimer's disease with novel dual-function 3,5-diaryl-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives

In the field of medicinal chemistry, the versatility of the thiosemicarbazone scaffold makes it a promising platform for the development of next-generation pharmaceuticals. In this paper the thiosemicarbazone scaffold was explored to obtain novel series of derivatives: a) thiosemicarbazones 15–31, and 33 containing a linear thiosemicarbazone scaffold, b) 34–38 and 44–64 containing pyrazoline ring, and c) 39–43 containing the dihydropyrimidine cycle. Among these, compounds 21, 23, 26, 33–35, 37, 38, 44, 57, 61, and 62 demonstrated no significant cytotoxic effects on HDFa cells at concentrations up to 500 μg/mL. Importantly, compounds 21, 23, 26, 33, 34, 35, and 37 exhibited significant protective effects against neurotoxicity induced by beta-amyloid peptide (1-42) in differentiated SHSY-5Y cell cultures. Enzymatic assays targeting BACE1 and AChE revealed modest inhibitory activity in compounds 21, 23, and 34, 37, respectively. The identification of compounds with inhibitory effects and neuroprotective activity against beta-amyloid peptide (1-42) offers a platform for further optimization and refinement of these compounds to enhance their potency and selectivity.

Inhibition of Pancreatic Lipase by Flavonoid Derivatives: In Vitro and In Silico Investigations.

Obesity, characterized by excessive adipose tissue accumulation, has emerged as a crucial determinant for a wide range of chronic medical conditions. The identification of effective interventions for obesity is of utmost importance. Widely researched antiobesity agents focus on pancreatic lipase, a significant therapeutic target. This study presented the evaluation of ten flavonoid compounds in terms of their inhibitory activities against pancreatic lipase, utilizing both in vitro and in silico approaches. The results indicated that all tested compounds demonstrated modest and weaker inhibitory activities compared to the reference compound, orlistat. Among the compounds investigated, F01 exhibited the highest potency, with an IC50 value of 17.68 ± 1.43 µM. The enzymatic inhibition kinetic analysis revealed that F01 operated through a competitive inhibition mechanism with a determined Ki of 7.16 μM. This value suggested a moderate binding affinity for the pancreatic lipase enzyme. Furthermore, the associated Vmax value was quantified at 0.03272 ΔA·min-1. In silico studies revealed that F01 displayed a binding mode similar to that of orlistat, despite lacking an active functional group capable of forming a covalent bond with Ser152 of the catalytic triad. However, F01 formed a hydrogen bond with this crucial amino acid. Furthermore, F01 interacted with other significant residues at the enzyme's active site, particularly those within the lid domain. Based on these findings, F01 demonstrates substantial potential as a candidate for further investigations.

A Mutation in Complement Factor H (W1183R) Enhances VWF Proteolysis By ADAMTS13 Under Shear

Introduction: Complement factor H (CFH) is the primary negative regulator of complement activation in the alternative pathway in both fluidic phase and on cell surface. Loss of function of CFH such as W1183R is associated with atypical hemolytic uremic syndrome (aHUS). Homozygous mutation W1206R in the murine CFH, corresponding to W1183R in human CFH, results in acute aHUS. Interestingly, in these mice, while plasma VWF antigen levels are significantly increased, plasma VWF multimer size is markedly reduced in ADAMTS13-depedent manner. However, the molecular mechanism underlying such a dramatic effect of the mutant CFH (W1206R) on VWF multimer distribution is not known. The goal of this study is to determine how wild type CFH and mutant CFH W1183R affects VWF proteolysis under shear, and the mechanism of action. Methods: Recombinant WT CFH, CFH W1183R, ADAMTS13, and VWF fragments were expressed in mammalian cells and purified to homogeneity. The effects of WT CFH or CFH W1183R on proteolytic cleavage of VWF73 peptide and full-length multimeric VWF were determined. Additionally, the binding and unfolding events were determined by micro scale thermophoresis (MST) and optical tweezer, respectively. Results : WT CFH showed no effect on the cleavage of peptide VWF73 substrate, but CFH W1183R enhanced the proteolytic cleavage of VWF73 by ADAMTS13 in a dose-dependent manner ( Fig. 1). Counterintuitively, WT CFH appeared to inhibit the proteolytic cleavage of multimeric VWF by ADAMTS13 under arterial shear, but CFH W1183R exhibited an opposite effect, modestly enhancing the proteolytic cleavage of multimeric VWF by ADAMTS13 under the same conditions. The MST binding assay demonstrated that both WT CFH and CFH W1183R bind to a short A1, a long AIM-A1, and A1-A2-A3 fragments with a dissociation constant ( K D) of 6.4 x 10 -7, 3.0 x 10 -9 M, and 3.3 x10 -9 mol/L, respectively. These results suggest that CFH may bind to the AIM, A1-A2 junction, and A2 domain. To further assess the impact of CFH binding to A2, we performed optical tweezer experiments. The results showed that both WT CFH (Lc: from 27.4 nm at 12 nM to 40 nm at 1.0 mM) and CFH W1183R (Lc: from 26 nm at 12 nM to 31.8 nm at 1.0 mM) resulted in significantly extended contour length (Lc) of VWF-A2 domain in a concentration-dependent manner ( Fig. 2), suggesting a dramatic conformational change in the A2 domain upon binding by WT CFH or CFH W1183R. Conclusions : Our results demonstrate that WT CFH at physiological concentrations may exhibit a modest inhibitory activity towards cleavage of VWF by ADAMTS13 under shear, but such an inhibitory activity disappears as the result of a point mutation in the C-terminal end of CFH (e.g., W1183R). Instead, the mutant CFH W1183R appears to enhance the VWF cleavage by ADAMTS13, likely through direct binding to the AIM, A1-A2 junction, and A2 domain of VWF, resulting in conformational changes in the central A2 domain.

Fragment-based and structure-guided discovery of perforin inhibitors

Perforin is a pore-forming protein whose normal function enables cytotoxic T and natural killer (NK) cells to kill virus-infected and transformed cells. Conversely, unwanted perforin activity can also result in auto-immune attack, graft rejection and aberrant responses to pathogens. Perforin is critical for the function of the granule exocytosis cell death pathway and is therefore a target for drug development. In this study, by screening a fragment library using NMR and surface plasmon resonance, we identified 4,4-diaminodiphenyl sulfone (dapsone) as a perforin ligand. We also found that dapsone has modest (mM) inhibitory activity of perforin lytic activity in a red blood cell lysis assay in vitro. Sequential modification of this lead fragment, guided by structural knowledge of the ligand binding site and binding pose, and supported by SPR and ligand-detected 19F NMR, enabled the design of nanomolar inhibitors of the cytolytic activity of intact NK cells against various tumour cell targets. Interestingly, the ligands we developed were largely inert with respect to direct perforin-mediated red blood cell lysis but were very potent in the context of perforin's action on delivering granzymes in the immune synapse, the context in which it functions physiologically. Our work indicates that a fragment-based, structure-guided drug discovery strategy can be used to identify novel ligands that bind perforin. Moreover, these molecules have superior physicochemical properties and solubility compared to previous generations of perforin ligands.

Food-inspired peptides from spinach Rubisco endowed with antioxidant, antinociceptive and anti-inflammatory properties.

Rubiscolin-6 (amino acid sequence: YPLDLF) is a selective δ-opioid receptor peptide isolated from spinach Rubisco. Its synthetic analogue, peptide YPMDIV is the most potent described so far for its increased opioid activity, thus in this work it was considered as lead compound for the design of twelve new analogues e.g. LMAS1-12. Firstly all the novel compounds have been tested for their antinociceptive and anti-inflammatory capacity in vitro and in vivo in order to evaluate their ability to maintain or loss the original activity. Among them peptides LMAS5-8 gave the best results, thus their antioxidant properties have been investigated along with their enzymatic inhibitory ability. Peptide LMAS6 shows a strong antioxidant (154.25mg TE/g CUPRAC) and inhibitor activity on tyrosinase (84.49mg KAE/g), indicating a potential role in food industry as anti-browning agent, while peptides LMAS5 and LMAS7 possess a modest cholinesterase inhibitory activity suggesting a conceivable use for nutraceuticals production.

Studying the Biological Activity of Trans-[Cu (quin)2(EtOH)2] as Potent Antimicrobial Cu(II) Complex through Computational Investigations: DFT, ADMET and Molecular Docking.

Trans-[Cu (quin)2(EtOH)2], a new copper (II) complex, was characterized using a variety of computational techniques to explore its biological role in pharmacological applications. The computational methods included density functional theory (DFT), ADMET and molecular docking. The optimized geometrical parameters revealed that the plane containing the Cu ion and the Quinaldinate ligands was confirmed to be nearly planar. DFT findings suggest that the complex has a stable structure with a moderate band gap of 3.88 eV. Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) analysis revealed a planar surface intramolecular charge transfer from its donor sites, in the center, to its ends instead of the vertical plane. Two electron-rich regions were observed around the oxygen ions in the molecular electrostatic potential (MEP) map, which were expected to be the sites of molecular bonding and interactions with target proteins. Drug-likeness and pharmacokinetics parameters were determined to provide insight into the safety level of the studied compound. The ADMET (absorption, distribution, metabolism, excretion, and toxicity) results showed favorable pharmacological features, as evidenced by a high oral bioavailability and a low risk of toxicity. A molecular docking study was performed by fitting the copper complex into the active sites of target proteins for Bacillus cereus, Staphylococcus aureus, and Escherichia coli bacteria. The title complex had the strongest antifungal effect within the inhibitory zone of B. cereus with a strong binding affinity of -9.83 kcal/mol. Also, maximum activity was exhibited against S.aureus (-6.65 kcal/mol) compared to the other recently reported Cu complexes within the limits of the screened references. Docking studies implicated modest inhibitory activity against E. coli bacteria. The findings highlighted the compound's biological activities and identified it as a possible treatment drug for the bacteria B. cereus and S. aureus.

Scientific Evaluation of Buddleja asiatica, Camellia sinensis, and Polygala arillata of Nepal

Diabetes is one of the most prevalent diseases in the world. Medicinal plants remain to play an important role in the amelioration of diabetes and its complications. In this study, Buddleja asiatica, Camellia sinensis, and Polygala arillata were investigated for α-amylase inhibition, antioxidant, and antimicrobial activities. Methanolic extracts of these three plants were investigated for their potential antioxidant activity using DPPH assay. Total phenolic and flavonoid contents of extracts were evaluated by the following standard methods. The α-amylase inhibition assay was also carried out by starch-iodine assay and DNS assay method. Methanolic extract of B. asiatica, C. sinensis, and P. arillata exhibits a total phenolic content of 116.47 ± 6.62, 157.17 ± 18.79, and 44.27 ± 2.97 mg GAE per gm in dry weight of extracts (p < 0.0001) and flavonoid levels 5.99 ± 1.00, 34.28 ± 2.63, and 37.07 ± 2.24 (p < 0.0001) mg QE per gm in dry weights of extracts respectively. The extract showed promising antioxidant activity against DPPH with the IC50 values of C. sinensis (19.15 ± 4.32 μg/mL), B. asiatica (26.86 ± 2.00 μg/mL), and the standard the quercetin (2.36 ± 0.13 μg/mL). The extract showed modest α-amylase inhibitory activity. Methanolic extract of B. asiatica and C. sinensis were found effective against Staphylococcus aureus with zone of inhibition of 12.5 mm and 17 mm respectively. Therefore, obtained results support the traditional uses of these plants and also showed α-amylase inhibition activities although there are no reports about it.

Severe Acute Respiratory Syndrome Coronavirus 2 Vaccination Boosts Neutralizing Activity Against Seasonal Human Coronaviruses.

BackgroundMost of the millions of people that are vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), have previously been infected by related circulating human coronaviruses (hCoVs) causing common colds and will experience further encounters with these viruses in the future. Whether COVID-19 vaccinations impact neutralization of seasonal coronaviruses is largely unknown.MethodsWe analyzed the capacity of sera derived from 24 individuals before and after heterologous ChAdOx1 nCoV-19 BNT162b2 prime-boost vaccination to neutralize genuine OC43, NL63, and 229E hCoVs, as well as viral pseudoparticles carrying the SARS-CoV-1, SARS-CoV-2, Middle East Respiratory Syndrome (MERS)-CoV, and hCoV-OC43, hCoV-NL63, and hCoV-229E spike proteins. Genuine hCoVs or spike containing pseudovirions were incubated with different concentrations of sera and neutralization efficiencies were determined by measuring viral RNA yields, intracellular viral nucleocapsid expression, or reporter gene expression in Huh-7 cells.ResultsAll individuals showed strong preexisting immunity against hCoV-OC43. Neutralization of hCoV-NL63 was more variable and all sera showed only modest inhibitory activity against genuine hCoV-229E. SARS-CoV-2 vaccination resulted in efficient cross-neutralization of SARS-CoV-1 but not of MERS-CoV. On average, vaccination significantly increased the neutralizing activity against genuine hCoV-OC43, hCoV-NL63, and hCoV-229E.ConclusionsHeterologous COVID-19 vaccination may confer some cross-protection against endemic seasonal coronaviruses.

In Silico and Ex Vivo Analyses of the Inhibitory Action of the Alzheimer Drug Posiphen and Primary Metabolites with Human Acetyl- and Butyrylcholinesterase Enzymes.

Alzheimer’s disease (AD) is the most common neurodegenerative disorder worldwide. Ongoing research to develop AD treatments has characterized multiple drug targets including the cholinergic system, amyloid-β peptide, phosphorylated tau, and neuroinflammation. These systems have the potential to interact to either drive or slow AD progression. Promising agents that simultaneously impact many of these drug targets are the AD experimental drug Posiphen and its enantiomer phenserine that, currently, are separately being evaluated in clinical trials. To define the cholinergic component of these agents, the anticholinesterase activities of a ligand dataset comprising Posiphen and primary metabolites ((+)-N1-norPosiphen, (+)-N8-norPosiphen, and (+)-N1,N8-bisnorPosiphen) were characterized and compared to those of the enantiomer phenserine. The “target” dataset involved the human cholinesterase enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Binding interactions between the ligands and targets were analyzed using Autodock 4.2. The computationally determined inhibitory action of these ligands was then compared to ex vivo laboratory-measured values versus human AChE and BChE. While Posiphen lacked AChE inhibitory action, its major and minor metabolites (+)-N1-norPosiphen and (+)-N1,N8-bisnorPosiphen, respectively, possessed modest AChE inhibitory activity, and Posiphen and all metabolites lacked BChE action. Phenserine, as a positive control, demonstrated AChE-selective inhibitory action. In light of AChE inhibitory action deriving from a major and minor Posiphen metabolite, current Posiphen clinical trials in AD and related disorders should additionally evaluate AChE inhibition; particularly if Posiphen should be combined with a known anticholinesterase, since this drug class is clinically approved and the standard of care for AD subjects, and excessive AChE inhibition may impact drug tolerability.

Biological Insights and NMR Metabolic Profiling of Different Extracts of Spermacoce verticillata (L.) G. Mey.

Spermacoce verticillata (L.) G. Mey. is commonly used in the folk medicine by various cultures to manage common diseases. Herein, the chemical and biological profiles of S. verticillata were studied in order to provide a comprehensive characterization of bioactive compounds and also to highlight the therapeutic properties. The in vitro antioxidant activity using free-radical scavenging, phosphomolybdenum, ferrous-ion chelating and reducing power assays, and the inhibitory activity against key enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase of S. verticillata extracts (dichloromethane, ethyl acetate, methanol and water) were investigated. The highest total phenolic and flavonoid content were observed in the methanolic and aqueous extracts. Exhaustive 2DNMR investigation has revealed the presence of rutin, ursolic and oleanoic acids. The methanolic extract, followed by aqueous extract have showed remarkable free radical quenching and reducing ability, while the dichloromethane extract was the best source of metal chelators. The tested extracts showed notable inhibitory activity against cholinesterases (AChE: 1.63-4.99 mg GALAE/g extract and BChE: 12.40-15.48 mg GALAE/g extract) and tyrosinase (60.85-159.64 mg KAE/g extract). No inhibitory activity was displayed by ethyl acetate and aqueous extracts against BChE and tyrosinase, respectively. All the tested extracts showed modest α-amylase inhibitory activity, while only the ethyl acetate and aqueous extracts were potent against α-glycosidase. This study further validates the use of S. verticillata in the traditional medicine, while advocating for further investigation for phytomedicine development.

Four new phenolic compounds from the tender leaves of Eucommia ulmoides Oliv. and their anti-inflammatory activities

• Four new phenolic compounds were isolated from the tender leaves of Eucommia ulmoides Oliv. • Compound 9 was isolated from Eucommiaceae for the first time. • Modest inhibitory activities were observed for compounds 2–5 and 9, with IC 50 values ranging from 8.3 to 31.0 μM. Four new phenolic compounds, 2-{[3-(3,4-dihydroxyphenyl)propanoyl]oxy} propanoic acid ( 1 ), 2-{[3-(3,4-dihydroxyphenyl)propanoyl]oxy} propanoic acid methyl ( 2 ), (±)3-{2-[1-(3′,4′-dihydroxy-phenyl)ethyl]-4,5-dihydroxyphenyl} propanoic acid methyl ( 3 ), and (±)3-{2-[1-(3′,4′-dihydroxy-phenyl)ethyl]-4,5-dihydroxyphenyl} propanoic acid ( 4 ), together with five known compounds, methyl 3-(3,4-dihydroxyphenyl)-propanoate ( 5 ), 3,4-dihydroxybenzenepropionic acid ( 6 ), caffeic acid ( 7 ), protocatechuic acid ( 8 ), and 1,3- trans -5,6-dihydroxy-3-(3′,4′-dihydroxyphenyl) indan-1-methyl ( 9 ) were isolated from the tender leaves of Eucommia ulmoides Oliv. Compound 9 was isolated from Eucommiaceae for the first time. The structures of the new compounds were elucidated from the spectra of 1D NMR and 2D NMR, and MS data. Compounds 1 - 9 were tested to determine their inhibitory effect on LPS-induced NO production in macrophage RAW264.7 cells. Modest inhibitory activities were observed for compounds 2–5 and 9, with IC 50 values ranging from 8.3 to 31.0 μM. This research enriches the current chemical information regarding the leaves of Eucommia ulmoides Oliv. and provides a reference for further research on its anti-inflammatory effects.

Structure-Activity Relationship and Molecular Docking of a Kunitz-Like Trypsin Inhibitor, Kunitzin-AH, from the Skin Secretion of Amolops hainanensis.

Kunitz-like trypsin inhibitors are one of the most noteworthy research objects owing to their significance in pharmacological studies, including anticarcinogenic activity, obesity regulation and anticoagulation. In the current study, a novel Kunitz-like trypsin inhibitor, Kunitzin-AH, was isolated from the skin secretion of Amolops hainanensis. The novel peptide displayed a modest trypsin inhibitory activity with the inhibitor constant (Ki) value of 1.18 ± 0.08 µM without inducing damage to healthy horse erythrocytes. Then, a series of shortened variants of Kunitzin-AH were designed by truncating a peptide loop and site mutation inside the loop to illustrate the structure–activity relationship of the trypsin inhibition function. Among the variants, a significant decrease was observed for the Cys-Cys loop domain, while the extension of an Arg at N-terminus (RCKAAFC) retained the inhibitory activity, indicating that the -RCK-motif is essential in forming the reactive domain for exerting the inhibitory activity. Furthermore, substitutions of Ala by hydrophobic or hydrophilic residues decreased the activity, indicating suitable steric hindrance provides convenience for the combination of trypsin. Additionally, the conformational simulation of the analogues processed with Chimera and Gromacs and further combination simulations between the peptides and trypsin conducted with HDOCK offered a potential opportunity for the natural trypsin inhibitory drug design. The truncated sequence, AH-798, may be a good replacement for the full-length peptide, and can be optimized via cyclization for further study.

Reinvestigation of the structure-activity relationships of isoniazid

Isoniazid (INH) remains a cornerstone for treatment of drug susceptible tuberculosis (TB), yet the quantitative structure-activity relationships for INH are not well documented in the literature. In this paper, we have evaluated a systematic series of INH analogs against contemporary Mycobacterium tuberculosis strains from different lineages and a few non-tuberculous mycobacteria (NTM). Deletion of the pyridyl nitrogen atom, isomerization of the pyridine nitrogen to other positions, replacement of the pyridine ring with isosteric heterocycles, and modification of the hydrazide moiety of INH abolishes antitubercular activity. Similarly, substitution of the pyridine ring at the 3-position is not tolerated while substitution at the 2-position is permitted with 2-methyl-INH 9 displaying antimycobacterial activity comparable to INH. To assess the specific activity of this series of INH analogs against mycobacteria, we assayed them against a panel of gram-positive and gram-negative bacteria, as well as a few fungi. As expected INH and its analogs display a narrow spectrum of activity and are inactive against all non-mycobacterial strains evaluated, except for 4, which has modest inhibitory activity against Cryptococcus neoformans. Our findings provide an updated analysis of the structure-activity relationship of INH that we hope will serve as useful resource for the community.

Phenolics from Scorzonera tomentosa L.: Exploring the potential use in industrial applications via an integrated approach

Scorzonera tomentosa L. (family Asteraceae), endemic to Turkey is reputed for its medicinal attributes in the folkloric medicine. However, only few studies on the chemical composition and pharmacological properties of this plant have been published so far. In this direction, this study aimed to shed light on the phenolic composition, antioxidant and key enzyme inhibitory properties of S. tomentosa aerial parts and roots extracts prepared using different solvents (dichloromethane, ethyl acetate, hexane, water and methanol). Overall, the methanolic extracts and the infusion of both plant parts were better sources of total polyphenolics with 40.33 and 39.30 mg gallic acid equivalent (GAE)/g, respectively, while for the aerial parts, 22.42 and 21.84 mg GAE/g were measured for methanolic extract and root infusion, respectively. Extracts of the aerial parts showed considerable amount of total flavonoid content (2.96–34.93 mg rutin equivalent (RE)/g) as compared with the root extract (0.40–2.65 mg RE/g), with highest content observed in methanolic extract. For this reason, the methanolic extract of roots and aerial parts were subjected to liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-MSn) analysis. The methanolic and aqueous extracts of both plant parts proved to be most significant radical quenchers (1.05–45.89 mg trolox equivalent (TE)/g in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; and 1.82–82.94 mg TE/g in 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay) and reducing agents (39.40–164.06 mg TE/g in cupric reducing antioxidant capacity (CUPRAC) and 15.54–79.78 mg TE/g in ferric reducing antioxidant power (FRAP)). The dichloromethane extracts were significant metal chelators (13.92 and 6.24 mg ethylenediaminetetraacetate equivalent (EDTAE)/g for aerial parts and roots). Extracts of both plant parts showed selective inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Notable anti-tyrosinase activity was observed for all the extracts (aerial part: 16.40 ± 1.30 - 64.83 ± 0.28 and roots: 6.29 ± 0.50–65.46 ± 0.31 mg kojic acid equivalent (KAE)/g), while modest inhibitory activity against α-amylase (0.08−0.61 mmol acarbose equivalent (ACAE)/g) and α-glucosidase (0.09−0.83 mmol ACAE/g) for all the tested extracts. In addition, to provide the first scientific insight on the biological and chemical profile of S. tomentosa, observations from this present study tend to identify this plant as a valuable source of biologically active molecules for possible phytopharmaceutical and cosmeceuticals exploitation.

Secondary metabolites isolated from Agrimonia pilosa Ledeb.

A pilot study on the ethanol extracts of Agrimonia pilosa found to have anti-α-glucosidase and anti-inflammatory activities. Subsequent chemical study afforded a new phenylethyl isocoumarin glycoside (1) and eight known compounds (2-9). The structure of 1 was elucidated by comprehensive spectroscopic analysis and chemical transformations. All compounds showed modest α-glucosidase inhibitory activity (IC50 values ranging from 36.8 to 210.7 μM), which was lower than that of the positive control acarbose (IC50=301.9 μM). Those compounds except inactive compounds 3 and 6 showed weak anti-inflammatory activity.

Phenylpyrazalopyrimidines as Tyrosine Kinase Inhibitors: Synthesis, Antiproliferative Activity, and Molecular Simulations.

N1-(α,β-Alkene)-substituted phenylpyrazolopyrimidine derivatives with acetyl and functionalized phenyl groups at α- and β-positions, respectively, were synthesized by the reaction of 3-phenylpyrazolopyrimidine (PhPP) with bromoacetone, followed by a chalcone reaction with differently substituted aromatic aldehydes. The Src kinase enzyme assay revealed modest inhibitory activity (half maximal inhibitory concentration, IC50 = 21.7–192.1 µM) by a number of PhPP derivatives. Antiproliferative activity of the compounds was evaluated on human leukemia (CCRF-CEM), human ovarian adenocarcinoma (SK-OV-3), breast carcinoma (MDA-MB-231), and colon adenocarcinoma (HT-29) cells in vitro. 4-Chlorophenyl carbo-enyl substituted 3-phenylpyrazolopyrimidine (10) inhibited the cell proliferation of HT-29 and SK-OV-3 by 90% and 79%, respectively, at a concentration of 50 µM after 96 h incubation. The compound showed modest inhibitory activity against c-Src (IC50 = 60.4 µM), Btk (IC50 = 90.5 µM), and Lck (IC50 = 110 µM), while it showed no activity against Abl1, Akt1, Alk, Braf, Cdk2, and PKCa. In combination with target selection and kinase profiling assay, extensive theoretical studies were carried out to explore the selectivity behavior of compound 10. Specific interactions were also explored by examining the changing trends of interactions of tyrosine kinases with the phenylpyrazolopyrimidine derivative. The results showed good agreement with the experimental selectivity pattern among c-Src, Btk, and Lck.

Bromo-spiroisoxazoline Alkaloids, Including an Isoserine Peptide, from the Caribbean Marine Sponge Aplysina lacunosa.

Three new bromotyrosine spiroisoxazoline alkaloids, lacunosins A and B (1 and 2) and desaminopurealin (3), were isolated from a MeOH extract of the marine sponge Aplysina lacunosa that showed modest α-chymotrypsin inhibitory activity. The structures of 1-3 share the spirocyclohexadienyl-isoxazoline ring system found in purealidin-R and several other Verongid sponge secondary metabolites. Compounds 1 and 2 are coupled to a glycine and an isoserine methyl ester, respectively. Alkaloid 3 is linked, contiguously, to an O-1-aminopropyl 3,5-dibromotyrosyl ether and, finally, to histamine through an amide bond. The planar structures of all three compounds were obtained from analysis of MS and 1D and 2D NMR data. The absolute configuration of the SIO unit of 1-3 was assigned by electronic circular dichroism (ECD). The isoserine amino acid residue in 2 was found to be a 1:1 mixture of epimers using a new Marfey's type reagent, derived from Trp-NH2. Allylic O-naphthoylation of the SIO subunit enhances the ECD spectrum of SIOs and improves discrimination of enantiomorphs. A unifying hypothesis is proposed that links the biosynthesis of several of the new compounds with previously reported analogues.

Green biosynthesis of silver nanoparticles with Eryngium caucasicum Trautv aqueous extract

In this research, silver nanoparticles (AgNPs) are prepared by green synthesis method at ambient temperature using Eryngium caucasicum Trautv aqueous extract as reducing and natural capping agents. The AgNPs were defined using ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). XRD analysis confirmed the crystalline structure of the synthesized nanoparticles. UV–Vis spectra showed a surface resonance peak at 480 nm indicating the formation of AgNPs. The AgNPs average particle size was approximately 17.5 nm. FT-IR analysis was performed to identify the biomolecules responsible for bio reduction of silver ions. Synthesized AgNPs inhibitory activity was also examined toward pathogenic bacteria such as Staphylococcus aureus and Escherichia coli. The outcomes revealed that the synthesized AgNPs demonstrated modest inhibitory activities, displaying its antibacterial rate toward pathogenic diseases.

Identifying the Naphthalene-Based Compound 3,5-Dihydroxy 2-Napthoic Acid as a Novel Lead Compound for Designing Lactate Dehydrogenase-Specific Antibabesial Drug

Human babesiosis is caused by apicomplexan Babesia parasites, including Babesia microti, Babesia crassa, Babesia sp. MOI, Babesia divergens, Babesia duncani, and Babesia venatorum. Among them, B. microti is the most common cause of human and rodent babesiosis. Currently, no vaccine is available, and drugs for the treatment have high failure rates and side effects. Due to lack of a traditional tricarboxylic acid cycle (TCA cycle) and its dominant dependence on anaerobic metabolism to produce ATP, B. microti lactate dehydrogenase (BmLDH) was assumed to play a critical role in B. microti ATP supply. Our previous study demonstrated that BmLDH is a potential drug target and Arg99 is a crucial site. Herein, a molecular docking was performed based on the crystal structure of BmLDH from a series of gossypol derivatives or structural analogs to find the potent inhibitors interacting with the residue Arg99, and three naphthalene-based compounds 2,6-naphthalenedicarboxylic acid (NDCA), 1,6-dibromo-2-hydroxynapthalene 3-carboxylic acid (DBHCA), and 3,5-dihydroxy 2-napthoic acid (DHNA) were selected for further tests. Enzyme activity inhibitory experiments show that DBHCA and DHNA inhibit recombinant BmLDH (rBmLDH) catalysis with ~109-fold and ~5,000-fold selectivity over human LDH, respectively. Surface plasmon resonance (SPR) assays demonstrate that DHNA has a lower K D value to BmLDH (3.766 x 10−5 M), in contrast to a higher value for DBHCA (3.988 x 10−8 M). A comparison of the kinetic parameters [association constant (k a) and dissociation constant (k d) values] reveals that DBHCA can bind the target faster than DHNA, while the complex of DHNA with the target dissociates slower than that of DBHCA. Both DBHCA and DHNA can inhibit the growth of B. microti in vitro with half-maximal inhibitory concentration (IC50) values of 84.83 and 85.65 μM, respectively. Cytotoxicity tests in vitro further indicate that DBHCA and DHNA have selectivity indexes (SI) of 2.6 and 22.1 between B. microti and Vero cells, respectively. Although the two naphthalene-based compounds only display modest inhibitory activity against both rBmLDH and the growth of B. microti, the compound DHNA features high selectivity and could serve as a novel lead compound for designing LDH-specific antibabesial drug.

Verruculosins A-B, New Oligophenalenone Dimers from the Soft Coral-Derived Fungus Talaromyces verruculosus.

In an effort to discover new bioactive anti-tumor lead compounds, a specific tyrosine phosphatase CDC25B and an Erb family receptor EGFR were selected as drug screening targets. This work led to the investigation of the soft coral-derived fungus Talaromyces verruculosus and identification of two new oligophenalenone dimers, verruculosins A–B (1–2), along with three known analogues, bacillisporin F (3), duclauxin (4), and xenoclauxin (5). Compound 1 was the first structure of the oligophenalenone dimer possessing a unique octacyclic skeleton. The detailed structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic data, X-ray crystallography, optical rotation, Electronic Circular Dichroism (ECD) analysis, and nuclear magnetic resonance (NMR) calculations. Among which, compounds 1, 3, and 5 exhibited modest inhibitory activity against CDC25B with IC50 values of 0.38 ± 0.03, 0.40 ± 0.02, and 0.26 ± 0.06 µM, respectively.