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Kombucha is a fermented tea drink using a symbiotic culture of bacteria and yeast. This drink has been widely used to maintain blood sugar levels. Meanwhile, leaf boiled water of Syzygium polyanthum (Wight) Walp. has been used as an alternative medicine for diabetes mellitus in Indonesia. If this herb is made into kombucha, it may have higher antihyperglycemic activity than kombucha from tea leaves. However, there are no scientific reports of antihyperglycemic activity from S. polyanthum leaf kombucha by inhibiting alpha-glucosidase. This study aims to determine the activity and kinetics inhibition of S. polyanthum leaves kombucha against α-glucosidase. Samples were prepared at varying concentrations (12.5, 25, 37.5, 50 g/L), while phytochemical components in the products were identified, and the inhibitory activity as well as kinetics were comprehensively analyzed. In silico evaluations were conducted to further explore the inhibitory activity. The results showed that the products contained secondary metabolites such as flavonoids, saponins, and tannins. The inhibitory activity against α-glucosidase ranged from 81.05 to 89.41%. The inhibition mechanism was identified as uncompetitive, with a Michaelis-Menten constant (KM) of 0.1357 mM and a vmax value of 27.7008 U/ml minute. Several metabolites showed promising inhibition potential due to their strong binding interactions with α-glucosidase, including hydrogen bonding (H-bond), hydrophobic interactions, van der Waals forces, and electrostatic forces. Additionally, two metabolites, farnesol and α-pinene, were found to interact with other human proteins. These observations showed the potential of S. polyanthum leaves kombucha as a health-promoting beverage that might aid blood sugar control in diabetic individuals. [ABSTRACT FROM AUTHOR]

This article explores the development of glycosyltransferase inhibitors, specifically focusing on FUT8 inhibitors. FUT8 is an enzyme that plays a crucial role in various biological processes. The researchers used diversity-oriented synthesis (DOS) to create compound libraries of FUT8 inhibitors. Through late-stage functionalization and the combination of glycosyl donor and acceptor mimics, they successfully developed a FUT8 inhibitor. The study also discusses the modification of guanine derivatives and the creation of bi-substrate mimics, which are expected to exhibit exceptional selectivity among FUTs. Overall, this article presents an efficient methodology for optimizing the structure of middle molecules. [Extracted from the article]

Introduction: Intestinal colitis, also known as ulcerative colitis, is an inflammatory bowel disease characterized by long-term inflammation and ulcers in the gastrointestinal tract. It has been suggested that the mucosal expression of angiotensin II (AT-II) is increased in colitis. This study aimed to examine the potential therapeutic effects of combination therapy with Enalapril, an angiotensin-converting enzyme inhibitor, and sulfasalazine (SSZ) in a murine colitis model. Methods: Male C57BL/6 mice were divided into five groups: control group (distilled water), dextran sulphate sodium (DSS) group (colitis group) (1% DSS), SSZ group (positive control group) with 100 mg/kg/day, Enalapril alone group with 4 mg/kg/day, and Enalapril (4 mg/kg/day) + SSZ (100 mg/kg/day) group. Results: There was a significant reduction in the disease activity index among the mice receiving the combination of Enalapril and SSZ compared to the colitis group. Enalapril and SSZ treatment was associated with a lower reduction in colon length, decreased colon weight, spleen weight, and spleen-to-body weight in mice with colitis. Following DSS administration, Enalapril and SSZ also significantly decreased MDA levels, an oxidant marker, and increased total thiol, SOD, and CAT levels, as antioxidants. Additionally, mucosal damage, crypt loss, pathological changes, and inflammation scores decreased after treatment with Enalapril and SSZ in comparison with the colitis group. The combination of Enalapril and SSZ reduced colon collagen content and caused a decrease in fibrosis compared to the colitis group. Conclusion: The results of this study indicated that Enalapril alone and in combination with SSZ decreased inflammation and clinical symptoms of colitis induced by DSS. [ABSTRACT FROM AUTHOR]

Methanolic stem bark extracts from ten Mexican Bursera Jacq. ex L. species were evaluated in vitro with regard to their inhibitory activity against two Tenebrio molitor-derived enzymes. Seven extracts (B. bicolor, B. copallifera, B. fagaroides, B. grandifolia, B. lancifolia, B. linanoe, and B. longipes) reduced α-amylase activity by 55.37% to 96.25%, with three samples proving to be particularly potent α-amylase inhibitors (B. grandifolia, B. lancifolia, and B. linanoe; IC50 = 162, 132, and 186 µg/mL, respectively). In contrast, no extract inhibited acetylcholinesterase activity by more than 39.94%. Quantitative HPLC analysis did not reveal any clear correlation between the species-specific flavonoid or phenolic acid profiles and the respective extracts' enzyme inhibitory activity. The findings reported herein do not only contribute to improving the current state of knowledge regarding the enzyme inhibitory potential of the Bursera genus, but could also lead to the development of new sustainable bioinsecticides. [ABSTRACT FROM AUTHOR]

Infectious diseases caused by trypanosomatids, including African trypanosomiasis (sleeping sickness), Chagas disease, and different forms of leishmaniasis, are Neglected Tropical Diseases affecting millions of people worldwide, mainly in vulnerable territories of tropical and subtropical areas. In general, current treatments against these diseases are old-fashioned, showing adverse effects and loss of efficacy due to misuse or overuse, thus leading to the emergence of resistance. For these reasons, searching for new antitrypanosomatid drugs has become an urgent necessity, and different metabolic pathways have been studied as potential drug targets against these parasites. Considering that trypanosomatids possess a unique redox pathway based on the trypanothione molecule absent in the mammalian host, the key enzymes involved in trypanothione metabolism, trypanothione reductase and trypanothione synthetase, have been studied in detail as druggable targets. In this review, we summarize some of the recent findings on the molecules inhibiting these two essential enzymes for Trypanosoma and Leishmania viability. [ABSTRACT FROM AUTHOR]

The shikimate pathway is crucial for the biosynthesis of aromatic amino acids in plants and represents a promising target for developing new herbicides. This work aimed to identify inhibitors of shikimate dehydrogenase (SDH), a key enzyme of the shikimate pathway that catalyzes the conversion of 3-dehydroshikimate to shikimate. Virtual screening and molecular dynamic simulations were performed on the SDH active site of Arabidopsis thaliana (AtSDH), and 6-nitroquinazoline-2,4-diol (NQD) was identified as a potential inhibitor. In vitro assays showed that NQD decreased the activity of AtSDH by reducing Vmax while keeping KM unchanged, indicating non-competitive inhibition. In vivo, hydroponic experiments revealed that NQD reduced the root length of soybean and maize. Additionally, NQD increased the total protein content and certain amino acids. Soybean roots uptake NQD more efficiently than maize roots. Furthermore, NQD reduced shikimate accumulation in glyphosate-treated soybean roots, suggesting its potential to restrict the flow of metabolites along the shikimate pathway in soybean. The simultaneous treatment of maize seedlings with glyphosate and NQD accumulated gallic acid in the roots, indicating that NQD inhibits SDH in vivo. Overall, the data indicate that NQD inhibits SDH both in vitro and in vivo, providing valuable insights into the potential development of herbicides targeting SDH. [ABSTRACT FROM AUTHOR]

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While cytochrome P450 (CYP; P450) enzymes are commonly associated with the metabolism of organic xenobiotics and drugs or the biosynthesis of organic signaling molecules, they are also impacted by a variety of inorganic species. Metallic nanoparticles, clusters, ions, and complexes can alter CYP expression, modify enzyme interactions with reductase partners, and serve as direct inhibitors. This commonly overlooked topic is reviewed here, with an emphasis on understanding the structural and physiochemical basis for these interactions. Intriguingly, while both organometallic and coordination compounds can act as potent CYP inhibitors, there is little evidence for the metabolism of inorganic compounds by CYPs, suggesting a potential alternative approach to evading issues associated with rapid modification and elimination of medically useful compounds. [ABSTRACT FROM AUTHOR]

IF1, an inhibitor protein of mitochondrial ATP synthase, suppresses ATP hydrolytic activity of F1. One of the unique features of IF1 is the selective inhibition in mitochondrial F1 (MF1); it inhibits catalysis of MF1 but does not affect F1 with bacterial origin despite high sequence homology between MF1 and bacterial F1. Here, we aimed to engineer thermophilic Bacillus F1 (TF1) to confer the susceptibility to IF1 for elucidating the molecular mechanism of selective inhibition of IF1. We first examined the IF1‐susceptibility of hybrid F1s, composed of each subunit originating from bovine MF1 (bMF1) or TF1. It was clearly shown that only the hybrid with the β subunit of mitochondrial origin has the IF1‐susceptibility. Based on structural analysis and sequence alignment of bMF1 and TF1, the five non‐conserved residues on the C‐terminus of the β subunit were identified as the candidate responsible for the IF1‐susceptibility. These residues in TF1 were substituted with the bMF1 residues. The resultant mutant TF1 showed evident IF1‐susceptibility. Reversely, we examined the bMF1 mutant with TF1 residues at the corresponding sites, which showed significant suppression of IF1‐susceptibility, confirming the critical role of these residues. We also tested additional three substitutions with bMF1 residues in α and γ subunits that further enhanced the IF1‐susceptibility, suggesting the additive role of these residues. We discuss the molecular mechanism by which IF1 specifically recognizes F1 with mitochondrial origin, based on the present result and the structure of F1‐IF1 complex. These findings would help the development of the inhibitors targeting bacterial F1. [ABSTRACT FROM AUTHOR]

Inhibition of insulin-regulated aminopeptidase (IRAP) has been shown to improve cognitive functions in several animal models. Recently, we performed a screening campaign of approximately 10,000 compounds, identifying novel small-molecule-based compounds acting as inhibitors of the enzymatic activity of IRAP. Here we report on the chemical synthesis, structure-activity relationships (SAR) and initial characterization of physicochemical properties of a series of 48 imidazo [1,5-α]pyridine-based inhibitors, including delineation of their mode of action as non-competitive inhibitors with a small L-leucine-based IRAP substrate. The best compound displays an IC50 value of 1.0 µM. We elucidate the importance of two chiral sites in these molecules and find they have little impact on the compound's metabolic stability or physicochemical properties. The carbonyl group of a central urea moiety was initially believed to mimic substrate binding to a catalytically important Zn2+ ion in the active site, although the plausibility of this binding hypothesis is challenged by observation of excellent selectivity versus the closely related aminopeptidase N (APN). Taken together with the non-competitive inhibition pattern, we also consider an alternative model of allosteric binding. [ABSTRACT FROM AUTHOR]

Thymus species (Lamiaceae), commonly referred to as thyme, have gained popularity due to their utilisation in traditional medicine for various ailments such as gastrointestinal disorders, colds, upper respiratory infections, vomiting, jaundice, oral hygiene and oral ulcers. Nevertheless, a significant number of Thymus species remain unexplored in terms of their bioactivity and phenolic content. In the present study, a thorough chemical analysis of endemic Thymus canoviridis methanol (METC)-water extracts (WETC) and Thymus pubescens var. pubescens methanol (METP)-water extracts (WETP) was carried out by Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS). In addition, the inhibitory effect and antioxidant properties of these extracts on the enzymes acetylcholinesterase (AChE), α -glycosidase and carbonic anhydrase II (CA II) were also evaluated. The antioxidant potential was assessed using six assays, namely DPPH, ABTS, DMPD, FRAP, CUPRAC and Fe3+ reducing assays. Our results suggest that the methanol extract from these two plants exhibits a higher level of antioxidant activity. Furthermore, WETP inhibited all enzymes in the best way. According to the UPLC-MS/MS analysis results, rosmarinic acid showed its highest content in METC (18285.55 µg/g extract), WETC (27.98 µg/g extract) and METP (2910.59 µg/g extract), while WETP (69.76 µg/g extract) and the following total amounts of phenolic compounds were METC 20726.55 µg/g extract, METP 5887.20 µg/g extract, WETP 348.98 µg/g extract, WETC 68.56 µg/g extract. It is consistent with the analytical result, total phenolic content, and activity ranking in antioxidant assays. Regard to the results of the molecular docking studies, there is a high binding affinity between the CA II enzyme and cyanidin-3- O -glycoside, between the AChE and keracyanin chloride, and between α -glycosidase enzyme and rosmarinic acid. The extracts were discovered to exhibit various biological activities, such as antioxidant, antidiabetic, anti-Alzheimer's disease, and antiglaucoma properties. [Display omitted] • Antioxidant and antimicrobial activities of Thymus species were evaluated using several bioassays. • Comprehensive metabolic profiling of Thymus species was relaized by UPLC-MS/MS. • Anti-Alzheimer, antidiabetic, anti-glaucoma effects of Thymus species were determined and compared to standards. • High binding affinity was detected between CA II enzyme-cyanidin-3- O -glucoside, AChE-keracyanin chloride, and α -glycosidase-rosmarinic acid. [ABSTRACT FROM AUTHOR]

Based on our previous success in using cyclobutanone derivatives as enzyme inhibitors, we have designed and prepared a 37-member library of α-aminocyclobutanone amides and sulfonamides, screened for inhibition of the bacterial enzyme diaminopimelate desuccinylase (DapE), which is a promising antibiotic target, and identified several inhibitors with micromolar inhibitory potency. Molecular docking suggests binding of the deprotonated hydrate of the strained cyclobutanone, and thermal shift analysis with the most potent inhibitor (3y, IC50 = 23.1 µM) enabled determination of a Ki value of 10.2 +/− 0.26 µM and observed two separate Tm values for H. influenzae DapE (HiDapE). [ABSTRACT FROM AUTHOR]

[Objectives]Gram-negative resistant bacteria producing New Delhi metallo-β-lactamase-5(NDM-5)pose great threat to the health of human and domestic animals. The study aimed to explore the inhibitory action and the involved mechanism of allicin on NDM-5, which could provide theoretical support for the development of novel β-lactamase inhibitors. [Methods]The binding site of allicin and NDM-5 was predicted by molecular docking with AutoDock. Mutant vector pET21a-NDM-5-C208A was constructed and transferred into E.coli BL21(DE3)competent cell after sequencing. Sensitive test was performed to verify the phenotype of mutant strain. Checkerboard method and time-kill curves assay were performed to assess the combination effect of allicin and meropenem against NDM-5 mutant strain. Enzyme activity assay was established to compare the inhibitory effect of allicin on the activities of C208 mutant NDM-5 and wild-type NDM-5 by expressing the mutant protein NDM-5-C208A in vitro. [Results]The C208A mutant strain BL21(DE3)pET21a-NDM-5-C208A was successfully constructed confirmed by sequencing. The C208A mutant strain regained susceptibility to cephalosporins and carbapenems, and the combination of allicin and meropenem showed independent effect, but not synergistic effect(FICI increased from 0.375 to 2). Enzyme activity assay showed that C208A mutation of NDM-5 caused the decrease of enzyme activity by 85% in vitro and the mutation resulted in the loss of inhibitory effect of allicin on NDM-5. [Conclusions]The Cys208 is a key site for maintaining the enzymatic hydrolysis activity of NDM-5, and allicin can exert an inhibitory effect on the enzyme activity by binding to this site. The results provide a strong support for developing and applying of allicin as a novel β-lactamase inhibitor. [ABSTRACT FROM AUTHOR]

Aminopeptidase N/CD13, a membrane-bound enzyme upregulated in tumor vasculature and involved in angiogenesis, can be used as a receptor for the targeted delivery of drugs to tumors through ligand-directed targeting approaches. We describe a novel peptide ligand (VGCARRYCS, called “G4”) that recognizes CD13 with high affinity and selectivity. Enzymological and computational studies showed that G4 is a competitive inhibitor that binds to the catalytic pocket of CD13 through its N-terminal region. Fusing the peptide C-terminus to tumor necrosis factor-alpha (TNF) or coupling it to a biotin/avidin complex causes loss of binding and inhibitory activity against different forms of CD13, including natural or recombinant ectoenzyme and a membrane form expressed by HL60 promyelocytic leukemia cells (likely due to steric hindrance), but not binding to a membrane form of CD13 expressed by endothelial cells (ECs). Furthermore, G4-TNF systemically administered to tumor-bearing mice exerted anticancer effects through a CD13-targeting mechanism, indicating the presence of a CD13 form in tumor vessels with an accessible binding site. Biochemical studies showed that most CD13 molecules expressed on the surface of ECs are catalytically inactive. Other functional assays showed that these molecules can promote endothelial cell adhesion to plates coated with G4-avidin complexes, suggesting that the endothelial form of CD13 can exert catalytically independent biological functions. In conclusion, ECs express a catalytically inactive form of CD13 characterized by an accessible conformation that can be selectively targeted by G4-protein conjugates. This form of CD13 may represent a specific target receptor for ligand-directed targeted delivery of therapeutics to tumors. [ABSTRACT FROM AUTHOR]

Unrestricted use of chemical insecticides, especially at high concentrations, has reduced their efficacy. Plant-based pesticides, due to their relatively high safety levels to humans and environment as well as effective control on insects, have become a suitable alternative to conventional pesticides. The aim of this study was to investigate the biological and physiological effects of the formulated essential oil of Trachyspermum ammi (L.) on the larvae of Helicoverpa armigera Hüb. The obtained essential oil was formulated into an emulsion using Tween 20 as emulsifier. Chemical analysis of the extracted essential oil indicated that Terpinen (14.4%), Cymene (18.5%), and Thymol (61.6%) were the major compounds. The essential oil of T. ammi have a significant repellency rate on third and sixth instar larvae of cotton bollworm at different observed time intervals, with an average repellency rate of 61-76%. Regarding fumigant toxicity, the highest concentration of the essential oil (500 µL/L) resulted in 100% larval mortality. The LC50 value for fumigant toxicity measured as 82.73 µL/L. The duration of larval development significantly increased in treatments compared to control. In EO concentrations of 2.5-1.25 percent an increase was observed respectively in the duration of the larval stage by 9 and 7 days. The pupae and adult’s emergence affected in dose dependent manner. At concentration of 50 µl/l, 89% inhibition of protease enzyme recorded. With regards to the biological and physiological effects observed in the formulated T. ammi essential oil, with complimentary researches, it could be used in integrated management programs of cotton bollworm. [ABSTRACT FROM AUTHOR]

Boronic acids/esters have recently emerged in the field of medicinal and pharmaceutical research due to their exceptional oxophilicity, low toxicity, and unique structure. They are known as potent enzyme inhibitors, cancer therapy capture agents, and can mimic certain types of antibodies to fight infections. They have been designed and developed into drugs, and this approach has emerged in the last 20 years. Five boronic acid drugs have been approved by the FDA and Health Canada, two of which are used to treat cancer, specifically multiple myeloma. The purpose of this review is to investigate boronic acid/ester derivatives as potential pharmaceutical agents as well as the mechanism of action. It will concentrate on six types of cancer: multiple myeloma, prostate cancer, breast cancer, lung cancer, cervical cancer, and colon cancer. Some newly developed boron-containing compounds have already demonstrated highly promising activities, but further investigation is required before final conclusions can be drawn. [ABSTRACT FROM AUTHOR]

Some furan/thiophene-2-carboxamide derivatives (1–3) were prepared from acyl chlorides and heterocyclic amine derivatives with good yields, employing synthetic route and their chemical structures were confirmed using different spectroscopic methods including IR, 1H NMR, 13C NMR and elemental analysis. Three different enzyme inhibition effect tests as urease, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibiting activities, were applied to these compounds. The biological evaluation results clearly showed that the compound 1 showed approximately 9.8-fold more activity against urease enzyme than thiourea standard while the compound 3 showed approximately 4.2-fold more activity against BChE enzyme than galantamine standard. The molecular interaction for each of the target compounds with the active sites of the urease, acetylcholinesterase and butyrylcholinesterase enzymes was investigated by molecular insertion simulations and the results were confirmed the experimental findings. The results also show that compounds such as 1 and 3 carrying thiophene/furan carbocamide moieties could be used promising structures in the development of more potent pharmaceutical agents in the future. [ABSTRACT FROM AUTHOR]

The shikimate pathway is crucial for the biosynthesis of aromatic amino acids in plants and represents a promising target for developing new herbicides. This work aimed to identify inhibitors of shikimate dehydrogenase (SDH), a key enzyme of the shikimate pathway that catalyzes the conversion of 3-dehydroshikimate to shikimate. Virtual screening and molecular dynamic simulations were performed on the SDH active site of Arabidopsis thaliana (AtSDH), and 6-nitroquinazoline-2,4-diol (NQD) was identified as a potential inhibitor. In vitro assays showed that NQD decreased the activity of AtSDH by reducing Vmax while keeping KM unchanged, indicating non-competitive inhibition. In vivo, hydroponic experiments revealed that NQD reduced the root length of soybean and maize. Additionally, NQD increased the total protein content and certain amino acids. Soybean roots uptake NQD more efficiently than maize roots. Furthermore, NQD reduced shikimate accumulation in glyphosate-treated soybean roots, suggesting its potential to restrict the flow of metabolites along the shikimate pathway in soybean. The simultaneous treatment of maize seedlings with glyphosate and NQD accumulated gallic acid in the roots, indicating that NQD inhibits SDH in vivo. Overall, the data indicate that NQD inhibits SDH both in vitro and in vivo, providing valuable insights into the potential development of herbicides targeting SDH.

While cytochrome P450 (CYP; P450) enzymes are commonly associated with the metabolism of organic xenobiotics and drugs or the biosynthesis of organic signaling molecules, they are also impacted by a variety of inorganic species. Metallic nanoparticles, clusters, ions, and complexes can alter CYP expression, modify enzyme interactions with reductase partners, and serve as direct inhibitors. This commonly overlooked topic is reviewed here, with an emphasis on understanding the structural and physiochemical basis for these interactions. Intriguingly, while both organometallic and coordination compounds can act as potent CYP inhibitors, there is little evidence for the metabolism of inorganic compounds by CYPs, suggesting a potential alternative approach to evading issues associated with rapid modification and elimination of medically useful compounds.

Boronic acids/esters have recently emerged in the field of medicinal and pharmaceutical research due to their exceptional oxophilicity, low toxicity, and unique structure. They are known as potent enzyme inhibitors, cancer therapy capture agents, and can mimic certain types of antibodies to fight infections. They have been designed and developed into drugs, and this approach has emerged in the last 20 years. Five boronic acid drugs have been approved by the FDA and Health Canada, two of which are used to treat cancer, specifically multiple myeloma. The purpose of this review is to investigate boronic acid/ester derivatives as potential pharmaceutical agents as well as the mechanism of action. It will concentrate on six types of cancer: multiple myeloma, prostate cancer, breast cancer, lung cancer, cervical cancer, and colon cancer. Some newly developed boron-containing compounds have already demonstrated highly promising activities, but further investigation is required before final conclusions can be drawn.

Thirteen novel compounds in a series of dihydrobenzo[h]quinazolin-2-yl thiourea compounds (7a–m) were synthesized and characterized using FT-IR, 1H, 13C NMR spectroscopy, and elemental analysis. Some inhibition parameters including IC50 and inhibition constant values (Ki) were determined for all the compounds. All studied compounds exhibited potent inhibition against carbonic anhydrases (CAs). They inhibited CAs with the IC50 values of 30.45 to 94.00 μM (Ki: 28.27–61.01 μM) for hCA I and 21.80 to 78.00 μM (Ki: 17.84–57.96 μM) for hCA II. The most active compounds were found to be compound 7m for hCA I (Ki: 28.27 μM) and compound 7d for hCA II (Ki : 17.84 μM). The absorption, distribution, metabolism, excretion, and toxicity (ADME-Tox) study revealed that all the derivatives had good oral bioavailability with respect to Lipinski's rule of five and Jorgensen's rule of three. All derivatives in the series can be considered as outstanding multitarget inhibitors for further investigations. [ABSTRACT FROM AUTHOR]

Background: Salivary glands from blood-feeding arthropods secrete several molecules that inhibit mammalian hemostasis and facilitate blood feeding and pathogen transmission. The salivary functions from Simulium guianense, the main vector of Onchocerciasis in South America, remain largely understudied. Here, we have characterized a salivary protease inhibitor (Guianensin) from the blackfly Simulium guianense. Materials and methods: A combination of bioinformatic and biophysical analyses, recombinant protein production, in vitro and in vivo experiments were utilized to characterize the molecula mechanism of action of Guianensin. Kinetics of Guianensin interaction with proteases involved in vertebrate inflammation and coagulation were carried out by surface plasmon resonance and isothermal titration calorimetry. Plasma recalcification and coagulometry and tail bleeding assays were performed to understand the role of Guianensin in coagulation. Results: Guianensin was identified in the sialotranscriptome of adult S. guianense flies and belongs to the Kunitz domain of protease inhibitors. It targets various serine proteases involved in hemostasis and inflammation. Binding to these enzymes is highly specific to the catalytic site and is not detectable for their zymogens, the catalytic site-blocked human coagulation factor Xa (FXa), or thrombin. Accordingly, Guianensin significantly increased both PT (Prothrombin time) and aPTT (Activated partial thromboplastin time) in human plasma and consequently increased blood clotting time ex vivo. Guianensin also inhibited prothrombinase activity on endothelial cells. We show that Guianensin acts as a potent anti-inflammatory molecule on FXa-induced paw edema formation in mice. Conclusion: The information generated by this work highlights the biological functionality of Guianensin as an antithrombotic and anti-inflammatory protein that may play significant roles in blood feeding and pathogen transmission. [ABSTRACT FROM AUTHOR]

Inhibition of insulin-regulated aminopeptidase (IRAP) has been shown to improve cognitive functions in several animal models. Recently, we performed a screening campaign of approximately 10,000 compounds, identifying novel small-molecule-based compounds acting as inhibitors of the enzymatic activity of IRAP. Here we report on the chemical synthesis, structure-activity relationships (SAR) and initial characterization of physicochemical properties of a series of 48 imidazo [1,5-α]pyridine-based inhibitors, including delineation of their mode of action as non-competitive inhibitors with a small L-leucine-based IRAP substrate. The best compound displays an IC50 value of 1.0 µM. We elucidate the importance of two chiral sites in these molecules and find they have little impact on the compound’s metabolic stability or physicochemical properties. The carbonyl group of a central urea moiety was initially believed to mimic substrate binding to a catalytically important Zn2+ ion in the active site, although the plausibility of this binding hypothesis is challenged by observation of excellent selectivity versus the closely related aminopeptidase N (APN). Taken together with the non-competitive inhibition pattern, we also consider an alternative model of allosteric binding.

Based on our previous success in using cyclobutanone derivatives as enzyme inhibitors, we have designed and prepared a 37-member library of α-aminocyclobutanone amides and sulfonamides, screened for inhibition of the bacterial enzyme diaminopimelate desuccinylase (DapE), which is a promising antibiotic target, and identified several inhibitors with micromolar inhibitory potency. Molecular docking suggests binding of the deprotonated hydrate of the strained cyclobutanone, and thermal shift analysis with the most potent inhibitor (3y, IC50 = 23.1 µM) enabled determination of a Ki value of 10.2 +/− 0.26 µM and observed two separate Tm values for H. influenzae DapE (HiDapE).

BackgroundSalivary glands from blood-feeding arthropods secrete several molecules that inhibit mammalian hemostasis and facilitate blood feeding and pathogen transmission. The salivary functions from Simulium guianense, the main vector of Onchocerciasis in South America, remain largely understudied. Here, we have characterized a salivary protease inhibitor (Guianensin) from the blackfly Simulium guianense.Materials and methodsA combination of bioinformatic and biophysical analyses, recombinant protein production, in vitro and in vivo experiments were utilized to characterize the molecula mechanism of action of Guianensin. Kinetics of Guianensin interaction with proteases involved in vertebrate inflammation and coagulation were carried out by surface plasmon resonance and isothermal titration calorimetry. Plasma recalcification and coagulometry and tail bleeding assays were performed to understand the role of Guianensin in coagulation.ResultsGuianensin was identified in the sialotranscriptome of adult S. guianense flies and belongs to the Kunitz domain of protease inhibitors. It targets various serine proteases involved in hemostasis and inflammation. Binding to these enzymes is highly specific to the catalytic site and is not detectable for their zymogens, the catalytic site-blocked human coagulation factor Xa (FXa), or thrombin. Accordingly, Guianensin significantly increased both PT (Prothrombin time) and aPTT (Activated partial thromboplastin time) in human plasma and consequently increased blood clotting time ex vivo. Guianensin also inhibited prothrombinase activity on endothelial cells. We show that Guianensin acts as a potent anti-inflammatory molecule on FXa-induced paw edema formation in mice.ConclusionThe information generated by this work highlights the biological functionality of Guianensin as an antithrombotic and anti-inflammatory protein that may play significant roles in blood feeding and pathogen transmission.

The effect of pH on microbial, enzyme inactivation, and bioactive retention in ultrasound (US) treated sweet lime (Citrus limetta) juice was studied. The pH of the juice varied at 3.5, 4.0, and 4.5, whereas the US duty cycle (DC) ranged between 75% and 95% (0.07–0.7 W/cm3), and the treatment time varied between 15 and 30 min. More than 5‐log reduction in Saccharomyces cerevisiae and Escherichia coli was achieved at DC 95% (25 min) while Listeria monocytogenes got inactivated at DC 85% (25 min). 95%–99% inactivation of peroxidase and pectin methylesterase was achieved at DC 95% (30 min), while 60% inactivation in polyphenol oxidase (PPO) was observed. The addition of ascorbic acid (1 g/L) as an EI resulted in the complete inactivation of PPO at DC 85% (25 min). A maximum color change (ΔE*) of 2.6 was noticed at the highest US treatment condition (DC 95%, 30 min). Eventually, pH showed a marginal effect (˂5%) on retaining vitamin C and bioactive compounds, but US treatment enhanced them. US treatment at DC 95% (30 min) produced microbially safe (˃5‐log cycle reduction) and enzymatically stable (99% enzyme inactivation) juice. To conclude, optimized US treatment increased total phenolic content (TPC), antioxidant capacity, and vitamin C in sweet lime juice by 16.7%, 10.7%, and 14.1%, respectively. Practical applications: Consumer demand for superior quality sweet lime juice with minimal processing. This explores the opportunity of applying US technology as one of the nonthermal treatments for such a product. Furthermore, the treated juice should be microbially safe and enzymatically stable with better bioactive preservation. Typically, the pH of the fruit juice is one of the main influencing factors controlling microbiological spoilage. The current study explores the consequence of matrix pH and US conditions on the microbial inactivation, enzyme stability, and bioactive compounds of US‐treated sweet lime juice. The hypothesis is that the ultrasonic power required to achieve microbial safety at a lower pH of sweet lime juice should be lower. This will eventually help the industry choose an optimal harvesting condition to obtain the desired pH during processing. [ABSTRACT FROM AUTHOR]

Polygoni Cuspidati Rhizoma et Radix (PCR), the rhizome and root of Polygonum cuspidatum Sieb. et Zucc., has been used as an herbal medicine for a long time. In this study, the ultrafiltration combined with high performance liquid chromatography (UF-HPLC) method was developed to screen tyrosinase (TYR), α-glucosidase (α-GLU), and xanthine oxidase (XOD) inhibitors from PCR. Firstly, the inhibitory activity of 50% methanol PCR extract on TYR, α-GLU, XOD, and acetylcholinesterase (ACHE) was tested. The extract showed a good inhibition on the enzymes, except for ACHE. Therefore, UF-HPLC experiments were carried out to screen TYR, α-GLU, and XOD inhibitors from PCR extract. Seven potential bioactive components were discovered, including methylgallate (1), 1,6-di-O-galloyl-D-glucose (2), polydatin-4′-O-D-glucoside (3), resveratrol-4′-O-D-glucoside (4), polydatin (5), malonyl glucoside resveratrol (6), and resveratrol-5-O-D-glucoside (7). Most of them were found as enzyme inhibitors from PCR for the first time, except polydatin (5), which had been reported as an α-GLUI in PCR in the literature. Finally, molecular docking analysis was applied to validate the interactions of these seven potential active components with the enzymes. Compounds 1–7 were proven as TYR inhibitors, compounds 2, 4–7 were identified as XOD inhibitors, and compounds 4–6 were confirmed as α-GLU inhibitors. In short, the current study provides a good reference for the screening of enzyme inhibitors through UF-HPLC, and provides scientific data for future studies of PCR. [ABSTRACT FROM AUTHOR]

BACKGROUND: Euryale ferox is an important cash crop and valuable tonic in traditional medicine. The seeds of E. ferox are rich in starch, which is hard to digest, and the digestion speed is significantly slower than that of rice starch. The goal of this study was to evaluate the effects of E. ferox seed‐coat phenolics (EFCPs) on the digestion of E. ferox seed starch. RESULTS: EFCPs were extracted and identified by ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry. We optimized the extraction parameters, and the final extraction yield was about 1.49%. We identified seven phenolics from the E. ferox seed‐coat extracts: gallic acid, digalloylhexoside, catechin, procyanidin B2, epicatechin, ellagic acid, and epicatechin gallate. Quantitative analysis results showed that the E. ferox seed phenolics mainly distributed in the seed coat and the gallic acid, digalloylhexoside, and epicatechin gallate were three main phenolic compounds. The phenolics displayed strong inhibitory activities on α‐glucosidase and α‐amylase with an IC50 of 3.25 μg mL−1 and 1.36 mg mL−1 respectively. Furthermore, these phenolics could interact with starch by hydrogen bonds, which might make its starch more difficult to digest. CONCLUSION: Our investigation suggests that the EFCPs can strongly inhibit the digestion of E. ferox seed starch by inhibiting the α‐amylase and α‐glucosidase activities and interacting with starch by hydrogen bonds; therefore, E. ferox seeds have a promising application prospect in foods for hypoglycemia. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Context Brassica incana Ten. (Brassicaceae) is an edible plant with very limited available information. Previous studies have demonstrated the polyphenolic profile and the antioxidant and cytotoxic properties of the leaf and flowering top hydroalcoholic extracts.Objective The volatile composition and the antidiabetic and anti-obesity potential of B. incana leaf and flowering top extracts have been investigated.Material and methods The volatile characterization of the extracts was attained by HS-SPME-GC/MS analysis. The antidiabetic and anti-obesity potential was investigated spectrophotometrically in vitro by the ability to modulate pancreatic lipase and α-glucosidase at different concentrations using orlistat and acarbose as reference drugs. The inhibition of advanced glycation end-products (AGEs) was measured with aminoguanidine as reference and the antioxidant activity with the xanthine/xanthine oxidase system and Trolox for comparative purposes.Results Several volatiles belonging to different chemical classes were identified, being sulphur compounds the most abundant in both leaf and flowering top extracts (56.33% and 64.40% of all volatiles). Although the leaf extract showed lower IC50 values in most of the assays (0.968 and 1.921 mg/mL for α-glucosidase; 0.192 and 0.262 mg/mL for AGEs; 0.022 and 0.038 mg/mL for superoxide scavenging), there were no statistically significant differences between both samples. These extracts showed a similar behaviour to Trolox in the xanthine oxidase assay (IC50 values of 0.022 mg/mL for leaf extract; 0.038 mg/mL for flowering top and 0.028 for Trolox).Conclusions Leaves and flowering tops from B. incana can be used as sources of functional compounds that could act as antidiabetic and anti-obesogenic agents.

Carbonic anhydrases (EC 4.2.1.1) catalyse the reversible hydration of CO2 into bicarbonate and protons. As a hypoxia-sensitive and tumour-associated isoform, isoform CA IX, is significantly overexpressed in various malignancies, being a validated target for new anticancer/antimetastatic drugs. A multitude of studies has shown that CA IX inhibition decreases cancer cell proliferation and metastasis through pHe/pHi modulation and enhancement of ferroptosis among others. Numerous studies demonstrated increased efficacy of cytotoxic drugs combined with CA inhibitors (CAIs) in various cancer types. We tested the inhibitory effect of boric acid (BA), an inorganic Lewis acid, on CA IX as well as other isoforms (CA I, II, and XII). BA acted as a millimolar in vitro CAI, decreased proliferation of two cancer cell lines, although not strong correlations between the in vitro inhibition and in vivo effects were observed. The mechanism of antiproliferative action of BA should be investigated in more detail.

The landscape of viral strains and lineages of SARS-CoV-2 keeps changing and is currently dominated by Delta and Omicron variants. Members of the latest Omicron variants, including BA.1, are showing a high level of immune evasion, and Omicron has become a prominent variant circulating globally. In our search for versatile medicinal chemistry scaffolds, we prepared a library of substituted ɑ-aminocyclobutanones from an ɑ-aminocyclobutanone synthon (11). We performed an in silico screen of this actual chemical library as well as other virtual 2-aminocyclobutanone analogs against seven SARS-CoV-2 nonstructural proteins to identify potential drug leads against SARS-CoV-2, and more broadly against coronavirus antiviral targets. Several of these analogs were initially identified as in silico hits against SARS-CoV-2 nonstructural protein 13 (Nsp13) helicase through molecular docking and dynamics simulations. Antiviral activity of the original hits as well as ɑ-aminocyclobutanone analogs that were predicted to bind more tightly to SARS-CoV-2 Nsp13 helicase are reported. We now report cyclobutanone derivatives that exhibit anti-SARS-CoV-2 activity. Furthermore, the Nsp13 helicase enzyme has been the target of relatively few target-based drug discovery efforts, in part due to a very late release of a high-resolution structure accompanied by a limited understanding of its protein biochemistry. In general, antiviral agents initially efficacious against wild-type SARS-CoV-2 strains have lower activities against variants due to heavy viral loads and greater turnover rates, but the inhibitors we are reporting have higher activities against the later variants than the wild-type (10–20X). We speculate this could be due to Nsp13 helicase being a critical bottleneck in faster replication rates of the new variants, so targeting this enzyme affects these variants to an even greater extent. This work calls attention to cyclobutanones as a useful medicinal chemistry scaffold, and the need for additional focus on the discovery of Nsp13 helicase inhibitors to combat the aggressive and immune-evading variants of concern (VOCs). [ABSTRACT FROM AUTHOR]

The reuse of food by-products is crucial for the well-being of the planet. Considering the high content of nutrients and other bioactive compounds in many of them, investigating their suitability for use as human food ingredients is an interesting challenge. In this study, in addition to the proximate composition, phenol content and antioxidant activity (AOA = 3.2 mmol Trolox equivalent (TE)/100 g, db) of orange juice powder by-product (CoP), different in vitro properties related to carbohydrate metabolism have been characterised. Specifically, the glycaemic index (GI), the glycaemic load (GL), the glucose dialysis retardation index (GDRI = 13.6%), the glucose adsorption capacity (GAC = 22.5 mM) and the inhibition capacity of α-amylase (α-A = 46.9%) and α-glucosidase (α-G = 93.3%) of powdered orange juice waste have been determined and related to fibre and phenolics composition. Taking advantage of the high fibre content of the by-product (36.67%), its GL was calculated for a CoP dose that allows labelling the food to which it is added as a source of fibre. The low GI value (24.4%) and the low GL (0.918 g available carbohydrates per serving) allowed us to conclude that the product studied could be an interesting opportunity for the food industry to offer it as a healthy food ingredient to be included in the diet, especially for those suffering from type 2 diabetes mellitus. Of the total phenolic compounds (TP = 509 mg equivalent of gallic acid (GAE)/100 g, db), 68% were found in free fraction (FP), and their contribution to the total AOA was 40.6%, while this was 54.9% for the 32% of phenols bound to plant tissues (BP). [ABSTRACT FROM AUTHOR]

Planar chromatography has recently been combined with six different effect-directed assays for three golden root (Rhodiola rosea L.) samples. However, the profiles obtained showed an intense tailing, making zone differentiation impossible. The profiling was therefore improved to allow for the detection of individual bioactive compounds, and the range of samples was extended to 15 commercial golden root products. Further effect-directed assays were studied providing information on 15 different effect mechanisms, i.e., (1) tyrosinase, (2) acetylcholinesterase, (3) butyrylcholinesterase, (4) β-glucuronidase, and (5) α-amylase inhibition, as well as endocrine activity via the triplex planar yeast antagonist-verified (6–8) estrogen or (9–11) androgen screen, (12) genotoxicity via the planar SOS-Umu-C bioassay, antimicrobial activity against (13) Gram-negative Aliivibrio fischeri and (14) Gram-positive Bacillus subtilis bacteria, and (15) antioxidative activity (DPPH• radical scavengers). Most of the golden root profiles obtained were characteristic, but some samples differed substantially. The United States Pharmacopeia reference product showed medium activity in most of the assays. The six most active compound zones were further characterized using high-resolution mass spectrometry, and the mass signals obtained were tentatively assigned to molecular formulae. In addition to confirming the known activities, this study is the first to report that golden root constituents inhibit butyrylcholinesterase (rosin was tentatively assigned), β-glucuronidase (rosavin, rosarin, rosiridin, viridoside, and salidroside were tentatively assigned), and α-amylase (stearic acid and palmitic acid were tentatively assigned) and that they are genotoxic (hydroquinone was tentatively assigned) and are both agonistic and antagonistic endocrine active. [ABSTRACT FROM AUTHOR]

Xanthomonas spp. are important plant pathogens that seriously endanger crop yields and food security. RpfF is a key enzyme that is involved in the synthesis of diffusible signal factor (DSF) signals and predominates in the signaling pathway regulating quorum sensing (QS) in Xanthomonas. Currently, novel RpfF enzyme-based quorum sensing agents have been proposed as a promising strategy for the development of new pesticides. However, few reports are available that comprehensively summarize the progress in this field. Therefore, we provide a comprehensive review of the recent advances in DSF-mediated QS and recently reported inhibitors that are proposed as bactericide candidates to target the RpfF enzyme and control plant bacterial diseases. [ABSTRACT FROM AUTHOR]

The acid catalyzed hydrolysis of the N-(p-substitutedphenyl) phthalimides in three different acids was investigated at 50.0 ± 0.1 °C. Two different antioxidant activity tests as DPPH• and ABTS•+ scavenging activities, and three various enzyme inhibition activity tests as urease, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibition activities, were applied. Compound 3c (2.03 μg/mL) has higher antioxidant activity than other compounds and standards according to DPPH test. In AChE assay, compounds 3a and 3b (13.13 and 9.59 μg/mL) has higher enzyme inhibition activity than the standard Galantamine (14.37 μg/mL). In BChE and urease tests, all compounds (6.84-13.60 and 10.49-17.73 μg/mL) have higher enzyme inhibition activity than the standard Galantamine (49.40 μg/mL) and thiourea (26.19 μg/mL), respectively. The molecule interaction for each of the three compounds with the active sites of AChE, BChE, and urease enzymes was examined via molecular docking simulations. [ABSTRACT FROM AUTHOR]

Aldehyde dehydrogenase 3A1 (ALDH3A1) by oxidizing medium chain aldehydes to their corresponding carboxylic acids, is involved in the detoxification of toxic byproducts and is considered to play an important role in antioxidant cellular defense. ALDH3A1 has been implicated in various other functions such as cell proliferation, cell cycle regulation, and DNA damage response. Recently, it has been identified as a putative biomarker of prostate, gastric, and lung cancer stem cell phenotype. Although ALDH3A1 has multifaceted functions in both normal and cancer homeostasis, its modes of action are currently unknown. To this end, we utilized a random 12-mer peptide phage display library to identify efficiently human ALDH3A1-interacting peptides. One prevailing peptide (P1) was systematically demonstrated to interact with the protein of interest, which was further validated in vitro by peptide ELISA. Bioinformatic analysis indicated two putative P1 binding sites on the protein surface implying biomedical potential and potent inhibitory activity of the P1 peptide on hALDH3A1 activity was demonstrated by enzymatic studies. Furthermore, in search of potential hALDH3A1 interacting players, a BLASTp search demonstrated that no protein in the database includes the full-length amino acid sequence of P1, but identified a list of proteins containing parts of the P1 sequence, which may prove potential hALDH3A1 interacting partners. Among them, Protein Kinase C Binding Protein 1 and General Transcription Factor II-I are candidates of high interest due to their cellular localization and function. To conclude, this study identifies a novel peptide with potential biomedical applications and further suggests a list of protein candidates be explored as possible hALDH3A1-interacting partners in future studies.

Campylobacter jejuni infection poses a serious global threat to public health. The increasing incidence and antibiotic resistance of this bacterial infection have necessitated the adoption of various strategies to curb this trend, primarily through developing new drugs with new mechanisms of action. The enzyme malate:quinone oxidoreductase (MQO) has been shown to be essential for the survival of several bacteria and parasites. MQO is a peripheral membrane protein that catalyses the oxidation of malate to oxaloacetate, a crucial step in the tricarboxylic acid cycle. In addition, MQO is involved in the reduction of the quinone pool in the electron transport chain and thus contributes to cellular bioenergetics. The enzyme is an attractive drug target as it is not conserved in mammals. As a preliminary step in assessing the potential application of MQO from C. jejuni (CjMQO) as a new drug target, we purified active recombinant CjMQO and conducted, for the first time, biochemical analyses of MQO from a pathogenic bacterium. Our study showed that ferulenol, a submicromolar mitochondrial MQO inhibitor, and embelin are nanomolar inhibitors of CjMQO. We showed that both inhibitors are mixed-type inhibitors versus malate and noncompetitive versus quinone, suggesting the existence of a third binding site to accommodate these inhibitors; indeed, such a trait appears to be conserved between mitochondrial and bacterial MQOs. Interestingly, ferulenol and embelin also inhibit the in vitro growth of C. jejuni, supporting the hypothesis that MQO is essential for C. jejuni survival and is therefore an important drug target.

A new triterpene glycoside, silviridoside, was isolated from the aerial parts of Silene viridiflora (Caryophyllaceae) using different chromatographic techniques. The structure of silviridoside was comprehensively elucidated as 3-O-β-D-galacturonopyranosyl-quillaic acid 28-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-fucopyranosyl ester by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). Silviridoside showed promising antioxidant activity in different antioxidant assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) (2.32 mg TE/g), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (1.24 mg TE/g), cupric-reducing antioxidant capacity (CUPRAC) (9.59 mg TE/g), ferric-reducing antioxidant power (FRAP) (5.13 mg TE/g), phosphomolybdenum (PHD) (0.28 mmol TE/g), and metal-chelating (MCA) (6.62 mg EDTA/g) assays. It exhibited a good inhibitory potential on acetylcholinesterase (AChE) (2.52 mg GALAE/g), butyrylcholinesterase (BChE) (7.16 mg GALAE/g), α-amylase (0.19 mmol ACAE/g), α-glucosidase (1.21 mmol ACAE/g), and tyrosinase (38.83 mg KAE/g). An in silico evaluation of the pharmacodynamic, pharmacokinetic, and toxicity properties of silviridoside showed that the new compound exhibited reasonable pharmacodynamic and pharmacokinetic properties without any mutagenic effect, but slight toxicity. Thus, it could be concluded that silviridoside could act as a promising lead drug for pharmaceutical and nutraceutical developments to combat oxidative stress and various disorders, but a future optimization is necessary. [ABSTRACT FROM AUTHOR]

Carbonic anhydrases (EC 4.2.1.1) catalyse the reversible hydration of CO2 into bicarbonate and protons. As a hypoxia-sensitive and tumour-associated isoform, isoform CA IX, is significantly overexpressed in various malignancies, being a validated target for new anticancer/antimetastatic drugs. A multitude of studies has shown that CA IX inhibition decreases cancer cell proliferation and metastasis through pHe/pHi modulation and enhancement of ferroptosis among others. Numerous studies demonstrated increased efficacy of cytotoxic drugs combined with CA inhibitors (CAIs) in various cancer types. We tested the inhibitory effect of boric acid (BA), an inorganic Lewis acid, on CA IX as well as other isoforms (CA I, II, and XII). BA acted as a millimolar in vitro CAI, decreased proliferation of two cancer cell lines, although not strong correlations between the in vitro inhibition and in vivo effects were observed. The mechanism of antiproliferative action of BA should be investigated in more detail. [ABSTRACT FROM AUTHOR]

Calcineurin (CN) controls the immune response by regulating nuclear factor of activated T cells (NFAT). Inhibition of CN function is an effective treatment for immune diseases. The PVIVIT peptide is an artificial peptide based on the NFAT-PxIxIT motif, which exhibits stronger binding to CN. A bioactive peptide (named pep4) that inhibits the CN/NFAT interaction was designed. Pep4 contains a segment of A238L as the linker and the LxVP motif and PVIVIT motif as CN binding sites. Pep4 has strong binding capacity to CN and inhibits CN activity competitively. 11-arginine-modified pep4 (11 R-pep4) inhibits the nuclear trans-location of NFAT and reduces the expression of IL-2. 11 R-pep4 improves the pathological characteristics of asthmatic mice to a certain extent. The above results indicated that pep4 is a high-affinity CN inhibitor. These findings will contribute to the discovery of new CN inhibitors and promising immunosuppressive drugs. [ABSTRACT FROM AUTHOR]

Context: Brassica incana Ten. (Brassicaceae) is an edible plant with very limited available information. Previous studies have demonstrated the polyphenolic profile and the antioxidant and cytotoxic properties of the leaf and flowering top hydroalcoholic extracts. Objective: The volatile composition and the antidiabetic and anti-obesity potential of B. incana leaf and flowering top extracts have been investigated. Material and methods: The volatile characterization of the extracts was attained by HS-SPME-GC/MS analysis. The antidiabetic and anti-obesity potential was investigated spectrophotometrically in vitro by the ability to modulate pancreatic lipase and α-glucosidase at different concentrations using orlistat and acarbose as reference drugs. The inhibition of advanced glycation end-products (AGEs) was measured with aminoguanidine as reference and the antioxidant activity with the xanthine/xanthine oxidase system and Trolox for comparative purposes. Results: Several volatiles belonging to different chemical classes were identified, being sulphur compounds the most abundant in both leaf and flowering top extracts (56.33% and 64.40% of all volatiles). Although the leaf extract showed lower IC50 values in most of the assays (0.968 and 1.921 mg/mL for α-glucosidase; 0.192 and 0.262 mg/mL for AGEs; 0.022 and 0.038 mg/mL for superoxide scavenging), there were no statistically significant differences between both samples. These extracts showed a similar behaviour to Trolox in the xanthine oxidase assay (IC50 values of 0.022 mg/mL for leaf extract; 0.038 mg/mL for flowering top and 0.028 for Trolox). Conclusions: Leaves and flowering tops from B. incana can be used as sources of functional compounds that could act as antidiabetic and anti-obesogenic agents. [ABSTRACT FROM AUTHOR]

Inhibition profiles of synthesized 4‐methyl benzene sulfonamide derivatives on carbonic anhydrase I (CA I) and II (CA II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were investigated in this study. All sulfonamide based compounds showed the inhibition profiles with KI values in the range 0.39–2.46 nM for CA I, 4.81–14.43 nM for CA II, 52.10–58.83 nM AChE and 50.78–57.38 nM for BChE, respectively. CA Isoenzymes are essential therapeutic targets and their inhibitors have been used for pharmacological purposes particularly in the remedy of diseases such as glaucoma, edema, cancer, etc. Cholinesterase inhibitors are important compounds that can be used in many diverse therapeutic applications, especially Alzheimer's disease (AD). The 4‐methyl benzene sulfonamides examined here and acetazolamide, the clinically used CA Inhibitor, showed similar results for CA I and II. Similarly, synthesized compounds demonstrated close inhibition ranges with neostigmine, a cholinesterase inhibitor, on AChE and BChE enzymes. These results indicate that these molecules can be used as potential inhibitors for these esterase enzymes. In addition, molecular docking studies were carried out to elucidate the mechanism of the observed activities of the potent compounds. [ABSTRACT FROM AUTHOR]

Aristotelia chilensis is a plant whose fruit is considered a powerful natural antioxidant. During the last years, some investigations of the fruit have been carried out, finding antioxidant properties in the juice or the phenolic fraction. The antioxidant properties of the plant are useful in the inhibition of enzymes related to diabetes such as pancreatic aldose reductase and alpha-amylase. Because many synthetic drugs used today have limitations and potentially harmful side effects, the use of naturally occurring compounds, such as flavonoids, is clinically attractive. In this study, the characterization of aqueous extracts of fruits and in vitro plants of A. chilensis was carried out based on their content of anthocyanins and total phenols, the antioxidant capacity by the antiradical activity 2,2-diphenyl-1-picrilhydrazil (DPPH), and the profile of anthocyanins and other phenolic compounds by liquid chromatography coupled to mass spectrometry (LC-MS/MS). Subsequently, the effect of these extracts on the inhibition of bovine aldose reductase and pancreatic alpha-amylase enzymes was determined. According to our results, extracts of fruits and in vitro plants of A. chilensis achieved inhibition of the bovine aldose reductase enzyme of 85.54 ± 1.86% and 75.67 ± 1.21%, respectively. Likewise, the percentage of inhibition of the pancreatic alpha-amylase enzyme for fruit extracts was 29.64 ± 0.63%, while for in vitro plant extracts it was 47.66 ± 0.66%. The antioxidant and enzymatic inhibition activity of the extracts were related to the content of anthocyanins, such as delphinidin and cyanidin glycosides as well as the phenols derived from quercetin, myricetin, and kaempferol. The results obtained allow us to suggest that the in vitro culture of plants of A. chilensis represents a viable biotechnological alternative to obtain phenolic compounds for the inhibition of aldose reductase and pancreatic alpha-amylase enzymes. [ABSTRACT FROM AUTHOR]

Background: Quercetin is a food supplement with multiple biological activities including antihypertensive, vasodilator effects, antiobesity, antihypercholesterolemic, antiatherosclerotic and other activities, it is available in wide range of dietary supplement and daily food intake, after oral ingestion, quercetin is metabolized by intestinal enzymes and absorbed by the duodenum, then be transported to the liver where is transformed into its glucuronidated, methylated and sulfo-substituted metabolites. Aim of Study: Boosting the bioavailability of Quercetin by enzyme inhibitor effect of ketoconazole. Method: 10 apparently healthy adult, male (5) and female (5) were grouped A and B, with a 1-week wash-period, Group A received Quercetin 1000 mg, group B received Quercetin 1000 mg and Ketoconazole 400 mg, and 15 blood samples are collected on the following timing 0, 0.5 - 12.5 by 1 hour interval and other by hour 24 for HPLC Assay. Results: Concurrent ketoconazole administration with Quercetin significantly improves the mean plasma concentration under the curve from zero time to infinity (AUC0-8) by 176% (403.41 ± 62.28 vs. 228.51 ± 28.67 µg.h/mL; P <0.0001) and prolonged time to complete elimination (44.66 ± 9.17 vs. 12.93 ± 1.4 hr.; P <0.0000) compared with Quercetin alone. Conclusion: Bioavailability of Quercetin will be increased by its administration together with ketoconazole, due to enzyme inhibiting effect of ketoconazole which delay elimination and increase the AUC of Quercetin. [ABSTRACT FROM AUTHOR]

ABSTRACT: Objectives: : Chagas disease, caused by the parasitic protozoan Trypanosoma cruzi, affects approximately 6–7 million people worldwide. There are limited available therapies and they exhibit low efficacy, often high toxicity in chronic cases and some drug resistance. In this study, our objective was to develop ester prodrugs that inhibit proline racemase (TcPRAC), a parasitic enzyme previously identified and characterised as a promising target because of its essential role in the parasite's life cycle and virulence, and to test their activity against T. cruzi. Methods: : Using structural bioinformatics, we modelled several functional intermediates of the catalytic site between the opened and closed conformations of TcPRAC based on its crystal structures in complex with its competitive inhibitor, pyrrole-2-carboxylic acid. Guided by these intermediates, which were later validated in cocrystals, we designed and evaluated numerous compounds and tested them enzymatically on live parasites and in mice with our quick and straightforward drug screening method, which is based on state-of-the-art bioluminescent T. cruzi parasites injected subcutaneously. Results: : Some of our novel compounds specifically inhibited racemase activity, as determined through biochemical assays, and covalently bound to TcPRAC. Furthermore, the corresponding ester prodrugs were effective in killing parasites in vitro. Bioluminescent T. cruzi assays in mice showed that JR1531, a TcPRAC inhibitor prodrug, can kill parasites in living animals, with boosted action when combined with low doses of benznidazole. Conclusion: : This approach, based on TcPRAC inhibitor prodrugs in association with low doses of benznidazole, may lead to more effective, specific and non-toxic therapies against Chagas disease.

Sex steroid hormones such as estrogen estradiol (E2) and androgen dihydrotestosterone (DHT) are involved in the development of hormone-dependent cancers. Blockade of 17β-hydroxysteroid dehydrogenase type 7 (17β-HSD7), a member of the short chain dehydrogenase/reductase superfamily, is thought to decrease E2 levels while increasing those of DHT. Therefore, its unique double action makes this enzyme as an interesting drug target for treatment of breast cancer. The chemical synthesis, molecular characterization, and preliminary biological evaluation as 17β-HSD7 inhibitors of novel carbamate derivatives 3 and 4 are described. Like previous 17β-HSD7 inhibitors 1 and 2 , compounds 3 and 4 bear a hydrophobic nonyl side chain at the C-17β position of a 4-aza-5α-androstane nucleus, but compound 3 has an oxygen atom replacing the CH 2 in the steroid A-ring C-2 position, while compound 4 has a C17-spiranic E-ring containing a carbamate function. They both inhibited the in vitro transformation of estrone (E1) into E2 by 17β-HSD7, but the introduction of a (17 R)-spirocarbamate is preferable to replacing C-2 methylene with an oxygen atom since compound 4 (IC 50 = 63 nM) is an inhibitor 14 times more powerful than compound 3 (IC 50 = 900 nM). Furthermore, when compared to the reference inhibitor 1 (IC 50 = 111 nM), the use of a C17-spiranic E-ring made it possible to introduce differently the hydrophobic nonyl side chain, without reducing the inhibitory activity. [Display omitted] • 17β-HSD7 is an interesting drug target for breast cancer treatment. • Hydrophobic nonyl steroid carbamates were synthesized as 17β-HSD7 inhibitors. • Steroid carbamates were fully characterized by nuclear magnetic resonance spectroscopy. • C17-spiranic carbamate 4 inhibited the formation of estradiol (IC 50 =63 nM) by 17β-HSD7. • Synthesis of 4 required only 4 steps starting from 4-methyl-aza-5α-androstane-3,17-dione. [ABSTRACT FROM AUTHOR]

The cyclooxygenases COX-1 and COX-2 oxygenate arachidonic acid (AA) to prostaglandin H2 (PGH2). COX-2 also oxygenates the endocannabinoids 2-arachidonoylglycerol (2-AG) and arachidonoylethanolamide (AEA) to the corresponding PGH2 analogs. Both enzymes are targets of nonsteroidal anti-inflammatory drugs (NSAIDs), but NSAID-mediated COX inhibition is associated with gastrointestinal toxicity. One potential strategy to counter this toxicity is to also inhibit fatty acid amide hydrolase (FAAH), which hydrolyzes bioactive fatty acid ethanolamides (FAEs) into fatty acids and ethanolamine. Here, we investigated the mechanism of COX inhibition by ARN2508, an NSAID that inhibits both COXs and FAAH with high potency, target selectivity, and decreased gastrointestinal toxicity in mouse models, presumably due to its ability to increase levels of FAEs. A 2.27-Å-resolution X-ray crystal structure of the COX-2·(S)-ARN2508 complex reveals that ARN2508 adopts a binding pose similar to that of its parent NSAID flurbiprofen. However, ARN2508's alkyl tail is inserted deep into the top channel, an active site region not exploited by any previously reported NSAID. As for flurbiprofen, ARN2508's potency is highly dependent on the configuration of the α-methyl group. Thus, (S)-ARN2508 is more potent than (R)-ARN2508 for inhibition of AA oxygenation by both COXs and 2-AG oxygenation by COX-2. Also, similarly to (R)-flurbiprofen, (R)-ARN2508 exhibits substrate selectivity for inhibition of 2-AG oxygenation. Site-directed mutagenesis confirms the importance of insertion of the alkyl tail into the top channel for (S)-ARN2508's potency and suggests a role for Ser-530 as a determinant of the inhibitor's slow rate of inhibition compared with that of (S)-flurbiprofen.