Synthesis of 4-sulfamoyl phenyl diazocarboxylic acid derivatives as novel non-classical inhibitors of human carbonic anhydrase II activity: an in vitro study

The first class of carbonic anhydrase inhibitors (CAIs) discovered was sulfonamides, but their clinical use is limited due to side effects caused by their inhibition of multiple CA isoforms. To overcome this, researchers have focused on developing isoform-selective CAIs. This study involved the synthesis and characterization of novel carboxylic acid/sulfonamide derivatives. We investigated the interaction between these compounds and the human carbonic anhydrase II (hCA II) isoform using spectroscopic and computational methods. The synthesized compounds were evaluated based on their IC50, Kd and Ki values, and it was found that the inhibitory potency and binding affinity of the compounds increased with the number of carboxylic acids zinc binding groups. Specifically, the compound C4, with three carboxylic acid groups, showed the strongest inhibitory potency. Fluorescence measurements revealed that all compounds quenched the intrinsic fluorescence of hCA II through a dynamic quenching process, and each compound had one binding site in the hCA II structure. Thermodynamic analysis indicated hydrogen bonds and van der Waals interactions played key roles in the binding of these compounds to hCA II. Docking studies showed that the carboxylic acid groups directly attached to the zinc ion in the active site, displacing water/hydroxide ions and causing steric hindrance. Overall, the strengthening of inhibitory activity and the binding power of these carboxylic acid derivatives for the hCA II makes these compounds interesting for designing novel hCA II inhibitors.Communicated by Ramaswamy H. Sarma.

An in situ and in vitro investigation of cytoplasmic TDP-43 inclusions reveals the absence of a clear amyloid signature

Introduction: Several neurodegenerative conditions are associated with a common histopathology within neurons of the central nervous system, consisting of the deposition of cytoplasmic inclusions of TAR DNA-binding protein 43 (TDP-43). Such inclusions have variably been described as morphologically and molecularly ordered aggregates having amyloid properties, as filaments without the cross-β-structure and dye binding specific for amyloid, or as amorphous aggregates with no defined structure and fibrillar morphology.Aims and Methods: Here we have expressed human full-length TDP-43 in neuroblastoma x spinal cord 34 (NSC-34) cells to investigate the morphological, structural, and tinctorial properties of TDP-43 inclusions in situ. We have used last-generation amyloid diagnostic probes able to cross the cell membrane and detect amyloid in the cytoplasm and have adopted Raman and Fourier transform infrared microspectroscopies to study in situ the secondary structure of the TDP-43 protein in the inclusions. We have then used transmission electron microscopy to study the morphology of the TDP-43 inclusions.Results: The results show the absence of amyloid dye binding, the lack of an enrichment of cross-β structure in the inclusions, and of a fibrillar texture in the round inclusions. The aggregates formed in vitro from the purified protein under conditions in which it is initially native also lack all these characteristics, ruling out a clear amyloid-like signature.Conclusions: These findings indicate a low propensity of TDP-43 to form amyloid fibrils and even non-amyloid filaments, under conditions in which the protein is initially native and undergoes its typical nucleus-to-cell mislocalization. It cannot be excluded that filaments emerge on the long time scale from such inclusions, but the high propensity of the protein to form initially other types of inclusions appear to be an essential characteristic of TDP-43 proteinopathies.KEY MESSAGESCytoplasmic inclusions of TDP-43 formed in NSC-34 cells do not stain with amyloid-diagnostic dyes, are not enriched with cross-β structure, and do not show a fibrillar morphology.TDP-43 assemblies formed in vitro from pure TDP-43 do not have any hallmarks of amyloid.

Curcumin-loaded porous particles functionalized with pH-responsive cell-penetrating peptide for colorectal cancer targeted drug delivery

The anticancer properties of curcumin have been broadly examined in several shapes, such as nanoparticles and nanocomposite structures. Despite its benefits, curcumin also has some disadvantages, including rapid metabolism, poor absorption, and rapid systemic excretion. Therefore, numerous strategies have been used to increase curcumin's bioavailability. One of these approaches is the use of porous particles like aerogels as drug carriers. Aerogels are special due to their peculiar physical structure. They have a high specific surface area, a significant amount of porosity, and a solid composition, which make them a good choice for drug delivery systems. In the present study, a pH-sensitive aerogel was constructed and evaluated for targeted drug delivery of curcumin to colon cancer. To control the release of curcumin, trehalose was used as a coating agent, and PLP (poly(l-lysine isophthalamide)) was used as a targeted drug delivery agent. PLP is a pseudo-peptidic polymer that increases the cell permeability. In order to investigate and compare the synthesized aerogel before and after loading curcumin and coating with trehalose, physicochemical characterization analyses were performed. Finally, the efficacy of the final formulation was evaluated on HT29 colon cells using the cell bioavailability test. The results indicated the successful synthesis of the aerogel with porous structure with solitary cavities. The trehalose coating performed well, preventing drug release at lower pH but allowing the drug to be released at its intended site. The designed curcumin-loaded porous particles functionalized with PLP showed significant efficacy due to increasing penetration of curcumin into cells, and has potential for use as a new drug carrier with dual effectivity in cancer therapy.

Synthesis, characterization and hypolipidemic effects of urazine derivatives on rat: Study of molecular modeling and enzyme inhibition

The prevalence of hyperlipidemia has increased dramatically worldwide. It is a major public health threat, characterized by the presence of an abnormal lipid profile, primarily with elevated serum total cholesterol (TC), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) levels, and reduced high-density lipoprotein (HDL) level. Genetic factors, dietary and lifestyle habits play important roles in hyperlipidemia. It can increase the risk of chronic metabolic disorders, such as obesity, cardiovascular disease, and type II diabetes. The main objective of the present study was to evaluate the effect of urazine derivatives on serum triglyceride, cholesterol, LDL, HDL, and nitric oxide (NO) levels in high-fat diet (HFD)-induced hyperlipidemic rats. Synthetic compounds were prepared and confirmed by spectroscopic methods. Then, 88 male Sprague-Dawley rats were divided into 11 groups: control, HFD-treated group, HFD plus atorvastatin-treated group, and HFD plus 8 synthetic compounds-treated groups. The body weight, triglyceride, cholesterol, LDL, HDL, and NO levels were measured. The data with p < 0.05 were considered significant. The results indicated that HFD significantly increased cholesterol, triglyceride, and LDL levels and decreased NO concentration and HDL level compared to the control group (p < 0.05). However, HFD plus urazine derivatives significantly decreased NO, cholesterol, and triglyceride levels and increased HDL levels compared to the HFD-treated group (p < 0.05). Urazine derivatives may improve liver dysfunction in HFD-induced hyperlipidemic rats by modulation of detoxification enzymes and their anti-oxidant effects and also blood lipid profile.

Synthesis of 4-hydroxy-L-proline derivatives as new non-classical inhibitors of human carbonic anhydrase II activity: an in vitro study

Carbonic anhydrase (CA) is a zinc metalloenzyme that facilitates the rapid conversion of water and carbon dioxide into proton and bicarbonate ion. CA isozymes have been broadly studied in many pathological/physiological processes. In the current research, a series of 4-hydroxy-L-proline derivatives were designed and chemically synthetized, and interaction of these carboxylic acid-based compounds with hCA II were evaluated. Results indicated that different derivatives had different potencies on hCAII inhibitory activity and among them, compounds 3 b and 3c had the lowest IC50 and Kd values than 4-hydroxy-L-proline and other derivatives and therefore had the most affinity to the hCA II enzyme. As a result, compounds 3 b and 3c were chosen for additional testing in this research. The Kinetic data demonstrated that 3 b and 3c inhibit the hCA II esterase activity in a linear competitive way, with Ki values in the low micromolar range. Fluorescence tests showed that the hCA II surface hydrophobicity is diminished in the presence of compounds 3 b and 3c, as confirmed by the decrease in ANS binding to hCA II in their presence. Docking results revealed that 3 b and 3c had more binding energy than 4-hydroxy-L-proline. Furthermore, these compounds could occupy the active site of hCA II, where they would interact with critical amino acid residues via non-covalent forces to inhibit hCA II. Overall, the strengthening of inhibitory activity and the binding power of these carboxylic acid derivatives (3 b and 3c) for the hCA II makes these compounds interesting for designing novel hCA II inhibitors.Communicated by Ramaswamy H. Sarma.

Optimization of an α-aminonaphthylmethylphosphonic acid inhibitor of purple acid phosphatase using rational structure-based design approaches

Purple acid phosphatases (PAPs) are ubiquitous binuclear metallohydrolases that have been isolated from various animals, plants and some types of fungi. In humans and mice, elevated PAP activity in osteoclasts is associated with osteoporosis, making human PAP an attractive target for the development of anti-osteoporotic drugs. Based on previous studies focusing on phosphonate scaffolds, as well as a new crystal structure of a PAP in complex with a derivative of a previously synthesized α-aminonaphthylmethylphosphonic acid, phosphonates 24-40 were designed as new PAP inhibitor candidates. Subsequent docking studies predicted that all of these compounds are likely to interact strongly with the active site of human PAP and most are likely to interact strongly with the active site of pig PAP. The seventeen candidates were synthesized with good yields and nine of them (26-28, 30, 33-36 and 38) inhibit in the sub-micromolar to nanomolar range against pig PAP, with 28 and 35 being the most potent mammalian PAP inhibitors reported with K_i values of 168 nM and 186 nM, respectively. This study thus paves the way for the next stage of drug development for phosphonate inhibitors of PAPs as anti-osteoporotic agents.

Synthesis of benzylidene-benzofuranone derivatives as probes for detection of amyloid fibrils in cells

Aggregated protein is the common cause of a wide variety of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease, etc. It is proven that protein aggregation like amyloid β (Aβ) is one of the critical factors causing AD and, its diagnosis in the early stages of the disease is important for the treatment or prevention of AD. To have a better understanding of protein aggregation and its pathologies, there is a huge need to design and develop new and more trustworthy probe molecules for in vitro amyloid quantification and in vivo amyloid imaging. In this study, 17 new biomarker compounds, have been synthesized from benzofuranone derivatives, to detect and identify amyloid in vitro (dye-binding assay) as well as in the cell by staining method. According to the results, some of these synthetic derivatives can be considered suitable identifiers and quantifiers to detect amyloid fibrils in vitro. Compared to thioflavin T, 4 probes out of 17 probes have shown good results in selectivity and detectability of Aβ depositions, and their binding properties were also confirmed with in silico analysis. The drug-likeness prediction results for selected compounds by the Swiss ADME server show a satisfactory percentage of blood-brain barrier (BBB) permeability and gastrointestinal (GI) absorption. Among all of them, compound 10 was able to show better binding properties than others, and in vivo study showed that this compound was capable of detecting intracellular amyloid.Communicated by Ramaswamy H. Sarma.

Synthesis of benzylidene-indandione derivatives as quantification of amyloid fibrils

The formation of amyloid fibrils due to its association with fatal diseases, including Alzheimer's, has been investigated by many researchers. These common diseases, mostly become verified when it is too late to be treated. Currently, no cure is available for neurodegenerative diseases, and the process of diagnosing amyloid fibrils in the early stages, while there are fewer amyloid fibrils, has become an issue of interest. To do so, determining new probes with the highest binding affinity to the lowest number of amyloid fibrils is necessary. In this study, we proposed to employ new synthesized benzylidene-indandione derivatives as amyloid fibrils fluorescent detection probes. Native soluble proteins of insulin, bovine serum albumin (BSA), BSA amorphous aggregation, and insulin amyloid fibrils were used to evaluate our compounds' specificity to the amyloid structure. While ten synthesized compounds were examined individually, four of them including 3d, 3g, 3i, and 3j showed a high binding affinity with selectivity and specificity to amyloid fibrils, and their binding properties were also confirmed with in silico analysis. The drug-likeness prediction results for selected compounds by Swiss ADME server shows a satisfactory percentage of blood-brain barrier (BBB) permeability and gastrointestinal (GI) absorption for the compounds 3g, 3i, and 3j. More evaluation is needed to determine all properties of compounds in vitro and in vivo.

Synthesis, in silico, in vitro and in vivo studies of novel natural-based arylidenes curcumin as potential glycohydrolase digestive enzymes inhibitors

Diabetes is one of the most common metabolic diseases in humans and the use of herbal medicines is of great clinical importance to inhibit carbohydrate-hydrolyzing enzymes and reduce blood glucose levels in diabetic patients. Inhibition of glycosidase activity is an effective way to treat and prevent diabetes. Therefore, in this study, curcumin-based benzaldehyde derivatives were synthesized and used as influential agents in the treatment of diabetes with inhibitory properties against two carbohydrate-hydrolyzing enzymes α-glucosidase (α-Glu) and α-amylase (α-Amy) as significant therapeutic targets for reducing postprandial hyperglycemia. Overall, the findings showed that due to the specific inhibitory activity against α-Glu in comparison with α-Amy, as well as more stability and antioxidant activity than curcumin, C5 and C8 derivatives are potentially important anti-diabetic drugs, not only to decrease glycemic index but also to limit the activity of the main production pathways of reactive oxygen species (ROS) in diabetic patients.Communicated by Ramaswamy H. Sarma.

Design, synthesis, spectroscopic characterizations, antidiabetic, in silico and kinetic evaluation of novel curcumin-fused aldohexoses

Curcumin (bis-α,β-unsaturated β-diketone) plays an important role in the prevention of numerous diseases, including diabetes. Curcumin, as an enzyme inhibitor, has ideal structural properties including hydrophobic nature, flexible backbone, and several available hydrogen bond (H-bond) donors and acceptors. In this study, curcumin-fused aldohexose derivatives 3(a-c) were synthesized and used as influential agents in the treatment of diabetes with inhibitory properties against two carbohydrate-hydrolyzing enzymes α-glucosidase (α-Gls) and α-amylase (α-Amy) which are known to be significant therapeutic targets for the reduction of postprandial hyperglycemia. These compounds were isolated, purified, and then spectrally characterized via FT-IR, Mass, ¹H, and ¹³C NMR, which strongly confirmed the targeted product's formation. Also, their inhibitory properties against α-Gls and α-Amy were evaluated spectroscopically. The Results indicated that all compounds strongly inhibited α-Amy and α-Gls by mixed and competitive mechanisms, respectively. The intrinsic fluorescence of α-Amy was quenched by the interaction with compounds 1 and 3b through a dynamic quenching mechanism, and the 1 and 3b/α-Amy complexes were spontaneously formed, mainly driven by the hydrophobic interaction and hydrogen bonding. Fourier transform infrared spectra (FT-IR) comprehensively verified that the binding of compounds 1 and 3b to α-Amy would change the conformation and microenvironment of α-Amy, thereby inhibiting the enzyme activity. Docking and molecular dynamics (MD) simulations showed that all compounds interacted with amino acid residues located in the active pocket site of the proteins. In vivo studies confirmed the plasma glucose diminution after the administration of compound 3b to Wistar rats. Accordingly, the results of the current work may prompt the scientific communities to investigate the possibility of compound 3b application in the clinic.

Synthesis and Characterization of Novel 4-aryl-4H-chromene Derivatives using Borax and Evaluation of their Anticancer Effects

BACKGROUND/INTRODUCTION

4-aryl-4H-chromenes have attracted attention as potential anticancer agents.

OBJECTIVE

In an effort to discover effective compounds, we designed a new series of these chromenes with methoxy substitution at 2, 3, 4, 5, and 6 positions.

METHODS

The synthesized compounds were tested for anticancer properties against two human cancer cell lines (MCF- 7 and PC3) as well as a normal cell line. Furthermore, induction of apoptosis was explored through various methods, such as flow cytometry analysis, morphological changes, activation of caspase 3, ROS, and MMP.

RESULTS

The MTT assay showed that the 5g derivative, with methoxy groups at ortho and meta positions, exhibited the highest potency (IC50 = 40 μM) against the PC3 cell line. Our findings revealed that compound 5g induced apoptosis in the PC3 cell line, which was demonstrated by activation of caspase 3, an increase in ROS levels, and early apoptosis percentage.

CONCLUSION

These results suggest that compound 5g holds promise as a potential therapeutic approach to cancer treatment.

Synthesis and Potential Antidiabetic Properties of Curcumin-Based Derivatives: An In Vitro and In Silico Study of α-Glucosidase and α-Amylase Inhibition

BACKGROUND

Over the past twenty years, the prevalence of diabetes as one of the most common metabolic diseases has become a public health problem worldwide. Blood glucose control is important in delaying the onset and progression of diabetes-related complications. α-Glycosidase (α- Glu) and α-amylase (α-Amy) are important enzymes in glucose metabolism. Diabetic control through the inhibition of carbohydrate hydrolyzing enzymes is established as an effective strategy.

METHODS

In this study, curcumin-based benzaldehyde derivatives with high stability, bioavailability, and favorable efficiency were synthesized.

RESULTS

The results showed that L13, L8, and L11 derivatives have the highest inhibitory effect on α-Glu with IC₅₀ values of 18.65, 20.6, and 31.7 μM and, also L11, L13, and L8 derivatives have the highest inhibitory effect on α-Amy with IC₅₀ value of 14.8, 21.8, and 44.9 μM respectively. Furthermore, enzyme inhibitory kinetic characterization was also performed to understand the mechanism of enzyme inhibition.

CONCLUSION

L13, compared to the other compounds, exhibited acceptable inhibitory activity against both enzymes. The L13 derivative could be an appropriate candidate for further study through the rational drug design to the exploration of a new class of powerful anti-diabetic drugs considering the antioxidant properties of the synthesized compounds. The derivative helps reduce the glycemic index and limits the activity of the major reactive oxygen species (ROS) producing pathways.

In Vitro Cytotoxicity and Apoptosis Inducing Evaluation of Novel Halogenated Isatin Derivatives

BACKGROUND

Isatin (1H-indole-2,3-dione) and its derivatives have been shown their responsibility in a wide range of biological activities. Among the range of beneficial properties, anticancer compounds were the most extensively highlighted and explored.

OBJECTIVE

Herein, we report the targeting effect of halogenated isatin derivatives on cancer cell mitochondria and their antiproliferative mechanism.

METHOD

A series of novel 5-halo-Isatin derivatives consisting 5-Amino-1,3,4-thiadiazole-2-thiol scaffold were synthesized and easily conducted in good yields through a condensation reaction between keto groups of Isatin and primary amine under alcoholic conditions, followed by S-benzylation. The compounds were fully characterized using spectroscopic methods such as 1H-NMR, FTIR, mass spectroscopy and then tested in vitro towards three cancer cell lines HT-29 (colon cancer), MCF-7 (breast cancer) and SKNMC (neuroblastoma). Apoptosis induction was investigated through assessment of caspase 3 and mitochondrial membrane potential.

RESULTS

The most potent compounds of 5b, 5r (IC50 = 18,13 µM) and 5n (IC50 = 20,17 µM) were found to show strong anticancer activity, especially for MCF7 cells. Further anticancer mechanism studies indicated that 5b and 5r induced apoptosis through the intrinsic mitochondrial pathway.

CONCLUSION

This research demonstrated that 5b and 5r have an anticancer property via the modulation of oxidative stress-mediated mitochondrial apoptosis and immune response, which deserves further studies on their clinical applications.

Curcumin-based Antioxidant and Glycohydrolase Inhibitor Compounds: Synthesis and In Vitro Appraisal of the Dual Activity Against Diabetes

Background:

Curcumin, as the substantial constituent of the turmeric plant (Curcuma longa), plays a significant role in the prevention of various diseases, including diabetes. It possesses ideal structure features as an enzyme inhibitor, including a flexible backbone, hydrophobic nature, and several available hydrogen bond (H-bond) donors and acceptors.

Objective:

The present study aimed at synthesizing several novel curcumin derivatives and further evaluation of these compounds for possible antioxidant and anti-diabetic properties along with inhibitory effect against two carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase, as these enzymes are therapeutic targets for attenuation of postprandial hyperglycemia.

Methods:

Therefore, curcumin-based pyrido[2,3-d]pyrimidine derivatives were synthesized and identified using an instrumental technique like NMR spectroscopy and then screened for antioxidant and enzyme inhibitory potential. Total antioxidant activity, reducing power assay and 1,1-diphenyl-2- picrylhydrazyl (DPPH•) radical scavenging activity were done to appraise the antioxidant potential of these compounds in vitro.

Results:

Compounds L6-L9 showed higher antioxidant activity while L4, L9, L12 and especially L8 exhibited the best selectivity index (lowest α-amylase/α-glucosidase inhibition ratio).

Conclusion:

These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index but also to limit the activity of the major reactive oxygen species (ROS) producing pathways.

Preparation, Characterization and In Vitro Biological Evaluation of Novel Curcumin Derivatives as Cytotoxic and Apoptosis-Inducing Agents

BACKGROUND

Curcumin is a natural polyphenol and lead compound of the rhizomes of curcuma longa and it has been widely used for pharmacological activities.

OBJECTIVE

In this study, a series of novel derivatives of curcumin, with this group linked to a 2-amino-4- phenylpyran-3-carbonitrile system, have been synthesized and tested for their antitumor activities in vitro against a panel of three human cancer cell lines (MCF-7, A2780, and U-87MG).

METHODS

The in vitro cytotoxic activity of the synthesized compounds was tested on three cancer cell lines (MCF-7, A2780, and U-87MG) using MTT colorimetric assay. Meanwhile, the ability of the active compounds to induce apoptosis in cancer cells was investigated by examination of caspase-3 and caspase-9 and mitochondrial membrane potential assay.

RESULTS

Under relatively mild conditions in ethanol, the reaction of a series of substrates afforded the corresponding derivatives of curcumin mostly in good yields (13 analogues, 48-94% yields). Bioassay results indicated that compounds L6 (para-Bromo), L9 (para-Nitro) and L12 (meta-Methoxy) were the most active members in this study demonstrating potent activities against A2780 cancer cells and experimental results of fluorescent staining and flow cytometry analysis revealed that L6 and L9 could induce apoptosis in A2780 cells with apoptosis ratios of about 40% and 46%, respectively at 24h of treatment at 15.35μM and 23μM in A2780 cells. On the other hand, they could increase the caspase-3 activity slightly (10%), while having no significant impact on the activities of caspase-9.

CONCLUSION

Those two derivatives could be considered as useful templates for future development to obtain more potent antitumor agents.

Antioxidant and glycohydrolase inhibitory behavior of curcumin-based compounds: Synthesis and evaluation of anti-diabetic properties in vitro

Naturally occurring anti-diabetic compound curcumin can prevent diabetes complications due to antioxidant and anti-inflammatory properties as well as the attenuation of postprandial hyperglycemia. In this line, we have synthesized thirteen curcumin based derivatives (L1-L13) by multi-component reaction, characterized by IR, ¹HNMR, 13C NMR, MS, elemental analysis and evaluated for possible antioxidant properties and α-glucosidase (α-Glu) and α-amylase (α-Amy) inhibitory potential. The curcumin-based pyrano[2,3-d]pyrimidine derivatives could inhibit α-Glu and α-Amy enzyme activity which showed desirable antioxidant activity. Furthermore, among the series, L5, L12, L9, L10, L8 and L11 were identified as more potent inhibitors of α-Glu enzyme than curcumin and the compounds of L12, L4, L9, L5, L10, L8, L13, and L11 were the stronger inhibitors of the α-Amy enzyme in vitro. Besides, among them, L12 had the lowest IC₅₀ for the inhibition of both enzymes. Since strong inhibitors for pancreatic α-Amy result in the progression of severe gastrointestinal side effects, the inhibitors that show the lower α-Amy/α-Glu inhibitory ratio have attracted much attention in medicinal chemistry. Besides, considering antioxidant characteristics of synthesized compounds, the L7 derivative with the highest antioxidant activity and the lowest "α-Amy/α-Glu inhibitory" ratio could be an appropriate candidate for further study through the rational drug design to the exploration of a new class of powerful anti-diabetic drugs.

Synthesis and in vitro quantification of amyloid fibrils by barbituric and thiobarbituric acid-based chromene derivatives

Neurodegenerative disease is caused by the abnormal build-up of proteins in and around cells called amyloid. The amyloid fibril formation and its mechanism have been investigated with various techniques, including dye-binding assay. Thioflavin T (ThT) has been one of the most widely used dyes for quantifying amyloid deposits, but ThT has a weak fluorescence signal especially at low concentration of amyloid fibrils, low lipophilicity and positive charge that makes it unable to cross the blood-brain barrier (BBB) to detect amyloid fibrils in vivo. Hence, there is a strong motivation for designing and developing the new compounds for in vitro amyloid quantification and in vivo amyloid imaging. The need for new probes to detect amyloid fibrils, especially within the cell, is highlighted by the fact that an accurate understanding of the molecular details of amyloid fibril formation is required to design and develop strategies for controlling the amyloid formation, and this needs more reliable probes for amyloid identification. In this work, we synthesized and applied barbituric and thiobarbituric acid-based chromene derivatives, as new fluorescent dyes to quantitatively detect the amyloid fibrils of bovine serum albumin (BSA) and human insulin in comparison with native soluble proteins or amorphous aggregation. Our results showed that among the 14 synthesized compounds, five compounds 4a, 4h, 4j, 4k, and 4l could selectively and specifically bind to amyloid fibrils while other compounds demonstrated a low-affinity binding. Furthermore, according to the cell viability experiment, compounds 4a, 4j and 4l at low concentration of compounds are not toxic, especially compound 4j which could be used as a suitable candidate for in vivo study. Further studies are needed to determine all the properties of compounds, especially in vivo experiments.

Synthesis and investigation of inhibitory activities of imidazole derivatives against the metallo-β-lactamase IMP-1

Mutations in bacteria can result in antibiotic resistance due to the overuse or abuse of β-lactam antibiotics. One strategy which bacteria can become resistance toward antibiotics is secreting of metallo β-lactamase enzymes that can open the lactam ring of the β-lactam antibiotic and inactivate them. This issue is a threat for human health and one strategy to overcome this situation is co-administration of β-lactam antibiotics with an inhibitor. So far, no clinically available inhibitors of metallo β-lactamases (MBLs) reported and the clinically inhibitors of serine β-lactamase are useless for MBLs. Accordingly, finding a potent inhibitor of the MBLs being very important. In this study, imidazole derivatives primarily were synthesized and their inhibitory activity were measured. Later in silico binding model was used to predict the configuration and conformation of the ligands into the active site of enzyme. Two molecules demonstrated with IC₅₀ of 39 µM and 46 µM against MBL (IMP-1).

Synthesis and enzyme-based evaluation of analogues L-tyrosine thiol carboxylic acid inhibitor of metallo-β-lactamase IMP-1

The emergence of drug-resistant pathogenic bacteria is occurring due to the global overuse and misuse of β-lactam antibiotics. Infections caused by some bacteria which secrete metallo-β-lactamases (enzymes that inactivate β-lactam antibiotics) are increasingly prevalent and have become a major worldwide threat to human health. These bacteria are resistant to β-lactam antibiotics and MBL-inhibitor/β-lactam antibiotic combination therapy can be a strategy to overcome this problem. So far, no clinically available inhibitors of metallo-β-lactamases (MBLs) have been reported. In this study, L-benzyl tyrosine thiol carboxylic acid analogues (2a–2k) were synthesized after the study of computational simulation by adding of methyl, chloro, bromo and nitro groups to the benzyl ring for investigation of SAR analysis. Although the synthesized molecules 2a–k shows the potent inhibitory effects against metallo-β-lactamase (IMP-1) with the range of K_ic values of 1.04–4.77 µM, they are not as potent as the candidate inhibitor.

Highly selective iodination of phenols using potassium iodide and benzyltriphenylphosphonium peroxymonosulfate

An easy and selective method for monoiodination of phenols using potassium iodide in the presence of benzyltriphenylphosphonium peroxymonosulfate is presented. The reactions have been carried out in acetonitrile to afford the corresponding iodophenols in moderate to high yields.

Differential α-amylase/α-glucosidase inhibitory activities of plant-derived phenolic compounds: a virtual screening perspective for the treatment of obesity and diabetes

Recently, due to their biological properties, polyphenol-rich functional foods have been proposed to be unique supplementary and nutraceutical treatments for diabetes mellitus. Inhibition of α-amylase and α-glucosidase enzymes using natural products (especially polyphenols) is a novel oral policy to regulate carbohydrate metabolism and hyperglycemia. The present study aims to evaluate the α-amylase and α-glucosidase inhibitory activity of 26 polyphenols using molecular docking and virtual screening studies. The results speculate that among selected compounds caffeic acid, curcumin, cyanidin, daidzein, epicatechin, eridyctiol, ferulic acid, hesperetin, narenginin, pinoresinol, quercetin, resveratrol and syringic acid can significantly inhibit the α-glucosidase enzyme. In addition, catechin, hesperetin, kaempferol, silibinin and pelargonidin are potent α-amylase inhibitors. Therefore the primary structure of polyphenols can change the inhibitory effect versus the α-amylase and α-glucosidase enzymes. Finally, we speculate that consumption of polyphenol-rich functional foods (by considering the best dose of each compound and assessing their possible side effects) in diabetic patients may be useful for regulating carbohydrate metabolism and related disorders. The findings of the current study may also shed light on a way of generating a new class of amylase/glucosidase inhibitors that will discriminately inhibit the on-target enzymes with negligible undesired off-target side effects.

Synthesis and Leishmanicidal Activity of 1-[5-(5-Nitrofuran-2-yl)-1, 3, 4-Thiadiazole-2-yl]-4-BenzoylePiperazines

A series of (5-nitrofuran-2-yl)-1, 3, 4-thiadiazole-2-yl derivatives 6a-6e have been synthesized and screened for in-vitro anti-leishmanial activity against the promastigote form of L. major. The structure of Schiff bases were confirmed by ¹H NMR, IR. Screening results indicate that all of the designed and synthesized final compounds (6a-6e) significantly reduced the viability of promastigotes of L. major in comparison toglucantime (IC₅₀ 3× 10³ μg/mL). Meta and Para substitutions in benzene ring containing compounds were more potent than other derivative and the most potent compounds were 6d, 6e with IC₅₀ value 94 µm and 77.6 µm, respectively. The experimental data proposes that (5-nitrofuran-2-yl)-1, 3, 4-thiadiazole-2-yl derivatives may be further investigated as a candidate drug for treatment of cutaneous leishmaniasis.

Diethylalkylsulfonamido(4-methoxyphenyl)methyl)phosphonate/phosphonic acid derivatives act as acid phosphatase inhibitors: synthesis accompanied by experimental and molecular modeling assessments

Purple acid phosphatases (PAPs) are binuclear metallo-hydrolases that have been isolated from various mammals, plants, fungi and bacteria. In mammals, PAP activity is associated with bone resorption and can lead to bone metabolic disorders such as osteoporosis; thus human PAP is an attractive target to develop anti-osteoporotic drugs. The aim of the present study was to investigate inhibitory effect of synthesized diethylalkylsulfonamido(4-methoxyphenyl)methyl)phosphonate/phosphonic acid derivatives as potential red kidney bean PAP (rkbPAP) inhibitors accompanied by experimental and molecular modeling assessments. Enzyme kinetic data showed that they are good rkbPAP inhibitors whose potencies improve with increasing alkyl chain length. Hexadecyl derivatives, as most potent compounds (K_i = 1.1 µM), inhibit rkbPAP in the mixed manner, while dodecyl derivatives act as efficient noncompetitive inhibitor. Also, analysis by molecular modeling of the structure of the rkbPAP-inhibitor complexes reveals factors, which may be important for the determination of inhibition specificity.

Active targeted nanoparticles: Preparation, physicochemical characterization and in vitro cytotoxicity effect

In this study, the folate decorated biodegradable poly (lactide-co-glycolide) (PLGA) nanoparticles were developed for tumor targeting of anticancer agents. Due to the overexpression of the folate receptor on tumor surface, the folate has been efficiently employed as a targeting moiety for various anticancer agents to avoid their non-specific attacks on normal tissues and also to increase their cellular uptake within target cells. Folate conjugate PLGA was synthesized successfully and its chemical structure was evaluated by FTIR, DSC and (1)HNMR spectroscopy. PLGA-folate nanoparticles (PLGA-Fol NPs) were prepared by nanoprecipitation method, adopting PLGA as a drug carrier, folic acid as a targeting ligand and 9-nitrocampthotecin as a model anticancer drug. The average size and encapsulation efficiency of the prepared PLGA-Fol NPs were found to be around 115 ± 12 nm and 57%, respectively. In vitro release profile indicated that nearly 85% of the drug was released in 50 h. The in vitro intracellular uptakes of PLGA-Fol NPs showed greater cytotoxicity on cancer cell lines compared to non-folate mediated carriers.

Synthesis and psychobiological evaluation of modafinil analogs in mice

Background and the purpose of the study

Modafinil, a novel wake-promoting agent with low potential for abuse and dependence, has a reliable structure to find some novel derivatives with better activity and lower potential for abuse and risk of dependency. This study was designed to evaluate psychobiological activity of some novel N-aryl modafinil derivatives.

Methods

Seven novel N-aryl modafinil derivatives were synthesized through three reactions: a) preparation of benzhydrylsulfanyl acetic acid through reaction of benzhydrol with thioglycolic acid, b) formation of desired amide by adding the substituted aniline to activated acid with EDC (1-ethyl-3-(3-dimethyl amino propyl) carbodiimide). This reaction was catalyzed by HOBt (N- hydroxylbenzotriazole), and c) oxidation of sulfur to sulfoxide group with H₂O₂. Then, their psychobiological effect on the performance of male albino mice were compared to that of modafinil as following: wakefulness by determining the effects of derivatives on phenobarbital-induced loss of the righting reflex (LOPR); exploratory activity by measuring activity in the open field test (OFT); depression by measuring immobility time (IT) during forced swimming test (FST) and the anxiogenic and anxiolytic like effects by using elevated plus-maze test (EPM). All tests were videotaped and analyzed for the frequency and duration of the behaviors during the procedures.

Conclusions

2-(Benzhydrylsulfonyl)-N-(4-chlorophenyl)acetamide (4c) showed comparable result in LOPR test. However, all analogs were found to be stimulant except 2-(benzhydrylsulfinyl)-N-phenylacetamide (4a). Also 4c led the most exploratory activity in mice among derivatives. FST results showed that 4a had the longest IT while modafinil, 2-(benzhydrylsulfinyl)-N-(3-chlorophenyl) acetamide (4b) and 2-(benzhydrylsulfinyl)-N-(4-ethylphenyl) acetamide (4d) had the shortest IT. In EPM, all derivatives showed anxiogenic-like behavior since they decreased open arms time and open arms entries and simultaneously increased close arms time.

Synthesis, and In-vitro Cytotoxicity Studies of a Series of Triazene Derivatives on Human Cancer Cell Lines

Compounds containing triazene ring structure are cytotoxic agents and clinically used as antitumor alkylating agents. In this study, a series of triazene derivatives holding alkyl and aryl moieties were synthesized and proved to be potent cytotoxic agents in-vitro particularly against eight cancer cell lines (PC3, HT29, Hela, HL60, Jurkat, K562, MCF7, HepG2) and a non-cancerous cell line (HUVEC). The cytotoxic activity was assessed using two methods, LDH assay, and trypan blue exclusion. Some of the triazene derivatives showed cytotoxic activity more than temozolomide (TMZ) as the reference drug. The synthesized triazenes showed marked cytotoxicity effects on all eight cancer cell lines. Among the compounds synthesized, 1,3-bis(2-ethoxyphenyl)triazene C had unique efficacy and selectivity so that it had IC50 between 0.560-3.33 μM on cancer cell lines and 12.61 μM on normal cell line (HUVEC). 1-(4-nitrophenyl)-3-(2-hydroxyethyl)triazene E shows weaker effect on cancer cell lines than the other compounds having IC50 between 3-15.54 μM.

Risk factors for spinal osteoporosis as compared with femoral osteoporosis in urban Iranian women

BACKGROUND

We aimed to define and compare the risk factors of spinal and femoral osteoporosis in postmenopausal Iranian women.

METHOD

It was a multicentre based study carried out in two stages during 2002 to 2005 among post menopausal women in Tehran. In first stage case group included 140 women with diagnosed spinal osteoporosis using DEXA method as definition of WHO and Controls were 167 women with normal spinal BMD. In second stage, among the same study population case groups were 72 women with total femoral neck osteoporosis. The controls included 191 women with normal femoral BMD.' Odds Ratio was used for estimation the association of risk factors with spinal and femoral osteoporosis.

RESULTS

PLUS COMMON WELL KNOWN OSTEOPOROSIS RISK FACTORS, SIGNIFICANT RISK FACTORS FOR EACH REGION WITH THEIR ODDS RATIOS INCLUDED: Steroid use (2.4) and low activity (3.6) for femoral osteoporosis and parity>3 (2) and lactation duration > 2 yr (1.9) for spinal osteoporosis.

CONCLUSIONS

There are some common and different protective and risk factors for spinal and femoral osteoporosis in this population.

Association between Anthropometric Measures and Bone Mineral Density: Population-Based Study

BACKGROUND

Osteoporosis is a major public health concern around the world. It has been shown that bone mineral density is correlated to anthropometric measures like height and weight, but this association may vary depending on ethnic and environmental factors. The aim of this study was to identify probable relations between anthropometric measures and bone mineral density.

METHODS

In this population-based study, we compiled the data collected from Iranian Multicenter Osteoporosis Study to assess the possible associations between different anthropometric indices and bone mineral density at femur and lumbar spine. The gathered data was analyzed using t-test and one way ANOVA.

RESULTS

Data was available for 4445 subjects, consisting 1900 males (42.7%) and 2545 females (57.3%). We observed statistically significant correlations between bone mineral density and height, weight, waist circumference, hip circumference, waist to hip ratio and body mass index (BMI). Based on the result of linear regression modeling studies, BMI could be considered an independent predictor of bone mineral density.

CONCLUSION

Iranian population shows similar measures compared to analogous studies in other populations. Lower weight should be carefully considered as a predisposing factor for bone loss and osteoporosis.

Coronary heart disease and associated risk factors in Qazvin: a population-based study

In a cross-sectional study in Qazvin, Islamic Republic of Iran, 846 residents (425 men and 421 women) aged > or = 25 years were assessed for coronary heart disease and its associated risk factors comparing ischaemic and non-ischaemic groups. The age-adjusted prevalence of possible myocardial infarction, ischaemic ECG changes and angina pectoris were 4.2%, 36.8% and 2.2% respectively. There was no difference in the mean systolic and diastolic blood pressure and body mass index between ischaemic and non-ischaemic groups. There was a significant association between possible myocardial infarction and hypertension, type 2 diabetes, and smoking in women. There was also a significant association between ischaemic ECG changes and waist-hip ratio in women and between ischaemic ECG changes and hypertension in men.

A convenient and efficient protocol for oxidative aromatization of Hantzsch 1,4-dihydropyridines using benzyltriphenylphosphonium peroxymonosulfate under almost neutral reaction conditions

Oxidative aromatization of 4-alkyl or aryl and heterocyclic-substituted derivatives of Hantzsch 1,4-dihydropyridines to the corresponding pyridine derivatives has been studied using benzyltriphenylphosphonium peroxymonosulfate as an oxidant in the presence of BiCl(3) under nearly neutral reaction conditions at ambient temperature.

The effect of Ramadan fasting on fasting serum glucose in healthy adults

The effect of Ramadan fasting on fasting serum glucose (FPG) is still a matter of controversy. One hundred and fifteen healthy volunteers fasted for > or = 25 days during Ramadan. Blood samples were taken 1 week before Ramadan and on the 14th and 28th day of Ramadan. Serum glucose was determined by the glucose oxidase method. FPG decreased from 88.4 + 9.0 mg/dl to 62.9 +/- 7.7 mg/dl (p < 0.001). Men and women both experienced a significant drop in FPG. Calorie intake decreased in all groups (p < 0.001) and was positively correlated with decreasing FPG. FPG decreases with Ramadan fasting and has no serious adverse effect on fasting adults.

Wet silica-supported permanganate for the cleavage of semicarbazones and phenylhydrazones under solvent-free conditions

Wet silica-supported potassium permanganate was used as an inexpensive and efficient reagent for conversion of semicarbazones and phenylhydrazones to the corresponding carbonyl compounds under solid-state conditions.