Atilla Akdemir

Atilla Akdemir
Bezmialem Vakıf Universty · Computer-aided drug discovery lab. Department of Pharmacology, Faculty of Pharmacy

PhD

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78
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1,538
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August 2011 - present
Bezmiâlem Vakif Üniversitesi

Publications

Publications (78)
Article
Full-text available
Melatonin (N‐acetyl‐5‐methoxytryptamine, MLT) is suggested as a preventive agent and potential therapeutic option for breast cancer via its antioxidant as well as anticancer effects by modulating estrogen dependent and independent pathways. However, its rapid metabolic inactivation led scientists to discover novel MLT analogues. Therefore, a series...
Article
Full-text available
Carbonic anhydrases (CAs) are widespread metalloenzymes with the core function of catalyzing the interconversion of CO2 and HCO3-. Targeting these enzymes using selective inhibitors has emerged as a promising approach for the development of novel therapeutic agents against multiple diseases. Method: A series of novel thiosemicarbazones-containing...
Article
Totally 15 novel flurbiprofen urea derivatives were synthesized bearing the thiadiazole ring. Their inhibition effects on tyrosinase were determined. 3c was found to be the strongest inhibitor with the IC50 value of 68.0 μM against tyrosinase. The enzyme inhibition types of the synthesized compounds were determined by examining the kinetic paramete...
Article
Tuberculosis is a curable disease that costs the lives of 1.5 million people per year. It continues to pose a threat to global public health owing to the prevalence of multi-drug resistant (MDR) Mycobacterium tuberculosis strains which make its eradication a continuous challenge. To explore novel and effective antimycobacterial agents, a series of...
Article
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In this study, sixty novel coumarin-monoterpene compounds were synthesized in two series [thirty-two compounds (12-43) bearing a triazole ring in the first series, and twenty-eight compounds (44-71) bearing an alkyl chain in the second one]. Their inhibitory effects on the human carbonic anhydrase (hCA) isoforms I, II, IX, and XII and anticancer po...
Article
EGFR is one of the important mediators of the signaling cascade that determines key roles in various biological processes such as growth, differentiation, metabolism and apoptosis in the cell in response to external and internal stimuli. In recent years, it has been proven that although this enzyme activity is tightly regulated in normal cells, if...
Chapter
Medicinal chemists around the world have been inspired by nature and have successfully extracted chemicals from plants. Research on enzymatic modifications of naturally occurring compounds has played a critical role in the search for biologically active molecules to treat diseases. This book explores compounds of interest to researchers and clinici...
Article
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Caulerpa cylindracea Sonder is a green alga belonging to the Caulerpaceae family. This is the first chemical investigation of C. cylindracea in the Dardanelles which resulted in the isolation of four compounds, caulerpin (1), monomethyl caulerpinate (2), beta-sitosterol (3), and palmitic acid (4). Their structures were elucidated by spectroscopic a...
Article
Full-text available
Fungal pathogens, including Candida spp., Aspergillus spp. and dermatophytes, cause more than a billion human infections every year. A large library of imidazole- and triazole-based compounds were in vitro screened for their antifungal activity against C. albicans, C. glabrata, C. krusei, A. fumigatus and dermatophytes, such as Microsporum gypseum,...
Article
Full-text available
A novel series of thiosemicarbazide-substituted coumarins was synthesized and the inhibitory effects against four physiologically relevant carbonic anhydrase isoforms I, II, IX and XII showed selective activities on the tumor-associated IX and XII isozymes. Molecular modeling studies on selected compounds 14a and 22a were performed. The binding mod...
Article
1‐Methyl/ethyl/benzyl‐5‐(un)substituted 1H‐indole‐2,3‐diones (2, 3, and 4) were synthesized by reaction of 5‐(un)substituted 1H‐indole‐2,3‐diones (1) with methyl iodide, ethyl chloride, and benzyl bromide. (3‐Sulfamoylphenyl)isothiocyanate (6) was obtained by the treatment of 3‐aminobenzenesulfonamide (5) with thiophosgene. Compound 6 was reacted w...
Article
Infectious diseases such as tuberculosis (TB) are leading causes of human death. Antibiotics are effective molecules to combat bacterial infections by affecting the processes required for bacterial cell growth and proliferation. The development of new antibiotics has become an important issue as overdosed or incorrect use of antibiotic lead to the...
Article
A series of new spirothiazolidinone derivatives with a mandelic acid moiety were synthesized and subsequently tested in growth inhibition assays against Mycobacterium tuberculosis strain H37Rv. Compound 16 displayed the highest inhibition value of 98% at lower than 6.25 µg/mL concentration. A single crystal X-ray analysis was conducted on this comp...
Article
Background The positively charged membrane impermeant sulfonamides were evaluated as a remarkable class of carbonic anhydrase inhibitors (CAIs) previously. Without affecting the cytosolic isoforms hCA I and II, inhibition of two membrane-associated isoforms hCA IX and XII especially over-expressed in hypoxic tumour cells, makes the pyridinium deriv...
Article
Full-text available
The neutralization effect of Montelukast on SARS-CoV-2 is shown by multiscale in silico simulations and combined in vitro studies The neutralization effect of Montelukast on SARS-CoV-2 is shown by multiscale in silico simulations and combined in vitro studies, Molecular Therapy (2021), doi: https://doi. Abstract Small molecule inhibitors have previ...
Article
Full-text available
Apigenin, a flavonoid, is reported to act as an estrogen receptor (ER) agonist and inhibit aromatase enzyme. However, amentoflavone, a biflavonoid bearing two apigenin molecules, has not been evaluated for its endocrine modulatory effects. Besides, it is highly consumed by young people to build muscles, enhance mood and lose weight. In the present...
Article
Full-text available
Tyrosinase inhibition is very important in controlling melanin synthesis. If melanin synthesis is not controlled in metabolism, an unwanted increase in melanin synthesis occurs. As melanin plays a role in the formation of skin color, its unusual levels cause some skin disorders such as pregnancy scars, age spots, and especially skin cancer (melanom...
Article
Carbonic anhydrase (CA) IX, and XII isoforms are known to be highly expressed in various human tissues and malignancies. CA IX is a prominent target for some cancers because it is overexpressed in hypoxic tumors and this overexpression leads to poor prognosis. Novel twenty-seven compounds in two series (sulfamoylcarbamate-based quinoline (2a-2o) an...
Article
Full-text available
Nonsteroidal aromatase inhibitors (NSAIs) are well-established drugs for the therapy of breast cancer. However, they display some serious side effects, and their efficacy can be compromised by the development of chemoresistance. Previously, we have reported different indazole-based carbamates and piperidine-sulphonamides as potent aromatase inhibit...
Article
Full-text available
Quinones, especially 1,4-naphthoquinones, are one of the most significant and widely distributed phytochemical groups in nature. 1,4-Naphthoquinones and their synthetic derivatives are found to possess remarkable cytotoxic activities. In this study, a series of 2-aminonaphtho[2,3-d][1,3]thiazole-4,9-dione derivatives were synthesized and their stru...
Preprint
Full-text available
Small molecule inhibitors have previously been investigated in different studies as possible therapeutics in the treatment of SARS-CoV-2. In the current drug repurposing study, we identified the leukotriene (D4) receptor antagonist Montelukast as a novel agent that simultaneously targets two important drug targets of SARS-CoV-2. We initially demons...
Article
Full-text available
The tumor microenvironment is crucial for the growth of cancer cells, triggering particular biochemical and physiological changes, which frequently influence the outcome of anticancer therapies. The biochemical rationale behind many of these phenomena resides in the activation of transcription factors such as hypoxia-inducible factor 1 and 2 (HIF-1...
Article
Full-text available
Tumor cells benefit from some certain signals, which are referred to as "immune checkpoints", to escape immune-mediated destruction. With that in mind, it is believed that the blockade of these points, such as programmed cell death Ligand-1 (PD-L1) and programmed cell death 1 (PD-1), can restore an adaptative immune response against tumoral cells....
Article
A small collection of 2-hydroxy-N-(5-methyl/nonsubstituted 4-oxo-2-substituted phenyl-1,3-thiazolidin-3- yl)-2-phenylacetamides (3-16) was synthesized from the cyclocondensation of 2-hydroxy-2-phenyl-N'- [(substitutedphenyl)methylene]acetohydrazides (2) and mercaptoethanoic acid or 2-mercaptopropanoic acid, characterized with spectral and elemental...
Article
Full-text available
Due to the increasing resistance of currently used antimicrobial drugs, there is an urgent problem for the treatment of cholera disease, selective inhibition of the α-class carbonic anhydrases (CA, EC 4.2.1.1) from the pathogenic bacterium Vibrio cholerae (VcCA) presents an alternative therapeutic target. In this study, a series of hydrazone deriva...
Article
Background Alzheimer’s Disease (AD) is one of the most prevalent causes of dementia in the world, and no drugs available that can provide a complete cure. Cholinergic neurons of the cerebral cortex of AD patients are lost due to increased activity of cholinesterase enzymes. Objectives Acetylcholinesterase (AChE) and Butyrylcholinesterase (BuChE) a...
Article
Full-text available
In our efforts to find new and selective thiazolidinone-based anti-Candida agents, we synthesized and tested 26 thiazolidinones against several Candida spp. and Gram-positive and Gram-negative bacteria. The compounds showed selective antifungal activity with potency similar to fluconazole and clotrimazole, while lacking strong antibacterial activit...
Article
Background Isoindole-1,3(2H)-dione derivatives are known to have cytotoxic effects on many cancer cells. The anticancer activity of these compounds varies depending on the substituents attached to them. Therefore, the effect of substituents is very important when determining the anticancer activities of molecules. We have recently reported an examp...
Article
Full-text available
An efficient and versatile synthesis method has been postulated for hydroxymethy-lated rac-and meso-cyclohexanoid derivatives. The synthesis of these stereoisomers was achieved easily with traditional methods using hexahydroisobenzofuran 6, prepared from commercially available cis-hydrophthalic anhydride. The study, involving diastereoselective epo...
Article
Carbonic anhydrases isoforms CA IX, and XII are known to be highly expressed in various human tissues and malignancies. CA IX is a prominent target for especially colorectal cancers, because it is overexpressed in colorectal cancer and this overexpression leads poor prognosis. Inhibition of CA IX activity by small molecule CA inhibitors like sulfon...
Article
Full-text available
A large library of derivatives based on the scaffold of 2-(benzylsulfinyl)benzoic acid were synthesised and tested as atypical inhibitors against four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). The exploration of the chemical space around the main functional groups led to the discovery of selective hCA IX in...
Article
Full-text available
Novel sulfonamidoindole-based hydrazones with a 2-(hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide scaffold were synthesized and tested in enzyme inhibition assays against the tumor-associated carbonic anhydrase isoforms, hCA IX and XII, and the off-targets, hCA I and II. The compounds showed selectivity against hCA IX and XII over hCA I and II...
Article
Full-text available
A large library of fibrate-based N-acylsulphonamides was designed, synthesised, and fully characterised in order to propose them as zinc binders for the inhibition of human carbonic anhydrase (hCA) enzymatic activity. Synthesised compounds were tested against four hCAs (I, II, IX, and XII) revealing a promising submicromolar inhibitory activity cha...
Article
Full-text available
Inhibition of the β-carbonic anhydrase (CA, EC 4.2.1.1) from pathogenic Candida glabrata (CgNce103) by 1H-indole-2,3-dione 3-[N-(4-sulfamoylphenyl)thiosemicarbazones] 4a–m was investigated. All the compounds were found to be potent inhibitors of CgNce103, with inhibition constants in the range of 6.4-63.9 nM. The 5,7-dichloro substituted derivative...
Article
Full-text available
A small collection of 26 structurally novel thiazolidinone-containing compounds, without the well-known sulphonamide zinc-binding group, were synthesised and tested in enzyme inhibition assays against the tumour-associated hCA IX enzyme. Inhibition constants in the lower micromolar region (KI < 25 μM) have been measured for 17 of the 26 compounds....
Article
In this study, 1‐(4‐substitued benzyl)‐3,5‐diphenyl‐1H‐1,2,4‐triazoles (2 a‐e) and ethyl(3,5‐diphenyl‐1H‐1,2,4‐triazole‐1‐yl)acetate (3) were synthesized starting from 3,5‐diphenyl‐1H‐1,2,4‐triazole (1). The ethyl acetate derivative (3) was converted to 2‐(3,5‐diphenyl‐1H‐1,2,4‐triazole‐1‐yl)acetohydrazide (4) in ethanolic medium with hydrazine hyd...
Article
1. A causal association is reported between prolonged exposures to elevated levels of estrogen and breast cancer. Therefore inhibiting aromatase (CYP19A), which catalyses the conversion of androgens to estrogens, is an important approach in prevention and treatment of estrogen receptor positive (ER+) breast cancer. 2. Melatonin, a natural indolic h...
Article
Full-text available
It has been proven that specific isoforms of human carbonic anhydrase (hCA) are able to fine-tune physiological pathways connected to signal processing, and that decreased CAs expression negatively influences cognition, leading to mental retardation, Alzheimer's disease, and aging-related cognitive dysfunctions. For this reason, a small library of...
Article
Full-text available
Cladribine (2-CdA) is used as an anti-cancer drug but is currently studied as a potential treatment for use in relapsing-remitting multiple sclerosis (MS). In this study, we computer designed, synthesized, and characterized two novel derivatives of 2-CdA, K1–5d and K2–4c, and investigated their underlying mechanism of beneficial effect using the CC...
Article
Human carbonic anhydrases IX and XII are upregulated in many tumors and form a novel target for new generation anticancer drugs. Here we report the synthesis of novel 2-indolinone derivatives with the sulfonamide group as a zinc binding moiety. Enzyme inhibition assays confirmed that the compounds showed selectivity against hCA IX and XII over the...
Article
Targeted delivery systems aim to deliver drugs to their intended site of action and as such they are expected to show more desired effects and less unwanted effects. The system itself is composed of a vesicle-encapsulated drug with "target recognition molecules" on the envelop. Ideally, these target recognition molecules, being either small non-pep...
Article
Multiple Sclerosis (MS) is a very common disease of vital importance. In the MS treatment, some drugs such as fingolimod which help to protect nerves from damage are used. The main goal of the drug therapy in MS is to take control of the inflammation which leads to the destruction of myelin and axons in nerve cell and thus prevent and stop the prog...
Article
Full-text available
A large number of novel secondary sulfonamides based on the open saccharin scaffold were synthesized and evaluated as selective inhibitors of four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). They were obtained by reductive ring opening of the newly synthesized N-alkylated saccharin derivatives and were shown...
Article
Enzyme inhibition data of structurally novel isatin-containing sulfonamides were determined for two carbonic anhydrases (CAs, EC 4.2.1.1) from pathogenic Candida species (CaNce103 from C. albicans and CgNce103 from C. glabrata). The compounds show KI values in the low nanomolar range for the fungal CAs, while they have significantly higher KI value...
Chapter
The human carbonic anhydrase isoforms VA and VB (hCA VA/VB) are located in the mitochondria of specific cells. They supply bicarbonate ions to various physiological processes including lipogenesis, insulin secretion from pancreatic cells, ureagenesis, gluconeogenesis, and probably also regulation of neuronal transmission. Inhibitors of hCA VA/VB ar...
Article
Synthetic sulfonamide derivatives are a class of potent matrix metalloproteinase inhibitors (MMPI) that have potential for the treatment of diseases related to uncontrolled expression of these enzymes. The lack of selectivity of the large majority of such inhibitors, leading to the inhibition of MMPs in tissues other than the targeted one, has dram...
Article
Full-text available
A series of 2/3/4-[(2-oxo-1,2-dihydro-3H-indol-3-ylidene)amino]benzenesulfonamides, obtained from substituted isatins and 2-, 3- or 4-aminobenzenesulfonamide, showed low nanomolar inhibitory activity against the tumor associated carbonic anhydrase (CA, EC 4.2.1.1) isoforms IX and XII – recently validated antitumor drug targets, being much less effe...
Article
A new series of dithiocarbamates (DTCs) was prepared from primary/secondary amines incorporating amino/hydroxyl-alkyl, mono- and bicyclic aliphatic ring systems based on the quinuclidine, piperidine, hydroxy-/carboxy-/amino-substituted piperidine, morpholine and piperazine scaffolds, and carbon disulfide. The compounds were investigated for the inh...
Article
Abstract In previous work, 14 salen and tetrahydrosalen compounds have been synthesized and tested in enzyme inhibition assays against cytosolic human carbonic anhydrase isozymes I and II (hCA I and II) and tumor-associated isozymes IX and XII (hCA IX and XII). These compounds show selectivity against hCA XII over hCA I, II and IX. In this study, m...
Article
Trypanosoma cruzi, the causative agent of Chagas disease, encodes for an a-carbonic anhydrase (CA, EC 4.2.1.1) possessing high catalytic activity (TcCA) whih was recently characterized (Pan et al. J. Med. Chem., 2013, 56, 1761-1771). A new class of sulfonamides possessing low nanomolar/subnanomolar TcCA inhibitory activity is described here. Aromat...
Article
Here, we investigate 28 structurally new sulfonamides and their subsequent testing for enzyme inhibition of cytosolic and tumor-associated carbonic anhydrases (CAs, EC 4.2.1.1). The compounds showed very potent inhibition of four physiologically relevant human (h) CA isoforms, namely hCA I, II, IX and XII. Interestingly, the KI values were in the n...
Article
Dithiocarbamates (DTCs) were recently discovered as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. A series of xanthates and a trithiocarbonate, structurally related to the DTCs, were prepared by reaction of alcohols/thiols with carbon disulfide in the presence of bases. These compounds were tested for the inhibition of 4 human (h) isoforms, hCA I...
Article
By using phthalimido-substituted aromatic sufonamides as lead molecules, a series of new sulfonamides incorporating ortho-benzenedisulfonimide moieties have been synthesized and tested against the human (h) cytosolic carbonic anhydrase (CA, EC 4.2.1.1) isozymes hCA I and hCA II and the transmembrane, tumor-associated isozymes hCA IX and hCA XII. Al...
Article
The α-carbonic anhydrase (CA, EC 4.2.1.1) from the extremophilic bacterium Sulfurihydrogenibium azorense (SazCA) was recently shown to be the fastest CA known. Here we investigated this enzyme for its activation with a series of amino acids and amines. The best SazCA activators were d-Phe, l-DOPA, l- and d-Trp, dopamine and serotonin, which showed...
Article
Full-text available
A hierarchical in silico screening procedure using the crystal structure of an agonist bound chimeric α7/Ls-AChBP protein was successfully applied to both proprietary and commercial databases containing drug-like molecules. An overall hit rate of 26% (pK(i) ⩾5.0) was obtained, with an even better hit rate of 35% for the commercial compound collecti...
Article
Using structure-based optimization procedures on in silico hits, dibenzosuberyl- and benzoate substituted tropines were designed as ligands for acetylcholine-binding protein (AChBP). This protein is a homolog to the ligand binding domain of the nicotinic acetylcholine receptor (nAChR). Distinct SAR is observed between two AChBP species variants and...
Article
Hierarchical in silico screening protocols against the agonist bound acetylcholine binding protein (AChBP) crystal structure were efficient in identifying novel chemotypes for AChBP and the human α7 receptor. Two hit structures were cocrystallized with AChBP revealing intermolecular cation-π interactions with loop C but lacking intermolecular hydro...
Article
Optimization of fragment hits toward high-affinity lead compounds is a crucial aspect of fragment-based drug discovery (FBDD). In the current study, we have successfully optimized a fragment by growing into a ligand-inducible subpocket of the binding site of acetylcholine-binding protein (AChBP). This protein is a soluble homologue of the ligand bi...
Article
Acetylcholine binding protein (AChBP) is widely considered as a functional and structural homologue of the ligand binding domain of Cys-loop receptors. We report the use of AChBP as template to identify ligands for the nicotinic receptors (nAChRs). An in silico screening protocol was set up and applied to crystal structures of AChBP. Several ligand...
Article
Full-text available
Recently, G protein-coupled receptors activated solely by synthetic ligands (RASSLs) have been introduced as new tools to study Galpha(i) signaling in vivo (1, 2). Also, Galpha(s)-coupled G protein-coupled receptors have been engineered to generate Galpha(s)-coupled RASSLs (3, 4). In this study, we exploited the differences in binding pockets betwe...

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