Synthesis, biological activity and docking calculations of bis-naphthoquinone derivatives from Lawsone

A biochemistry-oriented drug design: synthesis, anticancer activity, enzymes inhibition, molecular docking studies of novel 1,2,4-triazole derivatives

In this study, we researched the reactions of 5-(5-bromofuran-2-yl)-4-methyl-1,2,4-triazole-3-thiol and 5-thiophene-(3-ylmethyl)-4R-1,2,4-triazole-3-thiols with some halogen-containing compounds, a number of new compounds were synthesized (1.1-1.5 and 2.1-2.8). These compounds showed excellent to good inhibitory activities on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. For obtaining the effects of these compounds on AChE and BChE enzymes were determined spectrophotometrically according to Ellman. IC50 values of these enzymes were ranging between 1.63 and 17.68 nM for AChE and 8.71 and 84.02 nM for BChE. After, prostate cancer is the second leading cause of cancer-related mortality for men over the age of 65 in developed countries. Current treatment options remain limited in the treatment of advanced-stage prostate cancer leading to biochemical recurrence in almost 40% of the patients. Therefore, there is an urgent need for development of novel therapeutic tools for treatment of prostate cancer patients. In this study, we aimed at analyzing the potential of all compounds against prostate cancer cells. We found that, of the tested compounds, 2.1, 2.2 and 2.3 showed significant cytotoxic activities against PC3 prostate cancer cells, although their effect on the viability of normal prostate cells was limited. These findings suggest their selective targeting potential for prostate cancer cells and offer them as candidate therapeutic agents against prostate cancer. The inhibitory activities of some chemical compounds, such as (1.1-1.5 and 2.1-2.8) were assessed by performing the molecular docking study in the presence of AChE, BChE and prostate cancer protein. MM/GBSA methods are calculated binding free energy. Finally, ADME/T analysis was performed to examine the drug properties of the 13 studied molecules.Communicated by Ramaswamy H. Sarma.

Acetylphenyl-substituted imidazolium salts: synthesis, characterization, in silico studies and inhibitory properties against some metabolic enzymes

Herein, we present how to synthesize thirteen new 1-(4-acetylphenyl)-3-alkylimidazolium salts by reacting 4-(1-H-imidazol-1-yl)acetophenone with a variety of benzyl halides that contain either electron-donating or electron-withdrawing groups. The structures of the new imidazolium salts were conformed using different spectroscopic methods (1H NMR, 13C NMR, 19F NMR, and FTIR) and elemental analysis techniques. Furthermore, these compounds' the carbonic anhydrase (hCAs) and acetylcholinesterase (AChE) enzyme inhibition activities were investigated. They showed a highly potent inhibition effect toward AChE and hCAs with Ki values in the range of 8.30 ± 1.71 to 120.77 ± 8.61 nM for AChE, 16.97 ± 2.04 to 84.45 ± 13.78 nM for hCA I, and 14.09 ± 2.99 to 69.33 ± 17.35 nM for hCA II, respectively. Most of the synthesized imidazolium salts appeared to be more potent than the standard inhibitor of tacrine (TAC) against AChE and Acetazolamide (AZA) against CA. In the meantime, to prospect for potential synthesized imidazolium salt inhibitor(s) against AChE and hCAs, molecular docking and an ADMET-based approach were exerted.

Synthesis, anti-inflammatory activity, inverse molecular docking, and acid dissociation constants of new naphthoquinone-thiazole hybrids

Chronic Inflammation is associated with various types of diseases that involves pro-inflammatory cytokines like IL-6 and TNF-α. High costs and serious side effects of available anti-inflammatory/immunomodulatory drugs led us to design new compounds with promising anti-inflammatory activities. Many drugs and biologically important compounds involve naphthoquinone and thiazole moieties in their core structures. Thereby, here we report the synthesis, characterization and anti-inflammatory activities of new naphthoquinone thiazole hybrids by reaction of naphthoquinone acyl thioureas with various α-bromoketone derivatives. The position of NO2 group in one of the phenyl rings of naphthoquinone thiazole hybrids was changed while different substituents were introduced at the para position of the second phenyl ring. All compounds were tested for potential immunomodulatory effect. No inflammatory cytokines were observed in the absence of LPS stimulant. On the other hand, they had promising anti-inflammatory immunomodulatory activities by being able to decrease the production of the pro-inflammatory cytokines (TNF-α and IL-6) in the LPS-stimulated cells. In an effort to find the possible mechanism of action, several enzymes involved in signalling pathways that play critical roles in inflammatory responses were screened in silico. Subsequent to inverse molecular docking approach, PI3K was predicted be the potential target. The docked complexes of the most potent compounds 5g and 5i were subjected to molecular dynamics simulation to assess the binding stability of the igands with the putative target. Acid dissociation constants (pKa) of the products were also determined potentiometrically.

Design, syntheses, theoretical calculations, MM-GBSA, potential anti-cancer and enzyme activities of novel Schiff base compounds

In this study, new Schiff base compounds (SB-F-OH, SB-Cl-OH and SB-Br-OH) were derived from chalcone-derived amine compounds containing halogen groups and 4-hydroxybenzaldehyde. Also, their phthalonitrile compounds (SB-F-CN, SB-Cl-CN and SB-Br-CN) have been synthesized. The structures of these compounds were elucidated by NMR, FT-IR and Mass spectroscopic methods. The quantum chemical parameters were calculated at B3LYP/6-31++g(d,p), HF/6-31++g(d,p) and M062X/6-31++g(d,p) levels. As the biological application of the synthesized compounds, (i) their inhibition properties of the synthesized compounds on Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE) metabolic enzymes were investigated, and their potential anticancer activities against neuroblastoma (NB; SH-SY5Y) and healthy fibroblast (NIH-3T3) cell lines were determined by in vitro assays. All compounds showed inhibition at nanomolar level with the Ki values in the range of 97.86 ± 30.51-516.82 ± 31.42 nM for AChE, 33.21 ± 4.45-78.50 ± 8.91 nM for BChE, respectively. It has been determined that all tested compounds have a remarkable cytotoxic effect against SH-SY5Y, and IC50 values were significantly lower than NIH-3T3 cells. The lowest IC50 value was observed in SB-Cl-OH (7.48 ± 0.86 µM) and SB-Cl-CN (7.31 ± 0.69 µM). The molecular docking of the molecules was also investigated using crystal structure of AChE enzyme protein (PDB ID: 4M0E), crystal structure of BChE protein (PDB ID: 6R6V) and SH-SY5Y cancer protein (PDB ID: 2F3F, 3PBL and 5WIV). The ADME properties of the compounds were investigated. MM/GBSA method is calculated binding free energy. Afterwards, ADME/T analysis was performed to examine the some properties of the molecules.Communicated by Ramaswamy H. Sarma.

Novel Lawsone-Quinoxaline Hybrids as New Dual Binding Site Acetylcholinesterase Inhibitors

A new family of lawsone-quinoxaline hybrids was designed, synthesized, and evaluated as dual binding site cholinesterase inhibitors (ChEIs). In vitro tests revealed that compound 6d was the most potent AChEI (IC50 = 20 nM) and BChEI (IC50 = 220 nM). The compound 6d did not show cytotoxicity against the SH-SY5Y neuronal cells (GI50 > 100 μM). In silico and enzyme kinetic experiments demonstrated that compound 6d bound to both the catalytic anionic site and the peripheral anionic site of HuAChE. The lawsone-quinoxaline hybrids exhibited potential for further development of potent acetylcholinesterase inhibitors for the treatment of Alzheimer's disease.

Synthesis and Biological Activity of Some Bromophenols and Their Derivatives Including Natural Products

In addition to the first synthesis of the natural bromophenol butyl 2-(3,5-dibromo-4-hydroxyphenyl)acetate (1), indene derivatives 34 and 35 were synthesized from 3-phenylpropenal derivatives in BBr3 medium. Five known natural bromophenols and some derivatives were synthesized by known methods. Cholinesterase (ChEs) inhibitors reduce the breakdown of acetylcholine and are used in the treatment of Alzheimer's disease (AD) and dementia symptoms. The inhibition effects of all obtained compounds were examined towards acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and α-glycosidase enzymes. All synthesized compounds demonstrated the strong inhibition effects against both cholinergic enzymes. For determination of Ki values of novel bromophenols Lineweaver-Burk graphs were obtained. Ki values were found in the ranging of 0.13-14.74 nM for AChE, 5.11-23.95 nM for BChE, and 63.96-206.78 nM for α-glycosidase, respectively. All bromophenols and their derivatives exhibit effective inhibition profile when compared to positive controls.

The extraction and anti-inflammatory screening of Onosma glomeratum Y. L. Liu

"Zicao" has a long medicinal history and has a variety of pharmacological activities. As the main resource of "zicao" in Tibet, Onosma glomeratum Y. L. Liu (tuan hua dian zi cao), usually used for treating pneumonia in Tibet, has not been reported deeply. In order to determine the main anti-inflammatory active ingredients of Onosma glomeratum Y. L. Liu, in this study, the extracts enriched in naphthoquinones and polysaccharides were optimized prepared form Onosma glomeratum Y. L. Liu by ultrasonic extraction, and reflux extraction, respectively, with Box-Behnken design effect surface method. And their anti-inflammatory abilities were screened on LPS induced A549 cells model, for figuring out the anti-inflammatory active ingredients from Onosma glomeratum Y. L. Liu.The extract enriched naphthoquinone was obtained under following condition: extract with 85% ethanol in a liquid to material ratio of 1:40 g/mL at 30 °C for 30 minutes using ultrasound, leading to the extraction rate of total naphthoquinone as 0.98 ± 0.017%; the extract enriched polysaccharides was prepared as follows: extract 82 minutes at 100 °C with distilled water in a liquid to material ratio of 1:50 g/mL, with extraction rate of polysaccharide as 7.07 ± 0.02%.On the LPS-induced A549 cell model, the polysaccharide extract from Onosma glomeratum Y. L. Liu showed better anti-inflammatory effects than the naphthoquinone extract, indicating the extract enriched in polysaccharides is the anti-inflammatory extract of Onosma glomeratum Y. L. Liu, which could serve as a potential anti-inflammatory extract in medical and food industries in the future.

Repositioning of acefylline as anti-cancer drug: Synthesis, anticancer and computational studies of azomethines derived from acefylline tethered 4-amino-3-mercapto-1,2,4-triazole

Novel azomethines derived from acefylline tethered triazole hybrids (7a-k) have been synthesized and evaluated against human liver cancer cell line (Hep G2) using MTT assay. The synthesized series of azomethines exhibited promising efficacy against liver cancer cell line. Screening of the synthesized series identified compound 7d with the least cell viability value (11.71 ± 0.39%) as the most potent anticancer agent in contrast to the reference drug acefylline (cell viability = 80 ± 3.87%). In this study, the potentials of the novel agents (7a-k) to inhibit liver cancer proteins were assessed. Subsequently, the structure-activity relationship of the potential drug candidates was assessed via ADME/T molecular screening. The cytotoxic potential of these derivatives was also investigated by hemolysis and thrombolysis. Their hemolytic and thrombolytic studies showed that all of these drugs had very low cytotoxicity and moderate clot lysis activity. Compound 7g (0.26% hemolysis) and 7k (52.1% clot lysis) were the least toxic and moderate thrombolytic agents respectively.

Phthalimide-tethered imidazolium salts: Synthesis, characterization, enzyme inhibitory properties, and in silico studies

A series of new imidazolium salts were prepared in good yield by the reaction between 1-alkylimidazole and a variety of alkyl halides. The structures of the compounds were identified by FT-IR, ¹ H NMR, and ¹³ C NMR spectroscopy, elemental analysis, and mass spectrometry. The crystal structure of 1b was determined by the single-crystal X-ray diffraction method. The phthalimide-tethered imidazolium salts exhibited inhibition abilities toward acetylcholinesterase (AChE) and human carbonic anhydrases (hCAs) I and II, with K_i values in the range of 24.63 ± 3.45 to 305.51 ± 35.98 nM for AChE, 33.56 ± 3.71 to 218.01 ± 25.21 nM for hCA I and 17.75 ± 0.96 to 308.67 ± 13.73 nM for hCA II. The results showed that the new imidazolium salts can play a key role in the treatment of Alzheimer's disease, epilepsy, glaucoma, and leukemia, which is related to their inhibition abilities of hCA I, hCA II, and AChE. Molecular docking and in silico absorption, distribution, metabolism, excretion and toxicity studies were used to look into how the imidazolium salts interacted with the specific protein targets. To better visualize and understand the binding positions and the influence of the imidazolium salts on hCA I, hCA II, and AChE conformations, each one was subjected to molecular docking simulations.

Enzyme Inhibition Properties and Molecular Docking Studies of 4-Sulfonate Containing Aryl α-Hydroxyphosphonates Based Hybrid Molecules

In this study, a series of new hybrid molecules containing two important functional groups on the same skeleton were designed. 4-Hydroxybenzaldehyde and its two different derivatives were converted into their respective sulphonates by interacting with tosylchloride and methanesulfonyl chloride. Then, the desired molecules were synthesized by adding diethoxyphosphonate to the aldehyde group. Also, novel synthesis of hybrid compounds (4a-c and 5a-c) were tested toward some metabolic enzymes like carbonic anhydrase I and II isoenzymes (hCA I and hCA II) and acetylcholinesterase (AChE) enzyme. The synthesis of hybrid compounds (4a-c and 5a-c) showed K_i values of in range of 25.084±4.73-69.853±15.19 nM against hCA I, 32.325±1.67-82.761±22.73 nM against hCA II and 1.699±0.25 and 3.500±0.91 nM against AChE. For these compounds, compound 4c showed maximum inhibition effect against hCA I and hCA II isoenzymes and compound 5b showed maximum inhibition effect against AChE enzyme. By performing docking studies of the most active compounds for their binding modes and interactions were determined.

Polyphenol Contents, Potential Antioxidant, Anticholinergic and Antidiabetic Properties of Mountain Mint (Cyclotrichium leucotrichum)

In the present work, antioxidant and antidiabetic potentials of mountain mint [Cyclotrichium leu-cotrichum (Stapf ex Rech. Fil.) Leblebici] was the first time appraised. In this sense, methanol (MECL) and water (WECL) extracts were obtained from aerial parts of mountain mint (Cyclotrichium leucotrichum) and studied for their antioxidant ability by several bioanalytical assays. Also, their inhibition profiles were realized toward several metabolic enzymes connected to some diseases, including butyrylcholinesterase (BChE), α-glycosidase, acetylcholinesterase (AChE), and α-amylase enzymes. Additionally, their phenolic contents were determined by putative chromatographic method of LC-MS/MS. Consequently, nineteen phenolic molecules were identified in MECL and fifteen phenolic molecules were found in WECL. Also, antioxidant effects of both extracts were studied using by the methods of 1,1-diphenyl-2-picryl-hydrazyl (DPPH·), 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and (ABTS•+)N,N-dimethyl-p-phenylenediamine (DMPD•+) scavenging activities, ferric (Fe3+) and cupric (Cu2+) ions and Fe3+-2,4,6-tri(2-pyridyl)-S-triazine (TPTZ) reducing capacities. MECL and WECL were found as powerful DPPH· (IC50: 23.74 and 28.85 μg/mL), ABTS•+ (IC50: 12.53 and 14.05 μg/mL) and DMPD•+ scavenging effects (IC50: 43.52 and 54.80 μg/mL). Also, both extracts demonstrated the effective inhibition effects on AChE (IC50: 69.31 and 115.51 μg/mL), BChE (IC50: 57.75 and 86.62 μg/mL), α-glycosidase (IC50: 36.47 and 62.94 μg/mL) and α-amylase (IC50: 1.01 and 3.43 μg/mL). This study will be useful for future studies to determine the antioxidant properties and enzyme inhibition profile of food, medical and industrially important plants.

Biological effects of bis-hydrazone compounds bearing isovanillin moiety on the aldose reductase

Aldose reductase (ALR2), one of the metabolically important enzymes, catalyzes the formation of sorbitol from glucose in the polyol pathway. ALR2 inhibition is required to prevent diabetic complications. In the present study, the novel bis-hydrazone compounds bearing isovanillin moiety (GY1-12) were synthesized, and various chromatographic methods were applied to purify the ALR2 enzyme. Afterward, the inhibitory effect of the synthesized compounds on the ALR2 was screened in vitro. All the novel bis-hydrazones demonstrated activity in nanomolar levels as AR inhibitors with IC₅₀ and K_I values in the range of 12.55-35.04 nM, and 13.38-88.21 nM, respectively. Compounds GY-11, GY-7, and GY-5 against ALR2 were identified as the highly potent inhibitors, respectively, and were superior to the standard drug, epalrestat. Moreover, a comprehensive ligand-receptor interactions prediction was performed using ADME-Tox, Glide XP, and MM-GBSA modules of Schrödinger Small-Molecule Drug Discovery Suite to elucidate the novel bis-hydrazone derivatives, potential binding modes versus the ALR2. As a result, these compounds with ALR2 inhibitory effects may be potential alternative agents that can be used to treat or prevent diabetic complications.

Dual targeting of acetylcholinesterase and tau aggregation: Design, synthesis and evaluation of multifunctional deoxyvasicinone analogues for Alzheimer's disease

Development of multitargeted ligands have demonstrated remarkable efficiency as potential therapeutics for Alzheimer's disease (AD). Herein, we reported a new series of deoxyvasicinone analogues as dual inhibitor of acetylcholinesterase (AChE) and tau aggregation that function as multitargeted ligands for AD. All the multitargeted ligands 11(a-j) and 15(a-g) were designed, synthesized, and validated by ¹HNMR, ¹³CNMR and mass spectrometry. All the synthesized compounds 11(a-j) and 15(a-g) were screened for their ability to inhibit AChE, BACE1, amyloid fibrillation, α-syn aggregation, and tau aggregation. All the screened compounds possessed weak inhibition of BACE-1, Aβ₄₂ and α-syn aggregation. However, several compounds were identified as potential hits in the AChE inhibitory screening assay and cellular tau aggregation screening. Among all compounds, 11f remarkably inhibited AChE activity and cellular tau oligomerization at single-dose screening (10 µM). Moreover, 11f displayed a half-maximal inhibitory concentration (IC₅₀) value of 0.91 ± 0.05 µM and half-maximal effective concentration (EC₅₀) value of 3.83 ± 0.51 µM for the inhibition of AChE and cellular tau oligomerization, respectively. In addition, the neuroprotective effect of 11f was determined in tau-expressing SH-SY5Y cells incubated with Aβ oligomers. These findings highlighted the potential of 11f to function as a multifunctional ligand for the development of promising anti-AD drugs.

DMAP-catalyzed Efficient and Convenient Approach for the Synthesis of 3,3′-(Arylmethylene)bis(2-Hydroxynaphthalene-1,4-Dione) Derivatives

For the first time the 4-dimethylaminopyridine (DMAP) catalyzed straightforward and efficient procedure has been developed for the synthesis of 3,3′-(arylmethylene) bis(2-hydroxynaphthalene-1,4-dione) derivatives starting from lawsone (2-hydroxy-1,4-naphthoquinone) and a variety of (hetero)aromatic aldehydes in ethanol under microwave irradiation. Three of nine synthesized compounds are new. This method provides notable advantages over existing procedures including use of non-traditional basic catalyst and environmentally benign solvent, mild reaction conditions, excellent yields, short reaction time and simple workup.

Inhibition Profiles of Some Symmetric Sulfamides Derived from Phenethylamines on Human Carbonic Anhydrase I, and II Isoenzymes

In this work, the inhibitory effect of some symmetric sulfamides derived from phenethylamines were determined against human carbonic anhydrase (hCA) I, and II isoenzymes, and compared with standard compound acetazolamide. IC₅₀ values were obtained from the Enzyme activity (%)-[Symmetric sulfamides] graphs. Also, K_i values were calculated from the Lineweaver-Burk graphs. Some symmetric sulfamides compounds (11-18) demonstrated excellent inhibition effects against hCA I, and II isoenzymes. These compounds demonstrated effective inhibitory profiles with IC₅₀ values in ranging from 21.66-28.88 nM against hCA I, 14.44-30.13 nM against hCA II. Among these compounds, the best K_i value for hCA I (K_i : 8.34±1.60 nM) and hCA II (K_i : 16.40±1.00 nM) is compound number 11. Besides, the IC₅₀ value of acetazolamide used as a standard was determined as hCA I, hCA II 57.75 nM, 49.50 nM, respectively. Moreover, in silico ADME-Tox study showed that all synthesized compounds (11-18) had good oral bioavailability in light of Jorgensen's rule of three, and of Lipinski's rule of five.