Synthesis and biological evaluation of novel piperazine derivatives of flavone as potent anti-inflammatory and antimicrobial agent

Design, synthesis, molecular docking, molecular dynamic simulation, and MMGBSA analysis of 7-O-substituted 5-hydroxy flavone derivatives

A series of chrysin derivatives were designed, synthesized, and evaluated for their antibacterial activity against four different bacterial strains. We have synthesized new propyl-substituted and butyl-substituted chrysin-piperazine derivatives, which show marvellous inhibition against E. coli and S. aureus. The free hydroxyl group at the C-5 position of chrysin improved therapeutic efficacy in vivo and was a beneficial formulation for chemotherapy. All synthesized compounds were confirmed by various spectroscopic techniques such as IR, NMR, HPLC, and mass spectrometry. The compounds exhibited moderate to good inhibition, and their structure-activity relationship (SAR) has also been illustrated. Among the synthesised compounds, compounds 4 and 10 were the most active against S. pyogenes and E. coli, with 12.5 g/mL MICs; additionally, compound 12 exhibits significant activity on both the S. aureus and E. coli stains. Based on the promising activity profile and docking score of compound 12, it was selected for 100 ns MD simulation and post-dynamic binding free energy analysis within the active sites of S. aureus TyrRS (PDB ID: 1JIJ) and E. coli DNA GyrB (PDB ID: 6YD9) to investigate the stability of molecular contacts and to establish how the newly synthesized inhibitors fit together in the most stable conformations.Communicated by Ramaswamy H. Sarma.

Synthesis of Ursolic Acid-based Hybrids: In Vitro Antibacterial, Cytotoxicity Studies, In Silico Physicochemical and Pharmacokinetic Properties

BACKGROUND

There is a critical need for the discovery of novel and effective antibacterial or anticancer molecules.

OBJECTIVES

Amine-linked ursolic acid-based hybrid compounds were prepared in good yields in the range of 60-68%.

METHODS

Their molecular structures were successfully confirmed using different spectroscopic methods including 1H/13C NMR, UHPLC-HRMS and FTIR spectroscopy. The in vitro cytotoxicity of some of these hybrid molecules against three human tumour cells, such as MDA-MB23, MCF7, and HeLa was evaluated using the MTT colorimetric method.

RESULT

Their antibacterial efficacy was evaluated against eleven bacterial pathogens using a serial dilution assay. Majority of the bacterial strains were inhibited significantly by compounds 17 and 24, with the lowest MIC values in the range of 15.3-31.25 μg/mL. Compound 16 exhibited higher cytotoxicity against HeLa cells than ursolic acid, with an IC50 value of 43.64 g/mL.

CONCLUSION

The in vitro antibacterial activity and cytotoxicity of these hybrid compounds demonstrated that ursolic acid-based hybrid molecules are promising compounds. Further research into ursolic acid-based hybrid compounds is required.

A Profound Insight into the Structure-activity Relationship of Ubiquitous Scaffold Piperazine: An Explicative Review

Despite extensive research in the field of drug discovery and development, still there is a need to develop novel molecular entities. Literature reveals a substantial heterocyclic nucleus named, piperazine, which shows an immense therapeutic voyage. For several decades, molecules having the piperazine nucleus have entered the market as a drug exhibiting biological potential. It was known to possess antipsychotic, antihistamine, antianginal, antidepressant, anticancer, antiviral, cardioprotective, and anti-inflammatory activity with a specific basis for structural activity relationship. Thus, it is regarded as a key structural feature in most of the already available therapeutic drugs in the market. Reports also suggest that the extensive utilization of these currently available drugs having a piperazine nucleus shows increasing tolerance significantly day by day. In addition to this, various other factors like solubility, low bioavailability, cost-effectiveness, and imbalance between pharmacokinetics and pharmacodynamics profile limit their utilization. Focusing on that issues, various structural modification studies were performed on the piperazine moiety to develop new derivatives/analogs to overcome the problems associated with available marketed drugs. Thus, this review article aims to gain insight into the number of structural modifications at the N-1 and N-4 positions of the piperazine scaffold. This SAR approach may prove to be the best way to overcome the above-discussed drawbacks and lead to the design of drug molecules with better efficacy and affinity. Hence, there is an urgent need to focus on the structural features of this scaffold which paves further work for deeper exploration and may help medicinal chemists as well as pharmaceutical industries.

Novel Piperazine Derivatives as Potent Antihistamine, Anti-Inflammatory, and Anticancer Agents, their Synthesis and Characterization

INTRODUCTION

In this study, a series of novel piperazine derivatives were synthesised with high-to-good yields, and their structural analogies were confirmed using FTIR, 1H-NMR, and LC-MS techniques.

METHODS

The synthesised compounds were evaluated for antioxidant and antimicrobial activities. Among the four synthesised piperazine derivatives, compound PD-2 exhibited relatively good antioxidant activity, with an IC50 value of 2.396 μg/mL, while the other three derivatives showed moderate to low antioxidant activity. Furthermore, compound PD-2 displayed antimicrobial activity against Pseudomonas aeruginosa, a gram-negative bacterium, and Candida albicans, a fungus. However, all four compounds showed strong resistance against grampositive bacteria, Staphylococcus aureus.

RESULTS

Additionally, compound PD-1 exhibited significant antihistamine activity, eliciting an 18.22% reduction in histamine levels. Both PD-1 and PD-2 demonstrated noteworthy anti-inflammatory activity in a dosedependent manner (5-10 μM), leading to the inhibition of nitrite production up to 39.42% and 33.7% at higher concentrations (10 μM) and inhibition of tumour necrosis factor-alpha (TNF-α) generation up to 56.97% and 44.73% at 10 μM, respectively. Additionally, both novel molecules PD-1 and PD-2 effectively restrained the growth of HepG2 cells in a manner that is dependent on the dosage up to 55.44% and 90.45% at the highest concentrations (100 μg/mL), respectively.

CONCLUSION

These findings substantiate the rationale for further investigation into the novel series of persuasive piperazine analogues as potential agents with anti-inflammatory, antihistamine and anticancer properties.

Repurposing Study of 4-Acyl-1-phenylaminocarbonyl-2-substituted-piperazine Derivatives as Potential Anticancer Agents-In Vitro Evaluation against Breast Cancer Cells

Breast cancer is the most common type of cancer in women. Although current treatments can increase patient survival, they are rarely curative when the disease is advanced (metastasis). Therefore, there is an urgent need to develop new cytotoxic drugs with a high selectivity toward cancer cells. Since repurposing approved drugs for cancer therapy has been a successful strategy in recent years, in this study, we screened a library of antiviral piperazine-derived compounds as anticancer agents. The compounds included a piperazine ring and aryl urea functions, which are privileged structures present in several anti-breast cancer drugs. The selective cytotoxic activity of a set of thirty-four 4-acyl-2-substituted piperazine urea derivatives against MCF7 breast cancer cells and MCF 10A normal breast cells was determined. Compounds 31, 32, 35, and 37 showed high selective anticancer activity against breast cancer cells and were also tested against another common type of cancer, non-small cell lung cancer (A549 lung cancer cells versus MRC-5 lung normal cells). Compounds 35 and 37 also showed selectivity against lung cancer cells. These results suggest that compounds 35 and 37 may be promising hit compounds for the development of new anticancer agents.

Bacterial Tyrosinase Inhibition, Hemolytic and Thrombolytic Screening, and In Silico Modeling of Rationally Designed Tosyl Piperazine-Engrafted Dithiocarbamate Derivatives

Piperazine is a privileged moiety that is a structural part of many clinical drugs. Piperazine-based scaffolds have attracted the attention of pharmaceutical and medicinal scientists to develop novel, efficient therapeutic agents owing to their significant and promising biological profile. In the current study, an ecofriendly ultrasonic-assisted synthetic approach was applied to achieve a novel series of 1-tosyl piperazine dithiocarbamate acetamide hybrids 4a-4j, which was evaluated for in vitro tyrosinase inhibition and thrombolytic and hemolytic cytotoxic activities. Among all the piperazine-based dithiocarbamate acetamide target molecules 4a-4j, the structural analogs 4d displayed excellent tyrosinase inhibition efficacy (IC50 = 6.88 ± 0.11 µM) which was better than the reference standard drugs kojic acid (30.34 ± 0.75 µM) and ascorbic acid (11.5 ± 1.00 µM), respectively, which was further confirmed by in silico induced-fit docking (IFD) simulation Good tyrosinase activities were exhibited by 4g (IC50 = 7.24 ± 0.15 µM), 4b (IC50 = 8.01 ± 0.11 µM) and 4c (IC50 = 8.1 ± 0.30 µM) dithiocarbamate acetamides, which were also better tyrosinase inhibitors than the reference drugs but were less active than the 4d structural hybrid. All the derivatives are less toxic, having values in the 0.29 ± 0.01% to 15.6 ± 0.5% range. The scaffold 4b demonstrated better hemolytic potential (0.29 ± 0.01%), while a remarkably high thrombolytic chemotherapeutic potential was displayed by analog 4e (67.3 ± 0.2%).

Amino-Acid-Conjugated Natural Compounds: Aims, Designs and Results

Protein is one of the essential macronutrients required by all living things. The breakdown of protein produces monomers known as amino acids. The concept of conjugating natural compounds with amino acids for therapeutic applications emerged from the fact that amino acids are important building blocks of life and are abundantly available; thus, a greater shift can result in structural modification, since amino acids contain a variety of sidechains. This review discusses the data available on amino acid–natural compound conjugates that were reported with respect to their backgrounds, the synthetic approach and their bioactivity. Several amino acid–natural compound conjugates have shown enhanced pharmacokinetic characteristics, including absorption and distribution properties, reduced toxicity and increased physiological effects. This approach could offer a potentially effective system of drug discovery that can enable the development of pharmacologically active and pharmacokinetically acceptable molecules.

Modulating Properties of Piroxicam, Meloxicam and Oxicam Analogues against Macrophage-Associated Chemokines in Colorectal Cancer

The mechanisms underlying the antineoplastic effects of oxicams have not been fully elucidated. We aimed to assess the effect of classic and novel oxicams on the expression/secretion of macrophage-associated chemokines (RTqPCR/Luminex xMAP) in colorectal adenocarcinoma cells, and on the expression of upstream the non-steroidal anti-inflammatory drug (NSAID)-activated genes NAG1, NFKBIA, MYD88, and RELA, as well as at the chemokine profiling in colorectal tumors. Meloxicam downregulated CCL4 9.9-fold, but otherwise the classic oxicams had a negligible/non-significant effect. Novel analogues with a thiazine ring substituted with arylpiperazine and benzoyl moieties significantly modulated chemokine expression to varying degree, upregulated NAG1 and NFKBIA, and downregulated MYD88. They inhibited CCL3 and CCL4, and their effect on CCL2 and CXCL2 depended on the dose and exposure. The propylene linker between thiazine and piperazine nitrogens and one arylpiperazine fluorine substituent characterized the most effective analogue. Only CCL19 and CXCL2 were not upregulated in tumors, nor was CXCL2 in tumor-adjacent tissue compared to normal mucosa. Compared to adjacent tissue, CCL4 and CXCL2 were upregulated, while CCL2, CCL8, and CCL19 were downregulated in tumors. Tumor CCL2 and CCL7 increased along with advancing T and CCL3, and CCL4 along with the N stage. The introduction of arylpiperazine and benzoyl moieties into the oxicam scaffold yields effective modulators of chemokine expression, which act by upregulating NAG1 and interfering with NF-κB signaling.

Heat Shock Proteins HSPA1 and HSP90AA1 Are Upregulated in Colorectal Polyps and Can Be Targeted in Cancer Cells by Anti-Inflammatory Oxicams with Arylpiperazine Pharmacophore and Benzoyl Moiety Substitutions at Thiazine Ring

Heat shock proteins HSPA1/Hsp70α and HSP90AA1/Hsp90α are crucial for cancer growth but their expression pattern in colorectal polyps or whether they can be modulated by oxicams is unknown. We quantified (RTqPCR) HSPA1 and HSP90AA1 expression in 50 polyp-normal pairs in relation to polyp malignancy potential and examined the effect of piroxicam, meloxicam and five novel analogues on HSPA1 and HSP90AA1 expression (mRNA/protein) in colorectal adenocarcinoma lines. HSPA1 and HSP90AA1 were upregulated in polyps by 3- and 2.9-fold. Expression ratios were higher in polyps with higher dysplasia grade and dominant villous growth pattern, mostly a result of diminished gene expression in normal tissue. Classic oxicams had negligible/non-significant effect on HSP expression. Their most effective analogue inhibited HSPA1 protein and gene by 2.5-fold and 5.7-fold in Caco-2 and by 11.5-fold and 6.8-fold in HCT116 and HSPA1 protein in HT-29 by 1.9-fold. It downregulated HSP90AA1 protein and gene by 1.9-fold and 3.7-fold in Caco-2 and by 2-fold and 5.0-fold in HCT116. HSPA1 and HSP90AA1 are upregulated in colorectal polyps reflecting their potential for malignancy. HSPA1 in cancer cells and, to lesser degree, HSP90AA1 can be reduced by oxicam analogues with thiazine ring substituted via propylene linker by arylpiperazine pharmacophore with fluorine substituents and by benzoyl moiety.

Piperazine skeleton in the structural modification of natural products: a review

Piperazine moiety is a cyclic molecule containing two nitrogen atoms in positions 1 and 4, as well as four carbon atoms. Piperazine is one of the most sought heterocyclics for the development of new drug candidates with a wide range of applications. Over 100 molecules with a broad range of bioactivities, including antitumor, antibacterial, anti-inflammatory, antioxidant, and other activities, were reviewed. This article reviewed investigations regarding piperazine groups for the modification of natural product derivatives in the last decade, highlighting parameters that affect their biological activity.

Multitarget-directed therapeutics: (Urea/thiourea)2 derivatives of diverse heterocyclic-Lys conjugates

The synthesis of a new small library of molecules containing bis-urea/thiourea pendants in lysine conjugated to three different heterocycles is described. The heterocycles used in this study have benzisoxazole/piperazine/piperidine units. After a detailed antimicrobial, antioxidant, and anti-inflammatory evaluation, it was found that the most active compounds are 10, 11, 14, 15, 18, 19 and 10, 11, 19 and 8, 9, 12, 13, 16, 17, respectively. Further, it was observed that the presence of all three entities, that is, urea/thiourea, the substituent (OMe/F), as well as the heterocycle, is highly essential for exerting potent activity. Among the heterocycles, the presence of isoxazole seems to be highly beneficial for exerting good potency. In continuation, docking studies have revealed extraordinary binding efficiency for some of the active compounds. Given their potent biological results and docking score, some of the title compounds could be potential drug candidates for microbial-related diseases and provide a basis for future research into the development of molecules possessing multitask ability.

Synthesis and characterization of piperazine-substituted dihydrofuran derivatives viaMn(OAc) 3 mediated radical cyclizations

The aim of this study is to synthesize novel piperazine-containing dihydrofuran compounds (3a-n)from radical additions and cyclizations of diacyl and alkyl-acyl piperazine derivatives (1a-h) with 1,3-dicarbonyl compounds (2a-c) mediated by Mn(OAc) ₃ for the first time. From the reactions of 1a-c with dimedone (2a);1a, 1c, and 1d with acetylacetone (2b); and 1a with ethylacetoacetate(2c) ,the dihydrofuran-piperazine compounds 3a-c, 3d-f, and 3g were obtained in medium to high yields (31%–81%), respectively. In addition, dihydrofuran-piperazine compounds 3h-j and 3k-n were prepared at low to medium yields (20%–40%) from the reactions of 1e-g with 2a and 1e-h with 2c , respectively.

New 1,3,4-Oxadiazole Derivatives of Pyridothiazine-1,1-Dioxide with Anti-Inflammatory Activity

Numerous studies have confirmed the coexistence of oxidative stress and inflammatory processes. Long-term inflammation and oxidative stress may significantly affect the initiation of the neoplastic transformation process. Here, we describe the synthesis of a new series of Mannich base-type hybrid compounds containing an arylpiperazine residue, 1,3,4-oxadiazole ring, and pyridothiazine-1,1-dioxide core. The synthesis was carried out with the hope that the hybridization of different pharmacophoric molecules would result in a synergistic effect on their anti-inflammatory activity, especially the ability to inhibit cyclooxygenase. The obtained compounds were investigated in terms of their potencies to inhibit cyclooxygenase COX-1 and COX-2 enzymes with the use of the colorimetric inhibitor screening assay. Their antioxidant and cytotoxic effect on normal human dermal fibroblasts (NHDF) was also studied. Strong COX-2 inhibitory activity was observed after the use of TG6 and, especially, TG4. The TG11 compound, as well as reference meloxicam, turned out to be a preferential COX-2 inhibitor. TG12 was, in turn, a non-selective COX inhibitor. A molecular docking study was performed to understand the binding interaction of compounds at the active site of cyclooxygenases.

Synthesis and biological evaluation as well as in silico studies of arylpiperazine-1,2-benzothiazine derivatives as novel anti-inflammatory agents

Novel arylpiperazine-1,2-benzothiazine derivatives have been designed and synthesized as potential anti-inflammatory agents. Their structure and properties have been studied using spectroscopic techniques (¹H NMR, ¹³C NMR, FT-IR), MS, elemental analyses, and single-crystal X-ray diffraction (SCXRD, for compound 7b). This study aimed to evaluate the inhibitory activity of new derivatives against both cyclooxygenase isoforms COX-1 and COX-2 due to the similarity of new compounds to oxicams drugs from the NSAIDs group. All new compounds were divided into two series - A and B - with a different linker between thiazine and piperazines nitrogens. Series A included the three-carbon aliphatic linker and series B - two-carbon with a carbonyl group. According to in vitro and molecular docking studies all new compounds exhibited cyclooxygenase inhibitory activity. The series of A compounds included COX-1 inhibitors only. In contrast, the B series showed inhibition of both COX-1 and COX-2, which suggested the importance of the acetoxy linker for COX-2 inhibition. Moreover, the most selective compound 7b, towards COX-2, was non-toxic for the normal human cell line (in concentration of 10 µM) comparable to reference drug meloxicam. Additionally, investigation of influence on model membranes confirmed the ability of the compound 7b to penetrate lipid bilayers which seemed to be important to the influence with membrane protein-cyclooxygenase.

Design, synthesis and biological evaluation of novel osthole-based derivatives as potential neuroprotective agents

A total of 26 compounds based on osthole skeleton were designed, synthesized. Their cytoprotective abilities of antioxidation, anti-inflammation and Aβ₄₂(Amyloid β-protein 42)-induced neurotoxicity were evaluated by MTT assays. Mechanism of the action of selected compounds were investigated by molecular docking. AlogP, logS and blood-brain barrier (BBB) permeability of all these compounds were simulated by admetSAR. Most of the compounds showed better antioxidative and anti-inflammatory activities compared with osthole, especially OST7 and OST17. The compound OST7 showed relative high activity in neuroprotection against H₂O₂ (45.7 ± 5.5%), oxygen glucose deprivation (64.6 ± 4.8%) and Aβ₄₂ (61.4 ± 5.2%) at a low concentration of 10 μM. EC₅₀ of selected compounds were measured in both H₂O₂ and OGD induced cytotoxicity models. Moreover, NO inhibiting ability of OST17(50.4 ± 7.1%) already surpassed the positive drug indomethacin. The structure activity relationship study indicated that introduction of piperazine group, tetrahydropyrrole group and aromatic amine group might be beneficial for enhancement of osthole neuroprotective properties. Molecular docking explained that the reason OST7 exhibited relatively stronger neuroprotection against Aβ because of the greater area of interactions between molecule and target protein. OST7 and OST17 both provided novel methods to investigate osthole as anti-AD drugs.

L-Arginine/Nitric Oxide Pathway Is Altered in Colorectal Cancer and Can Be Modulated by Novel Derivatives from Oxicam Class of Non-Steroidal Anti-Inflammatory Drugs

L-arginine/nitric oxide pathway metabolites are altered in colorectal cancer (CRC). We evaluated underlying changes in pathway enzymes in 55 paired tumor/tumor-adjacent samples and 20 normal mucosa using quantitative-PCR and assessed the impact of classic and novel oxicam analogues on enzyme expression and intracellular metabolite concentration (LC-MS/MS) in Caco-2, HCT116, and HT-29 cells. Compared to normal mucosa, ARG1, PRMT1, and PRMT5 were overexpressed in both tumor and tumor-adjacent tissue and DDAH2 solely in tumor-adjacent tissue. Tumor-adjacent tissue had higher expression of ARG1, DDAH1, and DDAH2 and lower NOS2 than patients-matched tumors. The ARG1 expression in tumors increased along with tumor grade and reflected lymph node involvement. Novel oxicam analogues with arylpiperazine moiety at the thiazine ring were more effective in downregulating DDAHs and PRMTs and upregulating ARG2 than piroxicam and meloxicam. An analogue distinguished by propylene linker between thiazine's and piperazine's nitrogen atoms and containing two fluorine substituents was the strongest inhibitor of DDAHs and PRMTs expression, while an analogue containing propylene linker but no fluorine substituents was the strongest inhibitor of ARG2 expression. Metabolic reprogramming in CRC includes overexpression of DDAHs and PRMTs in addition to ARG1 and NOS2 and is not restricted to tumor tissue but can be modulated by novel oxicam analogues.

2-(Substituted amino)-8-azachromones from 4,6-Diaryl-2-pyridones: A Synthetic Strategy toward Compounds of Broad Structural Diversity

3-Acetoacetyl-4,6-diaryl-2-pyridones are synthesized in three steps from chalcones and then condense with carbon disulfide to afford 8-azachromones containing a methylthio group at C2. This leaving group offers an entry point for the insertion of more complex moieties via nucleophilic substitution. For this purpose, N-nucleophiles are explored according to their positions in the Mayr's nucleophilicity scale (N parameter), and three main classes are distinguished depending on whether the substitution takes place from their neutral forms, from their deprotonated anionic forms, or under nucleophilic catalysis. A broad range of primary and secondary amines may be inserted by this method, including enantiomerically pure amino acids, enabling us to explore structural diversity.

Exploration of piperazine-derived thioureas as antibacterial and anti-inflammatory agents. In vitro evaluation against clinical isolates of colistin-resistant Acinetobacter baumannii

A. baumannii is one of the most important multidrug-resistant microorganisms in hospital units. It is resistant to many classes of antibiotics and the development of new therapeutic strategies is necessary. The aim of this study was to evaluate the antibacterial activity of a set of piperazine-derived thioureas against 13 clinical strains of colistin-resistant A. baumannii. Six derivatives were identified to inhibit bacterial growth of 46% of the A. baumannii strains at low micromolar concentrations (Minimum Inhibitory Concentration from 1.56 to 6.25 μM). A common structural feature in most active compounds was the presence of a 3,5-bis-trifluoromethyl phenyl ring at the thiourea function. In addition, the ability of the compounds to inhibit production of nitric oxide (NO) was examined in RAW 264.7 murine macrophages, highlighting the potential of piperazine-derived thioureas as promising scaffolds for the design of new combined anti-bacterial/anti-inflammatory agents.

Current Strategies in Development of New Chromone Derivatives with Diversified Pharmacological Activities: A Review

Chromone derivatives possess a spectrum of biological activities. Chromone has been recognized as a privileged structure for new drug invention and development. Substitution pattern of chromone scaffold determines different type of biological activities. The type, number and position of substituents connected to the chromone core play a vital role in determining pharmacological activities. In the present review, we have discussed new chromone derivatives as anticancer, anti-diabetic, antimicrobial, anti-inflammatory, antioxidant and as anti-Alzheimer agents. This review deals with the chromone derivatives prepared by combining chromone molecule with various natural and synthetic pharmacophores and pharmacological activities presented by them. The main aim is to highlight the diversified pharmacological activities exhibited by chromone hybrid molecules during the last eight to ten years.

Piperazine clubbed with 2-azetidinone derivatives suppresses proliferation, migration and induces apoptosis in human cervical cancer HeLa cells through oxidative stress mediated intrinsic mitochondrial pathway

Piperazine scaffolds or 2-azetidinone pharmacophores have been reported to show anti-cancer activities and apoptosis induction in different types of cancer cells. However, the mechanistic studies involve in induction of apoptosis addressing these two moieties for human cervical cancer cells remain uncertain. The present study emphasizes on the anti-proliferating properties and mechanism involved in induction of apoptosis for these structurally related azoles derivatives in HeLa cancer cells. 1-Phenylpiperazine clubbed with 2-azetidione derivatives (5a-5h) were synthesized, characterized using various spectroscopic techniques and evaluated for their in-vitro anti-proliferative activities and induction of apoptosis. Further, we also evaluated oxidative stress generated by these synthetic derivatives (5a-5h). Cell viability studies revealed that among all, the compound N-(3-chloro-2-(3-nitrophenyl)-4-oxoazetidin-1-yl)-2-(4-phenylpiperazin-1-yl) acetamide 5e remarkably inhibited the growth of HeLa cells in a concentration dependent manner having IC₅₀ value of 29.44 ± 1.46 µg/ml. Morphological changes, colonies suppression and inhibition of migration clearly showed the antineoplasicity in HeLa cells treated with 5e. Simultaneously, phosphatidylserine externalization, DNA fragmentation and cell-cycle arrest showed ongoing apoptosis in the HeLa cancer cells induced by compound 5e in concentration dependent manner. Additionally, generation of intracellular ROS along with the decrease in mitochondrial membrane potential supported that compound 5e caused oxidative stress resulting in apoptosis through mitochondria mediated pathway. Elevation in the level of cytochrome c and upregulation in expression of caspase-3 clearly indicated the involvement of the intrinsic pathway of programmed cell death. In brief; compound 5e could serve as a promising lead for the development of an effective antitumor agent.

Natural chromones as potential anti-inflammatory agents: Pharmacological properties and related mechanisms

Chromones are a group of natural substances with a diversity of biological activities. Herein we assessed the pharmacological potential of three chromones (1, 2 and 3) isolated from Dictyoloma vandellianum as anti-inflammatory agents using in vitro and in vivo approaches. During in vitro screening, the production of NO and cytokines by macrophages stimulated with LPS and IFN-γ was inhibited by all chromones at concentrations (5-20 μM) that did not induce cytotoxicity. Analysis of pharmacokinetic parameters (in vitro half-life and intrinsic clearance) using human liver microsomes revealed that 3 has a superior pharmacokinetic profile, compared to 1 and 2. Treatment with 3 (100 mg/kg, ip) did not affect the mice motor performance, while 1 and 2 induced motor deficit. Taking into account the pharmacokinetic profile and absence of motor impairment, 3 was selected for further pharmacological characterization. Corroborating the data from in vitro screening, treatment of cell cultures with 3 (5-20 μM) reduced TNF-α, IL-6 and IL-1β production by stimulated macrophages. In the complete Freund's adjuvant-induced paw inflammation model in mice, 3 (25 and 50 mg/kg, ip) inhibited mechanical hyperalgesia, edema and cytokine production/release (IL-1β, IL-6 and TNF-α). 3 (5-20 μM) also reduced the transcriptional activity of NF-κB in stimulated macrophages. Furthermore, treatment with RU486, a glucocorticoid receptor (GR) antagonist, partially prevented the inhibitory effect of 3 on macrophages, indicating that this chromone exerts its anti-inflammatory effects in part through the activation of GR. The results presented herein demonstrate the pharmacological potential of natural chromones, highlighting 3 as a possible candidate for the drug discovery process targeting new anti-inflammatory drugs.

An efficient and concise access to 2-amino-4H-benzothiopyran-4-one derivatives

A highly efficient and convenient protocol was developed to access 2-amino-4H-benzothiopyran-4-ones through a process of conjugated addition–elimination. The sulfinyl group was proved to be the optimum leaving group by thorough investigations on the elimination of sulfide, sulfinyl, and sulfonyl groups at the 2-position of benzothiopyranone. Most 2-aminobenzothiopyranones were obtained in good to excellent yields under refluxing in isopropanol within 36 h. This method is base-free and the substrate scope in terms of electronic properties of the substituents of the benzothiopyranone is broad. The ten grams scale-up synthesis of the representative compounds 4a and 4d was implemented to show the practical application of this reaction, which afforded the corresponding compounds in good yields and excellent chemical purity without requiring column chromatographical purification.

Synthesis and pharmacological evaluation of novel arylpiperazine oxicams derivatives as potent analgesics without ulcerogenicity

Gastrotoxicity continues to be a major issue in therapy with nonsteroidal anti-inflammatory drugs (NSAIDs). Medicine is yet to develop absolutely safe analgesics. Numerous strategies are employed to discover new, safer NSAIDs, for example selective inhibition of cyclooxygenase-2, new molecular targets (e.g. microsomal prostaglandin E₂ synthase-1), incorporation of cytoprotective compounds in the drug molecule or modification of the classic NSAIDs currently available on the market. The research presented in this paper is indicative of a current worldwide trend in this area of science, and is an example of the fourth strategy noted above. Two series of new arylpiperazine derivatives of the classic NSAID - piroxicam, were developed by conventional synthesis. The full range of compounds obtained proved to be between two and five times analgesically more potent than the reference drug and, most importantly, they did not show any ulcerogenic activity.

MC19 (M = B, Si, Al and Ga) fullerenes: Adsorption mechanisms of 1,4-diformylpiperazine

Fullerenes and piperazines have been investigated, particularly, in the field of nanoscience and medicinal chemistry. In the present research, besides discussing structural and electronic properties, the most probable interaction mechanisms between C20, B-, Si-, Al-, Ga-doped C20 and 1,4-diformylpiperazine (1,4-dfp) were studied by employing density functional theory (DFT) in both the gas phase and water as the solvent. Stabilities of the investigated complexes were discussed based on the binding energy and electronic properties such as band gap energy, chemical hardness and electrophilicity index. It is found that doped complexes are more stabilized in water compared to the gas phase. However, the interaction between C20 and 1,4-dfp weakens upon the introduction of water as the solvent.

Absorption mechanism, structural and electronic properties of MC19 (M = B and Si) fullerenes with 1-acetylpiperazine

The interaction mechanisms of undoped, silicon- and boron-doped C20 fullerenes and 1-acetylpiperazine (1-ap) were investigated. Stability, electronic properties, influence of water on the solubility and stability, molecular parameters, descriptive vibrational bands and nuclear magnetic resonance shielding values are reported. The quantum mechanical calculations were carried out using the M06-2X functional and the 6-31G(d) basis set. It is observed that all the complexes are more stabilized in water compared to the gas phase. The most stable complex was found as silicon-doped fullerene interacting with the carbonyl edge of 1-ap releasing energy of 64.13 kcal/mol in water.

A novel piperazine linked β-amino alcohols bearing a benzosuberone scaffolds as anti-proliferative agents

A new series of 1-((9-chloro-2,3-dimethyl-6,7-dihydro-5H-benzo[7]annulen-8-yl)methoxy)-3-(4-phenylpiperzin-1-yl) propan-2-ols (6a-k) have been designed, synthesized and their structures were established by spectroscopic data (FT-IR, ¹H NMR, ¹³C NMR, HRMS) and further confirmed by X-ray analysis. The newly synthesized compounds 6a-k were evaluated for their in vitro anti-proliferative activity against four cancer cell lines such as HeLa (cervical), MDA-MB-231 (breast), A549 (lung) and MIAPACA (pancreatic). Among the compounds tested, the compound 6e displayed most potent activity against four cancer cell lines with GI₅₀ values ranging from 0.010 to 0.097μM. The structure and anti-proliferative activity relationship was further supported by in silico molecular docking study of the active compounds against Colchicine binding site of β-tubulin.

Synthesis of new pyrazolo[3,4-d]pyrimidine derivatives and evaluation of their anti-inflammatory and anticancer activities

This study reports the synthesis of two series of new purine bioisosteres comprising a pyrazolo[3,4-d]pyrimidine scaffold linked to piperazine moiety through different amide linkages. The newly synthesized compounds were evaluated for anticancer activity against four cell lines (MDA-MB-231, MCF-7, SF-268, B16F-10) and cyclooxygenase (COX-2) protein expression inhibition in lipopolysaccharide (LPS)-activated rat monocytes. The results revealed that most of the synthesized compounds showed moderate-to-high cytotoxic activity against at least one cell line, with compound 10b being the most active against all used cell lines (IC₅₀ values 5.5-11 μg/ml) comparable to cisplatin. In addition, six of these compounds (7b, 10a-d, and 12c) demonstrated inhibition of LPS-induced COX-2 protein expression at low concentration (25 μg/ml) as compared to the control non-stimulated cells and showed a COX-2 selectivity index range comparable to diclofenac sodium. The overall results indicate that many of these pyrazolopyrimidine derivatives possess in vitro anti-inflammatory and anticancer activities at varying doses, and the most active compounds will be subjected to in vivo pharmacological evaluation.

Synthesis of phenylpiperazine derivatives of 1,4-benzodioxan as selective COX-2 inhibitors and anti-inflammatory agents

1-((2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)methyl)-4-substituted-phenylpiperazine moiety was prepared and has been found to be a new and selective ligand for the enzyme cyclooxygenase-2 (COX-2). The biological activity of compound 3k as anti-inflammatory agent was further investigated both in vitro and in vivo. Notably, compound 3k exhibited the best anti-inflammatory activity among the eleven designed compounds with no toxicity, as determined by the ulcerogenic activity. Computational docking studies also showed that compound 3k has interaction with COX-2 key residues in the active site. Compound 3k maybe a new anti-inflammatory lead-candidate as powerful and novel non-ulcerogenic.

Hybrid molecules: The privileged scaffolds for various pharmaceuticals

The practice of polypharmacology is not a new concept but the approaches which are being adopted for administering the two or more drugs together are varied from time to time. Taking two or more drugs simultaneously, co-formulation of two or more active agents in a single tablet and development of hybrid molecular entities capable to modulate multiple targets are the three popular approaches for multidrug therapy. The simultaneous use of more than one drug for the chemotherapy of a single disease demands a lot of patient compliance. Hence the present form of polypharmacology is gaining popularity in the form of hybrid molecules (multiple ligand approach). From the last 1-2 decades, the synthesis of hybrid molecules by the combination of different biologically relevant moieties has been under constant escalation along with their evaluation as diverse range of pharmacological agents and as potent drugs. This review is focused on the biological potential of hybrid molecules with particular mention of those exhibiting anti-fungal, anti-tuberculosis, anti-malarial, anti-inflammatory and anti-cancer activities. A comparison of the drug potency of the hybrid molecules with their individual counterparts is discussed for quantifying the significance of the concept of molecular hybridisation.

A newly synthesized macakurzin C-derivative attenuates acute and chronic skin inflammation: The Nrf2/heme oxygenase signaling as a potential target

Impaired immune responses in skin play a pivotal role in the development and progression of chemical-associated inflammatory skin disorders. In this study, we synthesized new flavonoid derivatives from macakurzin C, and identified in vitro and in vivo efficacy of a potent anti-inflammatory flavonoid, Compound 14 (CPD 14), with its underlying mechanisms. In lipopolysaccharide (LPS)-stimulated murine macrophages and IFN-γ/TNF-α-stimulated human keratinocytes, CPD 14 significantly inhibited the release of inflammatory mediators including nitric oxide (NO), prostaglandins, and cytokines (IC50 for NO inhibition in macrophages: 4.61μM). Attenuated NF-κB signaling and activated Nrf2/HO-1 pathway were responsible for the anti-inflammatory effects of CPD 14. The in vivo relevance was examined in phorbol 12-myristate 13-acetate (TPA)-induced acute skin inflammation and oxazolone-induced atopic dermatitis models. Topically applied CPD 14 significantly protected both irritation- and sensitization-associated skin inflammation by suppressing the expression of inflammatory mediators. In summary, we demonstrated that a newly synthesized flavonoid, CPD 14, has potent inhibitory effects on skin inflammation, suggesting it is a potential therapeutic candidate to treat skin disorders associated with excessive inflammation.

Novel piperazine core compound induces death in human liver cancer cells: possible pharmacological properties

The current study evaluates the cytotoxic mechanism of a novel piperazine derivate designated as PCC against human liver cancer cells. In this context, human liver cancer cell lines, SNU-475 and 243, human monocyte/macrophage cell line, CRL-9855, and human B lymphocyte cell line, CCL-156, were used to determine the IC₅₀ of PCC using the standard MTT assay. PCC displayed a strong suppressive effect on SNU-475 and SNU-423 cells with an IC₅₀ value of 6.98 ± 0.11 μg/ml and 7.76 ± 0.45 μg/ml respectively, after 24 h of treatment. Significant dipping in the mitochondrial membrane potential and elevation in the released of cytochrome c from the mitochondria indicated the induction of the intrinsic apoptosis pathway by PCC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. PCC was also shown to activate the extrinsic pathways of apoptosis via activation of caspase-8 which is linked to the suppression of NF-ƙB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. This study suggests that PCC is a simultaneous inducer of intrinsic and extrinsic pathways of apoptosis in liver cancer cell lines.

Syntheses, biological activities and SAR studies of novel carboxamide compounds containing piperazine and arylsulfonyl moieties

A series of novel carboxamide compounds 19a-19j, 20a-20j and 22a-22d containing piperazine and arylsulfonyl moieties have been synthesized. The bioassay results showed that some compounds exhibited favorable herbicidal activities against dicotyledonous plants and many of them possessed excellent antifungal activities. Among 24 novel compounds, some showed superiority over the commercial fungicides Chlorothalonil, Dimethomorph, Thiophanate-methyl, Iprodione, and Zhongshengmycin at 500 mg/L concentration. Some compounds also exhibited high KARI inhibitory activity at 100 μg/mL concentration and could be used as new KARI lead inhibitors for further studies. Moreover, SAR of these new compounds were comprehensively investigated using different computational methods in which 3D-QSAR model obtained provided useful information for further structural optimization for the discovery of new fungicides. The results of this research will contribute to explore comprehensive biological activities of piperazine-containing compounds in different areas of chemistry.

Mechanism of action of novel piperazine containing a toxicant against human liver cancer cells

The purpose of this study was to assess the cytotoxic potential of a novel piperazine derivative (PCC) against human liver cancer cells. SNU-475 and 423 human liver cancer cell lines were used to determine the IC50 of PCC using the standard MTT assay. PCC displayed a strong suppressive effect on liver cancer cells with an IC50 value of 6.98 ± 0.11 µM and 7.76 ± 0.45 µM against SNU-475 and SNU-423 respectively after 24 h of treatment. Significant dipping in the mitochondrial membrane potential and elevation in the released of cytochrome c from the mitochondria indicated the induction of the intrinsic apoptosis pathway by PCC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. PCC was also shown to activate the extrinsic pathways of apoptosis via activation of caspase-8 which is linked to the suppression of NF-κB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. Results of this study suggest that PCC is a potent anti-cancer agent inducing both intrinsic and extrinsic pathways of apoptosis in liver cancer cell lines.

Combating Antimicrobial Resistance in Foodborne Microorganisms

This review addresses an important public health hazard affecting food safety. Antimicrobial agents are used in foods to reduce or eliminate microorganisms that cause disease. Many traditional organic compounds, novel synthetic organic agents, natural products, peptides, and proteins have been extensively studied for their effectiveness as antimicrobial agents against foodborne Campylobacter spp., Escherichia coli, Listeria spp. and Salmonella. However, antimicrobial resistance can develop in microorganisms, enhancing their ability to withstand the inhibiting or killing action of antimicrobial agents. Knowledge gaps still exist with regard to the actual chemical and microbiological mechanisms that must be identified to facilitate the search for new antimicrobial agents. Technical implementation of antimicrobial active packing films and coatings against target microorganisms must also be improved for extended product shelf life. Recent advances in antimicrobial susceptibility testing can provide researchers with new momentum to pursue their quest for a resistance panacea.

Design Synthesis and Biological Evaluation of NovelN-Nitro Acid Amide Derivatives as Lead Compounds of Herbicide

A series ofN-nitro acid amide derivatives compounds were synthesized based on the active site of target acetohydroxyacid synthase (AHAS, EC: 2.2.1.6) enzyme. All the structures of newly prepared compounds were thoroughly characterized by satisfied IR and1H NMR spectra. The IC50values against AHAS enzyme and EC50values for herbicidal activity againstAmaranthus mangostanus L.andSorghum sudanenseof all synthesized target compounds were determined. The compoundsII-10,II-21, andII-22with IC50values of 7.09 mg/L, 9.07 mg/L, and 9.11 mg/L and the compoundsII-8andII-22with EC50values of 9.87 mg/L and 19.88 mg/L against root ofAmaranthus mangostanus L.andSorghum sudanensewere illustrated, respectively. Meanwhile, the possible reasons for the lower activity of compounds were analyzed by molecular docking prediction.