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Fifty-eight curcumin analogues were prepared and evaluated for in vitro cytotoxicity against a panel of human tumor cell lines. Compound was the most potent analogue against several cell lines, including HOS (bone cancer) and 1A9 (breast cancer), with ED50 values of 0.97 and <0.63 μg/mL, respectively. [Copyright &y& Elsevier]

[Display omitted] • New bibenzyl comound 8Ae induced the apoptosis and simultaneously inhibited the glycolysis of A549 cells. • 8Ae reduce the hexokinase 2(HK2) activity and significantly down-regulated its level in mitochondria. • 8Ae induced mitochondria-mediated apoptosis via reducing MMP, increasing the Bax/Bcl-2 ratio and promoting Cyt c release. In this paper, we investigated the anticancer effect and the mechanism of our newly synthesized bibenzyl 8Ae against human lung cancer A549 cells. Compound 8Ae could induce apoptosis by inhibiting the glycolysis in A549 cells. Hexokinase 2 (HK2), the first key enzyme in glycolysis process, was significantly down-regulated by 8Ae. Besides, compound 8Ae induced HK2 dissociated from mitochondria to cytosol, which could be induced by inhibiting the phosphorylation of Akt. In addition, 8Ae could induce mitochondrial-mediated apoptosis, and mitochondrial membrane potential (MMP) was decreased. After 8Ae treatment, the Bax/Bcl-2 ratio was increased and cytochrome c (Cyt c) was release from mitochondria to cytosol. Molecular docking indicated that 8Ae have an interaction with HK2 by extending into acitve pockets of the protein to form stable hydrogen bonds. Additionally, 8Ae had significantly improved pharmacokinetic properties through the prediction, comparison, and analysis of the ADMET properties of 8Ae and moscatilin (MST). Taken together, 8Ae might inhibit glycolysis by stimulating the shedding of HK2 from mitochondria and promoting mitochondria-regulated apoptosis to inhibit the proliferation of A549 cells. This article provides a research basis for bibenzyl compounds as new small molecule drugs for lung cancer. [ABSTRACT FROM AUTHOR]

The current review highlighted the recent developments of small molecules identified and developed as potential molecular pharmacophore targeting Amloid beta (Aβ) protein, tau protein AChE and BuChE, as a target for treatment of Alzheimer's disease. This review mostly included those research papers appeared during 2019–2024 and focusing on above targets. This provides some insight into the structural and molecular scaffolds essential for developments of new Alzheimer's drugs. [Display omitted] Amyloid beta peptide (Aβ) and hyperphosphorylated neuronal tau proteins accumulate in neurofibrillary tangles in Alzheimer's disease (AD), a chronic neurodegenerative illness. Chronic inflammation in the brain, which promotes disease progression, is another feature of the Alzheimer's disease pathogenesis. Approximately 60–70 % of dementia cases are caused by AD. The development of effective therapies for the treatment of AD is urgently needed given the severity of the condition and its rapidly rising prevalence. Cholinesterase inhibitors, beta-amyloid (A-beta), tau inhibitors, and many other medications are currently used as preventive medicine for AD. These medications can temporarily suppress dementia symptoms but cannot halt or reverse the disease's progression. Many international pharmaceutical companies have tried numerous times to develop an amyloid clearing medication based on the amyloid hypothesis, but without success. Therefore, the amyloid theory may not be entirely plausible. This review mainly covers the recent and important reported pharmacophores as the starting point to discuss already known targets like tau, butyrylcholinesterase, amyloid beta, and acetylcholinesterase and covers the literature between years 2019–2024. [ABSTRACT FROM AUTHOR]

[Display omitted] Berberine is a quaternary ammonium isoquinoline alkaloid derived from traditional Chinese medicines Coptis chinensis and Phellodendron chinense. It has many pharmacological activities such as hypoglycemic, hypolipidemic, anti-tumor, antimicrobial and anti-inflammatory. Through structural modifications at various sites of berberine, the introduction of different groups can change berberine's physical and chemical properties, thereby improving the biological activity and clinical efficacy, and expanding the scope of application. This paper reviews the research progress and structure–activity relationships of berberine in recent years, aiming to provide valuable insights for the exploration of novel berberine derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] • Anthraquinone derivatives containing substituted with donor electrons bisbenzyloxy groups can further enhance ERS. • Compound KA-MO-g damaged ER, resulting in dysfunction and inadequate synthesis of glycoproteins and disulfides. • Compound KA-MO-g killed liver cancer cells mainly through damaged endoplasmic reticulum then inducing apoptosis. This paper reports the antitumor activity and possible mechanism of anthraquinone derivatives containing substituted bisbenzyloxy groups. Series of anthraquinone derivatives containing substituted bisbenzyloxy groups were designed and synthesized by etherification and esterification. The antitumor activities of the synthesized substituted bisbenzyloxy anthraquinone derivatives on liver cancer cell Huh7, triple negative breast cancer cell line MDA-MB-231 and lung cancer cell A549 were in the order of methoxy substitution > methyl substitution > chloral substitution. Among these, the Compound KA-MO-g showed strong antitumor activity, especially against liver cancer Huh7 cells. Further studies on the antitumor mechanism showed that the Compound KA-MO-g simultaneously activated three pathways of endoplasmic reticulum stress (ERS), also caused impairment of endoplasmic reticulum (ER) functions, such as glycoprotein synthesis and disulfide bond formation are impeded and caused calcium overload, then increased mitochondrial ROS, damaged of mitochondria, changed of apoptosis-related protein levels, activated Caspase 3, induced the apoptosis of Huh7 cells. Because KA-MO-g showed strong antitumor activity, it is expected to be a new candidate drug for treating liver cancer and is worth further study. [ABSTRACT FROM AUTHOR]

Potent and selective inhibitors for phospholipases A2 (PLA2) are useful for studying their intracellular functions. PLA2 enzymes liberate arachidonic acid from phospholipids activating eicosanoid pathways that involve cyclooxygenase (COX) and lipoxygenase (LOX) leading to inflammation. Anti-inflammatory drugs target COX and LOX; thus, PLA2 can also be targeted to diminish inflammation at an earlier stage in the process. This paper describes the employment of enzymatic assays, hydrogen/deuterium exchange mass spectrometry (DXMS) and computational chemistry to develop PLA2 inhibitors. Beta-thioether trifluoromethylketones (TFKs) were screened against human GVIA calcium-independent, GIVA cytosolic and GV secreted PLA2s. These compounds exhibited inhibition toward Group VIA calcium-independent PLA2 (GVIA iPLA2), with the most potent and selective inhibitor 3 (OTFP) obtaining an XI(50) of 0.0002 mole fraction (IC50 of 110nM). DXMS binding experiments in the presence of OTFP revealed the peptide regions of GVIA iPLA2 that interact with the inhibitor. Molecular docking and dynamics simulations in the presence of a membrane were guided by the DXMS data in order to identify the binding mode of OTFP. Clustering analysis showed the binding mode of OTFP that occupied 70% of the binding modes occurring during the simulation. The resulted 3D complex was used for docking studies and a structure-activity relationship (SAR) was established. This paper describes a novel multidisciplinary approach in which a 3D complex of GVIA iPLA2 with an inhibitor is reported and validated by experimental data. The SAR showed that the sulfur atom is vital for the potency of beta-thioether analogues, while the hydrophobic chain is important for selectivity. This work constitutes the foundation for further design, synthesis and inhibition studies in order to develop new beta-thioether analogues that are potent and selective for GVIA iPLA2 exclusively.

[Display omitted] • Synthesis of triazole- and ureido-type harmiprims, harmine and primaquine hybrids. • Antiproliferative screening identified ureido-type harmiprime 19 as the most active compound against all human cell lines. • Bis-harmiprime 15 exerts powerful triple-stage antiplasmodial activity. • Computational analysis shows binding of harmiprime 15 to Pf Hsp90. Although cancer and malaria are not etiologically nor pathophysiologically connected, due to their similarities successful repurposing of antimalarial drugs for cancer and vice-versa is known and used in clinical settings and drug research and discovery. With the growing resistance of cancer cells and Plasmodium to the known drugs, there is an urgent need to discover new chemotypes and enrich anticancer and antimalarial drug portfolios. In this paper, we present the design and synthesis of harmiprims, hybrids composed of harmine, an alkaloid of the β-carboline type bearing anticancer and antiplasmodial activities, and primaquine, 8-aminoquinoline antimalarial drug with low antiproliferative activity, covalently bound via triazole or urea. Evaluation of their antiproliferative activities in vitro revealed that N-9 substituted triazole-type harmiprime was the most selective compound against MCF-7, whereas C1-substituted ureido-type hybrid was the most active compound against all cell lines tested. On the other hand, dimeric harmiprime was not toxic at all. Although spectrophotometric studies and thermal denaturation experiments indicated binding of harmiprims to the ds-DNA groove, cell localization showed that harmiprims do not enter cell nucleus nor mitochondria, thus no inhibition of DNA-related processes can be expected. Cell cycle analysis revealed that C1-substituted ureido-type hybrid induced a G1 arrest and reduced the number of cells in the S phase after 24 h, persisting at 48 h, albeit with a less significant increase in G1, possibly due to adaptive cellular responses. In contrast, N-9 substituted triazole-type harmiprime exhibited less pronounced effects on the cell cycle, particularly after 48 h, which is consistent with its moderate activity against the MCF-7 cell line. On the other hand, screening of their antiplasmodial activities against the erythrocytic, hepatic, and gametocytic stages of the Plasmodium life cycle showed that dimeric harmiprime exerts powerful triple-stage antiplasmodial activity, while computational analysis showed its binding within the ATP binding site of Pf Hsp90. [ABSTRACT FROM AUTHOR]

This comprehensive review delves into the intricate world of the Quinoline scaffold, unravelling its pivotal role as a molecular cornerstone in the relentless battle against cancer, poised to emerge as an indispensable pharmacophore in the forefront of cutting-edge drug development. [Display omitted] • Mechanisms of Quinoline Anticancer Action. • Therapeutic Promise & Implications. • Quinoline-Based Compounds Review. This article includes a thorough examination of the inhibitory potential of quinoline-based drugs on cancer cells, as well as an explanation of their modes of action. Quinoline derivatives, due to their various chemical structures and biological activity, have emerged as interesting candidates in the search for new anticancer drugs. The review paper delves into the numerous effects of quinoline-based chemicals in cancer progression, including apoptosis induction, cell cycle modification, and interference with tumor-growth signaling pathways. Mechanistic insights on quinoline derivative interactions with biological targets enlightens their therapeutic potential. However, obstacles such as poor bioavailability, possible off-target effects, and resistance mechanisms make it difficult to get these molecules from benchside to bedside. Addressing these difficulties might be critical for realizing the full therapeutic potential of quinoline-based drugs in cancer treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] Aromatic rings are critical core substructures in the majority of pharmaceutical compounds. There is much recent interest in replacing aromatic structures with saturated bioisosteres of benzene, which are generally fused or bridged ring systems. These bioisosteres often show improved solubility properties compared to benzene, and may also undergo fewer unwanted metabolic processes. One key reason why aromatic rings have proven so successful in drug design is their rigidity. This paper uses molecular dynamics simulations supported by crystallographic data to assess the rigidity of bicyclopentane and cubane ring systems as two of the most common benzene bioisosteres and compares this to benzene. Whilst a benzene ring is shown to be more flexible than these two bioisosteres in terms of its dihedral ring flexibility, substituents around the ring tend to behave in a much more similar way in both benzene and the bioisosteric systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Discussion on hypothesis involved in the pathophysiological of Alzheimer's disease. • This paper highlighted role of BACE-1 in generation of Alzheimer's disease. • Co-crystal structures of BACE-1 with inhibitors are discussed and tabulated. • BACE-1 inhibitors in the clinical trials are tabulated. • SAR of guanidine-containing BACE-1 inhibitors with chemical features is summarized. Alzheimer's disease (AD) is an irreversible, progressive neurological disorder characterized by amyloid plaques, hyperphosphorylated tau protein (hyper p-tau), neuronal damage, memory loss, etc. Various factors, such as age, lifestyle, family history, environmental factors, and gene mutation, cause AD. BACE-1 is an interesting target to prevent or reverse AD progression. BACE-1 cleaves amyloid precursor protein (APP) into soluble amyloid precursor protein β (sAPPβ) and membrane-bound C-terminal fragment called C99, a rate-limiting step, and C99 is further cleaved by gamma-secretase to generate neurotoxic amyloid β (Aβ). Discovery and development of selective β amyloid precursor protein cleavage enzyme 1 (BACE-1) inhibitors have a great potential for the treatment and maintenance of Alzheimer's disease. In this review, we have compiled literature pertaining to guanidine-based novel BACE-1 inhibitors for the treatment and maintenance of AD. We have also discussed role of BACE-1 substrates, and its crystal structure, BACE-1 inhibitors in the clinical trial, and essential points to overcome challenges associated with selective development of BACE-1 inhibitors. This paper provides valuable information for the design and discovery of selective new BACE-1 inhibitors against other aspartyl protease enzymes to treat AD. [ABSTRACT FROM AUTHOR]

[Display omitted] • Passerini-3CR and Ugi-4CR proved to be an effective strategy for constructing multifunctional anti-AD agents. • Target compounds could be multifunctional anti-AD agents based on oxidative stress processes. • A3B3C1 exhibited versatility in antioxidant, Aβ 1-42 reduction and neuroprotection, which is deserve further development. As Alzheimer's disease (AD) is a neurodegenerative disease with a complex pathogenesis, the exploration of multi-target drugs may be an effective strategy for AD treatment. Multifunctional small molecular agents can be obtained by connecting two or more active drugs or privileged pharmacophores by multicomponent reactions (MCRs). In this paper, two series of polysubstituted pyrazine derivatives with multifunctional moieties were designed as anti-AD agents and synthesized by Passerini-3CR and Ugi-4CR. Since the oxidative stress plays an important role in the pathological process of AD, the antioxidant activities of the newly synthesized compounds were first evaluated. Subsequently, selected active compounds were further screened in a series of AD-related bioassays, including Aβ 1-42 self-aggregation and deaggregation, BACE-1 inhibition, metal chelation, and protection of SH-SY5Y cells from H 2 O 2 -induced oxidative damage. Compound A3B3C1 represented the best one with multifunctional potencies. Mechanism study showed that A3B3C1 acted on Nrf2/ARE signaling pathway, thus increasing the expression of related antioxidant proteins NQO1 and HO-1 to normal cell level. Furthermore, A3B3C1 showed good in vitro human plasma and liver microsome stability, indicating a potential for further development as multifunctional anti-AD agent. [ABSTRACT FROM AUTHOR]

Abstract: Caffeine (CAF) and other methylxanthines (MTX) may interact directly with several aromatic, intercalating ligands through mixed stacking aggregation. Formation of such stacking hetero-complexes may decrease their free form concentration and, in consequence, diminish their biological activity, which is often related to their direct interaction with DNA. In this paper interactions of acridine mutagen (ICR191) with DNA in the presence of three MTX: caffeine (CAF), pentoxifylline (PTX) and theophylline (TH) are investigated. Several mathematical models are used to calculate all association constant values and every component concentration in each analyzed mixture. Model McGhee–von Hippel is used to analyze ligand–DNA interaction, and model Zdunek et al.—to analyze ligand–MTX interactions. Finally, two distinct mathematical models are employed to analyze three-component mixture containing ligand, MTX and DNA molecules. The first model describes possible interactions of ligand with DNA and MTX, and rejects direct MTX interactions with DNA. The second model describes all interactions mentioned above and, additionally, allows MTX to interact directly with DNA. Results obtained using these models are similar. However, correspondence of theoretical results to experimental data is better for the first model than the second one. In this paper possible interactions of ICR191 with eukaryotic cell chromatin are also analyzed, showing that CAF reduces acridine mutagen potential to interact directly with cell chromatin. Additionally, it is demonstrated that MTX inhibit mutagenic activity of ICR191 in a dose-dependent manner. Furthermore, biological activity of ICR191–MTX mixtures corresponds with concentration of free mutagen form calculated using appropriate mathematical model. [Copyright &y& Elsevier]

Abstract: This paper describes our recent efforts to design and synthesise potent and selective PDE5 inhibitors and the use of in vitro predictors of clearance, absorption and permeability to maximise the potential for dose-proportional pharmacokinetics and good oral bioavailability in man. Optimisation of the preclinical profile resulted in the identification of UK-369003 (19a) and its nomination as a clinical candidate. The clinical pharmacokinetic and safety profile has enabled us to progress the compound to test its efficacy in patients with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) and a paper describing its efficacy has recently been published. [Copyright &y& Elsevier]

• Pyrrolo[3,4- c ]pyrrole derivatives were synthesized and their COX-1/COX-2 inhibition activities were evaluated. • All compounds exhibited higher analgesic activity than the reference drug. • The new pyrrolo[3,4- c ]pyrroles were not toxic (LD 50 ≥ 2000 mg/kg). • Three of the compounds may be promising inhibitors of COX-2. In the present paper we describe the biological activity of newly designed and synthesized series of pyrrolo[3,4- c ]pyrrole Mannich bases (7a - n). The Mannich bases were obtained in good yields by one-pot, three-component condensation of pyrrolo[3,4– c ]pyrrole scaffold (6a - c) with secondary amines and an excess of formaldehyde solution in C 2 H 5 OH. The chemical structures of the compounds were characterized by 1H NMR, 13C NMR, FT-IR, and elemental analysis. Moreover, single crystal X-ray diffraction has been recorded for compound 7l. All synthesized derivatives were investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. In order to analyse the intermolecular interactions between the ligands and cyclooxygenase, experimental data were supported with the results of molecular docking simulations. According to the results, all of the tested compounds inhibited the activity of COX-1 and COX-2. [ABSTRACT FROM AUTHOR]

Although active targeting liposomes with cancer-specific ligands can bind and internalize into cancer cells, only a few high-efficiency liposomes have been developed so far because traditional single branched ligand modified liposomes generally failed to deliver adequate therapeutic payload. In this paper, we broke the traditional design concept and synthesized the double branched biotin modified cholesterol (Bio 2 -Chol) for the first time. On this basis, different biotin density modified liposomes ((Bio-Chol)Lip, (Bio-Chol) 2 Lip and (Bio 2 -Chol)Lip) were successfully prepared and used as active targeting drug delivery systems for the treatment of breast cancer. The in vitro and in vivo breast cancer-targeting ability of these liposomes were systemically studied using paclitaxel (PTX) as the model drug. And the uptake mechanism of (Bio 2 -Chol)Lip was investigated. The results showed that (Bio 2 -Chol)Lip had the best breast cancer-targeting ability compared with naked paclitaxel, unmodified Lip, (Bio-Chol)Lip and (Bio-Chol) 2 Lip. In particular, the relative uptake efficiency (RE) and concentration efficiency (CE) of (Bio 2 -Chol)Lip were respectively enhanced by 5.61- and 5.06-fold compared to that of naked paclitaxel. Both distribution data and pharmacokinetic parameters suggested that the double branched biotin modified liposome ((Bio 2 -Chol)Lip) is a very promising drug delivery carrier for breast cancer. [ABSTRACT FROM AUTHOR]

In this paper we will outline the efforts we have made recently to establish the profiling platform known as cell painting in our laboratory. This platform, which is based on fluorescence microscopy, allows rapid and cheap access to bioactivity fingerprints for small molecules and thereby can contribute with important information in many experimental situations that is faced in laboratories involved in molecular probe design, mode-of-action studies or that perform focused phenotypic screens. We have tried to achieve the following two objectives: (1) provide a detailed description of the hurdles that we had to overcome during establishment and describe our final protocol; (2) provide a more pedagogical description of the different methods used to analyse and represent data from this experiment. Finally, we provide an example of how the method can be used to clarify mechanistic dichotomies. [ABSTRACT FROM AUTHOR]

Plasmodium vivax (Pv) is the second most malaria causing pathogen among Plasmodium species. M18 aspartic aminopeptidase (M18AAP) protein is a single gene copy present in Plasmodium. This protein is functional at the terminal stage of hemoglobin degradation of host and completes the hydrolysis process which makes it an important target for new chemotherapeutics. No experimental and structural study on M18AAP protein of P. vivax is reported till today. This paper advocates the application of multiple computational approaches like protein model prediction, ligand-based 3D QSAR study, pharmacophore, structure-based virtual screening and molecular docking simulation for identification of potent lead molecules against the enzyme. The 3D QSAR model was developed using known bioactive compounds against the PvM18AAP protein which statistically signify the k-NN model with q^2 = 0.7654. The study reports a lead molecule from ligand-centric approach with good binding affinity and possessing lowest docking score. The findings will be helpful for in-vivo and in-vitro validations and development of potent anti-malarial molecules against the drug resistant strains of malaria parasite. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis of a new series of α-aminophosphonates derivatives based in an efficient three-component reaction. All compounds prepared showed significant anti-inflammatory activity, being the compounds 1a , 1c, 1d , 1f , 2b and 2c the most promising ones, in terms of maximal efficacy (over 95%), potency (ED 50 range between 0.7 and 10.1 mg/ear) and relative potency (range from 0.04 to 0.67). Compounds 1a , 1c , 1d and 1f significantly decrease the number of neutrophils (range from 46.7 to 63.0%) and monocytes (18.9–34.1%) in blood samples from the orbital sinus. Additionally, QSAR model revealed that the spherical molecular shape and the location of the HOMO on the phenyl ring improves the anti-inflammatory activity of the compounds. The values of R 2, Q 2, s and F statistical parameters and the QUIK, asymptotic Q 2 and Overfitting rules validate the descriptive and predictive ability of the QSAR model. Altogether these results suggest that these new α-aminophosphonates are potential agents for the treatment of inflammation. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Bleomycin is considered to exert its antitumor activity via DNA cleavage mediated by activated oxygen generated from the iron complex in its chelator moiety. Spin-offs from this moiety, HPH-1Trt and HPH-2Trt, with anti-cancer activities were recently synthesized. In this paper, we developed inhibitors of nicotinamide adenine dinucleotide-dependent deacetylase isoform 2 of Sirtuin protein (SIRT2), based on HPH-1Trt/HPH-2Trt, and aimed to generate new anti-cancer drugs. HPH-1Trt and HPH-2Trt had in vitro anti-SIRT2 inhibitory activity with 50% inhibitory concentration (IC 50) values of 5.5 and 8.8 μM, respectively. A structural portion of HPH-1Trt/HPH-2Trt, a tritylhistidine derivative TH-1, had stronger activity (IC 50 = 1.7 μM), and thus, fourteen derivatives of TH-1 were synthesized. Among them, TH-3 had the strongest activity (IC 50 = 1.3 μM). Selective binding of TH-3 in the pocket of SIRT2 protein was confirmed with a molecular docking study. Furthermore, TH-3 strongly lowered viability of the breast cancer cell line MCF7 with an IC 50 of 0.71 μM. A structure-activity relationship study using cell lines suggested that the mechanism of TH-3 to suppress MCF7 cells involves not only SIRT2 inhibition, but also another function. This compound may be a new candidate anti-cancer drug. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Songorine isolated from Aconitum brachypodum Diels possesses prominent activity of inhibiting G protein-coupled receptors (GPCRs) in the early screening process. In this paper, a series of Songorine derivatives were synthesized and their inhibitory activities on GPCRs were also evaluated by using the Double Antibody Sandwich ELISA (DAS-ELISA) in vitro. Among them, three derivatives (3a , 4 , 7) exhibited significant inhibitory activity against GPCRs with IC 50 values of 0.08–0.29 nM. Moreover, the structure-activity relationships (SARs) of songorine derivatives were discussed in detail. They have great potentials as novel GPCRs antagonists in the future. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New arylpiperazine oxicams derivatives were designed and synthesized. • Compounds obtained proved to be between two and five times analgesically more potent than the reference drug piroxicam. • New derivatives did not show any ulcerogenic activity. Abstract 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 E 2 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. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Class C β-lactamases have previously been shown to be efficiently inactivated by O-aryloxycarbonyl hydroxamates. O-Phenoxycarbonyl- N -benzyloxycarbonylhydroxylamine (1) and O-phenoxycarbonyl-N-(R)-[(4-amino-4-carboxy-1-butyl)oxycarbonyl]hydroxylamine (2), for example, were found to be effective inactivators. The present paper describes a structure-activity study of these molecules to better define the important structural elements for high inhibitory activity. The results show that a well-positioned hydrophobic element (which may interact with the Tyr221 residue of the enzyme) and a negatively charged element, e.g. a carboxylate group (which may interact with Arg204), are required for high reactivity with the enzyme. The new compounds were found to inactivate by forming a carbonyl cross-linked enzyme (probably Ser64OCONHLys 315) as for 1 rather than the inert hydroxamoyl derivative observed with 2. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Myostatin is a negative regulator of skeletal muscle growth and myostatin inhibitors are promising lead compounds against muscle atrophic disorders such as muscular dystrophy. Previously, we published the first report of synthetic myostatin inhibitory 23-mer peptide 1 , which was identified from a myostatin precursor-derived prodomain protein. Our structure-activity relationship study afforded the potent inhibitory peptide 3. In this paper, we report an investigation of the synthesis of conformationally-constrained cyclic peptide based on the linear peptide 3. To examine the potency of side chain-to-side chain cyclized peptides, a series of disulfide-, lactam- and diester-bridged derivatives were designed and synthesized, and their myostatin inhibitory activities were evaluated. The diester-bridged peptide (11) displayed potent inhibitory activity with an in vitro IC 50 value of 0.26 µM, suggesting that it could serve as a new platform for development of cyclic peptide inhibitors. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Twenty-five new compounds were designed and synthesized. • BRD9 inhibitory activities of compounds were evaluated by AlphaScreen assay. • We evaluated the anti-proliferation activities in A549 and EOL-1 cells. Abstract BRD9 is the subunit of mammalian SWI / SNF chromatin remodeling complex (BAF). SWI / SNF complex mutations were found in nearly 20% of human cancers. The biological role played by BRD9 bromodomain remains poorly understood, and it is therefore imperative to identify potent and highly selective inhibitors to effectively explore the biology of individual bromodomain proteins. In this paper, we synthesized a series of imidazo[1,5- a ]pyrazin-8(7 H)-one derivatives as potent BRD9 inhibitors and evaluated their BRD9 inhibitory activity in vitro and anti-proliferation effects against tumor cells. Gratifyingly, compound 27 and 29 exhibited robust potency of BRD9 inhibition with IC 50 values of 35 and 103 nM respectively. Docking studies were performed to explain the structure-activity relationship. Furthermore, compound 27 potently inhibited cell proliferation in cell lines A549 and EOL-1 with an IC 50 value of 6.12 μM and 1.76 μM respectively. The chemical probe, compound 27 , was identified that should prove to be useful in further exploring BRD9 bromodomain biology in both in vitro and in vivo settings. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the synthesis of new derivatives (formed by two indole systems separated by a central moiety) analogous of potent antitumor agents previously described. The activity of the bis-indoles bearing a pyridine core confirms the good result described in the previous paper and compound 4c was chosen for the first in vivo experiment (Hollow Fiber Assay). COMPARE analysis and structure–activity relationships were also considered. Contrary to data reported by other Authors, no correlations were found between antitumor activity and NQO1 induction. [Copyright &y& Elsevier]

Abstract: AmpC β-lactamase is one of the leading causes of Pseudomonas aeruginosa (P. aeruginosa) resistance to cephalosporins. FR259647 is a cephalosporin having a novel pyrazolium substituent at the 3-position and exhibits excellent activity (MIC=1μg/mL) against the AmpC β-lactamase overproducing P. aeruginosa FP1380 strain in comparison with the third-generation cephalosporins FK518 [Abstracts of Papers, 30th Interscience Conference on Antimicrobial Agents and Chemotherapy, Atlanta, GA, October 21–24, 1990, Abs. 454; Abstracts of Papers, 30th Interscience Conference on Antimicrobial Agents and Chemotherapy, Atlanta, GA, October 21–24, 1990, Abs. 455; Abstracts of Papers, 30th Interscience Conference on Antimicrobial Agents and Chemotherapy, Atlanta, GA, October 21–24, 1990, Abs. 456; Abstracts of Papers, 30th Interscience Conference on Antimicrobial Agents and Chemotherapy, Atlanta, GA, October 21–24, 1990, Abs. 457] (MIC=16μg/mL) and ceftazidime (CAZ) (MIC=128μg/mL). The stability of FR259647 and FK518 to AmpC β-lactamase was evaluated using MIC assays against both the P. aeruginosa PAO1 strain and a PAO1 mutant strain overproducing AmpC β-lactamase as a differential assay, which indicates that the main difference derives from their stability to AmpC β-lactamase. A structural analysis using computer simulations indicated that the difference in stability may be due to steric hindrance of the 3-position substituents causing differential affinity. This steric hindrance may disturb entry of the cephalosporins into the binding pocket. We predicted the possibility of inhibition of entry as a potential means of enhancing stability by conformational analysis. In order to validate this speculation, novel FR259647 derivatives 4–9 were designed, calculated, synthesized, and evaluated. As a result, we demonstrated that their probability of entry correlated with the MIC ratio of the mutant strain to the parent strain and supports the validity of our model. [Copyright &y& Elsevier]

Abstract: β-Lactamases are serine- and metal-dependent hydrolases, produced by the bacteria as defense against β-lactam antibiotics. Commercially available inhibitors such as clavulanic acid, sulbactam, and tazobactam, which are currently used in the hospital settings, have reduced activity against newly emerging β-lactamases. Bacterial production of diverse β-lactamases including class-A, class-C, and ESBLs has motivated several research groups to search for inhibitors with a broader spectrum of activity. Previously, several novel 6-methylidene penems bearing, [5,5] [5,6] and [5,5,5] heterocycles have been synthesized in our laboratory and were shown to be potent and broad-spectrum β-lactamase inhibitors. As a continuation of our previous work and in order to extend the structure–activity relationships, in this paper, we describe herein the synthesis and in vitro, in vivo activities of several novel 5,5,6-fused tricyclic heterocycles attached to the 6-methylidene penem core. The compounds presented in the current paper are potent and broad-spectrum inhibitors of the TEM-1 and AmpC β-lactamases. In combination with piperacillin, their in vitro activities showed enhanced susceptibility to class A- and C-resistant strains studied in various bacteria. Some of the newly synthesized compounds such as 12a–c were shown to have in vivo activity in the acute lethal infection model against TEM-1 producing organisms. The 5,5,6-fused heterocyclic ring cores such as 21, 25, and 35 reported here are hitherto unknown in the literature. [Copyright &y& Elsevier]

Abstract: UCH-L3 (ubiquitin C-terminal hydrolase-L3) is a de-ubiquitinating enzyme that is a component of the ubiquitin–proteasome system and known to be involved in programmed cell death. A previous study of high-throughput drug screening identified an isatin derivative as a UCH-L3 inhibitor. In this study, we attempted to identify a novel inhibitor with a different structural basis. We performed in silico structure-based drug design (SBDD) using human UCH-L3 crystal structure data (PDB code; 1XD3) and the virtual compound library (ChemBridge CNS-Set), which includes 32,799 chemicals. By a two-step virtual screening method using DOCK software (first screening) and GOLD software (second screening), we identified 10 compounds with GOLD scores of over 60. To address whether these compounds exhibit an inhibitory effect on the de-ubiquitinating activity of UCH-L3, we performed an enzymatic assay using ubiquitin-7-amido-4-methylcoumarin (Ub-AMC) as the substrate. As a result, we identified three compounds with similar basic dihydro-pyrrole skeletons as UCH-L3 inhibitors. These novel compounds may be useful for the research of UCH-L3 function, and in drug development for UCH-L3-associated diseases. [Copyright &y& Elsevier]

Abstract: B-Cell lymphoma-2 (Bcl-2) protein is a new promising target for anticancer drugs. A number of anticancer Bcl-2 inhibitors with diverse chemical structures have been discovered in recent years. In this paper, the flexible docking was performed to determine the binding modes of the representative inhibitors from different structural types. Subsequently, the binding modes of inhibitor were used to construct a primary three- dimensional (3D) pharmacophore model. It proved that this model can effectively disrupt the binding of the BH3 domain of proapoptotic Bcl-2 family members to Bcl-2, and match the structural requirement of a new type of Bcl-2 inhibitors. However, these distances between pharmacophoric points are not optimal due to the fact that not all of individual functional groups are located in the ideal position when inhibitors bind to its receptor. In this paper, we proposed a new idea to improve the quality of the pharmacophore model: the multiple copy simultaneous search (MCSS) method was performed to determine the energetically favorable distribution of functional groups with similar features to these pharmacophoric points in the active site of Bcl-2 first. Then their most energetically favorable minima in the positions near the pharmacophoric points were used to optimize the distances between pharmacophoric points. By examining the binding modes of several inhibitors from the same structural type, it was found that the more potent the inhibitor was, the closer it was to the optimized distances between pharmacophoric points. The optimized 3D pharmacophore model obtained in this paper may provide a good starting point for further rational design of Bcl-2 inhibitors. [Copyright &y& Elsevier]

Abstract: A series of novel substituted 1-[bis(4-fluorophenyl)-methyl]piperazine derivatives (4a–g) and (5h–m) have been synthesized. The synthesized compounds were characterized by IR and 1H NMR. All the synthesized compounds were evaluated in vitro for their efficacy as antimicrobial agents against representative strains of Gram-positive (Staphylococcus aureus ATCC 25953, Streptococcus pneumoniae ATCC 49619, Bacillus cereus 11778, and Bacillus subtilis 6051) and Gram-negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 2853, Proteus vulgaris ATCC 2853, and Salmonella typhi ATCC 9484) by paper disc diffusion and microdilution methods. Among the newly synthesized compounds 4e, 5l, and 5m showed potent antimicrobial activities, when compared to the standard drug. [Copyright &y& Elsevier]

In an effort to find novel semisynthetic macrolides with extended antibacterial spectrum and improved activity we prepared a series of compounds based on commercially available clarithromycin, a potent and safe antimicrobial agent of outstanding clinical and commercial interest. According to the literature, improvement of antibacterial activity of erythromycin type antibiotics can be achieved by introduction of fused heterocycles such as cyclic carbonates or carbamates at positions 11 and 12 (such as in telithromycin). In the course of the work presented here, a similar, hitherto unprecedented set of compounds bearing a five-membered lactone ring fused to positions 11 and 12 was prepared based on carbon–carbon bond formation via intramolecular Michael addition of a [(hetero)arylalkylthio]acetic acid ester enolate to an α,β-unsaturated ketone as the key step. Some of the ketolide compounds described in this paper were highly active against a representative set of erythromycin sensitive and erythromycin resistant test strains. The best compound showed a similar antimicrobial spectrum and comparable activity in vitro as well as in vivo as telithromycin. Furthermore, some physicochemical properties of these compounds were determined and are presented here. On the basis of these results, the novel ketolide lactones presented in this paper emerged as valuable lead compounds with comparable properties as the commercial ketolide antibacterial telithromycin (KetekTM). [Copyright &y& Elsevier]

In previous papers (Colotta, V. et al. Arch. Pharm. Pharm. Med. Chem. 1999, 332, 39. Colotta, V. et al. J. Med. Chem. 2000, 43, 1158) we reported the synthesis and binding affinity at bovine (b) A1 and A2A and human (h) A3 adenosine receptors (ARs) of the 4-amino-6-benzylamino-2-phenyl-1,2,4-triazolo[4,3-a]quinoxalin-1-one (compound A) which resulted in a potent and selective A2A AR antagonist. Compound A provided the lead compound of a series of 6- or 8-(hetero)arylalkylamino-4-amino-2-phenyl-1,2,4-triazolo[4,3-a]quinoxalin-1-one derivatives (compounds 1–20) which are the object of this paper. Most of the newly synthesized compounds are inactive at hA3 ARs while they possess both nanomolar bA2A affinities and different degrees of bA2A versus bA1 selectivity. The binding data show that hydrophilic substituents on the benzyl moiety are the most profitable for bA2A receptor affinity. Furthermore, their steric hindrance seems to play an important role for the bA2A AR interaction, thus suggesting that the 6-aralkylamino moiety of these ligands interacts with a size-limited binding pocket of this AR subtype. Thus, the SAR studies provided us some new insights about the structural requirements of the bA2A AR recognition site. [Copyright &y& Elsevier]

In a previous paper (Colotta V. et al., J. Med. Chem. 2000, 43, 1158), we reported the synthesis and the binding activity of some 4-oxo (A) and 4-amino (B) substituted 1,2,4-triazolo[4,3-a]quinoxalin-1-ones, bearing different substituents on the appended 2-phenyl ring (region 1), some of which were potent and selective A1 or A3 antagonists. To further investigate the SAR in this class of antagonists, in the present paper some 2-phenyl-1,2,4-triazolo[4,3-a]quinoxalin-1-one derivatives of both series A and B, bearing simple substituents on the benzofused moiety (region 2), are reported. The binding data at bovine A1 (bA1) and A2A(bA2A) and at human A3 (hA3) adenosine receptors (ARs) show that in series A (compounds 1, 4–11) the presence of substituents on the benzofused moiety is, in general, not advantageous for anchoring at all three AR subtypes, while within series B (compounds 12–21) it exerts a beneficial effect for both bA1 and hA3 AR affinities which span the low nanomolar range. In particular, among the 4-amino derivatives 12–21, the 8-chloro-6-nitro (compound 17) and the 6-nitro (compound 18) substitutions afford, respectively, the highest bA1 and hA3 AR affinity. Moreover, compound 18, additionally investigated in binding assays at human A1 (hA1) receptors, shows a 183-fold selectivity for hA3 versus hA1 receptors. Finally, the SAR studies provide some new insights about the steric and lipophilic requirements of the hA3 receptor binding pocket which accommodates the benzofused moiety of our 4-amino-triazoloquinoxalin-1-one derivatives. [Copyright &y& Elsevier]