New -(2-phenyl-4-oxo-1,3-thiazolidin-3-yl)-1,2-benzothiazole-3-carboxamides and acetamides as antimicrobial agents.

A series of 21 novel -[2-phenyl-4-oxo-1,3-thiazolidin-3-yl]-1,2-benzothiazole-3-carboxamides/acetamides () as well as a series of '-(halophenylmethylidene)-1,2-benzothiazole-3-acetohydrazides () have been synthesized and evaluated for their antimicrobial activity against eight bacterial and eight fungal species, among them plant, animal and human pathogens and food contaminating species. All compounds appeared to be potent and the best activity was exhibited by compound with MIC in the range of 10.7-21.

4-Thiazolidinone Derivatives as MMP Inhibitors in Tissue Damage: Synthesis, Biological Evaluation and Docking Studies.

Nine 2-(1,2-benzothiazol-3-yl)--(4-oxo-2-phenyl-1,3-thiazolidin-3-yl)propanamides combining a benzisothiazole and 4-thiazolidinone in one framework were designed and synthesized. The aim of the study was to verify their effectiveness to affect the inflammatory/oxidative process in which free oxygen and nitrite (ROS and RNS) radicals, inflammatory mediators, such as nuclear factor κB (NF-κB), and matrix metalloproteinases (MMPs) are involved. Docking studies of all the compounds were performed in order to explore their binding mode at the MMP-9 protein.

Metadynamics for Perspective Drug Design: Computationally Driven Synthesis of New Protein-Protein Interaction Inhibitors Targeting the EphA2 Receptor.

Metadynamics (META-D) is emerging as a powerful method for the computation of the multidimensional free-energy surface (FES) describing the protein-ligand binding process. Herein, the FES of unbinding of the antagonist N-(3α-hydroxy-5β-cholan-24-oyl)-l-β-homotryptophan (UniPR129) from its EphA2 receptor was reconstructed by META-D simulations. The characterization of the free-energy minima identified on this FES proposes a binding mode fully consistent with previously reported and new structure-activity relationship data.

Exploiting Free-Energy Minima to Design Novel EphA2 Protein-Protein Antagonists: From Simulation to Experiment and Return.

The free-energy surface (FES) of protein-ligand binding contains information useful for drug design. Here we show how to exploit a free-energy minimum of a protein-ligand complex identified by metadynamics simulations to design a new EphA2 antagonist with improved inhibitory potency.

2-Benzisothiazolylimino-5-benzylidene-4-thiazolidinones as protective agents against cartilage destruction.

We report the synthesis, the antioxidant and the inhibitory activity (IC50) on metalloproteinases (MMPs) 3 and 13 of 2-benzo[d]isothiazolylimino-5-benzylidene-4-thiazolidinones. Their potential as protective agents in osteoarthritis (OA) was evaluated by biological assays on chondrocytes cultures, stimulated by IL-1β. The chondroprotective capability, related both to antioxidant activity and to inhibition of MMPs, was studied in vitro, by determining nitric oxide production and glycosaminoglycans release.

A new efficient route to 7-aryl-6-fluoro-8-nitroquinolones as potent antibacterial agents.

A series of 7-aryl-6-fluoro-8-nitroquinolones (6a-e) were synthesized through a novel, simple and clean synthetic procedure, through a Suzuki-Miyaura reaction. The target compounds were evaluated in vitro for their antimicrobial properties against bacterial and fungal strains. All of them showed antibacterial activity higher than the activity of ciprofloxacin, both towards Gram positive Bacillus subtilis and Staphylococcus aureus, and Gram negative Haemophilus influenzae strains.

Design synthesis and antibacterial activity studies of new thiadiazoloquinolone compounds.

Abstract New 9-(alkyl/aryl)-4-fluoro-6-oxo[1,2,5]thiadiazolo[3,4-h]quinoline-5-carboxylic acids and their esters were designed and synthesized. A detailed discussion of the reactions utilized in the preparation of the intermediate and target compounds is reported. All the newly synthesized compounds were fully characterized using all the physico-chemical means needed.

Synthesis and structure-activity relationships of amino acid conjugates of cholanic acid as antagonists of the EphA2 receptor.

The Eph-ephrin system plays a critical role in tumor growth and vascular functions during carcinogenesis. We had previously identified cholanic acid as a competitive and reversible EphA2 antagonist able to disrupt EphA2-ephrinA1 interaction and to inhibit EphA2 activation in prostate cancer cells. Herein, we report the synthesis and biological evaluation of a set of cholanic acid derivatives obtained by conjugation of its carboxyl group with a panel of naturally occurring amino acids with the aim to improve EphA2 receptor inhibition.

Amino acid conjugates of lithocholic acid as antagonists of the EphA2 receptor.

The Eph receptor-ephrin system is an emerging target for the development of novel antiangiogenetic agents. We recently identified lithocholic acid (LCA) as a small molecule able to block EphA2-dependent signals in cancer cells, suggesting that its (5β)-cholan-24-oic acid scaffold can be used as a template to design a new generation of improved EphA2 antagonists. Here, we report the design and synthesis of an extended set of LCA derivatives obtained by conjugation of its carboxyl group with different α-amino acids.

Structure-activity relationships and mechanism of action of Eph-ephrin antagonists: interaction of cholanic acid with the EphA2 receptor.

The Eph-ephrin system, including the EphA2 receptor and the ephrinA1 ligand, plays a critical role in tumor and vascular functions during carcinogenesis. We previously identified (3α,5β)-3-hydroxycholan-24-oic acid (lithocholic acid) as an Eph-ephrin antagonist that is able to inhibit EphA2 receptor activation; it is therefore potentially useful as a novel EphA2 receptor-targeting agent. Herein we explore the structure-activity relationships of a focused set of lithocholic acid derivatives based on molecular modeling investigations and displacement binding assays.

Fragment-based design, docking, synthesis, biological evaluation and structure-activity relationships of 2-benzo/benzisothiazolimino-5-aryliden-4-thiazolidinones as cycloxygenase/lipoxygenase inhibitors.

Balanced modulation of several targets is one of the current strategies for the treatment of multi-factorial diseases. Based on the knowledge of inflammation mechanisms, it was inferred that the balanced inhibition of cyclooxygenase-1/cyclooxygenase-2/lipoxygenase might be a promising approach for treatment of such a multifactorial disease state as inflammation. Detection of fragments responsible for interaction with enzyme's binding site provides the basis for designing new molecules with increased affinity and selectivity.

Structure-activity relationships of N-phenyl-N'-benzothiazol-6-ylurea synthetic derivatives: cytokinin-like activity and adventitious rooting enhancement.

Some years ago we demonstrated the cytokinin-like activity of the synthetic N-phenyl-N'-benzothiazol-6-ylurea (PBU) and a relevant adventitious rooting adjuvant activity of symmetric urea derivatives devoid of any cytokinin- or auxin-like activity per se. Here we report the synthesis and the biological activity evaluation of nine symmetric or asymmetric ureas/thioureas, structurally related to PBU. None of them show cytokinin-like activity, while we demonstrate for the first time that PBU interacts with Arabidopsis cytokinin receptor CRE1/AHK4 in a heterologous bioassay system.

Synthesis and biological evaluation of tetracyclic thienopyridones as antibacterial and antitumor agents.

A facile synthesis of model 4-oxopyrido[3',2':4,5]thieno[3,2-b]indole-3-carboxylic acids 9a-e was achieved via Stille arylation of 2-chloro-3-nitro-4-oxothieno[2,3-b]pyridine-5-carboxylate and a subsequent microwave-assisted phosphite-mediated Cadogan reaction. The new compounds were tested for their in vitro antimicrobial and antiproliferative activity. Compounds 9a-c and 9e exhibited very high potency against Gram positive Bacillus subtilis and Bacillus megaterium at concentrations 0.

Heteroarylimino-4-thiazolidinones as inhibitors of cartilage degradation.

2-Benzo[d]thiazolyl- and 2-benzo[d]isothiazolyl-imino-5-benzylidene-4-thiazolidinone derivatives were investigated as potential metalloproteinases (MMPs) inhibitors and evaluated for their antidegenerative activity on human chondrocyte cultures stimulated by IL-1β, using an experimental model that reproduces the mechanisms involved in osteoarthritic (OA) diseases. Cell viability, the amount of glycosaminoglycans (GAGs) and the production of nitric oxide (NO) were measured. The most potent compound, 5-(4-methoxy-benzylidene)-2-(benzo[d]isothiazol-3-ylimino)-thiazolidin-4-one (4b), a MMP-13 inhibitor at nanomolar concentration (IC(50)=0.

Synthesis and biological evaluation of tetracyclic fluoroquinolones as antibacterial and anticancer agents.

A simple and efficient synthesis of 6-fluoro-4-oxopyrido[2,3-a]carbazole-3-carboxylic acids (13a-e) and a structurally related 6-fluoro-4-oxothieno[2',3':4,5]pyrrolo[3,2-h]quinoline (13f) was achieved via Stille arylation of 7-chloro-6-fluoro-8-nitro-4-oxoquinoline-3-carboxylate and a subsequent microwave-assisted phosphite-mediated Cadogan reaction. The new compounds were tested for their in vitro antimicrobial and antiproliferative activity. The ability of 13a-f to inhibit the activity of DNA gyrase and topoisomerase IV was also investigated.

4-Methyl-N-(3-oxo-2,3-dihydro-1,2-benzisothia-zol-2-yl)benzene-sulfonamide.

In the title mol-ecule, C(14)H(12)N(2)O(3)S(2), the benzisothia-zolone ring system is essentially planar and forms a dihedral angle of 67.37 (6)° with the plane of the benzene ring. In the crystal structure, mol-ecules are linked via inter-molecular N-H⋯O and C-H⋯O hydrogen bonds to form chains parallel to the b axis.

4-Chloro-N-(4-chloro-phenyl-sulfon-yl)-N-(3-oxo-2,3-dihydro-1,2-benzisothia-zol-2-yl)benzene-sulfonamide.

In the title compound, C(19)H(12)Cl(2)N(2)O(5)S(3), the benzene rings of the chloro-phenyl-sulfonyl groups form a dihedral angle of 35.85 (8)° and are inclined at angles of 23.51 (6) and 59.

Complete 1H and 13C NMR spectral assignment of benzo[d]isothiazole derivatives and of an isoindole isoster.

The complete (1)H and (13)C NMR assignments of the novel compound methyl 2-amino-3-(benzo[d]isothiazol-3-yl)propanoate (1), of 3-amino-5-methylbenzo[d]isothiazole (2) and N-(t-butyloxycarbonyl)-2-aminobenzo[d]isothiazol-3(2H)-one (3) and of the desulfurated isostere of 3, N-(t-butyloxycarbonyl)-2-aminoisoindolin-1-one (4), using 1D and 2D NMR techniques, including COSY, INADEQUATE, HSQC, and HMBC experiments are reported.

Hybrid molecules between benzenesulfonamides and active antimicrobial benzo[d]isothiazol-3-ones.

Novel hybrid molecules between benzenesulfonamides and active antimicrobial 2-amino-benzo[d]isothiazol-3-ones were synthesized and characterised and their in vitro antimicrobial activity was evaluated by the minimal inhibitory concentration (MIC). The compounds exhibit moderate antibacterial properties against gram-positive bacteria (MIC 6-100 microg ml(-1)) such as several bacilli, staphylococci and streptococci, including methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis strains, while no inhibition of gram-negative Escherichia coli is detected up to the concentration of 100 microg ml(-1). Synergistic inhibitory activity occurs when sulfanilamides 4a and 4c are tested in combination with trimethoprim against S.

Anti-HIV evaluation of benzo[d]isothiazole hydrazones.

The synthesis and the anti-HIV-1 activity of novel benzo[d]isothiazole hydrazones are reported. Target compounds tested in MT-4 cells cultures for their anti-HIV properties against wild type HIV-1 and HIV strains carrying clinically relevant mutations (EFV(R), Y181C and K103/Y181C) showed good activity against wild type HIV-1 and against the EFV(R) mutant. In terms of SAR the relevant result was that, in the class of benzisothiazole hydrazones, the benzo[d]isothiazol-3(2H)-one moiety (compounds 1 and 4) is an essential structural requirement for the antiretroviral activity.

Evaluation of the local anaesthetic activity of 3-aminobenzo[d]isothiazole derivatives using the rat sciatic nerve model.

On the basis of computer prediction of biological activity by PASS and toxicity by DEREK, the most promising 32-alkylaminoacyl derivatives of 3-aminobenzo[d]isothiazole were selected for possible local anaesthetic action. This action was evaluated using an in vitro preparation of the isolated sciatic nerve of the rat and compared with lidocaine which was used as a reference compound. QSAR studies showed that the polarizability, polarity and molecular shape of molecules have a positive influence on their local anaesthetic activity, while contributions of aromatic CH and singly bonded nitrogen are negative.

2-Heteroarylimino-5-benzylidene-4-thiazolidinones analogues of 2-thiazolylimino-5-benzylidene-4-thiazolidinones with antimicrobial activity: synthesis and structure-activity relationship.

2-Heteroarylimino-5-benzylidene-4-thiazolidinones, unsubstituted or carrying hydroxy, methoxy, nitro and chloro groups on the benzene ring, were synthesised and assayed in vitro for their antimicrobial activity against gram positive and gram negative bacteria, yeasts and mould. The antimicrobial activity of the 2-benzo[d]thiazolyl- and of the 2-benzo[d]isothiazolyl-imino-5-benzylidene-4-thiazolidinones is, on the whole, lower in comparison with the high activity detected for the derivatives of the 2-thiazolylimino-5-benzylidene-4-thiazolidinone class. Nevertheless most of the benzo[d]thiazole analogues display good inhibition of the growth of gram positive bacilli and staphylococci, including methicillin-resistant Staphylococcus strains.

A fuzzy physiologically based pharmacokinetic modeling framework to predict drug disposition in humans.

To date, the application of physiologically based pharmacokinetic (PBPK) models in support of drug discovery remains limited, in part due to information deficit and uncertainty regarding model parameters. Fuzzy set theory provides a suitable way to objectively account for parameter uncertainty in models. Here, we present a fuzzy set-based PBPK modeling framework and demonstrate its utility in predicting diazepam pharmacokinetics in human plasma, following intravenous dosing, from available animal in vivo and literature data.

Benzo[d]isothiazol-3-yl-benzamidines: a class of protective agents on culture of human cartilage and chondrocytes stimulated by IL-1beta.

New derivatives of N-benzo[d]isothiazol-3-yl-benzamidine 6 a were synthesized as nonacidic anti-inflammatory/antidegenerative agents. We investigated the influence of the amidines 6 a-j on the production of NO, PGE(2), MMP-3, COX-2, ROS, and GAGs, key molecules involved in cartilage destruction in osteoarthritic diseases. The antidegenerative properties of the novel designed derivatives 6 b-j were improved with respect to N-benzo[d]isothiazol-3-yl-benzamidine 6 a.