Synthesis, antitumour and antimicrobial activities of new peptidyl derivatives containing the 1,3-benzodioxole system

Antimicrobial Properties of New Polyamines Conjugated with Oxygen-Containing Aromatic Functional Groups

Antibiotic resistance is now a first-order health problem, which makes the development of new families of antimicrobials imperative. These compounds should ideally be inexpensive, readily available, highly active, and non-toxic. Here, we present the results of our investigation regarding the antimicrobial activity of a series of natural and synthetic polyamines with different architectures (linear, tripodal, and macrocyclic) and their derivatives with the oxygen-containing aromatic functional groups 1,3-benzodioxol, ortho/para phenol, or 2,3-dihydrobenzofuran. The new compounds were prepared through an inexpensive process, and their activity was tested against selected strains of yeast, as well as Gram-positive and Gram-negative bacteria. In all cases, the conjugated derivatives showed antimicrobial activity higher than the unsubstituted polyamines. Several factors, such as the overall charge at physiological pH, lipophilicity, and the topology of the polyamine scaffold were relevant to their activity. The nature of the lipophilic moiety was also a determinant of human cell toxicity. The lead compounds were found to be bactericidal and fungistatic, and they were synergic with the commercial antifungals fluconazole, cycloheximide, and amphotericin B against the yeast strains tested.

Affecting AMPA Receptor Biophysical Gating Properties with Negative Allosteric Modulators

Glutamatergic chemical synapses mediate excitatory neurotransmission by the ion flow through α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors in the central nervous system (CNS). AMPA receptor-mediated synaptic transmission abnormalities may play a role in neurologic and neurodegenerative diseases, and compounds that can modulate AMPA receptor (AMPAR) signaling have been studied for decades as possible therapies for Alzheimer's disease, Parkinson's disease, depression, and epilepsy. Here, we aimed to determine the modulating effect of allosteric regulators on AMPA receptors by comparing their actions on AMPA-evoked currents, desensitization, and deactivation rate in human embryonic kidney cells (HEK293T) recombinant AMPAR subunits. In this study, patch-clamp electrophysiology was performed to examine how the AMPA subunit responded to benzodioxole (BDZ) derivatives. Our results showed that the BDZ derivatives affected AMPARs as negative modulators, particularly BDZs (8, 9, and 15), where they increased the desensitization rate and delayed the deactivation process. The BDZ compounds were utilized in this study as AMPA modulators to investigate fundamental and clinical AMPA receptor processes. We test BDZs as negative allosteric AMPAR modulators to reestablish glutamatergic synaptic transmission. These efforts have resulted in important molecules with neuroprotective properties on AMPA receptors.

4-Aminoquinolines Bearing a 1,3-Benzodioxole Moiety: Synthesis and Biological Evaluation as Potential Antifungal Agents

In search of new environmentally friendly and effective antifungal agents, a series of 4-aminoquinolines bearing a 1,3-benzodioxole moiety were prepared and their structures were fully elucidated by spectroscopic analyses. The antifungal activities of all the target compounds against five phytopathogenic fungi were evaluated in vitro. The results revealed that most of the newly synthesized compounds exhibited obvious inhibitory activities at the concentration of 50 μg/mL. Among them, 6-(furan-2-yl)-N-(4-methylphenyl)-2H-[1,3]dioxolo[4,5-g]quinolin-8-amine hydrochloride (7m) displayed more promising antifungal potency with EC₅₀ values of 10.3 and 14.0 μg/mL against C. lunata and A. alternate, respectively. Particularly, the EC₅₀ value of 7m against C. lunata was 7.3-fold as potent as the standard azoxystrobin. There were some significant morphological alterations in the mycelia of C. lunata when treated with 7m at 50 μg/mL. Additionally, the preliminary structure-activity relationships (SARs) were also discussed. Thus, this study suggests that 4-aminoquinolines bearing a 1,3-benzodioxole moiety are interesting scaffolds for the development of novel antifungal agents.

Tetrahydropiperic acid (THPA) conjugated cationic hybrid dipeptides as antimicrobial agents

The present work describes the synthesis of hybrid dipeptides H-Lys-Gpn-PEA, C1; H-Lys-β^3,3A_C6C-PEA, C2, and THPA conjugated dipeptides, THPA-Lys-Gpn-PEA, C3, and THPA-Lys-β^3,3A_C6C-PEA, C4. All the peptides were evaluated against both Gram-negative and Gram-positive bacterial strains. Among all, peptide C4 exhibited the most potent activity with MIC 1.56 μM against P. aeruginosa (MTCC 424) and S. aureus (MTCC 737). Further, time-kill kinetics, fluorescence assays, and scanning electron microscopy (SEM) studies were performed in order to understand the mechanism of action and efficacy of peptide C4, The fluorescence assays and SEM images demonstrated the bacterial killing through membrane disruption. The peptide C4 exhibited very low hemolytic activity with negligible cytotoxicity against normal human breast cell line FR2.

Synthesis and initial screening of lactate dehydrogenase inhibitor activity of 1,3-benzodioxole derivatives

Cancer is one of the main causes of mortality in the world. Many cancer cells produce ATP through high-level lactic acid fermentation catalyzed by lactate dehydrogenase (LDH), which converts pyruvic acid to lactic acid. LDH plays a dominant role in the Warburg effect, wherein aerobic glycolysis is favored over oxidative phosphorylation. Due to the high lactic acid production level in cancer cells, LDH-targeting could be a potential cancer treatment strategy. A few approaches, such as drug treatment, reportedly inhibited LDH activity. In this study, we describe new 1,3-benzodioxole derivatives that might be potential small molecule candidates for LDHA inhibition. The synthesis was carried out by trans-esterification between aryl ester and alcohol groups from piperonyl alcohol. Compounds 2 and 10 exhibited a selective LDHA IC₅₀ value of 13.63 µM and 47.2 µM, respectively. Whereas only compound 10 showed significant cytotoxicity in several lines of cancer cells, especially in human pancreatic cancer PANC-1 cells. These synthesized compounds possess 2 aromatic rings and –CF₃ moiety, which expectedly contributes to LDHA inhibition. The presented products have the potential to become a promising LDHA inhibitor drug candidate.

GC-MS-Based Metabolomics Analysis of Prawn Shell Waste Co-Fermentation by Lactobacillus plantarum and Bacillus subtilis

GC-MS-based metabolomics were used to investigate metabolic changes in prawn shell waste during fermentation. Microbial strains Lactobacillus plantarum and Bacillus subtilis were co-fermented in a shake flask comprising of 5% (w/v) prawn shell waste and 20% (w/v) glucose as a carbon source. Analysis of the prawn shell waste fermentation showed a total of 376 metabolites detected in the culture supernatant, including 14 amino acids, 106 organic acids, and 90 antimicrobial molecules. Results show that the liquid fraction of the co-fermentation is promising for harvesting valuable metabolites for probiotics application.

Novel N,N'-Disubstituted Acylselenoureas as Potential Antioxidant and Cytotoxic Agents

Selenium compounds are pivotal in medicinal chemistry for their antitumoral and antioxidant properties. Forty seven acylselenoureas have been designed and synthesized following a fragment-based approach. Different scaffolds, including carbo- and hetero-cycles, along with mono- and bi-cyclic moieties, have been linked to the selenium containing skeleton. The dose- and time-dependent radical scavenging activity for all of the compounds were assessed using the in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assays. Some of them showed a greater radical scavenging capacity at low doses and shorter times than ascorbic acid. Therefore, four compounds were evaluated to test their protective effects against H₂O₂-induced oxidative stress. One derivative protected cells against H₂O₂-induced damage, increasing cell survival by up to 3.6-fold. Additionally, in vitro cytotoxic activity of all compounds was screened against several cancer cells. Eight compounds were selected to determine their half maximal inhibitory concentration (IC₅₀) values towards breast and lung cancer cells, along with their selectivity indexes. The breast cancer cells turned out to be much more sensitive than the lung. Two compounds (5d and 10a) stood out with IC₅₀ values between 4.2 μM and 8.0 μM towards MCF-7 and T47D cells, with selectivity indexes greater than 22.9. In addition, compound 10b exhibited dual antioxidant and cytotoxic activities. Although further evidence is needed, the acylselenourea scaffold could be a feasible frame to develop new dual agents.

The role of dispersion and anharmonic corrections in conformational analysis of flexible molecules: the allyl group rotamerization of matrix isolated safrole

Conformational changes of the monomeric safrole (5-(2-propenyl)-1,3-benzodioxole) isolated in low temperature xenon matrices were induced thermally or using narrow-band UV radiation. The rotation of the allyl group taking place in the studied matrices was followed by FTIR spectroscopy. Safrole represents a challenging example of a flexible molecule highlighting the importance of dispersion interactions and anharmonic effects in the structural, spectroscopic and energetic analysis. Structures of the safrole conformers, their energetics and infrared spectra have been calculated using various computational methods ranging from density functional theory (DFT) to coupled cluster (CC). The best theoretical results were obtained by integrating CCSD(T) energies including complete basis set extrapolation and core-valence corrections with B2PLYP-D3 equilibrium structures and hybrid B2PLYP-D3/B3LYP-D3 anharmonic computations for IR spectra and thermodynamics.

Synthesis, structure elucidation, and antifungal potential of certain new benzodioxole-imidazole molecular hybrids bearing ester functionalities

Background

The incidence of fungal infections is a growing serious global health burden. There is an urgent medical demand to acquire new antifungal drug-like compounds having azole nuclei to get rid of the drawbacks of the currently available azole antifungal agents.

Methods

The target compounds 5a-r were synthesized in a four-step reaction sequence using the appropriate acetophenone derivative as a starting material. The antifungal potential of the title compounds was assessed using DIZ and MIC assays according to the reported standard procedures.

Results

The newly synthesized oximino esters 5a-r were identified with the aid of various spectroscopic approaches. Their assigned chemical structures were confirmed via single-crystal X-ray structure of compound 5o. The molecular structure of compound 5o was crystallized in the triclinic, P–1, a=9.898 (3) Å, b=10.433 (3) Å, c=11.677 (4) Å, α =86.886 (6)°, β =87.071 (7)°, γ  =64.385 (6)°, V=1,085.2 (6) Å3, Z=2. The synthesized compounds 5a-r were in vitro evaluated for antifungal potential against four fungal strains. Compounds 5l and 5m bearing a trifluoromethylphenyl moiety showed the best anti-Candida albicans activity with minimum inhibitory concentration (MIC) value of 0.148 μmol/mL, while compound 5b displayed the best activity toward Candida tropicalis with MIC value of 0.289 μmol/mL. Compounds 5o and 5l were the most active congeners against Candida parapsilosis and Aspergillus niger, respectively.

Conclusion

Single-crystal X-ray analysis of compound 5o confirmed without doubt the assigned chemical structures of the title compounds as well as confirmed the (E)-configuration of their oximino group. Compounds 5b, 5l, 5m, and 5o emerged as the most active compounds against the tested fungi and they could be considered as new antifungal lead candidates.

Synthesis and Spectroscopic Identification of Certain Imidazole-Semicarbazone Conjugates Bearing Benzodioxole Moieties: New Antifungal Agents

During the last three decades the extent of life-threatening fungal infections has increased remarkably worldwide. Synthesis and structure elucidation of certain imidazole-semicarbazone conjugates 5a–o are reported. Single crystal X-ray analysis of compound 5e unequivocally confirmed its assigned chemical structure and the (E)-configuration of its imine double bond. Compound 5e crystallized in the triclinic system, P-1, a = 6.3561 (3) Å, b = 12.5095 (8) Å, c = 14.5411 (9) Å, α = 67.073 (4)°, β = 79.989 (4)°, γ =84.370 (4)°, V = 1048.05 (11) ų, Z = 2. In addition, DIZ and MIC assays were used to examine the in vitro antifungal activity of the title conjugates 5a–o against four fungal strains. Compound 5e, bearing a 4-ethoxyphenyl fragment, showed the best MIC value (0.304 µmol/mL) against both C. tropicalis and C. parapsilosis species, while compounds 5c (MIC = 0.311 µmol/mL), 5k, and 5l (MIC = 0.287 µmol/mL) exhibited the best anti-C. albicans activity.

Synthesis, Single Crystal X-ray Structure, DFT Computations, Hirshfeld Surface Analysis and Molecular Docking Simulations on ({[(1E)-1-(1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]amino}oxy)(furan-2-yl)methanone: A New Antifungal Agent

The development of drug-resistance and high morbidity rates due to life-threatening fungal infections account for a major global health problem. A new antifungal imidazole-based oximino ester 5 has been prepared and characterized with the aid of different spectroscopic tools. Single crystal X-ray analysis doubtlessly identified the (E)-configuration of the imine fragment of the title compound. Compound 5, C18H15N3O5, was crystallized in the monoclinic, P21/c, a = 10.4067 (5) Å, b = 6.8534 (3) Å, c = 23.2437 (12) Å, β = 94.627 (2)°, V = 1652.37 (14) Å3, Z = 4. Spectral and electronic features of compound 5 have been thoroughly explored with the aid of density function theory (DFT) simulations and the data were compared with the experimental results. In addition, Hirshfeld surface analysis and molecular docking simulations were executed on the target compound. Molecular docking results are fairly consistent with the experimental in vitro antifungal potential of the oximino ester 5.

New Benzodioxole-based Pyrazoline Derivatives: Synthesis and Anticandidal, In silico ADME, Molecular Docking Studies

Background:

Azoles are commonly used in the treatment and prevention of fungal infections. They suppress fungal growth by acting on the heme group of lanosterol 14α-demethylase enzyme (CYP51), thus blocking the biosynthesis of ergosterol. </P><P> Objectives: Due to the importance of pyrazolines in the field of antifungal drug design, we aimed to design and synthesize new pyrazoline-based anticandidal agents.

Methods:

New pyrazoline derivatives were synthesized via the reaction of 1-(chloroacetyl)-3-(2- thienyl)-5-(1,3-benzodioxol-5-yl)-2-pyrazoline with aryl thiols. These compounds were evaluated for their in vitro antifungal effects on Candida species. Docking studies were performed to predict the affinity of the most effective anticandidal agents to substrate binding site of CYP51. Furthermore, MTT assay was performed to determine the cytotoxic effects of the compounds on NIH/3T3 mouse embryonic fibroblast cell line. A computational study for the prediction of ADME properties of all compounds was also carried out.

Results:

Compounds 5, 8, 10 and 12 were found as the most potent anticandidal agents against Candida albicans and Candida glabrata in this series with the same MIC values of ketoconazole and they also exhibited low toxicity against NIH/3T3 cells. Docking results indicated that all these compounds showed good binding affinity into the active site of CYP51. In particular, chloro substituted compounds 8 and 12 bind to CYP51 through direct coordination with the heme group. According to in silico studies, compound 8 only violated one parameter of Lipinski’s rule of five, making it a potential orally bioavailable agent.

Conclusion:

Compound 8 was defined as a promising candidate for further in vitro and in vivo studies.

Density functional theory calculations, vibration spectral analysis and molecular docking of the antimicrobial agent 6-(1,3-benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin-4-yl)ethyl] sulfanyl}pyrimidin-4(3H)-one

Vibrational spectral analysis and quantum chemical computations based on density functional theory have been performed on the antimicrobial agent 6-(1,3-benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin- 4-yl)ethyl]sulfanyl}pyrimidin-4-(3H)-one.The equilibrium structural geometry, various bonding features and harmonic vibrational wavenumbers of the title compound have been investigated using DFT-B3LYP function at 6-311++G(d, p) basis set. The detailed interpretations of the vibrational spectra have been carried out with the aid of VEDA 4 program. The various intramolecular interactions of the title compound have been exposed by natural bond orbital analysis. The FT-IR and FT-Raman spectra of the title molecule have been recorded and analyzed. Blue-shifting of the C-H wavenumber along with a decrease in the C-H bond length attribute for the formation of the C-H...O hydrogrn bonding provide an evidence for a charge transfer interaction. Also, the distribution of natural atomic charges reflects the presence of intramolecular hydrogen bonding. The analysis of the electron density of HOMO and LUMO gives an idea of the delocalization and the low value of energy gap indicates electron transfer within the molecule. Moreover, molecular docking studies revealed the possible binding of the title molecule to different antimicrobial target proteins.

Antimalarial and cytotoxic activities of roots and fruits fractions of Astrodaucus persicus extract

Objective(s):

Astrodaucus persicus (Apiaceae) is one of the two species of this genus which grows in different parts of Iran. Roots of this plant were rich in benzodioxoles and used as food additive or salad in Iran and near countries. The aim of present study was evaluation of antimalarial and cytotoxic effects of different fractions of A. persicus fruits and roots extracts.

Materials and Methods:

Ripe fruits and roots of A. persicus were extracted and fractionated by hexane, chloroform, ethyl acetate and methanol, separately. Antimalarial activities of fractions were performed based on Plasmodium berghei suppressive test in mice model and percentage of parasitemia and suppression were determined for each sample. Cytotoxicity of fruits and roots fractions were investigated against human breast adenocarcinoma (MCF-7), colorectal carcinoma (SW480) and normal (L929) cell lines by MTT assay and IC₅₀ of them were measured.

Results:

Hexane fraction of roots extract (RHE) and ethyl acetate fraction of fruits extract (FEA) of A. persicus demonstrated highest parasite inhibition (73.3 and 72.3%, respectively at 500 mg/kg/day) which were significantly different from negative control group (P<0.05). In addition, RHE showed potent anticancer activities against MCF-7 (IC₅₀ of 0.01 µg/ml), SW480 (IC₅₀ of 0.36 µg/ml) and L929 (IC₅₀ of 0.70 µg/ml) cell lines.

Conclusion:

According to the results, RHE and FEA fractions of A. persicus could be introduced as excellent choice for antimalarial drug discovery. In addition, cytotoxic activity of RHE was noticeable.

Amino acids/peptides conjugated heterocycles: A tool for the recent development of novel therapeutic agents

Amino acids/peptide conjugated heterocycles represent an important class of therapeutical agents. Biologically active heterocycles are conjugated with amino acids or peptides to increase the drug resistance. Furthermore, the amino acid/peptide based drugs have low toxicity, ample bioavailability and permeability, modest potency and good metabolic and pharmacokinetic properties. Synthetic amino acid/peptides based heterocyclic conjugates constitute a promising choice for the development of new, less toxic and safer conventional pharmaceutical drugs in the near future. In this review, we discuss and highlight the recent findings of the structural features that encourage biological applications of amino acid/peptides based conjugates.

Synthesis, Single Crystal X-ray Analysis, and Antifungal Profiling of Certain New Oximino Ethers Bearing Imidazole Nuclei

Fungal infections threaten human health, particularly in immune-compromised patients worldwide. Although there are a large number of antifungal agents available, the desired clinical attributes for the treatment of fungal infections have not yet been achieved. Azoles are the mainstay class of the clinically used antifungal agents. In the current study, the synthesis, spectroscopic characterization, and antifungal activity of certain new oximino ethers Va–n bearing imidazole nuclei are reported. The (E)-configuration of the imine double bond of the synthesized compounds Va–n has been confirmed via single crystal X-ray analysis of compound Vi as a representative example of this class of compounds. The molecular structure of compound Vi was crystallized in the monoclinic, P2₁/c, a = 18.7879(14) Å, b = 5.8944(4) Å, c = 16.7621(12) Å, β = 93.063(3)°, V = 1855.5(2) ų, Z = 4. The in vitro antifungal activity of the synthesized compounds Va–n were evaluated using diameter of the inhibition zone (DIZ) and minimum inhibitory concentration (MIC) assays against different fungal strains. Compound Ve manifested anti-Candida albicans activity with an MIC value of 0.050 µmol/mL, being almost equipotent with the reference antifungal drug fluconazole (FLC),while compounds Vi and Vn are the most active congeners against Candida parapsilosis, being equipotent and about twenty-three times more potent than FLC with an MIC value of 0.002 µmol/mL. The results of the current report might support the development of new potent and safer antifungal azoles.

Crystal structure of 1-(2H-1,3-benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propan-1-one, C13H12N2O3

C13H12N2O3, monoclinic, P21/n (no. 14), a = 7.3322(5) Å, b = 8.0341(5) Å, c = 19.4479(14) Å, β = 95.775(2)°, V = 1139.82(13) Å3, Z = 4, R gt(F) = 0.0533, wR ref(F 2) = 0.1335, T = 293(2) K.

Synthesis, X-ray Single Crystal Structure, Molecular Docking and DFT Computations on N-[(1E)-1-(2H-1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]-hydroxylamine: A New Potential Antifungal Agent Precursor

Mycoses are serious health problem, especially in immunocompromised individuals. A new imidazole-bearing compound containing an oxime functionality was synthesized and characterized with different spectroscopic techniques to be used for the preparation of new antifungal agents. The stereochemistry of the oxime double bond was unequivocally determined via the single crystal X-ray technique. The title compound 4, C₁₃H₁₃N₃O₃·C₃H₈O, crystallizes in the monoclinic space group P2₁with a = 9.0963(3) Å, b = 14.7244(6) Å, c = 10.7035(4) Å, β = 94.298 (3)°, V = 1429.57(9) ų, Z = 2. The molecules were packed in the crystal structure by eight intermolecular hydrogen bond interactions. A comprehensive spectral analysis of the title molecule 4 has been performed based on the scaled quantum mechanical (SQM) force field obtained by density-functional theory (DFT) calculations. A molecular docking study illustrated the binding mode of the title compound 4 into its target protein. The preliminary antifungal activity of the title compound 4 was determined using a broth microdilution assay.

Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η2-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC1)platinum(II)]

Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η²-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC¹)platinum(II)], [Pt₂(C₁₅H₁₉O₄)₂Cl₂], containing a derivative of the natural compound eugenol as ligand, have been performed. Using five different sets of crystallization conditions resulted in four different complexes which can be further used as starting compounds for the synthesis of Pt complexes with promising anticancer activities. In the case of vapour diffusion with the binary chloroform-diethyl ether or methylene chloride-diethyl ether systems, no change of the molecular structure was observed. Using evaporation from acetonitrile (at room temperature), dimethylformamide (DMF, at 313 K) or dimethyl sulfoxide (DMSO, at 313 K), however, resulted in the displacement of a chloride ligand by the solvent, giving, respectively, the mononuclear complexes (acetonitrile-κN)(η²-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC¹)chloridoplatinum(II) monohydrate, [Pt(C₁₅H₁₉O₄)Cl(CH₃CN)]·H₂O, (η²-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC¹)chlorido(dimethylformamide-κO)platinum(II), [Pt(C₁₅H₁₉O₄)Cl(C₂H₇NO)], and (η²-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC¹)chlorido(dimethyl sulfoxide-κS)platinum(II), determined as the analogue {η²-2-allyl-4-methoxy-5-[(ethoxycarbonyl)methoxy]phenyl-κC¹}chlorido(dimethyl sulfoxide-κS)platinum(II), [Pt(C₁₄H₁₇O₄)Cl(C₂H₆OS)]. The crystal structures confirm that acetonitrile interacts with the Pt^II atom via its N atom, while for DMSO, the S atom is the coordinating atom. For the replacement, the longest of the two Pt-Cl bonds is cleaved, leading to a cis position of the solvent ligand with respect to the allyl group. The crystal packing of the complexes is characterized by dimer formation via C-H...O and C-H...π interactions, but no π-π interactions are observed despite the presence of the aromatic ring.

Novel capsaicin analogues as potential anticancer agents: synthesis, biological evaluation, and in silico approach

A novel class of benzo[d][1,3]dioxol-5-ylmethyl alkyl/aryl amide and ester analogues of capsaicin were designed, synthesized, and evaluated for their cytotoxic activity against human and murine cancer cell lines (B16F10, SK-MEL-28, NCI-H1299, NCI-H460, SK-BR-3, and MDA-MB-231) and human lung fibroblasts (MRC-5). Three compounds (5f, 6c, and 6e) selectively inhibited the growth of aggressive cancer cells in the micromolar (µM) range. Furthermore, an exploratory data analysis pointed at the topological and electronic molecular properties as responsible for the discrimination process regarding the set of investigated compounds. The findings suggest that the applied designing strategy, besides providing more potent analogues, indicates the aryl amides and esters as well as the alkyl esters as interesting scaffolds to design and develop novel anticancer agents.

Nitropropenyl benzodioxole, an anti-infective agent with action as a protein tyrosine phosphatase inhibitor

We report on the activities of a broad spectrum antimicrobial compound,nitropropenyl benzodioxole (NPBD) which are of relevance to its potential as an anti-infective drug. These investigations support the proposal that a major mechanism of NPBD is action as a tyrosine mimetic, competitively inhibiting bacterial and fungal protein tyrosine phosphatases (PTP). NPBD did not affect major anti-bacterial drug targets, namely, ATP production, cell wall or cell membrane integrity, or transcription and translation of RNA. NPBD inhibited bacterial YopH and human PTP1B and not human CD45 in enzyme assays. NPBD inhibited PTP-associated bacterial virulence factors, namely, endospore formation in Bacillus cereus, prodigiosin secretion in Serratia marcescens , motility in Proteus spp., and adherence and invasion of mammalian cells by Yersinia enterocolitica . NPBD acts intracellularly to inhibit the early development stages of the Chlamydia trachomatis infection cycle in mammalian cells known to involve sequestration of host cell PTPs. NPBD thus both kills pathogens and inhibits virulence factors relevant to early infection, making it a suitable candidate for development as an anti-infective agent, particularly for pathogens that enter through, or cause infections at, mucosal surfaces. Though much is yet to be understood about bacterial PTPs, they are proposed as suitable anti-infective targets and have been linked to agents similar to NPBD. The structural and functional diversity and heterogeneous distribution of PTPs across microbial species make them suitably selective targets for the development of both broadly active and pathogen-specific drugs.

Synthesis, Single Crystal X-Ray Structure, and Antimicrobial Activity of 6-(1,3-Benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin-4-yl)ethyl]sulfanyl}pyrimidin-4(3H)-one

Synthesis, X-ray structure and antimicrobial activity of 6-(1,3-benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin-4-yl)ethyl]sulfanyl}pyrimidin-4(3H)-one (8) are reported. Compound8exhibited activity towardsS. aureuswith MIC value of 0.0619 μmol/mL while it showed activity towardsB. subtilis,B. cereus,C. albicans, andA. nigerwith MIC = 0.1859 μmol/mL. Single crystal X-ray structure of the title compound8confirmed itsS-alkylation. The title compound crystallizes in the triclinic,P-1,a=11.1220(5) Å,b=12.2241(5) Å,c=21.5246(9) Å,α=88.958(2)°,β=79.836(2)°,γ=79.384(2)°,V=2830.9(2) Å3,Z=6,R(F)=0.046,wR(F2)=0.110,T=100 K. The crystal structure is stabilized by weak intermolecular C–H⋯O and N–H⋯O hydrogen interactions.

Synthesis, structure-activity relationships (SAR) and in silico studies of coumarin derivatives with antifungal activity

The increased incidence of opportunistic fungal infections, associated with greater resistance to the antifungal drugs currently in use has highlighted the need for new solutions. In this study twenty four coumarin derivatives were screened in vitro for antifungal activity against strains of Aspergillus. Some of the compounds exhibited significant antifungal activity with MICs values ranging between 16 and 32 µg/mL. The structure-activity relationships (SAR) study demonstrated that O-substitutions are essential for antifungal activity. It also showed that the presence of a short aliphatic chain and/or electron withdrawing groups (NO(2) and/or acetate) favor activity. These findings were confirmed using density functional theory (DFT), when calculating the LUMO density. In Principal Component Analysis (PCA), two significant principal components (PCs) explained more than 60% of the total variance. The best Partial Least Squares Regression (PLS) model showed an r2 of 0.86 and q2(cv) of 0.64 corroborating the SAR observations as well as demonstrating a greater probe N1 interaction for active compounds. Descriptors generated by TIP correlogram demonstrated the importance of the molecular shape for antifungal activity.

Phosphine-initiated general base catalysis: facile access to benzannulated 1,3-diheteroatom five-membered rings via double-Michael reactions of allenes

General base-catalyzed double-Michael reactions of allenes with various dinucleophiles are described. The reactions are facilitated most efficiently by a catalytic amount of trimethylphosphine, affording six types of C2-functionalized benzannulated five-membered heterocycles: benzimidazolines, benzoxazolines, benzothiazolines, 1,3-benzodioxoles, 1,3-benzoxathioles, and 1,3-benzodithioles. This atom-economical reaction is operationally simple and provides the product heterocycles in good to excellent yields. Careful mechanistic studies unveiled the phosphine-triggered general base catalysis pathway. Furthermore, the double-Michael reaction can serve as an alternative method for the selective monoketalization of β-diketones.

New catechol derivatives of safrole and their antiproliferative activity towards breast cancer cells

Catechols were synthesized from safrole. Nine derivatives were prepared and assessed for antiproliferative effects using different human cell lines. The in vitro growth inhibition assay was based on the sulphorhodamine dye to quantify cell viability. The derivatives 4-allylbenzene-1,2-diol (3), 4 4-[3-(acetyloxy)propyl]-1,2-phenylene diacetate (6) and 4-[3-(acetyloxy)propyl]-5-nitro-1,2-phenylene diacetate (10) showed higher cytotoxicity than the parent compound 2 in tests performed on two breast cancer cell lines (MCF-7 and MDA-MB-231). The IC₅₀ values of 40.2 ± 6.9 μM, 5.9 ± 0.8 μM and 33.8 ± 4.9 μM, respectively, were obtained without toxicity towards dermal human fibroblast (DHF cells).

First synthesis of 2-(benzofuran-2-yl)-6,7-methylene dioxyquinoline-3-carboxylic acid derivatives

A facile and inexpensive synthesis of a series of novel methylenedioxy-bearing 2-(benzofuran-2-yl)-quinoline-3-carboxylic acid derivatives 3a-h via the one-pot reaction of ethyl 2-chloromethyl-6,7-methylenedioxyquinoline-3-carboxylate (5) with various substituted salicylaldehydes 6a-g as well as 2-hydroxy-1-naphthaldehyde (6h) is described. Substrate 5 was synthesized by the Friedländer condensation reaction of 2-amino-4,5-methylenedioxybenzaldehyde (4) with ethyl 4-chloro-3-oxobutanoate using KHSO(4) as catalyst under ultrasound irradiation conditions. The targeted compounds 3a-h were obtained in good yields of 52-82% and their structures were established based on spectral data and elemental analyses.

Synthesis of New Racemic α,α-Diaminocarboxylic Ester Derivatives

New racemic methyl or ethyl α-aminoglycinate derivatives were synthesized by N-alkylation of amines (aniline, 4-methylaniline, 2-methylaniline, 2,4-dimethoxyaniline, 2-nitroaniline, 4-chloro-2-fluoroaniline, 2-naphthylamine, benzylamine, N,N-dibenzylamine, and cyclohexylamine) with methyl or ethyl α-azidoglycinate.

2,2-Dimethyl-1,3-benzodioxol-4-yl N-methyl-carbamate

In the title compound, C(11)H(13)NO(4), the two fused rings are almost coplanar, making a dihedral angle of 3.02 (8)°. In the crystal, chains are formed parallel to [010] through N-H⋯O hydrogen bonds between the amine and carbonyl groups.