Search results for "Molecular chemistry"

Development and biological investigations of hypoxia-sensitive prodrugs of the tyrosine kinase inhibitor crizotinib

2019

Despite the huge success of tyrosine kinase inhibitors as anticancer agents, severe side effects are a major problem. In order to overcome this drawback, the first hypoxia-activatable 2-nitroimidazole-based prodrugs of the clinically approved ALK and c-MET inhibitor crizotinib were developed. The 2-aminopyridine functionality of crizotinib (essential for target kinase binding) was considered as ideal position for prodrug derivatization. Consequently, two different prodrugs were synthesized with the nitroimidazole unit attached to crizotinib either via carbamoylation (A) or alkylation (B) of the 2-aminopyridine moiety. The successful prodrug design could be proven by docking studies and a dr…

MYOCARDIAL POTENCY OF AQUEOUS EXTRACT OF HARUNGANA MADAGASCARIENSIS STEM BARK AGAINST ISOPROTERENOL-INDUCED MYOCARDIAL DAMAGE IN RATS

2018

Objectives: The present study was undertaken to evaluate the effects of Harungana madagascariensis on electrocardiographical, biochemical and histopathological changes in isoproterenol (ISO)-induced myocardial infarction in rats. Methods: Male Wistar albino rats were randomly divided and treated with the aqueous extract of Harungana madagascariensis stem bark (AEHM, 200 and 400 mg/kg per os), or normal saline or vitamin E for 7 days with concomitant administration of ISO (85 mg/kg, subcutaneously) on 8th and 9th days, at 24 h interval. Results: The ISO injections to the rats caused cardiac dysfunction evidenced by a marked (P<0.01) elevation in ST-segment, a reduction in R wave amplitude (P…

2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for the COVID-19 pandemic, which generated more than 1.82 million deaths in 2020 alone, in addition to 83.8 million infections. Currently, there is no antiviral medication to treat COVID-19. In the search for drug leads, marine-derived metabolites are reported here as prospective SARS-CoV-2 inhibitors. Two hundred and twenty-seven terpene natural products isolated from the biodiverse Red-Sea ecosystem were screened for inhibitor activity against the SARS-CoV-2 main protease (Mpro) using molecular docking and molecular dynamics (MD) simulations combined with molecular mechanics/generalized Born surface area b…

Salts of 5-amino-2-sulfonamide-1,3,4-thiadiazole, a structural and analog of acetazolamide, show interesting carbonic anhydrase inhibitory properties…

2015

Three salts of 5-amino-2-sulfonamide-1,3,4-thiadiazole (Hats) were prepared and characterized by physico-chemical methods. The p-toluensulfonate, the methylsulfonate, and the chlorhydrate monohydrate salts of Hats were evaluated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors (CAIs) and as anticonvulsants and diuretics, since many CAIs are clinically used as pharmacological agents. The three Hats salts exhibited diuretic and anticonvulsant activities with little neurotoxicity. The human (h) isoforms hCA I, II, IV, VII, IX, and XII were inhibited in their micromolar range by these salts, whereas pathogenic beta and gamma CAs showed similar, weak inhibitory profiles.

Supramolecular Modification of ABC Triblock Terpolymers in Confinement Assembly

2018

The self-assembly of AB diblock copolymers in three-dimensional (3D) soft confinement of nanoemulsions has recently become an attractive bottom up route to prepare colloids with controlled inner morphologies. In that regard, ABC triblock terpolymers show a more complex morphological behavior and could thus give access to extensive libraries of multicompartment microparticles. However, knowledge about their self-assembly in confinement is very limited thus far. Here, we investigated the confinement assembly of polystyrene-block-poly(4-vinylpyridine)-block-poly(tert-butyl methacrylate) (PS-b-P4VP-b-PT or SVT) triblock terpolymers in nanoemulsion droplets. Depending on the block weight fractio…

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays.

2017

Three polyaminocyclodextrin materials, obtained by direct reaction between heptakis(6-deoxy-6-iodo)-β-cyclodextrin and the proper linear polyamines, were investigated for their binding properties, in order to assess their potential applications in biological systems, such as vectors for simultaneous drug and gene cellular uptake or alternatively for the protection of macromolecules. In particular, we exploited polarimetry to test their interaction with some model p-nitroaniline derivatives, chosen as probe guests. The data obtained indicate that binding inside the host cavity is mainly affected by interplay between Coulomb interactions and conformational restraints. Moreover, simultaneous i…

Ceiba speciosa (A. St.-Hil.) Seeds Oil: Fatty Acids Profiling by GC-MS and NMR and Bioactivity

2020

This study aimed to evaluate the chemical composition by gas chromatography-mass spectrometry (GC-MS) and Nuclear Magnetic Resonance (NMR) analyses, the antioxidant activities evaluated by different in vitro assays namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2&prime

Ferulago nodosa Subsp. geniculata (Guss.) Troia &amp; Raimondo from Sicily (Italy): Isolation of Essential Oil and Evaluation of Its Bioactivity

2020

Ferulago nodosa (L.) Boiss. (Apiaceae) is a species occurring in the Balkan-Tyrrhenian area. The object of the present study is Sicilian F. nodosa subsp. geniculata (Guss.) Troia & Raimondo, classified as an endemic F. nodosa subspecies. Aerial parts of this plant species were subjected to hydrodistillation to obtain an essential oil. A total of 93 compounds were identified with 2,3,6-trimethyl benzaldehyde (19.0%), spathulenol (9.0%), (E)-caryophyllene (5.4%), and caryophyllene oxide (5.4%) as the main components. The biological activities of F. nodosa essential oil were also investigated. This oil showed an interesting antioxidant potential in a 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sul…

Feedback and Communication in Active Hydrogel Spheres with pH Fronts: Facile Approaches to Grow Soft Hydrogel Structures

2021

Abstract Compartmentalized reaction networks regulating signal processing, communication and pattern formation are central to living systems. Towards achieving life‐like materials, we compartmentalized urea‐urease and more complex urea‐urease/ester‐esterase pH‐feedback reaction networks into hydrogel spheres and investigate how fuel‐driven pH fronts can be sent out from these spheres and regulated by internal reaction networks. Membrane characteristics are installed by covering urease spheres with responsive hydrogel shells. We then encapsulate the two networks (urea‐urease and ester‐esterase) separately into different hydrogel spheres to devise communication, pattern formation and attracti…

Hexagonal Microparticles from Hierarchical Self-Organization of Chiral Trigonal Pd3L6 Macrotetracycles

2021

Construction of structurally complex architectures using inherently chiral, asymmetric, or multi-heterotopic ligands is a major challenge in metallosupramolecular chemistry. Moreover, the hierarchical self-organization of such complexes is unique. Here, we introduce a water-soluble, facially amphiphilic, amphoteric, chiral, asymmetric, and hetero-tritopic ligand derived from natural bile acid, ursodeoxycholic acid. We show that via the supramolecular transmetalation reaction, using nitrates of Cu(II) or Fe(III), and subsequently Pd(II), a superchiral Pd3L6 complex can be obtained. Even though several possible constitutional isomers of Pd3L6 could be formed, because of the ligand asymmetry a…