Design, synthesis and cytotoxicity of the antitumor agent 1-azabicycles for chemoresistant glioblastoma cells.

Twelve multi-functional pyrrolizidinones, indolizidinones and pyrroliazepinones were prepared from formal aza-[3 + 2] and aza-[3 + 3] cycloadditions of five- to seven-membered heterocyclic enaminones as diverse ambident electrophiles. The antitumor activity of these alkaloid-like compounds was investigated through an initial screening performed on human glioblastoma multiform (GBM) cell lines (GL-15, U251), on murine glioma cells line (C6) and on normal glial cells. Of the compounds tested, the new pyrrolo[1,2a]azepinone, [ethyl (3-oxo-1,2-diphenyl-6,7,8,9-tetrahydro-3H-pyrrolo[1,2a]azepin-9a(5H)-yl)acetate] or (Compound-13) exhibited selective cytotoxic effects on GBM-temozolomide resistant cells. Compound-13 exerted dose-dependent cytotoxic activity by promoting arrest of cells in the G0/G1 phase of the cell cycle in the first 24 h. The apoptotic effect observed was in a time-dependent manner. Anti-migratory effect promoted by the treatment with compound-13 was also observed. Moreover, healthy mixed glial cell cultures from rat brain exhibited no cytotoxicity effect upon exposure to compound-13. Thus, the present study paves the way for the use of compound-13 as novel antitumor scaffold candidate for glioma cell therapy.

Taraxerol 4-Methoxybenzoate, an in vitro Inhibitor of Photosynthesis Isolated from Pavonia multiflora A. St-Hil. (Malvaceae).

A phytochemical study of Pavonia multiflora A. St-Hil. (Malvaceae) led to the isolation through chromatographic techniques of 10 secondary metabolites: vanillic acid (1), ferulic acid (2), p-hydroxybenzoic acid (3), p-coumaric acid (4), loliolide (5), vomifoliol (6), 4,5-dihydroblumenol A (7), 3-oxo-α-ionol (9), blumenol C (10), and taraxerol 4-methoxybenzoate (8), the latter being a novel metabolite. Their structures were identified by (1) H- and (13) C-NMR, using one- and two-dimensional techniques, and X-ray crystallography. In this work, we report the effect of compounds 5 and 8 on several photosynthetic activities in an attempt to search for new compounds as potential herbicide agents that affect photosynthesis. Both compounds inhibited the electron flow from H2 O to methyl viologen; therefore, they act as Hill reaction inhibitors. Using polarographic techniques and studies of the fluorescence of chlorophyll a, the interaction sites of these compounds were located at photosystem II.

Chrysin bonded to ß-d-glucose tetraacetate enhances its protective effects against the neurotoxicity induced by aluminum in Swiss mice.

OBJECTIVES: To evaluate whether the glycosylation of chrysin (CHR) enhances its protective effects against aluminum-induced neurotoxicity. METHODS: To compare the antioxidant, anticholinesterase, and behavioral effects of CHR with its glycosylated form (CHR bonded to ß-d-glucose tetraacetate, denoted as LQFM280), we employed an integrated approach using both in vitro (SH-SY5Y cells) and in vivo (aluminum-induced neurotoxicity in Swiss mice) models. KEY FINDINGS: LQFM280 demonstrated higher antioxidant activity than CHR in both models. Specifically, LQFM280 exhibited the ability to exert antioxidant effects in the cytoplasm of SH-SY5Y cells, indicating its competence in traversing neuronal membranes. Remarkably, LQFM280 proved more effective than CHR in recovering memory loss and counteracting neuronal death in the aluminum chloride mice model, suggesting its increased bioavailability at the brain level. CONCLUSIONS: The glycosylation of CHR with ß-d-glucose tetraacetate amplifies its neuroprotective effects, positioning LQFM280 as a promising lead compound for safeguarding against neurodegenerative processes involving oxidative stress.

Design, synthesis, antinociceptive and anti-inflammatory activities of novel piroxicam analogues.

In this paper we report the design, synthesis, antinociceptive and anti-inflammatory activities of a series of benzothiazine N-acylhydrazones 14a­h, planned by structural modification of piroxicam (1), a non steroidal anti-inflammatory drug. Among the synthesized analogues, compounds 14f (LASSBio-1637) and 14g (LASSBio-1639) were identified as novel antinociceptive and anti-inflammatory prototypes, active by oral administration, acting by a mechanism of action that seems to be different from that of piroxicam, since they were inactive as an inhibitor of cyclooxygenase (COX-1 and COX-2) at concentrations of 10 mM.

Mononuclear and polynuclear copper(II) complexes derived from pyridylalkylaminomethylphenol polypodal ligands.

Four mononuclear complexes [Cu(HL(1))Cl]PF(6).CH(3)OH (1), [Cu(HSL(1))Cl]PF(6).0.75H(2)O (2), [Cu(HL(2))Cl]PF(6).CH (3)OH (3), [Cu(HSL(2))Cl]PF(6).1.5CH(3)OH (4), and two polynuclear complexes [Cu (2)(SL(2))(2)](PF(6))(2).2CH(3)OH (5) and {Cu[Cu(SL(2))(Cl)](2)}(PF(6))(2) (6) (HL(1): 2-[(bis(2-pyridylmethyl)-amino)methyl]-4-methylphenol; HSL(1): 2-[(bis(2-pyridylmethyl)amino) methyl]-4-methyl-6-(methyl-thio)phenol; HL(2): 2-[(2-pyridylmethyl)(2'-pyridylethyl)-aminomethyl)]-4-methylphenol; HSL(2): 2-[(2-pyridylmethyl)(2'-pyridylethyl)amino-methyl]-4-methyl-6-(methylthio)phenol were obtained and characterized. The crystal structures of the mononuclear complexes 1-4 show the copper centers in a square-base pyramidal environment with the phenolic oxygen coordinated at the axial position. Dinuclear complex 5 has two copper centers with different geometry and bridged by phenoxo oxygens; one of the copper atoms is square pyramidal while the other can be described with a highly distorted octahedral geometry with a long Cu-S distance (2.867 A). Density functional theory calculations were used to obtain the reported structure of 6, since single crystals suitable for X-ray diffraction were not isolated. Magnetic studies done for 5 and 6 show an antiferromagnetic behavior for 5 (J = -134 cm(-1)) and a ferromagnetic behavior for 6 (J = +11.9 cm(-1)). Redox potentials for the mononuclear complexes were measured by cyclic voltammetry; the values show the effect of the chelating ring size (-213 mV and -142 mV for Cu-HL(1) and Cu-HL(2), respectively) and the presence of the thiomethyl substituent (-213 mV and -184 mV for Cu-HL(1) and Cu-HSL(1), respectively).

LQFM030 reduced Ehrlich ascites tumor cell proliferation and VEGF levels.

AIMS: This study reports the biological properties of LQFM030 in vivo, a molecular simplification of the compound nutlin-1. MAIN METHODS: Ehrlich ascites tumor (EAT)-bearing mice were treated intraperitoneally with LQFM030 (50, 75 or 150mg/kg) for 10days to determine changes in ascites tumor volume, body weight, cytotoxicity and angiogenesis. Moreover, flow cytometric expression of p53 and p21 proteins and caspase-3/7, -8 and -9 activation were investigated in EAT cells from mice treated. Acute oral systemic toxicity potential of LQFM030 in mice was also investigated using an alternative method. KEY FINDINGS: Treatment of EAT-bearing mice with LQFM030 resulted in a marked decline in tumor cell proliferation and the vascular endothelial growth factor (VEGF) levels along with enhanced survival of the mice. Apoptotic tumor cell death was detected through p53 and p21 modulation and increase of caspase-3/7, -8 and -9 activity. LQFM030 also showed orally well tolerated, being classified in the UN GHS category 5 (LD50>2000-5000mg/Kg). SIGNIFICANCE: LQFM030 seems to be a promising antitumor candidate for combinatory therapy with typical cytotoxic compounds, reducing the toxicity burden while allowing a superior anticancer activity. Moreover, these data also open new perspectives for LQFM030 as an antiangiogenic agent for treatment of diseases involving VEGF overexpression.

Antinociceptive, anti-inflammatory and anxiolytic-like effects of the ethanolic extract, fractions and Hibalactone isolated from Hydrocotyle umbellata L. (Acariçoba) - Araliaceae.

Hydrocotyle umbellata Linn. (Araliaceae) is specie used in the treatment of inflammatory diseases. Crude extract (E-HU) was prepared from H. umbellata subterraneous parts and fractionated by liquid-liquid partition, resulting hexane fraction (HF-HU), dichloromethane fraction (DF-HU), ethyl acetate fraction (EAF-HU) and aqueous fraction (AF-HU). The hibalactone (HU-1) was isolated from the DF-HU and its structure was elucidated by 1H NMR and 13C NMR Spectroscopy, mass spectrometry and crystallographic x-ray analysis. The formalin-induced nociception was used to evaluate antinociceptive activity; carrageenan-induced edema and pleurisy tests to evaluate anti-inflammatory activity and light-dark box to evaluate anxiolytic-like activity in mice. The acute oral treatments with E-HU (1000mg/kg), DF-HU (150mg/kg), EAF-HU (400mg/kg) and HU-1 (33mg/kg) decreased the licking time in both phases of the formalin test. In the carrageenan-induced inflammation models, the treatment with the same doses of E-HU, DF-HU, EAF-HU and HU-1 reduced the paw edema formation and leukocytes account into pleural cavity. In silico findings suggest that hibalactone present anti-inflammatory activity by interacting with the enzymes 5-lipoxygenase and cyclooxygenase-2. In the light dark box, the treatments with DF-HU, EAF-HU and HU-1 revealed an anxiolytic like effect. Thus, the E-HU and fractions of H. umbellata showed antinociceptive, anti-inflammatory and anxiolytic like activities, as also hibalactone, a possible phytoconstituent responsible for the biological effects of this specie.

Metal complexes of a pentadentate N2O3bis(semicarbazone) Schiff-base. A case study of structure-spectroscopy correlation.

Schiff condensation of 2,6-diformyl 4-methylphenol with semicarbazide hydrochloride in 1:2 molar ratio produces the bis(semicarbazone) ligand, herein called H3L. A comprehensive spectroscopic analysis of the compound was performed by (1)H and (13)C NMR, FTIR and electronic spectroscopies. Assignments to the UV-vis spectrum of H3L were supported by semi-empirical quantum mechanics ZINDO/S calculations. The ligand H3L forms monoclinic crystals in the space group P21/c and its structure is stabilized by classic hydrogen bonds with propanone molecules. It promptly reacts with first row metal ions to produce the following coordination compounds: [Co2(L)(µ-NO3)]·DMF, [Ni2(H2L)(µ-CH3COO)(CH3COO)2]·2H2O, [Cu2(L)(µ-NO3)(H2O)2]·H2O, [Cu2(L)(µ-CH3COO)(H2O)2]·H2O and [Cu2(H2L)(µ-Cl)Cl2]·3H2O, that have different compositions, depending on the degree of deprotonation of the ligand upon coordination. Electronic and EPR spectroscopies as well as effective magnetic moment measurements of the complexes were used in an attempt to better understand their mode of coordination, the microsymmetry around the metal ions and magnetic properties.

Docking, synthesis and antiproliferative activity of N-acylhydrazone derivatives designed as combretastatin A4 analogues.

Cancer is the second most common cause of death in the USA. Among the known classes of anticancer agents, the microtubule-targeted antimitotic drugs are considered to be one of the most important. They are usually classified into microtubule-destabilizing (e.g., Vinca alkaloids) and microtubule-stabilizing (e.g., paclitaxel) agents. Combretastatin A4 (CA-4), which is a natural stilbene isolated from Combretum caffrum, is a microtubule-destabilizing agent that binds to the colchicine domain on ß-tubulin and exhibits a lower toxicity profile than paclitaxel or the Vinca alkaloids. In this paper, we describe the docking study, synthesis, antiproliferative activity and selectivity index of the N-acylhydrazone derivatives (5a-r) designed as CA-4 analogues. The essential structural requirements for molecular recognition by the colchicine binding site of ß-tubulin were recognized, and several compounds with moderate to high antiproliferative potency (IC50 values ≤18 µM and ≥4 nM) were identified. Among these active compounds, LASSBio-1586 (5b) emerged as a simple antitumor drug candidate, which is capable of inhibiting microtubule polymerization and possesses a broad in vitro and in vivo antiproliferative profile, as well as a better selectivity index than the prototype CA-4, indicating improved selective cytotoxicity toward cancer cells.

Disceratose congênita: síndrome de Zinsser, Engman e Cole / Dyskeratosis congenita: syndrome of Zinsser, Engman and Cole

Apresenta-se um paciente do sexo masculino, com 22 anos, portador de disceratose congênita, cujos primeiros sintomas tiveram início aos cinco anos de idade. Associados aos sintomas cutâneos e mucosos, observamos também sintomas hematológicos e intestinais