Thermal and spectroscopic investigation of novel Schiff base, its metal complexes, and their biological activities

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Terazosin (C 19 H 25 N 5 O 4 , MW = 387) drug is a selective alpha 1 antagonist. It is used for lowering the blood pressure. Also, it used for treatment of symptoms of an enlarged prostate and is therefore a drug of choice for men with hypertension and prostate enlargement. In the present study, mass spectrometry (MS) and thermal analyses (TA) were used to investigate the fragmentation decomposition pathways of terazosin and confirmed by semi-empirical molecular orbital (MO) calculation, using PM3 procedure on the neutral and the positively charged species of the drug. These calculations included, bond length, bond order, partial charge distribution, ionization energy and heats of formation (DH f ). The mass spectra and TA fragmentation pathways were proposed and compared to each other to select the most suitable scheme representing the correct fragmentation pathway of the drug in both techniques. This selection helps understanding of metabolism of the drug in vivo system. Therefore, comparison between MS and TA helps in selection, the proper pathway representing the fragmentation of this drug. This comparison successfully confirmed by MO calculation. Graphical Abstract In the present study, mass spectrometry (MS) and thermal analyses (TA) were used to investigate the fragmentation decomposition pathways of terazosin and confirmed by semi-empirical molecular orbital (MO) calculations. The mass spectra and thermal analyses fragmentation pathways were proposed and compared to each other to select the most suitable scheme representing the correct fragmentation pathway of the drug in both techniques. This selection helps understanding of metabolism of the drug in vivo system. Terazosin hydrochloride (C 19 H 25 N 5 O 4 ) drug (marketed ITRIN), has an IUPAC name; 2-[4-(2-tetrahydrofuranyl) carbonyl]-1 piperazinyl-6,7-dimethoxy-4-quinazolinamine monohydrochloride dihydrate, and its stereo structure is given below

Section: Resultsmentioning

confidence: 99%

Section: Thermal Analyses and Mocs Of Neutral Tera Moleculementioning

confidence: 90%

Structure characterization of terazosin drug using mass spectrometry and thermal analyses techniques in comparison with semi-empirical molecular orbital (MO) calculations

Zayed

Fahmey²,

El-Desawy³

et al. 2015

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“…Thermal properties of potentially biological active compounds are essential to their future usage. Therefore thermal analysis is a common part of characterizing compounds with biological activity [20,21,22,23,24,25]. Thermoanalytical methods provide important information on the thermal stability, polymorphic forms or structural changes [26,27,28], and purity of potential new drugs [29,30,31,32].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, physico-chemical characterization and bacteriostatic study of Pt complexes with substituted amine ligands

Holló

Szilágyi

Várhelyi

et al. 2016

Three complexes of general formula PtCl 2 R 2 were synthesized, where R is the amine ligand with aromatic substituents. Coordination compounds [Pt(an) 2 Cl 2 ] (1), [Pt(pa) 2 Cl 2 ] (2) and [Pt(aph) 2 Cl 2 ] (3), where an is 2-aminonaphtalene, pa is 2-pyrimidinamine and aph is 4-anilinophenol, were characterized by on-line coupled TG/DTA-MS, powder XRD and spectroscopic techniques (FTIR, ESI-MS and NMR), and tested against selected Gram(+) and Gram(-) bacteria. The thermal data show that all three compounds contain lattice or absorbed water, and the stability of the anhydrous compounds in nitrogen decreases in the order 2 > 1 > 3. Above 200 °C, the complexes loose characteristic fragments of their ligands. The spectroscopic data are in accordance with the thermal properties of the samples and prove their composition. The compounds are more effective inhibitors of Gram(+) than Gram(−) bacteria.

“…Numerous Schiff-base complexes exhibit remarkable biological [1] or electrocatalytic activity [2]. The thermal analysis of compounds with potential biological activity is a common part in their characterization [3,4] as offers valuable, sometimes essential data to develop new pharmaceutical forms [5] or to detect structural changes or polymorphism [6] in materials used in drug formulation or in their quality control [7].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and thermal behavior of copper(II) complexes with pyridoxal thiosemi (PLTSC)- and S-methylisothiosemicarbazone (PLITSC)

Vojinović-Ješić

Rodić

Holló

et al. 2015

The syntheses of complexes of Cu(II) with biological active ligand, pyridoxal thiosemicarbazone (PLTSC) and its derivative, pyridoxal S-methylisothiosemicarbazone, are described. All coordination compounds were characterized by elemental analysis, molar conductivity and infrared spectra. The crystal and molec-is determined by single-crystal X-ray crystallography, too. The thermal decomposition of all the ligands and complexes was determined by simultaneous TG/DSC measurements. The decomposition mechanisms were compared and analyzed from the aspects of the relationships between the structures of the compounds and their thermal decomposition pattern.