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

Abstract

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

Structure Studies of the Prepared Novel Hydrazone Schiff’s Base Complexes Using Spectroscopic, Thermal Analyses and Their Biological Activities

“…The transitions correspond to the octahedral geometry of the complex which is also supported by its magnetic susceptibility value (3.06 BM) [25,26,27,28].…”

Spectroscopic Studies and Applications of the Reactions of Some Anti-Diabetic and Anti-Hypertensive Drugs with Rose Bengal

“…From Table 4, the values of the recovery and the low values of SD of the proposed methods indicate the high accuracy and precision of the proposed methods for the microdetermination of TRZ, DOX and PIOG drugs in the pharmaceutical dosage forms. The accuracy and the precision of the proposed methods are compared with those obtained from the official methods by student's t-test and F-test, respectively, at confidence limit 95% and P=0.05 [29]. The obtained values of F-test and t-test indicate that there is no significant difference between the accuracy and the precision of the proposed and the official methods and hence the reliability of the proposed methods for the routine analysis of TRZ, DOX and PIOG drugs in pure and in their pharmaceutical formulations.…”

Catalyst‐free Synthesis of 5‐Arylimidazo[1,2‐c]quinazoline Derivatives in Ionic Liquids

“…There are many drugs on the market used for the treatment of various kinds of human diseases, such as Terazosin , Gefitinib , Erlotinib and Lapatinib . Of which, Terazosin is not only used to treat symptoms of an enlarged prostate but also used for men with hypertension and prostate enlargement . In addition, imidazo[1,2‐ c ]quinazoline is a fused tricyclic heterocycle; it is reported that its derivatives have many pharmacological and biological applications including cytotoxic , antimalarial , antimicrobial , and antiapoptotic activities .…”