UPLC-MS/MS determination of suvorexant in urine by a simplified dispersive liquid-liquid micro-extraction followed by ultrasound assisted back extraction from solidified floating organic droplets.

Suvorexant is a novel sedative/hypnotic drug approved for treatment of insomnia. It has significant forensic importance due to its hypnotic and depressant effects on central nervous system. In this study, a highly sensitive UPLC-MS/MS assay was developed and validated for the determination of suvorexant in urine sample.

Simultaneous Detection and Quantification of Three Novel Prescription Drugs of Abuse (Suvorexant, Lorcaserin and Brivaracetam) in Human Plasma by UPLC-MS-MS.

Suvorexant (SVR), lorcaserin (LCR) and brivaracetam (BVR) have been recently approved for the treatment of insomnia, obesity and epilepsy, respectively. Despite their clinical uses, these drugs have some abuse potential and have been enlisted under the schedule IV (SVR, LVR) and schedule V (BVR) categories of the Controlled Substances Act. A sensitive UPLC-MS-MS assay was developed for simultaneously determining SVR, LCR and BVR in human plasma.

UPLC/MS-MS assay development for estimation of mozavaptan in plasma and its pharmacokinetic study in rats.

Aim: Mozavaptan is a nonpeptide vasopressin receptor antagonist approved for the treatment of ectopic antidiuretic hormone secretion syndrome.

Methods & Results: A simple, rapid and fully validated UPLC/MS-MS method was developed for the quantitation of mozavaptan in rat plasma. The chromatographic separation was conducted on an Acquity UPLC BEH™ C column with an optimum mobile phase of 10 mM ammonium acetate buffer and 0.

A validated UPLC-MS/MS method for flibanserin in plasma and its pharmacokinetic interaction with bosentan in rats.

Aim: The purpose of this study was development, validation and application of ultra-performance liquid chromatography (UPLC)-ESI-MS/MS method for quantitation of flibanserin in plasma samples.

Method & Results: After extraction of analyte from plasma by diethyl ether, separation was performed on UPLC C column using mobile phase composition of 10 mM ammonium formate-acetonitrile (30:70, v/v) by isocratic elution of 0.3 ml/min.

Method development for quantification of quizartinib in rat plasma by liquid chromatography/tandem mass spectrometry for pharmacokinetic application.

Quizartinib is a highly potent inhibitor of the fms-like tyrosine kinase receptor, which is one of the most commonly mutated genes in acute myeloid leukemia. Quizartinib has shown a significant antileukemic clinical influence among relapsed/refractory acute myeloid leukemia patients. This study aimed at developing and validating an analytical method for the measurement of quizartinib in rat plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

High throughput μ-SPE based elution coupled with UPLC-MS/MS for determination of eluxadoline in plasma sample: Application in pharmacokinetic characterization of PLGA nanoparticle formulations in rats.

Eluxadoline is a novel μ- and κ-opioid receptor (OR) agonist and δ-OR antagonist, recently approved as a first line therapy for the treatment of irritable bowel syndrome. Due to abuse potential, poor bioavailability and high intersubject variability, a sensitive and reliable assay is prerequisite for its determination in biological samples. This work first time report the development and validation of UPLC-MS/MS assay for determination of eluxadoline in rat plasma sample using risperidone as an internal standard (IS).

Cancer stem cells CD133 inhibition and cytotoxicity of certain 3-phenylthiazolo[3,2-a]benzimidazoles: design, direct synthesis, crystal study and in vitro biological evaluation.

Cancer stem cells (CSCs) have been objects of intensive study since their identification in 1994. Adopting a structural rigidification approach, a novel series of 3-phenylthiazolo[3,2-a]benzimidazoles 4a-d was designed and synthesised, in an attempt to develop potent anticancer agent that can target the bulk of tumour cells and CSCs. The anti-proliferative activity of the synthesised compounds was evaluated against two cell lines, namely; colon cancer HT-29 and triple negative breast cancer MDA-MB-468 cell lines.

UPLC-MS/MS assay for identification and quantification of brivaracetam in plasma sample: Application to pharmacokinetic study in rats.

Brivaracetam (BVR) is a novel antiepileptic drug (AED), approved clinically for the treatment of partial onset seizures in adults and adolescents. It has some abuse potential and assigned to Schedule V category under the Controlled Substance Act by the Drug Enforcement Administration. Being an AED and drug of abuse, a sensitive and robust assay is necessary for determination of BVR in biological fluids.

Simple and Highly Sensitive UPLC-ESI-MS/MS Assay for Rapid Determination of Suvorexant in Plasma.

Suvorexant is a dual orexin receptor antagonist, recently approved by USFDA for the treatment of insomnia. It is drug-of-abuse and listed in Schedule IV drug of the Controlled Substances Act. In this study, a simple and highly sensitive UPLC-MS/MS assay was developed and fully validated for the determination of suvorexant in rat plasma.

Determination of apremilast in rat plasma by UPLC-MS/MS in ESI-negative mode to avoid adduct ions formation.

Background: Quantification of target analyte by LC-MS/MS is sometimes hampering due to competitive adduct ions formation (sodium and/or ammonium) in positive ionization mode. A UPLC-MS/MS assay was developed for the determination of apremilast in rat plasma using ESI-negative mode to avoid adduct ions formation.

Method & Results: After extraction from plasma by ethyl acetate, analyte and IS were separated on Aquity BEH C column using acetonitrile-10 mM ammonium acetate (85:15) as mobile phase.

A Validated UPLC-MS-MS Assay for the Rapid Determination of Lorcaserin in Plasma and Brain Tissue Samples.

Lorcaserin is a novel, potent and highly efficacious 5-HT2C receptor agonist, recently approved by US Food and Drug Administration for the treatment of obesity. It has some abuse potential also and is listed as a Schedule IV drug in the Controlled Substances Act. Herein, a sensitive, selective and reliable UPLC-MS-MS assay was developed and validated for the quantitative analysis of lorcaserin in rat plasma and brain tissue using carbamazepine as an internal standard (IS).

2-((Benzimidazol-2-yl)thio)-1-arylethan-1-ones: Synthesis, crystal study and cancer stem cells CD133 targeting potential.

In order to develop a potent anti-tumor agent that can target both cancer stem cells and the bulk of tumor cells, a series of 2-((benzimidazol-2-yl)thio)-1-arylethan-1-ones 5a-o was synthesized. All compounds were evaluated for their anti-proliferative activity towards colon HT-29 cancer cell line. In addition, their inhibitory effect against cell surface expression of CD133, a potent cancer stem cells (CSCs) marker, in the same cells was evaluated by flow cytometry at 10 μM.

Preclinical pharmacokinetics, tissue distribution and excretion studies of a novel anti-candidal agent-thiosemicarbazide derivative of isoniazid (TSC-INH) by validated UPLC-MS/MS assay.

A simple and sensitive UPLC-MS/MS assay was developed and validated for rapid determination of thiosemicarbazide derivative of isoniazid (TSC-INH), a potent anti-candidal agent in rat plasma, tissues, urine and feces. All biological samples were prepared by protein precipitation method using celecoxib as an internal standard (IS). Chromatographic separation was achieved on Acquity BEH™ C18 (50×2.

Synthesis, biological evaluation and 2D-QSAR study of halophenyl bis-hydrazones as antimicrobial and antitubercular agents.

In continuation of our endeavor towards the development of potent and effective antimicrobial agents, three series of halophenyl bis-hydrazones (14a-n, 16a-d, 17a and 17b) were synthesized and evaluated for their potential antibacterial, antifungal and antimycobacterial activities. These efforts led to the identification of five molecules 14c, 14g, 16b, 17a and 17b (MIC range from 0.12 to 7.

A validated UPLC-MS/MS assay using negative ionization mode for high-throughput determination of pomalidomide in rat plasma.

In this study, a sensitive UPLC-MS/MS assay was developed and validated for high-throughput determination of pomalidomide in rat plasma using celecoxib as an internal standard (IS). Liquid liquid extraction using dichloromethane was employed to extract pomalidomide and IS from 200μL of plasma. Chromatographic separation was carried on Acquity BEH™ C18 column (50mm×2.

Rapid determination of canagliflozin in rat plasma by UHPLC-MS/MS using negative ionization mode to avoid adduct-ions formation.

Canagliflozin is the first sodium-glucose co-transporter-2 inhibitor, approved by the US Food and Drug Administration for the treatment of type 2 diabetes mellitus. In this study, a sensitive UHPLC-MS/MS assay for rapid determination of canagliflozin in rat plasma was developed and validated for the first time. Chromatographic separation of canagliflozin and zafirlukast (IS) was carried out on Acquity BEH C18 column (100×2.

A simple and fast UHPLC-MS-MS assay for rapid determination of vilazodone in plasma sample.

Vilazodone is a novel antidepressant agent, approved by the US Food and Drug Administration (US FDA) for the treatment of major depressive disorder. In this study, a fast sensitive ultra-high performance liquid chromatography-tandem mass spectroscopy method was developed and validated for the determination of vilazodone in human plasma. After a simple protein precipitation by acetonitrile, both vilazodone and risperidone (internal standard, IS) were separated on an Acquity UPLC BEH™ C18 column (50 × 2.

Synthesis of N-benzenesulfonamide-1H-pyrazoles bearing arylsulfonyl moiety: novel celecoxib analogs as potent anti-inflammatory agents.

The reaction of arylsulfones 11a-d with hydrazonoyl chloride derivative 13 furnished celecoxib analogs 4-(3-acetyl-5-aryl-4-(arylsulfonyl)-1H-pyrazol-1-yl)benzenesulfonamides 15a-d, respectively. Oximes 16a, b and hydrazones 17a, b were prepared by reacting sulfones 11a, b with hydroxyl amine and phenyl hydrazine, respectively. The anti-inflammatory activity of the synthesized compounds showed that, 5-(4-bromophenyl)-4-(phenylsulfonyl)pyrazole 15c and 5-(4-bromophenyl)-4-(4-tolylsulfonyl)pyrazole 15d exhibited excellent anti-inflammatory activity with ED50 = 68 ± 2.

Multistage fragmentation of ion trap mass spectrometry system and pseudo-MS3 of triple quadrupole mass spectrometry characterize certain (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones: a comparative study.

A new approach was recently introduced to improve the structure elucidation power of tandem mass spectrometry simulating the MS(3) of ion trap mass spectrometry system overcoming the different drawbacks of the latter. The fact that collision induced dissociation in the triple quadrupole mass spectrometer system provides richer fragment ions compared to those achieved in the ion trap mass spectrometer system utilizing resonance excitation. Moreover, extracting comprehensive spectra in the ion trap needs multistage fragmentation, whereas similar fragment ions may be acquired from one stage product ion scan using the triple quadrupole mass spectrometer.

Simple and rapid determination of zafirlukast in plasma by ultra-performance liquid chromatography tandem mass spectrometric method: application into pharmacokinetic study in rabbits.

Zafirlukast is a selective leukotriene receptor antagonist used for the prophylaxis and chronic treatment of asthma. The aim of the present study was to develop a simple sensitive ultra-performance liquid chromatography tandem mass spectroscopy method for rapid determination of zafirlukast in plasma. After a simple one step protein precipitation by acetonitrile, zafirlukast and montelukast (IS) were separated on Acquity UPLC BEH(TM) C18 column (50 × 2.

Synthesis and anticancer potential of certain novel 2-oxo-N'-(2-oxoindolin-3-ylidene)-2H-chromene-3-carbohydrazides.

Treatment of ethyl 3-hydrazinyl-3-oxopropanoate (6) with indoline-2,3-dione derivatives 7a-g gave ethyl 3-oxo-3-(2-(2-oxoindolin-3-ylidene)hydrazinyl)propanoates 8a-g which were allowed to react with the appropriate salicyaldehyde 9a and/or 9b to furnish the chromene-based hydrazones 10a-i. Compounds 10a-i displayed a significant activity against HT-29 colon cancer cell line and a moderate activity against leukemia K562 cell line. Compound 10f emerged as the most active congener toward HT-29 colon cancer cell line with IC₅₀ = 7.

1-(4-Methyl-phen-yl)-2-(phenyl-sulfon-yl)ethanone.

In the title compound, C(15)H(14)O(3)S, the benzene and phenyl rings make a dihedral angle of 33.56 (16)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds into a layer parallel to the ab plane.

3-(1H-Imidazol-1-yl)-1-phenyl-propan-1-ol.

In the title compound, C(12)H(14)N(2)O, the imidazole ring forms a dihedral angle of 66.73 (5)° with the phenyl ring. In the crystal, mol-ecules are linked via O-H⋯N and C-H⋯O hydrogen bonds into sheets lying parallel to (100).

5,6-Dimethyl-4-(thio-phen-2-yl)-1H-pyrazolo-[3,4-b]pyridin-3-amine.

In the title mol-ecule, C(12)H(12)N(4)S, the thio-phene ring is disordered over two orientations with a refined site-occupancy ratio of 0.777 (4):0.223 (4).