Jayathirtha Rao Vaidya

Simultaneous determination of atorvastatin, amlodipine, ramipril and benazepril in human plasma by LC‐MS/MS and its application to a human pharmacokinetic study

A rapid, simple, sensitive and specific LC-MS/MS method has been developed and validated for the simultaneous estimation of atorvastatin (ATO), amlodipine (AML), ramipril (RAM) and benazepril (BEN) using nevirapine as an internal standard (IS). The API-4000 LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. Analytes and IS were extracted from plasma by simple liquid-liquid extraction technique using ethyl acetate. The reconstituted samples were chromatographed on C(18) column by pumping 0.1% formic acid-acetonitrile (15:85, v/v) at a flow rate of 1 mL/min. A detailed validation of the method was performed as per the FDA guidelines and the standard curves were found to be linear in the range of 0.26-210 ng/mL for ATO; 0.05-20.5 ng/mL for AML; 0.25-208 ng/mL for RAM and 0.74-607 ng/mL for BEN with mean correlation coefficient of ≥0.99 for each analyte. The intra-day and inter-day precision and accuracy results were well with in the acceptable limits. A run time of 2.5 min for each sample made it possible to analyze more than 400 human plasma samples per day. The developed assay method was successfully applied to a pharmacokinetic study in human male volunteers.

Stability Indicating RP-HPLC Studies for the Estimation of Irbesartan and Amlodipine Besylate in Pharmaceutical Formulations and Identification and Characterization of Degradants Using LC-MS

A simple, specific, accurate, and stability-indicating reversed-phase high-performance liquid chromatography method was developed for simultaneous estimation of irbesartan and amlodipine besylate in pharmaceutical formulations. The chromatographic separation was achieved on a Zorbax CN column using a mixture of 1 mM potassium dihydrogen phosphate (pH 3.0) and acetonitrile (70:30, v/v) as the mobile phase at a flow rate of 0.9 mL/min. Detection was carried out at 240 nm. The calibration curves were linear (R 2 ≥ 0.99) over a concentration range of 6–42 µg/mL for irbesartan and 2–14 µg/mL for amlodipine besylate. The retention times of irbesartan and amlodipine besylate were 9.6 and 7.6 min, respectively. For stability studies, irbesartan and amlodipine besylate stock solutions were subjected to acid, alkali hydrolysis, chemical oxidation, and dry heat degradation. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention times and resolution. To elucidate structures of degradation products, the LC-MS method was used. The proposed method was successfully validated in accordance to the ICH guidelines acceptance criteria.

An efficient catalyst-free one-pot synthesis of primary amides from the aldehydes of the Baylis–Hillman reaction

Herein, a facile and efficient method for the preparation of allyl amides from the aldehyde of Baylis–Hillman adducts has been developed using a hydroxylamine/methanol system under a catalyst-free condition. The effects of solvents and temperature on the reaction and substituents on the phenyl ring have been examined. This method is best demonstrated by its advantages such as operational simplicity, moderate to excellent yields, short reaction time, and simple reaction procedure. Most importantly, the reaction proceeds smoothly in the absence of a catalyst and an external oxidant.

In silico and in vitro studies of novel 7-azaindole and 7-azaisatin derivatives as potent anticancer agents

Abstract A series of novel 7-azaindole (1a–j) and 7-azaisatin (2a–j) derivatives were screened for their in vitro breast, lung and liver cytotoxic activities against MCF-7, A549 and HEPG2 cell lines, respectively, by MTT assay method. Among them, compounds 1h, 1i, 2h and 2i have shown good breast cytotoxic activity, and compounds 1h and 1i showed good lung cytotoxic activity and liver cytotoxic activity. These derivatives were also subjected to molecular docking study to investigate the mode of binding with the EGFR kinase, and the compounds showing similar type of docking score and binding patterns with that of the existing drug molecules such as gefitinib. 3D-QSAR studies were done using V-Life Sciences MDS 4.3 drug designing module to explain the structural requirements for the anticancer activity. Since compounds 1h and 1i exhibited high potent activity against MCF-7, A549 and HEPG2 cell lines, they could be effective epidermal growth factor receptor kinase inhibitors.Graphical Abstract

Triphosgene mediated chlorination of Baylis–Hillman adducts

AbstractAn efficient method for the preparation of allyl chlorides from Baylis–Hillman adducts has been developed using triphosgene/pyridine system. This method is best illustrated by its advantages like operational simplicity, excellent yields, short reaction time, simple procedure and stereoselectivity. Graphical AbstractThe preparation of allyl chlorides from Baylis-Hillman adducts has been described using triphosgene & pyridine system. The efficiency of this method is best illustrated by some of the advantages, like operational simplicity, excellent yields, short reaction time, simple procedure and stereoselectivity.

IITZ-01, a novel potent lysosomotropic autophagy inhibitor, has single-agent antitumor efficacy in triple-negative breast cancer in vitro and in vivo

Autophagy is a homeostatic process that recycles damaged organelles and long-lived proteins by delivering them in double-membrane vesicles to lysosomes for degradation. Autophagy has a prominent role in survival, proliferation, and resistance of tumors in metabolic and chemotherapeutic stress conditions. Clinical trials with chloroquine—a known autophagy inhibitor—were unable to achieve complete autophagy inhibition in vivo, warranting the search for more potent autophagy inhibitors. In a process of exploring the mechanism of action of previously identified cytotoxic s-triazine analogs, we discovered that both IITZ-01 and IITZ-02 act as potent autophagy inhibitors. Treatment with these compounds resulted in the vacuolated appearance of cells due to their specific accumulation in lysosomes. In addition, these basic compounds also deacidify lysosomes as evidenced by the decrease in lysotracker red staining and inhibit maturation of lysosomal enzymes leading to lysosomal dysfunction. IITZ-01 and IITZ-02 enhance autophagosome accumulation but inhibit autophagosomal degradation by impairing lysosomal function, finally resulting in the inhibition of autophagy. Interestingly, compound IITZ-01 exhibited more than 10-fold potent autophagy inhibition along with 12- to 20-fold better cytotoxic action than CQ. IITZ-01 and IITZ-02 also abolished mitochondrial membrane potential and triggered apoptosis through the mitochondria-mediated pathway. Furthermore, IITZ-01 and IITZ-02 displayed potent antitumor action in vivo through autophagy inhibition and apoptosis induction in MDA-MB-231 breast cancer xenograft model with IITZ-01 exhibiting superior anticancer efficacy. Overall, these data demonstrate that IITZ-01 is potent autophagy inhibitor with single-agent anticancer activity and awaits further preclinical development as potential anticancer therapeutic.

PhI(OAc)2/NaX-mediated Halogenation Providing Access to Valuable Synthons 3-Haloindole derivatives

This paper describes a mild phenyliodine diacetate mediated method for selective chlorination, bromination, and iodination of indole C–H bonds using sodium halide as a source for analogous halogenations. The combination of NaX and phenyliodine diacetate provides an invincible system for halogenation of indoles. This protocol was compatible with a wide array of indole substrates and provides straight forward access to potential halogenated arenes.

Synthesis and Bioevaluation of Quaternary Centered 3-hydroxy-3 (alkynyl)indolin-2- one Derivatives as Potential Cytotoxic Agents and Akt Kinase Inhibitors

BACKGROUND Alkynes are fundamental building blocks in synthetic chemistry with high pharmaceutical applications. Among the bioactive acetylenic molecules, propargylic alcohol is most important as almost all the marketed drugs contains quaternary centered propargylic alcohol functionality. OBJECTIVE In this study we have synthesised and evaluated 3-hydroxy-3-ethynylindolin-2-one derivatives for in vitro cytotoxic activity. METHOD An expeditious method for direct alkynylation of isatins (ketones) has been developed using tetrabutylammonium fluoride (TBAF) as a catalyst in THF solvent at room temperature under metal-free conditions. Furthermore, this method is an economically viable process that also compliments green aspects like being a ligand/metal free process under ambient conditions. This reaction tolerated a wide range of substrates with good to excellent yields (80-94%). RESULTS The results showed that the synthesized compounds (4m, 4n and 4p) has the ability to inhibit Akt kinase activity with IC50 values ranging from 7.7 to 9.8 µM. CONCLUSION All the 3-hydroxy-3-ethynylindolin-2-one derivatives were subjected for in vitro cytotoxic activity on five different cancer cell lines. Further, the synthesized compounds (4m, 4n and 4p) were evaluated for their ability to inhibit Akt kinase activity and exhibited good inhibition with IC50 values ranging from 7.7 to 9.8 µM..