Month: February 2023

Development of a pH-dependent homogeneous liquid-liquid extraction by cold-induced phase separation in acetonitrile/water mixtures for determination of quinolone residues in animal-derived foods was written by Hu, Shuping;Zhao, Min;Wang, Zhongle;Yang, Jiaying;Chen, Dawei;Yan, Pengcheng. And the article was included in Journal of Chromatography A in 2021.Product Details of 113617-63-3 This article mentions the following:

A simple extraction procedure coupled with liquid chromatog.-Q Orbitrap high resolution mass spectrometry (LC-Q Orbitrap HRMS) for the determination of 19 quinolones in animal-derived foods (pork, fish, egg and milk) has been developed. Sample preparation is based on homogeneous liquid-liquid extraction at pH > 9 using water-miscible acetonitrile with cold-induced phase separation The procedure allowed one-step enrichment and cleanup of all the 19 quinolones with different logP properties to lower aqueous phase, which eliminated the process of preconcentration and re-dissolution for sample solution Furthermore, an adsorption phenomenon was observed between conventional borosilicate glass injection vials and most of quinolones. In detection anal., a scheduled variable full scan strategy was performed to improve detection performance in Q Orbitrap HRMS. Under optimal conditions, a superior limit of quantitation (0.028-0.192μg/kg) in animal-derived foods was achieved using this proposed method. Lastly, this method was validated and applied successfully in real samples. In the experiment, the researchers used many compounds, for example, 1-Cyclopropyl-7-(cis-3,5-dimethylpiperazin-1-yl)-5,6,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (cas: 113617-63-3Product Details of 113617-63-3).

1-Cyclopropyl-7-(cis-3,5-dimethylpiperazin-1-yl)-5,6,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (cas: 113617-63-3) belongs to piperazine derivatives. A form in which piperazine is commonly available industrially is as the hexahydrate, C4H10N2. 6H2O, which melts at 44 °C and boils at 125–130 °C. Although many piperazine derivatives occur naturally, piperazine itself can be synthesized by reacting alcoholic ammonia with 1,2-dichloroethane, by the action of sodium and ethylene glycol on ethylene diamine hydrochloride, or by reduction of pyrazine with sodium in ethanol.Product Details of 113617-63-3

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

Synthesis and biological evaluation of benzopyran analogues bearing class III antiarrhythmic pharmacophores was written by Koufaki, Maria;Kiziridi, Christina;Papazafiri, Panagiota;Vassilopoulos, Athanasios;Varro, Andras;Nagy, Zsolt;Farkas, Attila;Makriyannis, Alexandros. And the article was included in Bioorganic & Medicinal Chemistry in 2006.Formula: C11H13N3O3 This article mentions the following:

We have synthesized a series of compounds combining the hydroxy-benzopyran ring of vitamin E with the methylsulfonylaminophenyl group of class III antiarrhythmic drugs, connected through tertiary amine moieties. Evaluation of the antiarrhythmic and antioxidant activity of the new compounds was carried out on isolated rat heart preparations using the non-recirculating Langendorff mode. The new analogs were present, at 10 μM concentration, during ischemia and reperfusion. Selected compounds were further studied by a conventional microelectrode method in order to get insight into their cellular mode of action. The most active compound, N-[4-[2-[[2-(3,4-dihydro-6-hydroxy-2,2,7,8-tetramethyl-2H-1-benzopyran-5-yl)ethyl] methylamine]ethyl]phenyl]methanesulfonamide (19a, I), reduces premature beats, prolongs QT and QRS intervals during ischemia and reperfusion, and reduces MDA content, leading to a fast recovery of the heart. In addition, it exhibits moderate class III antiarrhythmic action. In the experiment, the researchers used many compounds, for example, (4-Nitrophenyl)(piperazin-1-yl)methanone (cas: 72141-41-4Formula: C11H13N3O3).

(4-Nitrophenyl)(piperazin-1-yl)methanone (cas: 72141-41-4) belongs to piperazine derivatives. Piperazine causes primary dermal irritation and skin burns at high concentrations. Piperazine also causes eye irritation in humans. Piperazines are very broad chemical group, covering a wide range of drugs from antidepressants to antihistamines. The connecting property of all these chemicals is the presence of a piperazine functional group.Formula: C11H13N3O3

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

Multifaceted activity of polycyclic MDR revertant agents in drug-resistant leukemic cells: Role of the spacer was written by Caciolla, Jessica;Picone, Giovanna;Farruggia, Giovanna;Valenti, Dario;Rampa, Angela;Malucelli, Emil;Belluti, Federica;Trezza, Alfonso;Spiga, Ottavia;Iotti, Stefano;Gobbi, Silvia;Cappadone, Concettina;Bisi, Alessandra. And the article was included in Bioorganic Chemistry in 2021.HPLC of Formula: 27469-60-9 This article mentions the following:

A small library of derivatives carrying a polycyclic scaffold recently identified by us as a new privileged structure in medicinal chem. was designed and synthesized, aiming at obtaining potent MDR reverting agents also endowed with antitumor properties. In particular, as a follow-up of our previous studies, attention was focused on the role of the spacer connecting the polycyclic core with a properly selected nitrogen-containing group. A relevant increase in reverting potency was observed, going from the previously employed but-2-ynyl- to a pent-3-ynylamino moiety, as in compounds 3d and 3e, while the introduction of a triazole ring proved to differently impact on the activity of the compounds The docking results supported the data obtained by biol. tests, showing, for the most active compounds, the ability to establish specific bonds with P-glycoprotein. Moreover, a multifaceted anticancer profile and dual in vitro activity was observed for all compounds, showing both revertant and antitumor effects on leukemic cells. In this respect, 3c emerged as a “triple-target” agent, endowed with a relevant reverting potency, a considerable antiproliferative activity and a collateral sensitivity profile. In the experiment, the researchers used many compounds, for example, 4,4-Difluorobenzhydrylpiperazine (cas: 27469-60-9HPLC of Formula: 27469-60-9).

4,4-Difluorobenzhydrylpiperazine (cas: 27469-60-9) belongs to piperazine derivatives. The piperazine scaffold is often found in biologically active compounds in different therapeutic areas. These therapeutic areas include antifungals, antidepressants, antivirals, and serotonin receptor (5-HT) antagonists/agonists. Piperazines are very broad chemical group, covering a wide range of drugs from antidepressants to antihistamines. The connecting property of all these chemicals is the presence of a piperazine functional group.HPLC of Formula: 27469-60-9

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

Pharmacological inhibition of S6K1 increases glucose metabolism and Akt signalling in vitro and in diet-induced obese mice was written by Shum, Michael;Bellmann, Kerstin;St-Pierre, Philippe;Marette, Andre. And the article was included in Diabetologia in 2016.Safety of 2-((4-(5-Ethylpyrimidin-4-yl)piperazin-1-yl)methyl)-6-(trifluoromethyl)-1H-benzo[d]imidazole This article mentions the following:

Aims/hypothesis: The mammalian target of rapamycin complex 1 (mTORC1)/p70 ribosomal S6 kinase (S6K)1 pathway is overactivated in obesity, leading to inhibition of phosphoinositide 3-kinase (PI3K)/Akt signalling and insulin resistance. However, chronic mTORC1 inhibition by rapamycin impairs glucose homeostasis because of robust induction of liver gluconeogenesis. Here, we compared the effect of rapamycin with that of the selective S6K1 inhibitor, PF-4708671, on glucose metabolism in vitro and in vivo. Methods: We used L6 myocytes and FAO hepatocytes to explore the effect of PF-4708671 on the regulation of glucose uptake, glucose production and insulin signalling. We also treated high-fat (HF)-fed obese mice for 7 days with PF-4708671 in comparison with rapamycin to assess glucose tolerance, insulin resistance and insulin signalling in vivo. Results: Chronic rapamycin treatment induced insulin resistance and impaired glucose metabolism in hepatic and muscle cells. Conversely, chronic S6K1 inhibition with PF-4708671 reduced glucose production in hepatocytes and enhanced glucose uptake in myocytes. Whereas rapamycin treatment inhibited Akt phosphorylation, PF-4708671 increased Akt phosphorylation in both cell lines. These opposite effects of the mTORC1 and S6K1 inhibitors were also observed in vivo. Indeed, while rapamycin treatment induced glucose intolerance and failed to improve Akt phosphorylation in liver and muscle of HF-fed mice, PF-4708671 treatment improved glucose tolerance and increased Akt phosphorylation in metabolic tissues of these obese mice. Conclusions/interpretation: Chronic S6K1 inhibition by PF-4708671 improves glucose homeostasis in obese mice through enhanced Akt activation in liver and muscle. Our results suggest that specific S6K1 blockade is a valid pharmacol. approach to improve glucose disposal in obese diabetic individuals. In the experiment, the researchers used many compounds, for example, 2-((4-(5-Ethylpyrimidin-4-yl)piperazin-1-yl)methyl)-6-(trifluoromethyl)-1H-benzo[d]imidazole (cas: 1255517-76-0Safety of 2-((4-(5-Ethylpyrimidin-4-yl)piperazin-1-yl)methyl)-6-(trifluoromethyl)-1H-benzo[d]imidazole).

2-((4-(5-Ethylpyrimidin-4-yl)piperazin-1-yl)methyl)-6-(trifluoromethyl)-1H-benzo[d]imidazole (cas: 1255517-76-0) belongs to piperazine derivatives. The piperazine scaffold is often found in biologically active compounds in different therapeutic areas. These therapeutic areas include antifungals, antidepressants, antivirals, and serotonin receptor (5-HT) antagonists/agonists. Piperazines are very broad chemical group, covering a wide range of drugs from antidepressants to antihistamines. The connecting property of all these chemicals is the presence of a piperazine functional group.Safety of 2-((4-(5-Ethylpyrimidin-4-yl)piperazin-1-yl)methyl)-6-(trifluoromethyl)-1H-benzo[d]imidazole

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

1-{4-[Bis(4-fluorophenyl)methyl]piperazin-1-yl}ethanone was written by Dayananda, A. S.;Yathirajan, H. S.;Keeley, Amanda C.;Jasinski, Jerry P.. And the article was included in Acta Crystallographica, Section E: Structure Reports Online in 2012.Electric Literature of C17H18F2N2 This article mentions the following:

In the title compound, C₁₉H₂₀F₂N₂O, the six-membered piperazine group adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the two benzene rings is 73.4(6)°. The mean plane of the ethanone group is twisted from the mean planes of the two benzene rings by 66.7(8) and 86.2(6)°. In the crystal, C-H···O and C-H···F interactions link the mols., forming a three-dimensional structure. Crystallog. data and at. coordinates are given. In the experiment, the researchers used many compounds, for example, 4,4-Difluorobenzhydrylpiperazine (cas: 27469-60-9Electric Literature of C17H18F2N2).

4,4-Difluorobenzhydrylpiperazine (cas: 27469-60-9) belongs to piperazine derivatives. Piperazine was first introduced as an anthelmintic in 1953. Piperazine compounds mediate their anthelmintic action by generally paralyzing parasites, allowing the host body to easily remove or expel the invading organism. Outside the body, piperazine has a remarkable power to dissolve uric acid and producing a soluble urate, but in clinical experience it has not proved equally successful. Electric Literature of C17H18F2N2

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

The combination of Nutlin-3 and Tanshinone IIA promotes synergistic cytotoxicity in acute leukemic cells expressing wild-type p53 by co-regulating MDM2-P53 and the AKT/mTOR pathway was written by Guo, Yong;Li, Yi;Wang, Fang-Fang;Xiang, Bing;Huang, Xiao-Ou;Ma, Hong-Bing;Gong, Yu-Ping. And the article was included in International Journal of Biochemistry & Cell Biology in 2019.Electric Literature of C30H30Cl2N4O4 This article mentions the following:

The overexpression of mouse double minute 2 (MDM2) causes the inactivation of p53 in acute leukemia. MDM2 inhibitors that activate p53 and induce apoptosis are currently being developed for potential treatment of acute leukemia. Combining other drugs to enhance the efficacy of MDM2 inhibitors is the thus considered as a potential treatment scheme. Here, we report that the combination of Nutlin-3 and Tanshinone IIA synergistically induces cytotoxicity, cell cycle arrest, apoptosis, and autophagic cell death, thereby imparting anti-leukemia effect in an acute leukemia cell line with wild-type p53 by effectively activating p53, inhibiting the AKT/mTOR pathway, and activating the RAF/MEK pathway. Using primary samples from acute leukemia patients, we show that the combination of Nutlin-3 plus Tanshinone IIA synergistically induces cytotoxicity by activating p53 and inhibiting the AKT/mTOR pathway. This specific combination of Nutlin-3 and Tanshinone IIA is also effective in preventing the recurrence of refractory leukemia, such as Ph+ ALL with the ABL kinase T315I mutation and AML with the FLT3-ITD mutation. Taken together, the results of this study demonstrate that the Nutlin-3 plus Tanshinone IIA combination exerts synergistic anti-leukemia effects by regulating the p53 and AKT/mTOR pathways, although further investigation is warranted. Small-mol. MDM2 antagonists plus Tanshinone IIA may thus be a promising strategy for the treatment of acute leukemia. In the experiment, the researchers used many compounds, for example, 4-(cis-4,5-Bis(4-chlorophenyl)-2-(2-isopropoxy-4-methoxyphenyl)-4,5-dihydro-1H-imidazole-1-carbonyl)piperazin-2-one (cas: 548472-68-0Electric Literature of C30H30Cl2N4O4).

4-(cis-4,5-Bis(4-chlorophenyl)-2-(2-isopropoxy-4-methoxyphenyl)-4,5-dihydro-1H-imidazole-1-carbonyl)piperazin-2-one (cas: 548472-68-0) belongs to piperazine derivatives. Piperazine belongs to the family of medicines called anthelmintics. Piperazine is formed as a co-product in the ammoniation of 1,2-dichloroethane or ethanolamine. These are the only routes to the chemical used commercially.Electric Literature of C30H30Cl2N4O4

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

Perception and experience of oncologists regarding vaccination of cancer patients on active treatment was written by Hussien, Nervana;Eldin, Mai Ezz;Abdelaziz, Ahmed;Shaheen, Haitham;El-Kassas, Mohamed;Elzayat, Ibrahim;Elkhatib, Walid F.;Ahmed, Soha. And the article was included in International Journal of Cancer and Biomedical Research in 2022.Formula: C23H30N8O This article mentions the following:

The COVID-19 epidemic has wreaked havoc on individuals of all ages throughout the world. I In unprecedented time frame, its vaccination has been produced and made available to the general population. However, due to varying levels of its acceptance, vaccination did not gain widespread adoption. We aimed to measure the perception and experience of oncologists towards COVID19 vaccination in cancer patients on active therapy. A cross-sectional survey with a self-administered questionnaire was circulated among oncol. specialists in Egypt between Sept. – and Dec. 2021. A total of 83 respondents participated of which 59% had more than 10 years of experience in the oncol. field. The majority of the respondents 75 (90.4%) recommended giving the vaccine once available in case of hormonal treatment meanwhile the lowest percentage 32 (38.5%) was for anti CD20 monoclonal antibody, either as a single agent or combined with chemotherapy. Choices of 49 (59%), 46 (55%), and 43 (51.8%) to vaccinate patients on active treatment with cytotoxic chemotherapy, MoAb (except anti CD20), and immunotherapy resp. were reported. The inactivated COVID-19 virus vaccine was recommended by 39 (47%), followed by Vector vaccines in 20 (24.1%), 8 (9.6%) for the mRNA (mRNA) vaccines, while 16(19.3%) of them were undecided. Thirty-nine (47%) of the participants reported that patients on active treatment developed side effects from vaccination. The most conveyed side effects were fatigue in 34 (87%), fever or a local reaction each in 28 (71.8%), headache and myalgia equally in 19 (48.7%), and chills in 11 (28.2%), and myalgia in10 (25.6%). Strategies to address the practicality of dealing with vaccination in cancer patients are needed. Emphasis on the installation of the latest data in caring for this population and increased awareness of the services provided is crucial. Surveys are a useful tool reflecting real-world practice. In the experiment, the researchers used many compounds, for example, 7-Cyclopentyl-N,N-dimethyl-2-((5-(piperazin-1-yl)pyridin-2-yl)amino)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxamide (cas: 1211441-98-3Formula: C23H30N8O).

7-Cyclopentyl-N,N-dimethyl-2-((5-(piperazin-1-yl)pyridin-2-yl)amino)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxamide (cas: 1211441-98-3) belongs to piperazine derivatives. Piperazine causes primary dermal irritation and skin burns at high concentrations. Piperazine also causes eye irritation in humans. Piperazines are very broad chemical group, covering a wide range of drugs from antidepressants to antihistamines. The connecting property of all these chemicals is the presence of a piperazine functional group.Formula: C23H30N8O

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

Ultrasound-assisted dispersive liquid-liquid microextraction for determination of enrofloxacin in surface waters was written by Dias, Reyla A. S.;Sousa, Eliane R.;Silva, Gilmar S.;Silva, Lanna K.;Freitas, Arlan S.;Lima, Diana L. D.;Sousa, Erika M. L.. And the article was included in Microchemical Journal in 2021.Synthetic Route of C20H17F2N3O3 This article mentions the following:

This work describes the development of an HPLC-FLD methodol. for the separation of five fluoroquinolones (ciprofloxacin, enrofloxacin, sarafloxacin, norfloxacin and levofloxacin) followed by optimization of the DLLME process for the clean-up and preconcentration of enrofloxacin in samples of seawater and river water. The mobile phase used for the chromatog. separation consisted of methanol: phosphate buffer (NaHPO4 H2O 0.04 M pH 3 with H3PO4 85%), gradient eluted at a ratio of 20:80 (v:v). The mobile phase flow was maintained at 1.2 mL min-1. For the ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME), the following conditions were used: 8 mL of sample with pH adjusted to 8, extraction solvent: 500μL of chloroform, dispersive solvent: 500μL of acetonitrile; samples were vortexed and sonicated for 2 min, each. The enrichment factor (EF) was 54.7 and the recovery was 70%, achieving a limit of detection (LOD) of 0.11μg L-1. Repeatability and intermediate reproducibility presented values of relative standard deviation (RSD) lower than 2%. Finally, the optimized method was applied to the anal. of water and enrofloxacin was detected in both water samples with a concentration of 0.20μg L-1 in the river and 0.12μg L-1 in the seawater. However, recovery tests performed to evaluate the water matrixes’ effects on the extraction performance, presented recoveries of 72 ± 6.1 for river water and 27 ± 8.3 for seawater. These results demonstrate that hereby developed method is only suitable for water samples with a low salinity content. In the experiment, the researchers used many compounds, for example, 6-Fluoro-1-(4-fluorophenyl)-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid (cas: 98105-99-8Synthetic Route of C20H17F2N3O3).

6-Fluoro-1-(4-fluorophenyl)-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid (cas: 98105-99-8) belongs to piperazine derivatives. Simple N-substituted piperazines have been found in many drug molecules. Two common salts in the form of which piperazine is usually prepared for pharmaceutical or veterinary purposes are the citrate, 3C4H10N2.2C6H8O7 (i.e. containing 3 molecules of piperazine to 2 molecules of citric acid), and the adipate, C4H10N2.C6H10O4 (containing 1 molecule each of piperazine and adipic acid).Synthetic Route of C20H17F2N3O3

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

Development of validated spectrofluorimetric method for the estimation of buclizine hydrochloride from the tablet dosage form was written by Suganthi, A.;Fathimunnisa, A.;Sumithra, S.;Ravi, T. K.. And the article was included in Indo American Journal of Pharmaceutical Research in 2016.Application of 129-74-8 This article mentions the following:

Buclizine hydrochloride from its tablet dosage form was estimated by developing a novel validated indirect spectrofluorimetric method. Here the Buclizine hydrochloride was derivatized into nitro compound using nitrating mixture with an aid of heat which showed good fluorescence in water at 446 nm after excited at 350 nm. The calibration graph showed linear over the range 200-1000 ng/mL. The assay of buclizine hydrochloride in marketed formulations was found to be 98.96 ± 0.1586. Recovery values were close to 100% with the % RSD values of 0.432% and 0.673% at 50% and 100% level resp. From the results of validation it was observed that the method was found to be simple, accurate, sensitive and reproducible. Hence the proposed method can be used for routine quality control anal. In the experiment, the researchers used many compounds, for example, 1-(4-(tert-Butyl)benzyl)-4-((4-chlorophenyl)(phenyl)methyl)piperazine dihydrochloride (cas: 129-74-8Application of 129-74-8).

1-(4-(tert-Butyl)benzyl)-4-((4-chlorophenyl)(phenyl)methyl)piperazine dihydrochloride (cas: 129-74-8) belongs to piperazine derivatives. Piperazine was first introduced as an anthelmintic in 1953. Piperazine compounds mediate their anthelmintic action by generally paralyzing parasites, allowing the host body to easily remove or expel the invading organism. Piperazines are very broad chemical group, covering a wide range of drugs from antidepressants to antihistamines. The connecting property of all these chemicals is the presence of a piperazine functional group.Application of 129-74-8

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics

A new dried blood spot LC-MS/MS method for therapeutic drug monitoring of palbociclib, ribociclib, and letrozole in patients with cancer was written by Poetto, Ariana Soledad;Posocco, Bianca;Gagno, Sara;Orleni, Marco;Zanchetta, Martina;Iacuzzi, Valentina;Canil, Giovanni;Buzzo, Mauro;Montico, Marcella;Guardascione, Michela;Basile, Debora;Pelizzari, Giacomo;Alberti, Martina;Gerratana, Lorenzo;Puglisi, Fabio;Toffoli, Giuseppe. And the article was included in Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences in 2021.Electric Literature of C23H30N8O This article mentions the following:

Therapeutic drug monitoring TDM is strongly suggested to define the proper drug dosage to overcome inter- and intra-patient variability in drug exposure, which is typically observed with oral anticancer agents, such as palbociclib PALBO, ribociclib RIBO and letrozole LETRO, all approved for the treatment of HR+, HER2- locally advanced or metastatic breast cancer BC. Optimal TDM implementation requires a blood sampling organization that can be hampered by limited availability of health and laboratory personnel. Dried Blood Spot DBS sampling is proposed to overcome such limitations. The aim of this work was the development of a new LC-MS/MS method to analyze DBS samples containing PALBO, RIBO, and LETRO. Analytes extraction from DBS was performed by adding a methanolic solution containing the corresponding internal standards LC-MS/MS anal. was performed using a LC Nexera Shimadzu system coupled with an API 4000 QTrap SCIEX mass spectrometer. The chromatog. separation was performed on a Luna Omega Polar C18 column Phenomenex. The method was applied to 38 clin. samples collected by finger prick. The influence of hematocrit and spot size, sample homogeneity, stability, and correlation between finger prick and venous DBS measurement were assessed. The anal. validation was performed according to EMA and FDA guidelines. The anal. range of the method was 1 to 250 ng/mL for PALBO, 40 to 10000 ng/mL for RIBO, and 2 to 500 ng/mL for LETRO, where linearity was assessed, obtaining mean coefficients of determination R2 of 0.9979 for PALBO, 0.9980 for RIBO, and 0.9987 for LETRO. The LC-MS/MS method runtime was 6.6 min. Incurred sample reanal. demonstrated reproducibility, as the percentage difference between the two quantifications was lower than 20% for 100% of PALBO, 81.8% of RIBO, and 90.9% of LETRO paired samples. Intra- and inter-day precision CV % was lower than 11.4% and intra- and inter-day accuracy was between 90.0 and 106.5%. DBS sample stability at room temperature was confirmed for 2.5 mo. A pos. correlation was observed between DBS and plasma concentrations for the 3 drugs, Lins concordance correlation coefficients obtained by DBS normalization applying a selected strategy were 0.958 for PALBO, 0.957 for RIBO, and 0.963 for LETRO. In conclusion, a fast, easy, and reproducible DBS LC-MS/MS method for the simultaneous quantification of palbociclib; ribociclib and letrozole was developed to be used in clin. practice. In the experiment, the researchers used many compounds, for example, 7-Cyclopentyl-N,N-dimethyl-2-((5-(piperazin-1-yl)pyridin-2-yl)amino)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxamide (cas: 1211441-98-3Electric Literature of C23H30N8O).

7-Cyclopentyl-N,N-dimethyl-2-((5-(piperazin-1-yl)pyridin-2-yl)amino)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxamide (cas: 1211441-98-3) belongs to piperazine derivatives. Piperazine was first introduced as an anthelmintic in 1953. Piperazine compounds mediate their anthelmintic action by generally paralyzing parasites, allowing the host body to easily remove or expel the invading organism. Although many piperazine derivatives occur naturally, piperazine itself can be synthesized by reacting alcoholic ammonia with 1,2-dichloroethane, by the action of sodium and ethylene glycol on ethylene diamine hydrochloride, or by reduction of pyrazine with sodium in ethanol.Electric Literature of C23H30N8O

Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics