Multi-functionalization of reduced graphene oxide nanosheets for tumor theragnosis: Synthesis, characterization, enzyme assay, in-silico study, radiolabeling and in vivo targeting evaluation.

BACKGROUND: In this study, a combination of nanotechnology, organic synthesis and radiochemistry were utilized in order to design an efficient nano-system conjugated with a suitable radionuclide and an antitumor agent for possible application as tumor theragnostic agent. METHOD: Four novel compounds (3 and 4a-c) bearing tetrahydroquinazoline-7-sulfonohydrazide or 1,2,3,4-tetrahydroquinazoline-7-sulfonamide scaffold were designed. Then, docking study predicted that the compounds can be considered as potential inhibitors for PARP-1. Following that; the four compounds were synthesized and properly characterized using 1HNMR, 13CNMR, IR and Mass spectroscopy. The cytotoxic effect of the four compounds was evaluated against breast cancer cell line (MDA-MB-436), where compound 3 showed the most promising cytotoxic effect. The inhibitory effect of the four compounds was evaluated in vitro against PARP-1. RESULT: Carboxylated graphene oxide nanosheets (NGO-COOH) were synthesized by a modified Hummer's method and has size of range 40 nm. The NGO-COOH nanosheets were proven to be safe and biocompatible when tested in vitro against normal human lung fibroblast cells (MRC-5). The prepared NGO-COOH nanosheets were conjugated with compound 3 then radiolabeled with 99mTc to yield 99mTc-NGO-COOH-3 with a radiochemical yield of 98.5.0 ± 0.5%. 99mTc-NGO-COOH-3 was injected intravenously in solid tumor bearing mice to study the degree of localization of the nano-system at tumor tissue. The results of the study revealed, excellent localization and retention of the designed nano-system at tumor tissues with targeting ratio of 9.0. CONCLUSION: Stirred a new candidate tumor theragnostic agent that is safe, selective and stable.

New phenothiazine conjugates as apoptosis inducing agents: Design, synthesis, In-vitro anti-cancer screening and 131I-radiolabeling for in-vivo evaluation.

Phenothiazines (PTZs) are a group of compounds characterized by the presence of the 10H-dibenzo-[b,e]-1,4-thiazine system. PTZs used in clinics as antipsychotic drugs with other diverse biological activities. The current aim of the study is to investigate and understand the effect of potent PTZs compounds using a group of In-vitro and In-vivo assays. A total of seventeen novel phenothiazine derivatives have been designed, synthesized, and evaluated primarily in-vitro for their ability to inhibit proliferation activity against NCI-60 cancer cell lines, including several multi-drug resistant (MDR) tumor cell lines. Almost all compounds were active and displayed promising cellular activities with GI50 values in the sub-micromolar range. Four of the most promising derivatives (4b, 4h, 4g and 6e) have been further tested against two selected sensitive cancer cell lines (colon cancer; HCT-116 and breast cancer; MDA-MB231). The apoptosis assay showed that all the selected compounds were able to induce early apoptosis and compound 6e was able to induce additional cellular necrosis. Cell cycle assay showed all selected compounds were able to induce cell cycle arrest at sub-molecular phase of G0-G1 with compound 6e induced cell cycle arrest at G2M in HCT-116 cells. Accordingly, the apoptotic effect of the selected compounds was extensively investigated on genetic level and Casp-3, Casp-9 and Bax gene were up-regulated with down-regulation of Bcl-2 gene suggesting the activation of both intrinsic and extrinsic pathways. In-vivo evaluation of the antitumor activity of compound 4b in solid tumor bearing mice showed promising therapeutic effect with manifestation of dose and time dependent toxic effects at higher doses. For better evaluation of the degree of localization of 4b, its 131I-congener (131I-4b) was injected intravenously in Ehrlich solid tumor bearing mice that showed good localization at tumor site with rapid distribution and clearance from the blood. In-silico study suggested NADPH oxidases (NOXs) as potential molecular target. The compounds introduced in the current study work provided a cutting-edge phenothiazine hybrid scaffold with promising anti-proliferation action that may suggest their anti-cancer activity.

Novel substituted 1,8-naphthyridines: Design, synthesis, radiolabeling, and evaluation of apoptosis and topoisomerase II inhibition.

A series of seventeen 1,8-naphthyridine derivatives (5a-5q) conjugated at N1 to various substituted phenyl rings were designed and synthesized as potential topoisomerase II (Topo II) inhibitors. The antiproliferative activity of the target compounds against three cancer cell lines showed that compounds 5g and 5p had the highest antiproliferative activity. In addition, 5p and 5g displayed a high selectivity index (SI) for cancer cells when tested on WI38 normal cells, whereby compound 5p showed the highest SI. Furthermore, 5g and 5p induced cell cycle arrest at the S and G1/S phases, respectively, triggering apoptosis in HepG-2 cells. The in vitro Topo II inhibitory effect (plasmid-based) of both compounds revealed that 5p had better inhibition of Topo II. In addition, 5p displayed potent topoisomerase IIß inhibitory effect when compared to known topoisomerase inhibitors (doxorubicin and topotecan). Molecular docking proposed a unique binding pattern of 5p in the etoposide binding pocket of topoisomerase IIß, endorsing its potential role as a Topo II poison. Accordingly, 5p was chosen for radioiodination to study the degree of tumor localization following administration in solid tumor-bearing mice. The radioiodinated 5p showed a selective localization at the tumor site, which further confirmed the value of 5p as a lead 1,8-naphthyridine anticancer agent.

Purine analogs: synthesis, evaluation and molecular dynamics of pyrazolopyrimidines based benzothiazole as anticancer and antimicrobial CDK inhibitors.

Cyclin dependent kinases (CDKs) enzymes regulate cell proliferation and transcriptional processes and can be considered as important targets for the development of anticancer and antimicrobial drugs. In this work, novel benzothiazolyl pyrazolopyrimidine carboxamide and benzothiazolyl pyrazolopyrimidine carbonitrile derivatives were synthesized and characterized. The synthetic process was carried out via the reaction of ylidine benzothiazole derivatives with pyrazolocarboxamide and pyrazolocarbonitrile through a Michael addition pathway. Docking studies were done against CDK2 and CDK9 enzymes and revealed that compound 8a showed high free energy of binding against CDK2 (-8.10 kcal/mol) while compound 15a showed the highest free energy of binding against CDK2 (-8.16 kcal/mol) and CDK9 (-7.87 kcal/mol). Molecular dynamics simulations were conducted to compare the stability of binding of the most active compound 15a and the potent reference drugs roscovitine and dinaciclib. A CDK enzyme assay was done against CDK2 and CDK9 for the previously mentioned top-ranked compounds, 8a and 15a. It was found that compound 15a was the most potent inhibitor for both enzymes with IC50 of 127 ± 1.01 nM and 65 ± 0.50 nM. The anticancer activity of the synthesized compounds was also determined by NCI against 60 cell lines. Compound 8a showed the highest cytotoxic activity against a large number of the tested cell lines. The antimicrobial activity of the synthesized compounds was determined against various gram positive and gram-negative bacteria as well as fungi. The results showed that compound 15a had the strongest antibacterial activity.

Design, Synthesis, Molecular Docking, Dynamics and in vitro Evaluation of Novel 2-substituted-1-hydroxyethane-1, 1-bis(phosphonic acid) Derivatives as Human Farnesyl Pyrophosphate Synthase Inhibitors with Expected Anticancer Activity.

BACKGROUND: Nitrogenous bisphosphonates (NBPs) are the major class of drugs that are used to treat osteoporosis. Recently, bisphosphonates (BPs) were reported to have an anticancer effect. These agents feature a high affinity that enables them to bind strongly to the human farnesyl pyrophosphate synthase enzyme. The correlation between this affinity and their anticancer effect was confirmed. OBJECTIVE: To date, the use of an oxygen atom as an isosteric replacement for the electronegative nitrogen atom in NBPs has not been reported, and its ability to retain the linker length and bisphosphonate pharmacophore remains unknown. The main aim of this work was to design some isosteric bisphosphonate analogs with oxygen atoms and evaluation of their binding affinity and anticancer activity. METHODS: The binding mode and stability of the designed compounds were achieved using human farnesyl pyrophosphate synthase (HFPPS) by docking and dynamic simulations. The compounds were synthesized, characterized, and screened for their anticancer activity against the breast cancer MCF-7 cell line and lung cancer A-549 cell line. The inhibitory activity of the tested compounds against HFPPS was evaluated. RESULTS: The compounds under investigation showed potential anticancer activity against the lung cell line with IC50 values of 41.7, 47.4, and 34.8 µg/ml in comparison to that of Risedronic acid (115 µg/ml). However, they do not exhibit potential activity against the breast cancer cell line. CONCLUSION: Compounds VII and VIII showed in vitro inhibition of human farnesyl pyrophosphate synthase with IC50 values of 82.2 and 98.8 µg/ml, respectively. Further optimization may be required in the future.

Medicinal Chemistry of Pyrazolopyrimidine Scaffolds Substituted with Different Heterocyclic Nuclei.

BACKGROUND: Medicinal chemistry of pyrazolopyrimidine scaffolds substituted with different heterocyclic nuclei has attracted great attention due to their wide range of biological activities that have been reported. Pyrazolopyrimidine scaffold is an important privileged heterocycle nucleus in drug discovery. METHODS: All pharmacological activities of pyrazolopyrimidine scaffold have been mentioned, such as anticancer, anti-inflammatory, antihypertensive, antitubercular, antiviral, antibacterial, antifungal, antidiabetic, and anti-obesity agents. In addition, it was used in both osteoporosis and neurological disorders. The difference in potency and bioavailability of pyrazolopyrimidine derivatives refers to the substituent groups that can increase the activity against specific targets and enhance their selectivity. RESULTS: This review provides an overview of different synthetic pathways, structure activity relationships, and preclinical studies of pyrazolopyrimidine scaffolds substituted with a variety of heterocyclic nuclei, as well as it provides a discussion on the significant biological findings of these important scaffolds. In addition, it provides some insights on the different macromolecular targets that pyrazolopyrimidine scaffold can effectively work on, such as; cyclin dependent kinases; CDK2, CDK7, and CDK9, checkpoint kinases; CHK1 and CHK2 and their correlation with the anticancer activity, PI3Kα, transient receptor potential canonical 6, B-Raf kinase, Interleukin- 1 receptor-associated kinase 4, B-cell lymphoma 6, TRKA-C kinase, potent kDa ribosomal protein S6 kinase, colon cancer cell line (CaCo-2), domain receptor kinase (KDR), HepG-2 carcinoma cell, FLT3. The antibacterial activity against B. subtilis and E. coli and antifungal activity against C. albicans, C. tropicalis, A. niger, and A. clavatus are discussed. CONCLUSION: This review provides an overview of the different pharmacological activities of the pyrazolopyrimidine scaffold and its correlation with chemical structure. Some exciting new developments in pyrazolopyrimidine scaffolds are also presented in this review.

Purine analogues as potential CDK9 inhibitors: New pyrazolopyrimidines as anti-avian influenza virus.

Cyclin dependent kinases (CDKs) are a group of enzymes involved in different phases of the cell cycle. In addition, it has been reported that CDK9 could be used as a crucial target for the development of antiviral drugs such as purine analogues; roscovitine and dinaciclib. A new series of benzothiazolyl pyrazolopyrimidine carboxamide derivatives were synthesized and evaluated for their antiviral activity against avian influenza "bird flu" (H5N1). The novel compounds were synthesized via the reaction of pyrazolo carboxamide derivatives with different derivatives of ylidine benzothiazole. The reaction proceeded via a Michael addition pathway. Antiviral activity was determined using a plaque reduction assay against the H5N1 virus. Five compounds showed the highest inhibitory activity in the range of 61.6 to 71.6% at 0.1 µmol/mL. Based on a molecular docking study, an enzyme assay was carried out against CDK9 for the previously mentioned top-ranked compounds. It was found that compound 11f was the most potent inhibitor of CDK9 with an IC50 of 0.062 µmol/mL. A QSAR model was built to determine the hidden feature responsible for the biological activity of the novel compounds. It was found that two sets of descriptors, 3 D Potential energy descriptors and 2 D Atom Counts and Bond Counts descriptors, were correlated to a linear model with RMSE and r2 coefficient values of 0.75 and 0.80, respectively. A molecular dynamic simulations study of 11f over 10 ns against dinaciclib showed that both 11f and dinaciclib achieved equilibrium at 2 Å.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2022.2059674 .

Hepatoprotective, antioxidant and anti-inflammatory potentials of Vit-E/C@SeNPs in rats: Synthesis, characterization, biochemical, radio-biodistribution, molecular and histopathological studies.

This study aimed to synthesize a nano-structure between selenium, Vit. C, and Vit. E (Vit-E/C@SeNPs) as a promising protective and therapeutic agent for hepatocellular carcinoma. Vit-E/C@SeNPs were characterized using TEM and DLS and its zetapotential was measured to evaluate its stability. DPPH assay and SRB test were performed to estimate its antioxidant capacity and cytotoxicity, respectively. A radiosynthesis of 99mTc-Vit-E/C@SeNPs was done for further in-vivo pharmacokinetic studies on normal and solid tumor induced mice. Further, in-vivo studies were conducted to investigate Vit-E/C@SeNPs efficacy against hepatocellular damage in Wistar albino rats induced by diethylnitrosamine (DEN) / Carbon Tetra chloride (CCl4). The synthesis results showed spherical Vit-E/C@SeNPs with core size of 50 nm, radical scavenging activity (%RSC) of 75.9%, and IC50 of 27.9 µg/ml. The biochemical analysis results showed that the lower liver function biomarker values (ALT, AST, ALP, total bilirubin and GGT) has gone for the Vit-E/C@SeNPs prevention and treated group, which also showed significant depletion of liver tissue l-MDA, and obvious increase in GSH concentration and CAT activity and marked improvement in the histological feature of liver tissue. Additionally, a significant up-regulation of mRNA gene expression levels of inflammatory gene (TGFß1, NFκB, iNOS, PPAR-γ and TNFα) and Apoptotic gene (P53) were determined by using Quantitative real-time PCR (qPCR). The values down regulate and tend to normal in prevention and control group. All of these introduce Vit-E/C@SeNPs as a promising agent as protective and therapeutic agent against DEN/ CCl4-induced hepatocellular damage (Hepatocellular carcinoma).

Discovery of New Coumarin-Based Lead with Potential Anticancer, CDK4 Inhibition and Selective Radiotheranostic Effect: Synthesis, 2D & 3D QSAR, Molecular Dynamics, In Vitro Cytotoxicity, Radioiodination, and Biodistribution Studies.

Novel 6-bromo-coumarin-ethylidene-hydrazonyl-thiazolyl and 6-bromo-coumarin-thiazolyl-based derivatives were synthesized. A quantitative structure activity relationship (QSAR) model with high predictive power r2 = 0.92, and RMSE = 0.44 predicted five compounds; 2b, 3b, 5a, 9a and 9i to have potential anticancer activities. Compound 2b achieved the best ΔG of -15.34 kcal/mol with an affinity of 40.05 pki. In a molecular dynamic study 2b showed an equilibrium at 0.8 Å after 3.5 ns, while flavopiridol did so at 0.5 Å after the same time (3.5 ns). 2b showed an IC50 of 0.0136 µM, 0.015 µM, and 0.054 µM against MCF-7, A-549, and CHO-K1 cell lines, respectively. The CDK4 enzyme assay revealed the significant CDK4 inhibitory activity of compound 2b with IC50 of 0.036 µM. The selectivity of the newly discovered lead compound 2b toward localization in tumor cells was confirmed by a radioiodination biological assay that was done via electrophilic substitution reaction utilizing the oxidative effect of chloramine-t. 131I-2b showed good in vitro stability up to 4 h. In solid tumor bearing mice, the values of tumor uptake reached a height of 5.97 ± 0.82%ID/g at 60 min p.i. 131I-2b can be considered as a selective radiotheranostic agent for solid tumors with promising anticancer activity.

Novel thienopyrimidine analogues as potential metabotropic glutamate receptors inhibitors and anticancer activity: Synthesis, In-vitro, In-silico, and SAR approaches.

There is a continuous need in drug development approach for synthetic anticancer analogues with new therapeutic targets to diminish chemotherapeutic resistance of cancer cells. This study presents new group of synthetic thienopyrimidine analogues (1-9) aims as mGluR-1 inhibitors with anticancer activity. In-vitro antiproliferative assessment was carried out using viability assay against cancer cell lines (MCF-7, A-549 and PC-3) compared to WI-38 normal cell line. Analogues showed variable anticancer activity with IC50 ranging from 6.60 to 121 µg/mL with compound 7b is the most potent analogue against the three cancer cell lines (MCF-7; 6.57 ± 0.200, A-549; 6.31 ± 0.400, PC-3;7.39 ± 0.500 µg/mL) compared to Doxorubicin, 5-Flurouracil and Riluzole controls. Selected compounds were tested as mGluR-1 inhibitors in MCF-7 cell line and results revealed compound 7b induced significant reduction in extracellular glutamate release (IC50; 4.96 ± 0.700 µM) compared to other analogues and next to Riluzole (IC50; 2.80 ± 0.500 µM) of the same suggested mode of action. Furthermore, both cell cycle and apoptosis assays confirmed the potency of compound 7b for early apoptosis of MCF-7 at G2/M phase and apoptotic positive cell shift to (91.4%) compared to untreated control (19.6%) and Raptinal positive control (51.4%). On gene expression level, compound 7b induced over-expression of extrinsic (FasL, TNF-α and Casp-8), intrinsic (Cyt-C, Casp-3, Bax) apoptotic genes with down-regulation of anti-apoptotic Bcl-2 gene with boosted Bax/Bcl-2 ratio to 2.6-fold increase. Molecular docking and dynamic studies confirmed the biological potency through strong binding and stability modes of 7b where it was faster in reaching the equilibrium point and achieving the stability than Riluzole over 20 ns MD. These results suggest compound 7b as a promising mGluR inhibitory scaffold with anticancer activity that deserves further optimization and in-depth In-vivo and clinical investigations.

QSAR-based rational discovery of novel substituted-4'-iminospiro[indoline-3,3'-[1,2,5]thiadiazolidinyl]-2-one 1',1'-dioxide with potent in vitro anticancer activity.

Recent studies have suggested that aldose reductase inhibition preferentially inhibits the growth of cancer cells. However, the investigations of this issue are not many. Novel nine substituted- 4'-iminospiro[indoline-3,3'-[1,2,5] thiadiazolidinyl]-2-one 1',1'-dioxide derivatives were designed by both isosteric replacement of the imidazolidine-2,5-dione moiety in spirohydantoin scaffold and conformational rigidification approaches. A QSAR with high predictive power (r2 = 0.99) was created from a series of potent aldose reductase inhibitors and was used to predict the activity of our new compounds. Compound 5 showed the best docking score (- 33.24 kcal/mol) with the least RMSD value (< 1.5) obtained by molecular dynamic simulations over 20 ns. All compounds showed promising anticancer activities especially compound 5 that achieved the highest inhibitory activities with IC50; 0.013, 0.031, 0.064, and 0.048 mmol/L against breast, colon, prostate, and lung cell lines respectively. The discovery of this lead compound confirmed the rational design. Further investigations may be required for optimization of this compound.

Synthesis and in vitro anticancer evaluation of some fused indazoles, quinazolines and quinolines as potential EGFR inhibitors.

derivatives of benzo[g]indazole 5a, b, benzo[h]quinazoline 7, 12a-c, 13a-c and 15a-c and benzo[h]quinoline 17a-c and 19a-c were synthesized from 6-methoxy-3,4-dihydronaphthalen-1(2H)-one (1). Anticancer activity of all the synthesized compounds was evaluated against four cancerous cell lines; HepG2, MCF-7, HCT116 and Caco-2. MCF-7 cells emerged as the most sensitive cell line against the target compounds. All the examined compounds, except 5a and 5b, displayed potent to moderate anticancer activity against MCF-7 cells with an IC50 values ranging from 7.21 to 21.55 µM. In particular, compounds 15c and 19b emerged as the most potent derivatives against EGFR-expressing MCF-7 cells with IC50 values = 7.70 ±â€¯0.39 and 7.21 ±â€¯0.43 µM, respectively. Additionally, both compounds did not display any significant cytotoxicity towards normal BHK-21 fibroblast cells (IC50 value > 200 µM), thereby providing a good safety profile as anticancer agents. Furthermore, compounds 15c and 19b displayed potent inhibitory activity towards EGFR in the sub-micromolar range (IC50 = 0.13 ±â€¯0.01 and 0.14 ±â€¯0.01 µM, respectively), compared to that of Erlotinib (IC50 = 0.11 ±â€¯0.01 µM). Docking studies for 15c and 19b into EGFR active site was carried out to explore their potential binding modes. Therefore, compounds 15c and 19b can be considered as interesting candidates for further development of more potent anticancer agents.

Radioiodination and biological distribution of a new s-triazine derivative for tumor uptake evaluation.

A newly synthesized s-triazine derivative 1,1',1″-(((1,3,5-triazine-2,4,6-triyl) tris (azanediyl)) tris (benzene-4,1-diyl))tris (ethan-1-one), (1), was synthesized as a part of an ongoing research for development of novel s-triazine-based radiopharmaceuticals. In-vitro cell viability assay against different human cancer cell lines showed very promising inhibitory activity of the synthesized compound. This finding encouraged the radioiodination of 1 to study the degree of its localization in tumor site for evaluating the possibility of its use as a tumor imaging agent. The biodistribution study showed good localization of the radioiodinated derivative 2 at tumor site following i.v. administration in solid tumor-bearing mice. Finally, in a trial to understand the mechanism of the anticancer effect exerted by 1, a target prediction study and a docking study were performed. The results of the first study showed that focal adhesion kinase is a possible target for compound 1 and the docking study confirmed successful binding of both compound 1 and its radioiodinated derivative 2 to the binding site of focal adhesion kinase. As a conclusion, the results of this study suggest that, compound 2 could be used as a potential agent for tumor imaging after preclinical trials.

Different Spectrophotometric Methods for Simultaneous Determination of Trelagliptin and Its Acid Degradation Product.

New spectrophotometric and chemometric methods were carried out for the simultaneous assay of trelagliptin (TRG) and its acid degradation product (TAD) and applied successfully as a stability indicating assay to recently approved Zafatek® tablets. TAD was monitored using TLC to ensure complete degradation. Furthermore, HPLC was used to confirm dealing with one major acid degradation product. The proposed methods were developed by manipulating zero-order, first-derivative, and ratio spectra of TRG and TAD using simultaneous equation, first-derivative, and mean-centering methods, respectively. Using Spectra Manager II and Minitab v.14 software, the absorbance at 274 nm-260.4 nm, amplitudes at 260.4 nm-274.0 nm, and mean-centered values at 287.6 nm-257.2 nm were measured against methanol as a blank for TRG and TAD, respectively. Linearity and the other validation parameters were acceptable at concentration ranges of 5-50 µg/mL and 2.5-25 µg/mL for TRG and TAD, respectively. Using one-way analysis of variance (ANOVA), the optimized methods were compared and proved to be accurate for the simultaneous assay of TRG and TAD.

Development, Potential Anticancer Activity and the Receptor Profile of Different Functionalized 1,3,5-Triazine Derivatives.

1,3,5-Triazine-based compounds form a privileged class of compounds in the medicinal chemistry field as they are versatile synthetic scaffolds possessing wide spectra of biological effects including potential anticancer activity. 1,3,5-Triazine compounds explored for anticancer activities have been reported to act by various mechanisms on several molecular targets in human cells such as methyltransferase (DNMT), heat shock protein 90 (Hsp90) and phosphoinositide 3-kinase (PI3K). This review focuses on the synthetic strategies for current developments of 1,3,5-triazine-based anticancer agents and discuses the docking studies that confirm their unique binding modes in the targeted receptors active sites. This article also aims to highlight the future directions for the easy access to these frameworks of more potent and specific anticancer activity.

Suitability of various chromatographic and spectroscopic techniques for analysis and kinetic degradation study of trelagliptin.

Multifaceted comparative analytical methods for trelagliptin (TRL) were investigated, applied to ZAFATEK tablets and HPLC-UV was selected for a degradation kinetic study. UPLC-MS/MS (Method I), UPLC-UV (Method II), HPLC-UV (Method III), UHPLC-UV (Method IV) and direct UV (Method V) methods were developed. Methods (I-V) showed satisfactory results using TRL concentration ranges of 50-800 ng/mL, 2.5-80 µg/mL, 5-100 µg/mL, 5-100 µg/mL and 5-50 µg/mL, respectively. Multiple Reaction Monitoring (MRM) of the transition pairs of m/z 358.176 to 134.127 for TRL and m/z 340.18 to 116.08 for alogliptin (IS) were employed utilizing positive mode Electrospray Ionization (ESI). The degradation kinetic study (Method VI) was carried out using 1 N HCl based on three different temperatures (70 °C, 80 °C and 90 °C). Through the optimized method-3, a good chromatographic separation of TRL from its major degradation product was achieved. Arrhenius plot was used in the kinetic study and the apparent 1st order degradation rate constant (K), t1/2, t90, and the activation energies were calculated for each temperature and at 25 °C. The optimized UPLC-MS/MS method is suitable for further TRL assay either in biological fluids or in the presence of impurities.

Comparative study between different simple methods manipulating ratio spectra for the analysis of alogliptin and metformin co-formulated with highly different concentrations.

Different simple spectrophotometric methods were developed for simultaneous determination of alogliptin and metformin manipulating their ratio spectra with successful application on recently approved combination, Kazano® tablets. Spiking was implemented to detect alogliptin in spite of its low contribution in the pharmaceutical formulation as low quantity in comparison to metformin. Linearity was acceptable over the concentration range of 2.5-25.0µg/mL and 2.5-15.0µg/mL for alogliptin and metformin, respectively using derivative ratio, ratio subtraction coupled with extended ratio subtraction and spectrum subtraction coupled with constant multiplication. The optimized methods were compared using one-way analysis of variance (ANOVA) and proved to be accurate for assay of the investigated drugs in their pharmaceutical dosage form.

Comparative Liquid Chromatographic Study for Concurrent Determination of Canagliflozin and Metformin in Combined Tablets.

New HPLC-UV method (method A), for simultaneous determination of metformin (MET) and canagliflozin (CANA), was developed and compared to another novel UPLC-UV method (method B) in their tablet combination. Concerning method A, isocratic separation was done by C18 column (100 mm × 2.1 mm, 3 µm) using methanol and 0.03 M phosphate buffer (75 : 25, v/v) at pH 3.2 as a mobile phase. Meanwhile, chromatographic separation in method B was achieved via Hypersil® gold (50 mm × 2.1 mm, 1.9 µm). Mobile phase was methanol and 0.03 M phosphate buffer at ratio of 80 : 20 v/v. In both, detection was done at wavelength of 240 nm. Method A showed satisfactory linearity results over 1-50 µg·mL-1 and 0.5-100 µg·mL-1, while method B linearity was at 0.1-50 µg·mL-1 and 0.25-100 µg·mL-1 for CANA and MET, respectively. In terms of accuracy and precision, method A accuracy was 99.81 ± 0.73 and 99.37 ± 0.54, while method B gave accuracy of 99.47 ± 1.03 and 99.73 ± 0.89 for CANA and MET, respectively. For precision, the % RSD was found to be less than 2% for three concentrations analyzed three times. The two methods are convenient for quality laboratories, yet the UPLC method offered the advantage of shorter run times and higher sensitivity.

Salmeterol Xinafoate.

Salmeterol xinafoate is a potent and a long-acting ß2-adrenoceptor agonist. It is prescribed for the treatment of severe persistent asthma and chronic obstructive pulmonary disease. Different methods were used to prepare (R)-(-)-salmeterol such as: mixing a sample of 4-benzyloxy-3-hydroxymethyl-ω-bromoacetophenone with sodium lauryl sulfate and the mixture was added to the microbial culture of Rhodotorula rubra, treatment of p-hydroxyacetophenone with Eschenmoser's salt and carbonate exchange resin followed by a sequence of supported reagents and scavenging agents or via Rh-catalyzed asymmetric transfer hydrogenation. The enantioselective synthesis of (S)-salmeterol was achieved via asymmetric reduction of the azidoketone 4 by Pichia angusta yeast. Physical characteristics of salmeterol xinafoate were confirmed via: X-ray powder diffraction pattern, thermal analysis and UV, vibrational, nuclear magnetic resonance, and mass spectroscopical data. Initial improvement in asthma control may occur within 30 min following oral inhalation of salmeterol in fixed combination with fluticasone propionate. Clinically important improvements are maintained for up to 12 h in most patients. It is extensively metabolized in the liver by hydroxylation, thus increased plasma concentrations may occur in patients with hepatic impairment.

3-Eth-oxy-methyl-1,4-dihydro-quinolin-4-one.

In the title mol-ecule, C(12)H(13)NO(2), the dihydro-quinolinone fused-ring system is nearly planar [maximum deviation = 0.012 (3) Å], and the mean plane passing through the extended eth-oxy-methyl substituent is aligned at 86.9 (2)° with respect to the fused-ring system. In the crystal, adjacent mol-ecules are linked by an N-H⋯O(carbon-yl) hydrogen bond to generate a chain running along the b-axis direction.