Publications by authors named "Debasis Das"

173 Publications

Eye movements in patients in early psychosis with and without a history of cannabis use.

NPJ Schizophr 2021 May 12;7(1):24. Epub 2021 May 12.

Institute of Psychiatry, Psychology and Neurosciences King's College London, London, UK.

It is unclear whether early psychosis in the context of cannabis use is different from psychosis without cannabis. We investigated this issue by examining whether abnormalities in oculomotor control differ between patients with psychosis with and without a history of cannabis use. We studied four groups: patients in the early phase of psychosis with a history of cannabis use (EPC; n = 28); patients in the early phase of psychosis without (EPNC; n = 25); controls with a history of cannabis use (HCC; n = 16); and controls without (HCNC; n = 22). We studied smooth pursuit eye movements using a stimulus with sinusoidal waveform at three target frequencies (0.2, 0.4 and 0.6 Hz). Participants also performed 40 antisaccade trials. There were no differences between the EPC and EPNC groups in diagnosis, symptom severity or level of functioning. We found evidence for a cannabis effect (χ = 23.14, p < 0.001), patient effect (χ = 4.84, p = 0.028) and patient × cannabis effect (χ = 4.20, p = 0.04) for smooth pursuit velocity gain. There was a large difference between EPC and EPNC (g = 0.76-0.86) with impairment in the non cannabis using group. We found no significant effect for antisaccade error whereas patients had fewer valid trials compared to controls. These data indicate that impairment of smooth pursuit in psychosis is more severe in patients without a history of cannabis use. This is consistent with the notion that the severity of neurobiological alterations in psychosis is lower in patients whose illness developed in the context of cannabis use.
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http://dx.doi.org/10.1038/s41537-021-00155-2DOI Listing
May 2021

Next generation kinase inhibitors targeting specific biomarkers in non-small cell lung cancer (NSCLC): A recent overview.

ChemMedChem 2021 Apr 30. Epub 2021 Apr 30.

Arromax Pharmatech Co Ltd, Discovery Chemistry, CHINA.

Lung cancer is one of the cancers and causes many deaths globally. Due to mutations of regulatory genes, irregularities of specific signal transductions or alteration of signalling pathways are observed in non-small cell lung cancer (NSCLC) cases. Over the past two decades, a few kinases have been identified, validated and studied as the biomarkers for NSCLC. Among them, EGFR, ALK, ROS1, MET, RET, NTRK, and BRAF are marked as targetable biomarkers to cure and/or control the diseases.  In recent years, the FDA approved more than fifteen kinase inhibitors for these validated biomarkers of NSCLC. The chemotherapy, immunotherapy, surgery, radiation or a combination of  therapies are treatment options for the disease. The kinase inhibitors significantly improve the progression-free survival (PFS) of NSCLC patients, still challenges remain for metastatic diseases and advanced NSCLC cases.  New discoveries of potent kinase inhibitors and  rapid development of medical technologies give more options to manage NSCLC scinetifically. An overview of the discoverires of different type kinase inhibitors against NSCLC, medicinal chemistry aspects and related development of next generation kinase inhibitors in recent years are discussed in this article.
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http://dx.doi.org/10.1002/cmdc.202100166DOI Listing
April 2021

Basics of extra corporeal membrane oxygenation: a pediatric intensivist's perspective.

Perfusion 2021 Mar 26:2676591211005260. Epub 2021 Mar 26.

Department of Cardiac Surgery, NH Narayana Superspeciality Hospital, Howrah, West Bengal, India.

Extra Corporeal membrane oxygenation (ECMO) is one of the most advanced forms of life support therapy in the Intensive Care Unit. It relies on the principle where an external artificial circuit carries venous blood from the patient to a gas exchange device (oxygenator) within which blood becomes enriched with oxygen and has carbon dioxide removed. The blood is then returned to the patient via a central vein or an artery. The goal of ECMO is to provide a physiologic milieu for recovery in refractory cardiac/respiratory failure. The technology is not a definitive treatment for a disease, but provides valuable time for the body to recover. In that way it can be compared to a bridge, where patients are initiated on ECMO as a bridge to recovery, bridge to decision making, bridge to transplant or bridge to diagnosis. The use of this modality in children is not backed by a lot of randomized controlled trials, but the use has increased dramatically in our country in last 10 years. This article is not intended to provide an in-depth overview of ECMO, but outlines the basic principles that a pediatric intensive care physician should know in order to manage a kid on ECMO support.
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http://dx.doi.org/10.1177/02676591211005260DOI Listing
March 2021

Utility of late pulmonary artery banding in single-ventricle physiology: A mid-term follow-up.

Ann Pediatr Cardiol 2021 Jan-Mar;14(1):26-34. Epub 2020 Sep 17.

Department of Pediatric Cardiology, Narayana Superspeciality Hospital, Howrah, West Bengal, India.

Background: The standard first stage palliation for univentricular heart with unrestricted pulmonary blood flow (PBF) is surgical pulmonary artery (PA) banding for which the ideal age is within the first 8 weeks of life. This study aimed to look for the utility of PA band done beyond 3 months of age for patients presenting beyond the stipulated period.

Materials And Methods: This is a retrospective analysis of the outcome of twenty patients with single ventricle (SV) physiology with unrestricted PBF who presented late and were selected on the basis of clinical, radiological, and echocardiographic parameters for PA banding.

Results: The median age of the patients was 5.5 months (3.5-96 months), and the median body weight was 4.7 kg (3.2-22.0 kg). The patients were divided into three groups as follows: ten patients between 3 and 6 months of age (Group A), seven patients between 6 months to 1 year of age (Group B), and three patients > 1 year of age with additional features of pulmonary venous hypertension (Group C). The mean reduction of PA pressures following PA band was 60.9%, 48.8%, and 58.3% and the mean fall in oxygen saturation was 10.4%, 8.0%, and 6.6% in the three groups, respectively. The postoperative mortality rate was 10%. The mean follow up duration was 13.5 months (7-23 months). There was a statistically significant improvement in weight for age Z scores following PA band ( = 0.0001). On follow up cardiac catheterization, the mean PA pressures were 16.6 (±3.6), 22.7 (±5.7), and 33.3 (±12.4) mmHg, respectively, in the three groups, and the mean pulmonary vascular resistance index was 1.86 (±0.5), 2.45 (±0.7), and 3.5 (±1.6) WU.m2, respectively. Subsequently, seven patients in Group A, three patients in Group B, and one patient from Group C underwent successful bidirectional Glenn (BDG) surgery.

Conclusions: Late PA band in selected patients with SV physiology can have definite benefit in terms of correction of heart failure symptoms and subsequent conversion to BDG and can potentially change the natural history of disease both in terms of survival and quality of life.
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http://dx.doi.org/10.4103/apc.APC_128_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7918013PMC
September 2020

Atrial fibrillation - Can HbA1c levels really predict the risk?

Asian Cardiovasc Thorac Ann 2021 Mar 2:218492321998933. Epub 2021 Mar 2.

Department of Cardiac Surgery, NH Rabindranath Tagore International Institute of Cardiac Sciences, Kolkata, India.

Background: Diabetes is associated with higher mortality and worse post-operative outcomes in patients undergoing coronary artery bypass grafting and HbA1c levels have consistently been reported to be associated with adverse post-operative outcomes. However, the role of HbA1c still remains unclear with regards to the occurrence of atrial fibrillation.

Method: Data for the patients undergoing off-pump coronary artery bypass grafting was analysed in a retrospective fashion. Patients were divided into-those with HbA1c < 6.5% and those with HbA1c ≥ 6.5% and the incidence of atrial fibrillation observed in these two groups. We also compared patient who developed atrial fibrillation in the post-operative period and compared them with those who did not.

Results: Of the 5259 patients included in the study HbA1c was <6.5 in 2808 (53.4%) patients and was ≥6.5 in 2451 (46.6%) patients; 623 (11.8%) patients in our study developed atrial fibrillation. Onset of atrial fibrillation in the post-operative period was seen most commonly 235 (38.3%) on between 24 and 48 h after the operation with more than half of them 338 (54.2%) occurring within the first 48 h. On multivariate analysis, HbA1c was not a risk factor for atrial fibrillation (odd's ratio 1.144, 95% confidence interval 0.967-1.354). Only increased age (odd's ratio 1.08; 95% confidence interval 1.069-1.091); EuroSCORE (odd's ratio 1.073; 95% confidence interval 1.048-1.099); history of recent MI (odd's ratio 0.768; 95% confidence interval 0.606-0.971) and peripheral vascular disease (odd's ratio 1.667; 95% confidence interval 1.091-2.517) were found to be independently associated with increased risk of atrial fibrillation in the post-operative period.

Conclusions: After adjusting for confounders HbA1c levels do not independently predict risk of atrial fibrillation after off-pump coronary artery bypass grafting.
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http://dx.doi.org/10.1177/0218492321998933DOI Listing
March 2021

Total circulatory arrest as a support modality in congenital heart surgery: review and current evidence.

Indian J Thorac Cardiovasc Surg 2021 Jan 9;37(Suppl 1):165-173. Epub 2020 Mar 9.

Department of Cardiac Surgery, BM Birla Heart Research Centre, 1, National Library Avenue, Alipore, Kolkata, 700027 India.

The use of total circulatory arrest (TCA)/deep hypothermic circulatory arrest (DHCA) as a support modality in congenital heart surgery is a time-tested strategy. However, with technological advances, the widespread use of this technique has decreased. Adjunctive cerebral perfusion with continuous cardiopulmonary bypass (CPB) gradually has become more popular with a view to reduce the complications related to DHCA. In addition, better neuromonitoring and neuroprotective strategies have made DHCA much safer. However, the level of evidence to support the best way to protect the brain during congenital heart surgery is insufficient. This review analyzes the history, physiology, techniques of DHCA, as well as other alternative strategies like selective cerebral perfusion and presents the current available evidence.
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http://dx.doi.org/10.1007/s12055-020-00930-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7859125PMC
January 2021

Development of a Nursing Application to Minimize Drug Calculation Errors and Estimate Patient Assessment Scores.

Comput Inform Nurs 2021 Feb;39(2):57-60

Author Affiliations: Pediatric Cardiac Critical Care Unit (Mr Kurian and Mr George and Dr S. Das); and Department of Cardiothoracic Surgery (Mr D. Das, Mr Dutta, and Ms P. Das), NH Narayana Superspeciality Hospital, Howrah, West Bengal, India.

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http://dx.doi.org/10.1097/CIN.0000000000000717DOI Listing
February 2021

Clinicohistological correlation of etiological spectrum of chronic liver disease diagnosed during noncirrhotic stages in children: Can need of liver biopsy be obviated?

JGH Open 2021 Jan 30;5(1):20-27. Epub 2020 Oct 30.

Department of Pediatrics KPC Medical College Kolkata India.

Background And Aim: Limited data exist regarding the etiological spectrum of the subset of chronic liver diseases (CLDs) diagnosed in noncirrhotic states in children. Our primary objective was to study the clinicoetiological profile of CLDs detected in noncirrhotic stages in children younger than 12 years of age. The secondary objective was to find the hepatic histological correlation of provisional diagnosis by different ranks of doctors.

Methods: This was an observational epidemiological study, cross-sectional in design, conducted in a tertiary-care setting over a 2-year period.

Results: Thirty-seven cases were enrolled, with a mean ± SD age of 8 ± 4.1 years and a male:female ratio of 1.8:1. Etiologies noted were Wilson disease ( = 8), autoimmune hepatitis ( = 4), secondary hemochromatosis ( = 4), chronic hepatitis B ( = 3), chronic hepatitis C ( = 2), non-alcoholic steatohepatitis ( = 2), progressive familial intrahepatic cholestasis ( = 2), extrahepatic biliary atresia ( = 2), Alagille syndrome ( = 1), galactosemia ( = 1), Gaucher disease ( = 1), Niemann-Pick disease ( = 1), and Budd-Chiari syndrome ( = 1), with an inconclusive diagnosis in five children. Relevant investigations were ordered more frequently by the specialist consultant (SC) and super specialist (SS) combined in comparison with the senior resident (SR) and junior resident (JR) together. ( = 0.0013). Irrelevance of the tests ordered was significantly higher in the junior tier (JR and SR; SR > JR) in contrast to the senior tier of doctors (SC and SS) ( < 0.01). The clinicohistological correlation of an etiological diagnosis significantly differed between the junior and senior ranks of physicians. We noted that an ideal clinical acumen could help to avoid liver biopsy for etiological diagnosis in 78.3% (29/37) of the study population.

Conclusion: Interpretation of clinical presentation by the senior set of doctors is preferable, which could obviate the need for liver biopsy regarding diagnosis in a proportion of pediatric CLD patients.
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http://dx.doi.org/10.1002/jgh3.12441DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7812483PMC
January 2021

Congenital right ventricular diverticulum: An atypical presentation.

Ann Pediatr Cardiol 2020 Oct-Dec;13(4):368-370. Epub 2020 Jul 24.

Department of Pediatric Intensive Care, Narayana Superspeciality Hospital, Howrah, West Bengal, India.

Congenital ventricular diverticulum is a rare congenital malformation of the heart. It remains mostly asymptomatic unless associated with other congenital cardiac defects. We present a case of a 4-month-old child who had dextrocardia, large inlet ventricular septal defect, amounting to single ventricle, and severe pulmonary artery hypertension. There was a right ventricular diverticulum which passed through the foramina of Morgagni to give rise to a pulsating lump in the epigastrium. Right ventricular diverticulum presenting with a pulsating mass in the abdomen is a rare entity. The confirmation of diverticulum was made with histopathology.
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http://dx.doi.org/10.4103/apc.APC_49_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7727917PMC
July 2020

Recent Applications of Azo Dyes: A Paradigm Shift from Medicinal Chemistry to Biomedical Sciences.

Mini Rev Med Chem 2020 Nov 23. Epub 2020 Nov 23.

Department of Chemistry, RK University, Rajkot, Gujrat-360020,. India.

Azo molecules are one of the fascinating organic molecular architectures with azo bond (-N=N-). Since the last century, the bright colored azo molecules are used as dyes for printing, food, paper, cosmetic laser, electronics, optics, material sciences etc. After the discovery of Prontosil as an antibacterial drug, azo molecules became into limelight in medicinal chemistry. Later a number of azo molecules such as Phenazopyridine, Basalazide, Sulfasalazine etc., occupied the drug market. Many azo molecules have been demonstrated as antibacterial, anti-malarial, antifungal, antioxidant, antiviral agents and many more. Metabolic degradation of many azo dyes can cause problem to liver that limits the application of azo dyes in medicinal chemistry. Azo dyes are significantly used in cancer chemotherapy. Recently, a paradigm shift has been observed in the application of azo dyes from medicinal chemistry to biomedical science area. The application of azo molecules in biomedical science such as imaging, drug deliver, photo pharmacology and photo switch areas are reported. In this article, we have complied and discussed the recent work done on azo dye molecules for medicinal importance and future prospects.
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http://dx.doi.org/10.2174/1389557520999201123210025DOI Listing
November 2020

Naked Eye Cd Ion Detection and Reversible Iodine Uptake by a Three-Dimensional Pillared-Layered Zn-MOF.

Inorg Chem 2020 Dec 16;59(23):17758-17765. Epub 2020 Nov 16.

Department of Chemistry, University College of Science, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India.

A novel metal-organic framework (MOF), [Zn(tdca)(bppd)]·2DMF, has been synthesized solvothermally using the ligand thiophene-2,5-dicarboxylic acid (Htdca), coligand ,'-bis(4-pyridylmethylene)-1,4-benzenediamine (bppd), and Zn(NO). Single crystal X-ray crystallography reveals that the titled MOF is a three-dimensional pillared-layered MOF. A layer is constituted by a Zn(tdca) unit, and the layers are stabilized by the long hydrocarbon coligand, bppd, which acts as a pillar. A rectangular pore size of 11.42 × 8.12 Å is found in the framework. The porous framework is found to be an excellent fluorescence sensor for the detection of toxic Cd ion. The sensor shows high selectivity and sensitivity and a quick response toward Cd. The synthesized MOF is able to not only detect cadmium ions but also adsorb iodine in the gas phase. The MOF can adsorb ∼66% iodine, verified by thiosulfate-iodine titration and TG analysis. Adsorbed iodine can also be removed easily in acetonitrile as well as in -hexane, which shows that iodine can be reversibly loaded as well as unloaded into the framework.
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http://dx.doi.org/10.1021/acs.inorgchem.0c02985DOI Listing
December 2020

Validation of Revised Baveno VI Criteria for Screening of Varices Needing Treatment in Children with Cirrhosis.

Clin Exp Gastroenterol 2020 5;13:503-509. Epub 2020 Nov 5.

Department of Pediatrics, KPC Medical College, Kolkata, India.

Background: Baveno VI criteria for screening varices needing treatment (VNT) have not yet been validated in an exclusive pediatric and adolescent set of the population, in whom baseline parameters differ in relation to adults. Therefore, our primary objective was to validate Baveno VI and its expanded form in children below 18 years of age. The secondary aim was to elicit whether any revision of the above criteria with a target of not missing more than 5% VNT could be more accurate for this age group.

Materials And Methods: The work was carried out in two medical institutes, over a span of 3 years. Consecutively enrolled patients below 18 years of age, with compensated cirrhosis confirmed by liver biopsy, were evaluated for related blood parameters, transient elastography (TE) and esophagogastroduodenoscopy.

Results: Out of the 33 recruited patients, five (15.15%) met the criteria for VNT. The sensitivity, specificity, PPV and NPV of Baveno VI and Expanded Baveno VI were observed as 60%, 92.3%, 60% and 92.3%, and 20%, 100%, 100% and 88%, respectively. We found that the Revised Baveno VI criteria with TE <19 kPa and platelet count of >175×10 cells/L, with sensitivity 100%, specificity 79%, PPV 45%, NPV 100% and accuracy of 82%, are more appropriate for this age group.

Conclusion: We propose that further multicentrer studies with a larger sample size should be conducted before incorporating Revised Baveno VI criteria for high-risk varices in patients below 18 years in future guidelines.
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http://dx.doi.org/10.2147/CEG.S276182DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7652065PMC
November 2020

Structure and synthesis of copper-based Schiff base and reduced Schiff base complexes: a combined experimental and theoretical investigation of biomimetic catalytic activity.

Dalton Trans 2020 Nov;49(43):15461-15472

Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, India.

Three copper(ii) complexes, [Cu(L1)(NCS)]n (1), [Cu(L1)(N3)]n (2) and [Cu(L2)(N3)] (3) were synthesized from one Schiff base ligand and one reduced Schiff base ligand, (E)-4-chloro-2-[(2-propylaminoethylimino)methyl]phenol (HL1) and 4-chloro-2-[(2-(propylaminoethylamino) methyl]phenol (HL2), respectively. All complexes were characterized by various physicochemical studies, such as FT-IR, UV-Vis, ESI-MS, EPR and single crystal X-ray diffraction. Complexes 1 and 2 have 1D polymeric chain-like structures bridging through thiocyanate and azide anions, whereas complex 3 has a mononuclear structure in the solid state. All the complexes are active towards mimicking two well-known proteins, phosphatase and phenoxazinone synthase, using the disodium salt of 4-nitrophenylphosphate (4-NPP) and 2-aminophenol (OAP) as the substrate in DMF medium. Complexes 2 and 3 show the highest activity towards phosphatase and phenoxazinone synthase activity with kcat values of 22.6 s-1 and 134.4 h-1, respectively. EPR studies confirmed that for complex 1, the OAP oxidation goes through the generation of an organic radical at g = 1.99, which is due to an imine radical formation, whereas the metal center redox pathway is followed for complex 3. Extensive DFT calculations have been performed for both catalytic studies to put forward the most probable mechanistic pathways.
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http://dx.doi.org/10.1039/d0dt02784gDOI Listing
November 2020

Green facile synthesis to develop nanoscale coordination polymers as lysosome-targetable luminescent bioprobes.

Biomater Sci 2021 Jan;9(1):124-132

Department of Chemistry, University of Calcutta, 92 APC Road, Kolkata 700109, India.

Three new coordination polymers (CPs), namely [{M(HL)(L)(H2O)}(ClO4)(H2O)]∞ (M = Zn for CP 1, Mn for CP 2, Cu for CP 3) were synthesized to explore their efficacy as lysosome-targetable luminescent bioprobes. The synthesized CPs were characterized by techniques including single-crystal X-ray analysis, FTIR spectroscopy and elemental analysis. Single-crystal analysis revealed the formation of iso-structural CPs displaying distorted adamantoid topology developed by bridging ligands and H-bonds connections and metals at the nodes. A green hand-grinding technique with a mortar and pestle resulted in nanoscale coordination polymers (NCPs) suitable for cell permeability and was further confirmed by SEM and DLS analyses. Two of these hand-ground nanoscale coordination polymers NCP 1 and NCP 2 showed excellent green luminescence and were explored as potential and selective long-time biotrackers towards lysosome using the human lung carcinoma cell line (A549). Strikingly, the developed bioprobe displayed excellent bio-availability, photostability and excellent selectivity towards lysosomes sustained by various in vitro cell imaging experiments. Moreover, the long-term probing ability of these NCPs turned out to be better than the commercially available lysosome tracker i.e. LysoTracker Red, indicating their potential real-life application in bio-imaging. To the best ofour knowledge, this is the first example of nonexpensive and less toxic essential transition metal-based nanoscale coordination polymers that can behave as effective lysosome-targetable luminescent bioprobes.
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http://dx.doi.org/10.1039/d0bm01328eDOI Listing
January 2021

Cannabis use in patients with early psychosis is associated with alterations in putamen and thalamic shape.

Hum Brain Mapp 2020 10 20;41(15):4386-4396. Epub 2020 Jul 20.

Institute of Psychiatry, Psychology and Neurosciences King's College London, London, UK.

Around half of patients with early psychosis have a history of cannabis use. We aimed to determine if there are neurobiological differences in these the subgroups of persons with psychosis with and without a history of cannabis use. We expected to see regional deflations in hippocampus as a neurotoxic effect and regional inflations in striatal regions implicated in addictive processes. Volumetric, T1w MRIs were acquired from people with a diagnosis psychosis with (PwP + C = 28) or without (PwP - C = 26) a history of cannabis use; and Controls with (C + C = 16) or without (C - C = 22) cannabis use. We undertook vertex-based shape analysis of the brainstem, amygdala, hippocampus, globus pallidus, nucleus accumbens, caudate, putamen, thalamus using FSL FIRST. Clusters were defined through Threshold Free Cluster Enhancement and Family Wise Error was set at p < .05. We adjusted analyses for age, sex, tobacco and alcohol use. The putamen (bilaterally) and the right thalamus showed regional enlargement in PwP + C versus PwP - C. There were no areas of regional deflation. There were no significant differences between C + C and C - C. Cannabis use in participants with psychosis is associated with morphological alterations in subcortical structures. Putamen and thalamic enlargement may be related to compulsivity in patients with a history of cannabis use.
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http://dx.doi.org/10.1002/hbm.25131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7502838PMC
October 2020

A Chemodosimetric Approach for Fluorimetric Detection of Hg Ions by Trinuclear Zn(II)/Cd(II) Schiff Base Complex: First Case of Intermediate Trapping in a Chemodosimetric Approach.

Inorg Chem 2020 Jul 23;59(13):9014-9028. Epub 2020 Jun 23.

Department of Chemistry, University College of Science, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India.

The present work discloses the application of two fluorescent zinc and cadmium complexes ( and ) for sensing of Hg(II) ions through a chemodosimetric approach. The ligand under consideration in this work is a NO donor Schiff base ligand ()-4-bromo-2-(((2-morpholinoethyl)imino)methyl)phenol (), which has been harnessed to generate complexes [ZnL(OAc)] () and [CdL(OAc)] (). X-ray single crystal diffraction studies unveil the trinuclear skeleton of complexes and . Both complexes have been found to be highly fluorescent in nature. However, the quantum efficiency of Zn(II) complex () dominates over the Cd(II) analogue (). The absorption and emission spectroscopic properties of the complexes have been investigated by density functional theory. Complexes and can detect Hg ions selectively by fluorescence quenching, and it is noteworthy to mention that the mechanism of sensing is unique as well as interesting. In the presence of Hg ions, complexes and are transformed to mononuclear mercuric intermediate complex () and finally to a trinuclear mercuric complex () by hydrolysis. We have successfully trapped the intermediate complex , and we characterized it with the aid of X-ray crystallography. Transformation of complexes and to intermediate complex and finally to has been established by UV-vis spectroscopy, fluorescence spectroscopy, ESI-MS spectroscopy, H NMR spectroscopy, and X-ray crystallography. The spontaneity of the above conversion is well supported by thermodynamic aspects as reflected from density functional theoretical calculations.
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http://dx.doi.org/10.1021/acs.inorgchem.0c00857DOI Listing
July 2020

Irreversible Kinase Inhibitors Targeting Cysteine Residues and their Applications in Cancer Therapy.

Mini Rev Med Chem 2020 ;20(17):1732-1753

Discovery Chemistry Research, ArromaxPharmatech Co. Ltd. Sangtian Island Innovation Park, No. 1 Huayun Road, Suzhou 215123, China.

Protein kinases are conserved enzymes that catalyse the phosphorylation process in cells. They are recognized as the targets for many diseases. The FDA has approved many kinase inhibitors for the treatment of cancer and confirmed kinases as relevant targets for drug discovery. Major approved drugs are ATP competitive reversible non-covalent inhibitors that achieve selectivity by recognition of specific binding pockets of targeted kinases. In recent years, scientists have paid attention on developing irreversible covalent kinase inhibitors to achieve better selectivity, less toxicity and side effects. Since 2013, seven Irreversible Kinase Inhibitors (IKIs), including; afatinib, ibrutinib, neratinib, dacomitinib, osimertinib, acalabrutinib and zanubrutinib have been approved by the FDA for treatment of severe diseases, like; Metastatic Non-Small Cell Lung Cancer (NSCLC), Mantle Cell Lymphoma (MCL) and HER2-positive breast cancer. These inhibitors target the cysteine residues of kinases. Many IKIs that target cysteine residues are in clinical trials for different diseases and are yet to be approved. We have reviewed the research done and efforts made for finding novel cysteine targeted IKIs as drugs in the recent years.
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http://dx.doi.org/10.2174/1389557520666200513121524DOI Listing
January 2020

A polynuclear Cu(ii) complex for real time monitoring of mitochondrial cytochrome C release during cellular apoptosis.

Chem Commun (Camb) 2020 Jun 12;56(48):6563-6566. Epub 2020 May 12.

Department of Chemistry, The University of Burdwan, Burdwan, WB 713104, India.

A new amide-imine conjugate, 2-hydroxybenzoic acid-(2-hydroxybenzylidene)-hydrazide (L), is employed to prepare a single crystal X-ray structurally characterized poly-nuclear Cu(ii) complex (M1). M1 selectively and spatially interacts with cytochrome C (Cyt C) to allow fluorescence imaging of intracellular translocation events in living cells. Thus, direct visualization of a Cyt C translocation event during an apoptotic process is achieved for the first time. The binding constant and LOD are 7.52 × 10 M and 34.0 nM, respectively.
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http://dx.doi.org/10.1039/d0cc01606cDOI Listing
June 2020

Association of cannabis with glutamatergic levels in patients with early psychosis: Evidence for altered volume striatal glutamate relationships in patients with a history of cannabis use in early psychosis.

Transl Psychiatry 2020 04 21;10(1):111. Epub 2020 Apr 21.

Institute of Psychiatry, Psychology and Neurosciences, King's College London, London, UK.

The associative striatum, an established substrate in psychosis, receives widespread glutamatergic projections. We sought to see if glutamatergic indices are altered between early psychosis patients with and without a history of cannabis use and characterise the relationship to grey matter. 92 participants were scanned: Early Psychosis with a history of cannabis use (EPC = 29); Early Psychosis with minimal cannabis use (EPMC = 25); Controls with a history of cannabis use (HCC = 16) and Controls with minimal use (HCMC = 22). Whole brain T1 weighted MR images and localised proton MR spectra were acquired from head of caudate, anterior cingulate and hippocampus. We examined relationships in regions with known high cannabinoid 1 receptor (CB1R) expression (grey matter, cortex, hippocampus, amygdala) and low expression (white matter, ventricles, brainstem) to caudate Glutamine+Glutamate (Glx). Patients were well matched in symptoms, function and medication. There was no significant group difference in Glx in any region. In EPC grey matter volume explained 31.9% of the variance of caudate Glx (p = 0.003) and amygdala volume explained 36.9% (p = 0.001) of caudate Glx. There was no significant relationship in EPMC. The EPC vs EPMC interaction was significant (p = 0.042). There was no such relationship in control regions. These results are the first to demonstrate association of grey matter volume and striatal glutamate in the EPC group. This may suggest a history of cannabis use leads to a conformational change in distal CB1 rich grey matter regions to influence striatal glutamatergic levels or that such connectivity predisposes to heavy cannabis use.
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http://dx.doi.org/10.1038/s41398-020-0790-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7174331PMC
April 2020

Synthesis of MnO nanozymes from structurally characterized phenoxazinone synthase models based on manganese(iii) Schiff base complexes.

Dalton Trans 2020 May 21;49(18):5999-6011. Epub 2020 Apr 21.

Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, India.

Three mononuclear and one hexanuclear manganese(iii) complexes, [Mn(L)(HO)]·Cl (1), [Mn(L)(HO)]·Br (2), [Mn(L)(HO)]·NO (3), and [Mn(L)(NCS)] (4), have been synthesized using a Schiff-base ligand, namely (E)-2-((3-(2-hydroxyethylamino)propylimino)methyl)phenol (HL), and structurally characterized by the usual physicochemical techniques such as UV-Vis, FT-IR, ESI-MS, EPR and single crystal XRD. The structure of complex 4 is unique among all four complexes as the sixth coordination position of manganese is fulfilled by the oxygen atom of a neighbouring unit by covalent interaction. The phenoxazinone synthase like activity of all four complexes has been thoroughly investigated using three different substrates, o-aminophenol (OAP), 2-amino-4-methylphenol (MAP) and 3-amino-4-hydroxybenzoic acid (CAP). All complexes were found to be active towards catalysis and complex 4 showed the highest activity. The EPR study reveals that the oxidative dimerization of the substrates occurred through metal centered redox participation rather than a radical formation pathway. The experimental observations have been supported by DFT calculations to put forward the most probable mechanistic pathways operating in the catalytic cycle. Moreover, MnO nanoparticles (NPs) having two different morphologies have been synthesized using complexes 1 and complex 4 simply by calcination, respectively, with the aim to prepare nanozymes. These two synthesized NPs were also able to show phenoxazinone synthase like activity and thus complexes 1 and 4 can be claimed as precursors of nanozymes.
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http://dx.doi.org/10.1039/d0dt00355gDOI Listing
May 2020

In vivo efficacy studies of novel quinazoline derivatives as irreversible dual EGFR/HER2 inhibitors, in lung cancer xenografts (NCI-H1975) mice models.

Bioorg Chem 2020 06 24;99:103790. Epub 2020 Mar 24.

Discovery Chemistry Research, Arromax Pharmatech Co. Ltd., Sangtian Island Innovation Park, No. 1 Huayun Road, Suzhou 215123, PR China. Electronic address:

Lung cancer is the most common cancer and leading cause of cancer-related deaths worldwide. The first-generation reversible, ATP-competitive inhibitors gefetinib and elotinib showed good clinical responses in lung adenocarcinoma tumors (NSCLC). But almost all patients developed resistance to these inhibitors over time. Such resistance of EGFR inhibitors was frequently linked to the acquired L858R and T790M point mutations in the kinase domain of EGFR. To overcome these resistance problems, the second and the third generation inhibitors have been discovered. FDA approved afatinib, the second generation irreversible inhibitor and osimitinib, the third generation irreversible EGFR inhibitors for the treatments of NSCLC. We identified new covalent quinazoline inhibitors (E)-N-(4-(3-chloro-4-fluorophenylamino)-7-(2-ethoxyethoxy)quinazolin-6-yl)-4-(dimethylamino)but-2-enamide (6d) and (E)-N-(4-(3-chloro-4-(pyridin-2-ylmethoxy)phenylamino)-7-(2-ethoxyethoxy)quinazolin-6-yl)-4-(dimethyl-amino)but-2-enamide (6h) that exhibited potent EGFR kinase inhibitory activities on L858R and T790M mutations. The compound 6 h showed selectivity similar to AZD9291 (osimertinib) in mutated and wild type tumor cell lines. In vitro cell assay 6d and 6h were better than afatinib and osimertinib. In vivo antitumor efficacy studies of these compounds were done in NCI-H1975 mice xenografts.
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http://dx.doi.org/10.1016/j.bioorg.2020.103790DOI Listing
June 2020

Complete sternal cleft with tetralogy of Fallot.

Ann Pediatr Cardiol 2020 Jan-Mar;13(1):81-83. Epub 2019 Dec 4.

Department of Pediatric Cardiology, Narayana Superspeciality Hospital, Howrah, West Bengal, India.

Complete sternal cleft is a very rare congenital midline defect of the sternum. It is not uncommonly associated with intracardiac defects. We report a case of a 2-year-old child with complete sternal cleft and tetralogy of Fallot who presented with cyanotic spells. The child underwent total correction, followed by chest wall reconstruction on the next day.
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http://dx.doi.org/10.4103/apc.APC_86_19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979026PMC
December 2019

Resolving kinetic intermediates during the regulated assembly and disassembly of fusion pores.

Nat Commun 2020 01 13;11(1):231. Epub 2020 Jan 13.

Department of Neuroscience and Howard Hughes Medical Institute, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, 53705, USA.

The opening of a fusion pore during exocytosis creates the first aqueous connection between the lumen of a vesicle and the extracellular space. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediate the formation of these dynamic structures, and their kinetic transitions are tightly regulated by accessory proteins at the synapse. Here, we utilize two single molecule approaches, nanodisc-based planar bilayer electrophysiology and single-molecule FRET, to address the relationship between SNARE complex assembly and rapid (micro-millisecond) fusion pore transitions, and to define the role of accessory proteins. Synaptotagmin (syt) 1, a major Ca-sensor for synaptic vesicle exocytosis, drove the formation of an intermediate: committed trans-SNARE complexes that form large, stable pores. Once open, these pores could only be closed by the action of the ATPase, NSF. Time-resolved measurements revealed that NSF-mediated pore closure occurred via a complex 'stuttering' mechanism. This simplified system thus reveals the dynamic formation and dissolution of fusion pores.
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http://dx.doi.org/10.1038/s41467-019-14072-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6957489PMC
January 2020

Designing of novel zinc(ii) Schiff base complexes having acyl hydrazone linkage: study of phosphatase and anti-cancer activities.

Dalton Trans 2020 Jan 6;49(4):1232-1240. Epub 2020 Jan 6.

Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India.

Three asymmetric tridentate acyl hydrazone Schiff base ligands namely L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde, 1-(pyridin-2-yl)ethanone and phenyl(pyridin-2-yl)methanone respectively. Three bio-relevant mononuclear zinc(ii) complexes [Zn(L1)Cl]·2HO (1), [Zn(L2)Cl] (2) and [Zn(L3)Cl] (3) were synthesized by treatment of zinc(ii) chloride with the corresponding Schiff base ligands and characterised by the usual physicochemical techniques. The solid state structures of complexes 1 and 3 were evaluated by single crystal X-ray analysis. All complexes were able to hydrolyse the P-O bond of the phosphate monoester in 90% (v/v) DMSO-water medium using 4-nitrophenylphosphate (4-NPP) as the model substrate and the trend in their activity is 1≈2 > 3. On considering the highly efficient hydrolysis properties, complexes 1-3 were tested as potential therapeutic agents for cancer using HCT116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and A549 (human non-small lung carcinoma) cells. Complex 2 showed the highest IC values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study. The internucleosomal degradation of DNA during apoptosis can be detected by cell death detection ELISA. DNA fragmentation that leads to cell death was examined and when induced by complex 2 in HepG2 cells a significant level of DNA fragmentation was observed at regular intervals of time.
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http://dx.doi.org/10.1039/c9dt04636dDOI Listing
January 2020

Organically Functionalized Mesoporous SBA-15 Type Material Bearing Fluorescent Sites for Selective Detection of Hg from Aqueous Medium.

ACS Omega 2019 Oct 14;4(18):17857-17863. Epub 2019 Oct 14.

Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India.

Hg(II) contamination in water resources is one of the major health issues in keeping the purity standard of the municipal water supply. Herein, we report a new mesoporous sensor probe material SBA-ABZ-PEA having a 2D-hexagonally ordered mesoporous framework bearing covalently bonded fluorescent sites, and this has been synthesized through a two-step post-synthesis grafting route. A pure silica mesoporous SBA-15 material has been functionalized with (3-chloropropyl)triethoxysilane (ClPTES) to obtain chloro-functionalized SBA-15, which was further reacted with 4aminobenzaldehyde followed by treatment with 2-(2-pyridyl)-ethylamine resulting in functionalized 2D-hexagonal mesoporous sensor probe SBA-ABZ-PEA. Small angle PXRD, N adsorption/desorption, HRTEM, TGA, and FT-IR studies have been carried out to characterize these materials. Our experimental results suggested successful grafting of the organic moiety on the SBA-15 surface along with preservation of mesoporosity throughout the grafting process. Photoluminescence measurements were carried out in the aqueous suspension of SBA-ABZ-PEA in the presence of different metal cations, like Na, Mg, Al, K, Ca, Mn, Co, Cu, Zn, Cd, Pb, and Hg. This result revealed that, among the various metal-ions, the emission intensity of the mesoporous sensing probe material SBA-ABZ-PEA has been dramatically quenched in the presence of the Hg ion. To check the sensitivity of the sensor probe, the fluorescence emission was also studied in the presence of different concentrations of Hg ions. A perfect linear plot between the concentrations of Hg ions in the aqueous medium with their corresponding fluorescence intensities with a detection limit of 1.2 × 10 M has been observed.
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http://dx.doi.org/10.1021/acsomega.9b02631DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822104PMC
October 2019

Exploration of catecholase-like activity of a series of magnetically coupled transition metal complexes of Mn, Co and Ni: new insights into the solution state behavior of Mn complexes.

Dalton Trans 2019 Oct 11;48(37):14164-14177. Epub 2019 Sep 11.

Department of Chemistry, University College of Science, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India.

A series of tri-nuclear complexes of general formula [ML(OAc)], where M = Mn (1), Co (2) and Ni (3), (HL = (E)-4-bromo-2-(((2-morpholinoethyl)imino)methyl)phenol), have been synthesized. Single crystal X-ray crystallography reveals that each molecule contains three metal ions which are bridged by four acetate moieties. In the solution phase, the complexes are present as mononuclear species. Amongst them, the manganese atom of complex 1 switches its oxidation state from +ii to +iii with time, as confirmed by time dependent UV-Vis and EPR spectroscopic techniques. Furthermore, complex 1 with Mn in both oxidation states can oxidise 3,5-DTBC to 3,5-DTBQ through the ligand centred radical formation pathway. It is remarkable that complex 1 in the Mn oxidation state shows an abnormally high rate constant value in the oxidation of 3,5-DTBC to 3,5-DTBQ. This difference in rate constant values for catechol oxidation reaction by complex 1 can be explained by considering the binding constant value of catechol with Mn and Mn respectively from experimental and theoretical aspects. Similar to complex 1, complexes 2 and 3 also catalyse catechol oxidation following ligand centred imine radical formation pathways. Furthermore, magnetic properties of all the complexes were explored. DC magnetic susceptibility studies of complexes 1 and 2 revealed that in both the complexes the metal centres are antiferromagnetically coupled with adjacent metal centres, whereas in the case of complex 3, weak ferromagnetic interaction occurs between the neighbouring Ni centres at low temperature.
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http://dx.doi.org/10.1039/c9dt02399bDOI Listing
October 2019

Green synthesis of nanoscale cobalt(ii)-based MOFs: highly efficient photo-induced green catalysts for the degradation of industrially used dyes.

Dalton Trans 2019 Sep;48(36):13869-13879

Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, India.

Two new metal-organic frameworks (MOFs) based on cobalt metal, namely, [{Co0.5(5N3-IPA)0.5(1,2-bpe)1.25}]∞ (1) and [{Co(5NH2-IPA)(1,2-bpe)}]∞ (2) (5N3-IPA = 5-azidoisophthalic acid, 5NH2-IPA = 5-aminoisophthalic acid, 1,2-bpe = 1,2-bis(4-pyridyl)ethylene) were synthesized under a solvothermal condition and characterized. MOF 1 has a rare three-dimensional structure with 3-fold interpenetration, while MOF 2 has a 2D "pillar-layered" structure. The particle size of the as-synthesized MOFs was reduced to produce nanoscale MOFs (NMOFs) by a hand grinding technique while retaining the composition and structural regularity of the as-synthesized MOFs. SEM studies revealed that NMOFs 1 and 2 were hexagonal and square shaped, respectively. Since the band gap energy for MOFs 1 and 2 (2.81 eV and 2.65 eV, respectively) falls in the visible region, heterogeneous catalytic activities of NMOFs 1 and 2 in aqueous medium towards Reactive Yellow HE4R (RY84), Reactive Black HFGR (RBH), Rhodamine B (RhB) and methylene blue (MEB) were investigated under visible light irradiation. The introduction of hydrogen peroxide was observed to significantly increase the photocatalytic efficiency via dye degradation. Hydroxyl radical (OH˙) is supposed to act as the main active species during oxidation, which was further verified by performing the degradation experiment in the presence of tert-butyl alcohol, which can act as a radical trapper for hydroxide radicals in the reaction.
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http://dx.doi.org/10.1039/c9dt02394aDOI Listing
September 2019

Sequential Fluorescence Recognition of Molybdenum(VI), Arsenite, and Phosphate Ions in a Ratiometric Manner: A Facile Approach for Discrimination of AsO and HPO.

ACS Omega 2019 Jun 21;4(6):10877-10890. Epub 2019 Jun 21.

Department of Chemistry, The University of Burdwan, Burdwan 713104, West Bengal, India.

An amide-based smart probe (L) is explored for nanomolar detection of Mo(VI) ion in a ratiometric manner, involving hydrogen-bond-assisted chelation-enhanced fluorescence process through inhibition of photoinduced electron transfer process. The recognition of Mo(VI) is associated with a 17-fold fluorescence enhancement and confirmed by single-crystal X-ray diffraction of the resulting Mo(VI) complex (M1). Further, M1 selectively recognizes arsenite through green emission of their adduct (C1) with an 81-fold fluorescence enhancement. Interestingly, dihydrogen phosphate causes dissociation of C1 back to free L having weak fluorescence. The methods are fast, highly selective, and allow their bare eye visualization at physiological pH. All of the interactions have been substantiated by time-dependent density functional theory calculations to rationalize their spectroscopic properties. The corresponding lowest detection limits are 1.5 × 10 M for Mo(VI), 1.2 × 10 M for AsO, and 3.2 × 10 M for HPO, whereas the respective association constants are 4.21 × 10 M for Mo(VI), 6.49 × 10 M for AsO, and 2.11 × 10 M for HPO. The L is useful for efficient enrichment of Mo(VI) from aqueous solution, while M1 efficiently removes AsO from environmental samples by solid-phase extraction.
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http://dx.doi.org/10.1021/acsomega.9b00377DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6648501PMC
June 2019

Metal-Ion Displacement Approach for Optical Recognition of Thorium: Application of a Molybdenum(VI) Complex for Nanomolar Determination and Enrichment of Th(IV).

ACS Omega 2018 Nov 28;3(11):16089-16098. Epub 2018 Nov 28.

Department of Chemistry, The University of Burdwan, Burdwan, 713104 West Bengal, India.

An azine-based molybdenum (Mo(VI)) complex (M1) is exploited for selective detection of thorium (Th(IV)) ions through a metal-ion displacement protocol. Th(IV) displaces Mo(VI) from M1 instantly leading to the formation of the Th(IV) complex, having orange-red emission. Consequently, a red shift of the emission wavelength along with 41-fold fluorescence enhancement is observed. This unique method allows detection of Th(IV) as low as 1.5 × 10 M. The displacement of Mo(VI) from M1 by Th(IV) is established by spectroscopic studies and kinetically followed by the stopped-flow technique. The displacement binding constant for Th(IV) is notably strong, 4.59 × 10 M. Extraction of Th(IV) from aqueous solution to the ethyl acetate medium using M1 has been achieved. The silica-immobilized M1 efficiently enriches Th(IV) from its reservoir through solid-phase extraction. Computational studies (density functional theory) support experimental findings.
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http://dx.doi.org/10.1021/acsomega.8b01901DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643418PMC
November 2018

Design, synthesis of orally bioavailable novel anaplastic lymphoma kinase (ALK) inhibitor diphenylaminopyrimidine analogs and efficacy study on NCI-H2228 xenografts mice model.

Bioorg Med Chem Lett 2019 06 8;29(12):1514-1517. Epub 2019 Apr 8.

Discovery Chemistry Research, Arromax Pharmatech Co. Ltd., Sangtian Island Innovation Park, No. 1 Huayun Road, SIP, Suzhou 215123, PR China. Electronic address:

Anaplastic lymphoma kinase (ALK) is an attractive therapeutic target for the treatment of non-small cell lung cancer (NSCLC). Within our ALK drug discovery program, we identified novel deuterated 2,4-diarylamino pyrimidine compounds as potent ALK inhibitors. The compound 11 showed better in vitro activity and in vivo efficacy with good pharmacokinetic profile. In vivo efficacy of compound 11 was better than standard drug ceritinib in NCI-H2228 xenograft mice model.
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http://dx.doi.org/10.1016/j.bmcl.2019.04.012DOI Listing
June 2019