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Ho JY, Mattei J, Tetzlaff M, Williams M, Davies M, Diab A, Glitza I, Mcquade J, Patel S, Tawbi H, Wong M, Yee C, Fisher S, Hanna E, Keung E, Ross M, Su S, Faria S, Nagaraja P, Amaria R. 801P Neoadjuvant checkpoint inhibitor immunotherapy (IMT) for resectable mucosal melanoma (MM). Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.07.927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Bhagwati AM, Singhi S, Ramachandran B, Ramakrishnan N, Gopalakrishnan R, Kamat VN, Nagaraja P, Prayag S, Todi SK, Rajagopalan RE. Guidelines for the Prevention of Infections Associated with the Use of Vascular Catheters in Indian Intensive Care Units. Indian J Crit Care Med 2020. [DOI: 10.5005/ijccm-17-s1-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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3
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Supriya B, Nagaraja P, Byrappa K. Hydrothermal synthesis and characterization of carbon spheres using citric-acid-catalyzed carbonization of starch. e-Polymers 2015. [DOI: 10.1515/epoly-2015-0025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe synthesis of well-dispersed carbon spheres using starch as a carbon source, citric acid as a catalyst, and distilled water as a medium without involving any organic solvent at 120–150°C for 16 h under hydrothermal treatment is presented. The use of citric acid promoted starch dehydration and allowed the use of a lower hydrolysis temperature. Under similar conditions the formation of carbon spheres was not possible in the absence of citric acid. We noticed the significant effect of temperature on the particle size and shape. The particle size increased with the increase in temperature. The synthesized carbon spheres were characterized using field-emission scanning electron microscope (FE-SEM), scanning electron microscope (SEM), X-ray diffraction, Fourier-transform infrared (FTIR) and Raman spectroscopy.
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Affiliation(s)
- B.S. Supriya
- 1Department of Studies in Chemistry, University of Mysore, Mysore – 570006, Karnataka, India
| | - P. Nagaraja
- 1Department of Studies in Chemistry, University of Mysore, Mysore – 570006, Karnataka, India
| | - K. Byrappa
- 2Department of Studies in Earth Science, University of Mysore, Mysore – 570006, Karnataka, India
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Affiliation(s)
- P Nagaraja
- From the Renal Unit, Morriston Hospital, Swansea, West Glamorgan, SA6 6NL, UK and Department of Nephrology, Glan Clwyd Hospital, Rhyl, Denbighshire, LL18 5UJ, UK
| | - A Thangavelu
- From the Renal Unit, Morriston Hospital, Swansea, West Glamorgan, SA6 6NL, UK and Department of Nephrology, Glan Clwyd Hospital, Rhyl, Denbighshire, LL18 5UJ, UK
| | - H Nair
- From the Renal Unit, Morriston Hospital, Swansea, West Glamorgan, SA6 6NL, UK and Department of Nephrology, Glan Clwyd Hospital, Rhyl, Denbighshire, LL18 5UJ, UK
| | - M Kumwenda
- From the Renal Unit, Morriston Hospital, Swansea, West Glamorgan, SA6 6NL, UK and Department of Nephrology, Glan Clwyd Hospital, Rhyl, Denbighshire, LL18 5UJ, UK
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Affiliation(s)
- P Nagaraja
- From the Nephrology and Transplantation Directorate, University Hospital of Wales, Heath Park, Cardiff, UK
| | - M R Davies
- From the Nephrology and Transplantation Directorate, University Hospital of Wales, Heath Park, Cardiff, UK
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Neves FMDO, Leite TT, Meneses GC, Araujo De Souza NH, Martins AMC, Parahyba MC, Queiroz REB, Liborio A, Liu Y, Li Y, Li X, Chen L, Zulkarnaev A, Vatazin A, Nikolaj S, Stadler T, Raddatz A, Hubner W, Poppleton A, Fliser D, Klingele M, Castellano G, Intini A, Stasi A, Divella C, Pontrelli P, Gigante M, Zito A, Pertosa GB, Gesualdo L, Grandaliano G, Powell TC, Donnelly JP, Wang HE, Warnock DG, De Loor J, Hoste E, Herck I, Francois K, Decrop L, Clauwaert C, Bracke S, Vermeiren D, Demeyere K, Meyer E, Mitra P, Rahim MA, Gupta RD, Samdani TS, Rahman SA, Enam SF, Mursalin G, E-Khoda MM, Haque WMM, Iqbal S, Mansur MA, Guglielmetti G, Cena T, Musetti C, Quaglia M, Battista M, Radin E, Airoldi A, Izzo C, Stratta P, Haase-Fielitz A, Albert C, Westphal S, Hoffmann J, Mertens PR, Plass M, Westerman M, Bellomo R, Maisel A, Ronco C, Haase M, Wu PC, Wu VC, Prasad B, Wong B, St.Onge JR, Rungta R, Das P, Ray DS, Gupta S, De Gracia MDC, Osuna A, Quesada A, Manzano F, Montoro S, Jimenez MDM, Wangensteen R, Strunk AK, Schmidt J, Schmidt B, Bode-Boger S, Martens-Lobenhoffer J, Welte T, Kielstein JT, Wang AY, Bellomo R, Cass A, Myburgh J, Finfer S, Gatta D, Chadban S, Jardine M, Lo S, Barzi F, Gallagher M, Marn-Pernat A, Benedik M, Bren A, Buturovic-Ponikvar J, Gubensek J, Knap B, Premru V, Ponikvar R, Koba L, Teixeira M, Macedo E, Altunoren O, Balli M, Tasolar H, Eren N, Arpaci A, Caglayan CE, Yavuz YC, Sahin M, Gliga ML, Gliga PM, Frigy A, Bandea A, Magdas AM, Dogaru G, Mergulhao C, Pinheiro H, Vidal E, Sette L, Amorim G, Fernandes G, Valente L, Hornum M, Penninga L, Rasmussen A, Plagborg UB, Oturai P, Feldt-Rasmussen B, Hillingso JG, Klimenko A, Villevalde S, Kobalava Z, Arias Cabrales C, Rodriguez E, Bermejo S, Sierra A, Pascual J, Huang TM, Wu VC, Oh WC, Rigby M, Mafrici B, Sharman A, Harvey D, Welham S, Mahajan R, Gardner D, Devonald M, Wu VC, Lin MC, Wu PC, Wu CH, Nagaraja P, Clark A, Brisk R, Jennings V, Jones H, Hashmi M, Parker C, Mikhail A, Schraut J, Keller F, Mertens T, Duprel JB, Quercia AD, Cantaluppi V, Dellepiane S, Pacitti A, Biancone L, Chang KY, Park HS, Kim HW, Choi BS, Park CW, Yang CW, Jin DC, Quercia AD, Cantaluppi V, Dellepiane S, Medica D, Besso L, Gai M, Leonardi G, Guarena C, Biancone L, Obrencevic K, Jovanovic D, Petrovic M, Ignjatovic L, Tadic J, Mijuskovic M, Maksic D, Vavic N, Pilcevic D, Mistry HD, Bramham K, Seed PT, Lynham S, Ward MA, Poston L, Chappell LC. CLINICAL ACUTE KIDNEY INJURY 1. Nephrol Dial Transplant 2014. [DOI: 10.1093/ndt/gfu144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Fontsere N, Mestres G, Burrel M, Barrufet M, Montana X, Arias M, Ojeda R, Maduell F, Campistol JM, Nagaraja P, Rees D, Husein T, Chess J, Lin CC, Yang WC, Khosravi M, Kandil H, Cross J, Hopkins S, Collier S, Lopes D, Pereira S, Gomes AM, Ventura A, Martins V, Seabra J, Rothuizen TC, Damanik F, Visser MJT, Lavrijsen T, Cox MAJ, Moroni L, Rabelink TJ, Rotmans JI, Fontsere N, Cardozo C, Donate J, Soriano A, Muros M, Pons M, Mensa J, Campistol JM, Navarro-Gonzalez JF, Maduell F, Wijewardane A, Murley A, Powers S, Allen C, Baharani J, Wilmink T, Esenturk M, Zengin M, Dal M, Tahtal N, Shibata K, Shinzato T, Satta H, Nishihara M, Koguchi N, Kuji T, Kawata S, Kaneda T, Yasuda G, Scrivano J, Pettorini L, Rutigliano T, Ciavarella GM, De Biase L, Punzo G, Mene P, Pirozzi N, El Haggan W, Belazrague K, Ehoussou S, Foucher V, El Salhy M, Ouellet G, Davis J, Caron P, Leblanc M, Pettorini L, Romitelli F, Fazzari L, Scrivano J, Ortu G, Di Stasio E, Punzo G, Mene P, Pirozzi N, Loizzo G, Vigano SM, Bacchini G, Rocchi E, Sala V, Pontoriero G, Letachowicz K, Go biowski T, Kusztal M, Letachowicz W, Weyde W, Klinger M, Murley A, Wijewardane A, Powers S, Allen C, Hollingsworth L, Wilmink T, Baharani J, Roca-Tey R, Samon R, Ibrik O, Roda A, Gonzalez-Oliva JC, Martinez-Cercos R, Viladoms J, Renaud CJ, Lim EK, Seow TY, Teh HS, Tosic J, Jankovic A, Djuric P, Radovic Maslarevic V, Popovic J, Dimkovic N, Kazantzi A, Trigka K, Buono F, Laurino S, Toriello G, Di Luccio R, Galise A, Kim YO, Yoon SA, Kim YS, Choi SJ, Min JW, Cheong MA, Asano M, Oguchi K, Saito A, Onishi Y, Yamamoto Y, Fukuhara S, Akiba T, Akizawa T, Kurokawa K, Guedes Marques M, Ibeas J, Maia P, Ponce P, Chang KY, Park HS, Kim HW, Choi BS, Park CW, Yang CW, Jin DC, Likaj E, Seferi S, Caco G, Petrela E, Barbullushi M, Idrizi A, Thereska N, Lomonte C, Casucci F, Libutti P, Lisi P, Basile C, Ancarani P, Valsuani G, Cavallo L, Parodi D, Lorusso C, Renaud C, Lai BC, Tho S, Yeoh L, Guedes Marques M, Botelho C, Maia P, Ponce P, Yankovoy A, Alexandr S, Smoliacov A, Stepanov V, Rees D, Parker C, Davies P, Taylor S, Mikhail A, Kim YO, Yoon SA, Kim YS, Choi SJ, Min JW, Cheong MA, Gubensek J, Persic V, Vajdic B, Ponikvar R, Buturovic-Ponikvar J, Hadimeri U, Warme AV, Stegmayr B, Jankovic A, Suvakov S, Tosic J, Damjanovic T, Djuric P, Bajcetic S, Radovic-Maslarevic V, Popovic J, Simic T, Dimkovic N, Likaj E, Seferi S, Petrela E, Idrizi A, Rroji M, Barbullushi M, Thereska N, Chua HL, Kanda H, See SL, Liew NC, Tsuchida K, Tomo T, Fukasawa M, Kawashima S, Minakuchi J, Thanaraj V, Dhaygude A, Ikeda K, Forneris G, Cecere P, Pozzato M, Trogolo M, Vallero A, Mesiano P, Roccatello D, Esenturk M, Zengin M, Keskin L, Loizzo G, Vigano SM, Bacchini G, Rocchi E, Sala V, Pontoriero G, Casey JR, Hanson CS, Winkelmayer WC, Craig J, Palmer S, Strippoli G, Tong A, Ferrara D, Scamarda S, Bernardino L, Amico L, Lorito MC, Incalcaterra F, Visconti L, Visconti G, Valenza F, D'Amato F, Di Napoli A, Tazza L, Chicca S, Lapucci E, Silvestri P, Di Lallo D, Michelozzi P, Davoli M. DIALYSIS VASCULAR ACCESS. Nephrol Dial Transplant 2014. [DOI: 10.1093/ndt/gfu156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Bhagwati AM, Singhi S, Ramachandran B, Ramakrishnan N, Gopalakrishnan R, Kamat VN, Nagaraja P, Prayag S, Todi S. Guidelines for the Prevention of Infections Associated with the Use of Vascular Catheters in Indian Intensive Care Units. Indian J Crit Care Med 2013. [DOI: 10.5005/ijccm-17-5-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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9
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Dinesh ND, Nagaraja P, Made Gowda NM, Rangappa KS. Extractive spectrophotometric methods for the assay of sildenafil citrate (Viagra) in pure form and in pharmaceutical formulations. Talanta 2013; 57:757-64. [PMID: 18968678 DOI: 10.1016/s0039-9140(02)00097-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2001] [Revised: 02/25/2002] [Accepted: 03/01/2002] [Indexed: 10/27/2022]
Abstract
Two simple and sensitive extractive spectrophotometric methods for the determination of sildenafil citrate (SC) are proposed. The methods are based on the formation of ion-association complexes of sildenafil citrate with bromocresol green (BCG, method A) and with chromoxane cyanine R (CCR, method B) in aqueous acidic buffer. The complex species, extractable to chloroform phase, were quantitatively measured at 415 and 460 nm for methods A and B, respectively. Beer's law was obeyed in the SC concentration range 1.25-25 mug ml(-1) with a limit of detection 0.16 mug ml(-1) and 1.5-60 mug ml(-1) with a limit of detection 0.18 mug ml(-1), respectively, for methods A and B. The methods have been successfully applied to the analysis of bulk drug and its tablets. No interference was observed from common pharmaceutical adjuvants.
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Affiliation(s)
- N D Dinesh
- Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysore 570006, India
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Nagaraja P, Vasantha RA, Sunitha KR. A sensitive and selective spectrophotometric estimation of catechol derivatives in pharmaceutical preparations. Talanta 2012; 55:1039-46. [PMID: 18968454 DOI: 10.1016/s0039-9140(01)00438-6] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2000] [Revised: 04/23/2001] [Accepted: 04/26/2001] [Indexed: 11/18/2022]
Abstract
A sensitive and simple spectrophotometric method for the estimation of catechol and its derivatives like dopamine hydrochloride (DPH), levodopa (LDP), methyldopa (MDP) and adrenaline hydrochloride (ADH) in both pure form and in pharmaceutical formulation, is described. The method is based on the interaction of diazotised sulphanilamide (DSA) with catechol derivatives in the presence of molybdate ions in acidic medium. Absorbance of the resulting red coloured product is measured at 490 nm for pyrocatechol (PCL) and at 500 nm for other catechol derivatives. The colour reaction is stable for 24-30 h. Under optimal conditions, Beer's Law range for pyrocatechol was found to be between 0.04 and 2.4 (R.S.D.=0.78%), for DPH was 0.02-2.8 (R.S.D.=0.98%) for LDP was 0.1-2.8 (R.S.D.=1.21%) for MDP was 0.5-7 (R.S.D.=1.41%) and for ADH was 0.5-7 (R.S.D.=1.58%). The method is highly reproducible and specific for these selected catechol derivatives. The common excipients used as additives do not interfere in the proposed method. Analytical data for the determination of the pure compound is presented together with the application of the proposed method to the analysis of some pharmaceutical formulations. The results compare favourably with those of official and reported methods.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, Mysore University, Manasagangotri, Mysore 570006, India
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Nagaraja P, Prakash JS, Asha SC, Bhaskara BL, Kumar SA. Dibenzazepin hydrochloride as a new spectrophotometric reagent for determination of hydrogen peroxide in plant extracts. Environ Monit Assess 2012; 184:5983-5988. [PMID: 22270583 DOI: 10.1007/s10661-011-2395-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 10/04/2011] [Indexed: 05/31/2023]
Abstract
A rapid, simple, accurate, and sensitive visible spectrophotometric method for the determination of trace amounts of hydrogen peroxide in acidic buffer medium is reported. The proposed method is based on the oxidative coupling of Ampyrone with dibenzazepin hydrochloride by hydrogen peroxide in the buffer medium of pH 4.0 which is catalyzed by ferrous iron. The blue-colored product formed with maximum absorption at 620 nm was found to be stable for 2 h. Beer's law is obeyed for hydrogen peroxide concentration in the range of 0.03-0.42 μg ml(-1). The optimum reaction conditions and other important optical parameters are reported. The molar absorptive and Sandell's sensitivity are found to be 5.89 × 10(4) mol(-1) cm(-1) and 0.57 g/cm(2), respectively. The interference due to diverse ions and complexing agents was studied. The method is successfully applied to the determination of hydrogen peroxide in green plants satisfactorily.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, University of Mysore, Mansagangotri, Mysore 570 006, India
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Al-Tayar NGS, Nagaraja P, Vasantha RA, Shresta AK. A spectrophotometric assay method for vanadium in biological and environmental samples using 2,4-dinitrophenylhydrazine with imipramine hydrochloride. Environ Monit Assess 2012; 184:181-191. [PMID: 21625927 DOI: 10.1007/s10661-011-1957-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/09/2011] [Indexed: 05/30/2023]
Abstract
A simple, rapid, and sensitive method involving the interaction of 2,4-dinitrophenylhydrazine with imipramine hydrochloride in presence of vanadium (V) in sulfuric acid medium has been proposed for the determination of vanadium. The purple-colored product developed showed an absorption maximum at 560 nm and was stable for 24 h. The working curve was linear over the concentration range of 0.1-2.8 μg ml( - 1), with sensitivity of detection of 0.0124 μg ml( - 1). Molar absorptivity and Sandell's sensitivity were found to be 2.6 × 10(4) l/mol cm and 0.0039 μg cm( - 1), respectively. The accuracy of the proposed method was assessed by Student's t test and variance ratio F test, and the results were on par with the reported method. The method was successfully used in the determination of V in water, human urine, soil, and plant samples, and it was free from interference by various concomitant ions.
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Chandrashekara MS, Nagaraja P, Paramesh L, Rajesh BM. Studies on radon concentration in aqueous samples at Mysore city, India. Radiat Prot Environ 2012. [DOI: 10.4103/0972-0464.111403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
Fifty strains of Gardnerella vaginalis isolated from 321 high vaginal swabs over a period of five months were tested for their antibiotic sensitivity. Sixty eight per cent of all isolates were resistant to metronidazole while 76% were sensitive to clindamycin. All the strains isolated from cases with recurrence of infection were resistant to metronidazole. Clindamycin therapy has a better clinical efficacy than metronidazole in cases of recurrent bacterial vaginosis.
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Affiliation(s)
- P Nagaraja
- Department of Microbiology, Farwaniya Hospital, Post Box 18373, Kuwait 81004, State of Kuwait.
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Yathirajan HS, Nethaji M, Prabhuswamy B, Raju CR, Nagaraja P, Shashikanth S, Ponnuswamy MN, Palani K. Crystal structure of a tetrazole derivative. Cryst Res Technol 2006. [DOI: 10.1002/crat.200510577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nagaraja P, Bhaskara BL. Sensitive spectrophotometric assessment of carbofuran using dapsone as a new chromogenic reagent in formulations and environmental samples. Eclet Quím 2006. [DOI: 10.1590/s0100-46702006000400006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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17
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Rathore RS, Narasimhamurthy T, Vijay T, Yathirajan HS, Nagaraja P. Proton-bifurcated C—H...(O,O) hydrogen bonds in 2,3-dichloro-6-nitrobenzylaminium chloride. Acta Crystallogr C 2005; 62:o36-8. [PMID: 16397339 DOI: 10.1107/s0108270105038114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Accepted: 11/18/2005] [Indexed: 11/11/2022] Open
Abstract
In the crystal structure of the title salt, C7H7Cl2N2O2+.Cl-, the chloride anions participate in extensive hydrogen bonding with the aminium cations and indirectly link the molecules through multiple N+-H...Cl- salt bridges. There are two independent molecules in the asymmetric unit, related by a pseudo-inversion center. The direct intermolecular coupling is established by C-H...O, C-H...Cl and C-Cl...Cl(-) interactions. A rare three-center (donor bifurcated) C-H...(O,O) hydrogen bond is observed between the methylene and nitro groups, with a side-on intramolecular component of closed-ring type and a head-on intermolecular component.
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Affiliation(s)
- R S Rathore
- Oriental Organization of Molecular and Structural Biology, 204 Agarwal Bhavan, Malleshwaram, Bangalore 560055, India.
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Nagaraj B, Narasimhamurthy T, Yathirajan HS, Nagaraja P, Narasegowda RS, Rathore RS. C-halogen...pi dimer and C-H...pi interactions in 1-(2-bromo-4,5-dimethoxybenzyl)-2-butyl-4-chloro-1H-imidazole-5-carbaldehyde and 2-butyl-4-chloro-1-(6-methyl-1,3-benzodioxol-5-ylmethyl)-1H-imidazole-5-carbaldehyde. Acta Crystallogr C 2005; 61:o177-80. [PMID: 15750249 DOI: 10.1107/s0108270105001794] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 01/18/2005] [Indexed: 11/10/2022] Open
Abstract
The structures of the title compounds, C17H20BrClN2O3, (I), and C17H19ClN2O3, (II), are stabilized by intramolecular C-H...O and C-H...pi interactions. The stability of the molecular packing in (I) and (II) arises from a diverse set of weak intermolecular C-H...O, C-H...pi and C-halogen...pi interactions. In the crystal structure of (I), molecules aggregate in dimeric subunits via C-Br...pi interactions. The dimers are interlinked by C-H...O hydrogen bonds. The halogens cluster together and form a channel along the b axis. In (II), the packing is mainly governed by intermolecular C-H...O and C-H...pi interactions.
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Affiliation(s)
- B Nagaraj
- Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India
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19
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Sieroń L, Nagaraj B, Prabhuswamy B, Yathirajan HS, Nagaraja P, Narasegowda RS, Gaonkar SL. Trityl losartan. Acta Crystallogr C 2004; 60:o821-3. [PMID: 15528831 DOI: 10.1107/s0108270104024096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Accepted: 09/24/2004] [Indexed: 11/10/2022] Open
Abstract
The title compound (systematic name: [2-butyl-4-chloro-1-[2'-(2-trityl-2H-tetrazol-5-yl)biphenyl-4-ylmethyl]-1H-imidazol-5-yl]methanol), C(41)H(37)ClN(6)O, crystallizes in the centrosymmetric space group P-1 with two independent molecules in the asymmetric unit. These molecules differ significantly only in the relative orientations of the rings in the biphenylyltetrazole moieties. One of the molecules shows disorder for three C atoms in the n-butyl group. Hydrogen bonds link the molecules in an infinite chain along the a axis.
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Affiliation(s)
- Lesław Sieroń
- Institute of General and Ecological Chemistry, Technical University of Łódź, Zeromskiego 116, 90-924 Łódź, Poland.
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Nagaraja P, Yathirajan HS, Raju CR, Vasantha RA, Nagendra P, Hemantha Kumar MS. 3-Aminophenol as a novel coupling agent for the spectrophotometric determination of sulfonamide derivatives. ACTA ACUST UNITED AC 2003; 58:1295-300. [PMID: 14630242 DOI: 10.1016/s0014-827x(03)00093-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A rapid, simple and sensitive spectrophotometric method for the determination of some sulfa drugs is described. The method is based on the formation of orange yellow colored azo product by the diazotization of sulfonamides, viz., dapsone (DAP), sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG) and sulfadimidine (SFDd) followed by a coupling reaction with 3-aminophenol in aqueous medium. Absorbance of the resulting orange yellow product is measured at 460 nm and is stable for 6 days at 27 degrees C. Beer's law is obeyed in the concentration range of 0.05-8.0 microg/ml at the wavelength of maximum absorption. The method is successfully employed for the determination of sulfonamides in various pharmaceutical preparations and common excipients used as additives in pharmaceuticals do not interfere in the proposed method. Plausible reaction mechanism is proposed for the formation of the azo product.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570006, India.
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21
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Abstract
A simple, sensitive and selective spectrophotometric method for the determination of indomethacin (INM) either in pure form or in capsules is described. The method is based on the coupling reaction of hydrolyzed INM with diazotized p-phenylenediamine dihydrochloride (PPDD) in sulphuric acid medium to give a red coloured product having the absorption maximum at 510 nm. The product is stable for 20 h. Beer's law is obeyed in the concentration range of 0.2-10 microg/ml. Results of the proposed method compare favourably with those of the official methods and offer the merits of sensitivity and stability. Common excipients used as additives in pharmaceutical preparations do not interfere in the proposed method.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India.
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22
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Kumar MSH, Nagaraja P, Yathirajan HS. Copper(II)-catalysed oxidative coupling reaction of 3-hydroxyacetanilide with 3-methyl-2-benzothiazolinone hydrazone for the spectrophotometric determination of traces of copper(II). Anal Bioanal Chem 2003; 375:315-8. [PMID: 12560980 DOI: 10.1007/s00216-002-1655-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2002] [Revised: 10/09/2002] [Accepted: 10/18/2002] [Indexed: 11/24/2022]
Abstract
A spectrophotometric method is developed for the determination of traces of copper(II), based on the catalytic oxidative coupling reaction of 3-hydroxyacetanilide with 3-methyl-2-benzothiazolinone hydrazone in the presence of ammonia and hydrochloric acid. Beer's law is obeyed in the copper(II) concentration range of 0.008-0.16 microg mL(-1), and the molar absorptivity at 530 nm is 2.5x10(5) L mol(-1) cm(-1). The Sandell's sensitivity of the product is 0.000254 microg cm(-2). The optimum reaction conditions and other important analytical parameters have been investigated. The proposed method is applied to the analysis of water and soil samples and the results are compared with the literature method.
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Affiliation(s)
- M S Hemantha Kumar
- Department of Studies in Chemistry/Environmental Sciences, University of Mysore, Manasagangotri, India
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Dinesh ND, Vishukumar BK, Nagaraja P, Made Gowda NM, Rangappa KS. Stability indicating RP-LC determination of sildenafil citrate (Viagra) in pure form and in pharmaceutical samples. J Pharm Biomed Anal 2002; 29:743-8. [PMID: 12093504 DOI: 10.1016/s0731-7085(02)00123-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A simple, precise, sensitive and stability-indicating reverse-phase high performance liquid chromatographic (RP-HPLC) method has been developed for the quantitation of sildenafil citrate (SC) in pure form and its pharmaceutical formulations. Method employs water and acetonitrile (48:52 v/v) as mobile phase with flow rate of 1 ml min(-1), LiChrospher C18-5 microm (25 x 0.46 cm) column and UV detection set at 245 nm. The internal standard method using piroxicam (PX) as the internal standard is used. The linear dynamic range of SC was found to be 0.05-7.5 microg ml(-1). The proposed method is successfully employed for the determination of SC in the tablets. The excipients present in the formulations do not interfere with the assay procedure. Analytical parameters were calculated and full statistical evaluation is included.
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Affiliation(s)
- N D Dinesh
- Department of Studies in Chemistry, University of Mysore, Manasagangotri, 570 006, Mysore, India
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24
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Nagaraja P, Yathirajan HS, Arunkumar HR, Vasantha RA. Novel coupling reagents for the sensitive spectrophotometric determination of nimesulide in pharmaceutical preparations. J Pharm Biomed Anal 2002; 29:277-82. [PMID: 12062687 DOI: 10.1016/s0731-7085(02)00060-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Novel coupling reagents are used for the sensitive spectrophotometric determination of nimesulide (NIME) in either pure form or in its pharmaceutical preparations. The methods are based on the diazotisation of reduced NIME, followed by either coupling with alcoholic iminodibenzyl (IDB) in acid medium to give a deep blue coloured product (lambda(max) of 600 nm) or coupling with 3-aminophenol (AP) in acid medium to produce an orange red coloured product (lambda(max) of 470 nm). Both the methods are highly reproducible and have been applied to a wide variety of pharmaceutical preparations and the results compare favourably with the reported method. Common excipients used as additives in pharmaceutical preparations do not interfere in the proposed methods.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India.
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25
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Nagaraja P, Sunitha KR, Vasantha RA, Yathirajan HS. Spectrophotometric determination of metronidazole and tinidazole in pharmaceutical preparations. J Pharm Biomed Anal 2002; 28:527-35. [PMID: 12008132 DOI: 10.1016/s0731-7085(01)00685-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Sensitive and simple spectrophotometric methods for the determination of metronidazole (MNZ) and tinidazole (TNZ) in either pure form or in its pharmaceutical formulations are described. The first method is based on the interaction of 3-methylbenzothiazolin-2-one hydrazone (MBTH) with MNZ/TNZ (reduced drug) in presence of copper sulphate and pyridine in acidic medium. The resulting yellowish orange products have lambda(max) of 500 and 490 nm, respectively, for MNZ and TNZ and are stable for about 4 h. The second method describes the reaction between reduced diazotised drugs with N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) in neutral medium to yield pink products which have lambda(max) of 520 and 505 nm, respectively, for MNZ and TNZ, respectively. The products are stable for more than 24 h. Common excipients used as additives in pharmaceutical preparations do not interfere in the proposed method. Both the methods are highly reproducible and have been applied to a wide variety of pharmaceutical preparations and the results compare favourably with those of official methods.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore, 570 006, India.
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Nagaraja P, Vasantha RA, Yathirajan HS. Spectrophotometric methods for the rapid determination of menadione and menadione sodium bisulphite and their application in pharmaceutical preparations. J Pharm Biomed Anal 2002; 28:161-8. [PMID: 11861119 DOI: 10.1016/s0731-7085(01)00599-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Two simple, rapid and sensitive spectrophotometric determination of menadione and its sodium bisulphite derivative (MSB) have been carried out. The first method involves the reaction of menadione and its sodium bisulphite derivative with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) is sodium hydroxide medium to give blue coloured product having maximum absorption at 625 nm and the coloured species is stable for more than 1 h. The Beer's law is obeyed in the range 0.4-16 microg ml(-1). The second method proposes the reaction of menadione and its sodium bisulphite derivative with resorcinol in concentrated sulphuric acid medium to give red coloured product having maximum absorption at 520 nm and is stable for 3 h. The Beer's law was obeyed in the range of 1-24 microg ml(-1). Molar absorptivity for the above two methods were found to be 7.6 x 10(3) and 4.5 x 10(3) l mol(-1) cm(-1), respectively. All the measurements were carried out at room temperature. These two methods have been successfully applied for menadione and its sodium bisulphite derivatives in injections and tablets of pharmaceutical formulations. The results compare favourably with official method.
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Affiliation(s)
- P Nagaraja
- Department of studies in Chemistry, Mysore University, Manasa Gangotri, India.
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27
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Nagaraja P, Vasantha RA, Sunitha KR. A new sensitive and selective spectrophotometric method for the determination of catechol derivatives and its pharmaceutical preparations. J Pharm Biomed Anal 2001; 25:417-24. [PMID: 11377021 DOI: 10.1016/s0731-7085(00)00504-5] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A sensitive and simple spectrophotometric method for the estimation of certain catechol derivatives like pyrocatechol (PCL), dopamine hydrochloride (DPH), levodopa (LDP), methyl dopa (MDP) and adrenaline (ADH) in either pure form or in its pharmaceutical formulation is described. The method is based on the interaction of diazotised p-nitro aniline (DPNA) with catechol derivatives in presence of molybdate ions in acidic medium. Absorbance of the resulting red complex is measured at 500-510 nm, respectively, and is stable for 2-10 h. The method is highly reproducible and specific for these selected catechol derivatives. The common excipients used as additives in pharmaceuticals and phenol, hydroquinone, resorcinol, pyrogallol and phloroglucinol do not interfere in the proposed method. Analytical data for determination of the pure compound is presented together with the application of the proposed method to the analysis of some pharmaceutical formulations. The results compare favourably with those of official and reported methods.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, Mysore University, Manasagangothri, 570 006, Mysore, India.
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Nagaraja P, Kumar MS, Rangappa KS. Dapsone and iminodibenzyl as novel reagents for the spectrophotometric determination of trace amounts of nitrite in water samples. ANAL SCI 2001; 17:439-42. [PMID: 11990624 DOI: 10.2116/analsci.17.439] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A rapid, simple, sensitive and selective spectrophotometric determination of nitrite using new diazotizing and coupling reagents is described. The method is based on a diazotization-coupling reaction between dapsone and iminodibenzyl in a hydrochloric acid medium. The molar absorptivity and Sandell's sensitivity were found to be 7.5 x 10(4) l mol(-1) cm(-1) and 0.000613 microg ml(-1), respectively. The interference effects of various cations and anions were also studied and reported. This method has been found to be applicable for the determination of nitrite in various water samples.
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Affiliation(s)
- P Nagaraja
- Department of Chemistry, University of Mysore, Manasagangothri, India.
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Abstract
A sensitive and simple spectrophotometric method for the determinations of reduction product of flutamide (FLA) is described. The method is based on the interaction of diazotized flutamide reduction product with N-(1-naphthyl) ethylenediamine dihydrochloride (NEDA) in neutral or resorcinol (RSL) in alkaline medium. Absorbance of the resulting chromophores is measured at 525 or 480 nm, respectively, and is stable for at least 7 days. The two coupling reagents are applied successfully for the determination of FLA in tablets. The common excipients used as additives in pharmaceutical preparations do not interfere with the determination. Results from the analysis of pure FLA and its commercial tablets by the proposed methods agree well with the reported method.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, Mysore University, Manasagangotri, India.
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Nagaraja P, Silwadi M, Syed A. Sensitive Spectrophotometric Determination of Some Dibenzazepine Drugs with Diazotized P-Phenylenediamine Dihydrochloride. ANAL LETT 2000. [DOI: 10.1080/00032710008543230] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
A rapid, sensitive and simple spectrophotometric method is proposed for the determination of hydrolysis products of paracetamol (PRL) and phenacetin (PHN) with sodium 1,2-naphthoquinone-4-sulphonate and cetyltrimethyl ammonium bromide (CTA) in alkaline medium. The absorbances are measured at 570 and 500 nm and the molar absorptivities found to be 1.118 x 10(4) and 4.54 x 10(3) l mol-1 cm-1 for PRL and PHN, respectively. The coloured species conforms to Beer's law over the range 1-20 micrograms ml-1 for PRL and 2-24 micrograms ml-1 of PHN. The sensitivity is enhanced by the addition of CTA. The method is successfully employed for determination of PRL or PHN in various pharmaceutical preparations and laboratory made tablets and results have been statistically compared with those obtained by the official method.
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Affiliation(s)
- P Nagaraja
- Department of Studies in Chemistry, Mysore University, India
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