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Uma Devi T, Priya S, Selvanayagam S, Ravikumar K, Anitha K. Synthesis, structural elucidation and spectroscopic analysis of 3a,8b-dihydroxy-4-oxo-1H,2H,3H,3aH,4H,8bH-indeno[1,2-d]imidazolidin-2-iminium chloride. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 97:1063-1071. [PMID: 22925983 DOI: 10.1016/j.saa.2012.07.118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 06/30/2012] [Accepted: 07/10/2012] [Indexed: 06/01/2023]
Abstract
Ninhydrin guanidinium chloride (3a,8b-dihydroxy-4-oxo-1H,2H,3H,3aH,4H,8bH-indeno [1,2-d]imidazolidin-2-iminium chloride) a semiorganic crystal was synthesized. The structure was determined using X-ray single crystal technique. Comparisons between the FT-IR spectrum of ninhydrin guanidinium chloride with ninhydrin were made. Melting point was found using thermal measurements. The molecular geometry, vibrational frequencies and Mulliken charges of the compound in the ground state have been calculated by the density functional theory (DFT) method with 3-21G(d,p) basis set and theoretical frequencies were compared with the experimental FT-IR spectrum. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, natural bond orbitals (NBO) and thermodynamic properties at various temperatures of the compound were investigated by theoretical calculations.
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Ravikumar K, Sridhar B, Nanubolu JB, Hariharakrishnan V, Singh AN. Structures of benzoxazine-fused triazoles as potential diuretic agents. Acta Crystallogr C 2012; 68:o302-7. [PMID: 22850856 DOI: 10.1107/s0108270112029800] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 06/29/2012] [Indexed: 11/10/2022] Open
Abstract
6,8-Dinitro-2,4-dihydro-1H-benzo[b][1,2,4]triazolo[4,3-d][1,4]oxazin-1-one, C(9)H(5)N(5)O(6), (I), a potential diuretic, and its acetylacetone derivative (E)-2-(2-hydroxy-4-oxopent-2-en-3-yl)-6,8-dinitro-2,4-dihydro-1H-benzo[b][1,2,4]triazolo[4,3-d][1,4]oxazin-1-one, C(14)H(11)N(5)O(8), (II), both crystallize from methanol but in centrosymmetric and noncentrosymmetric space groups, respectively. To the best of our knowledge, this is the first report of crystal structures of benzoxazine-triazole fused systems. The acetylacetone group in (II) exists as the keto-enol tautomer and is oriented perpendicular to the triazol-3-one ring. Of the two nitro groups present, one is rotated significantly less than the other in both structures. The oxazine ring adopts a screw-boat conformation in (II), whereas it is almost planar in (I). N-H···N and N-H···O hydrogen bonds form centrosymmetric dimers in (I), while C-H···O interactions associate the molecules into helical columns in (II).
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Devi TU, Kalpana G, Priya S, Ravikumar K, Selvanayagam S. 4-[( E)-(Hydroxyimino)methyl]- N, N-dimethylanilinium chloride. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o1705. [PMID: 22719496 PMCID: PMC3379298 DOI: 10.1107/s1600536812020211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 05/05/2012] [Indexed: 11/21/2022]
Abstract
In the title compound, C9H13N2O+·Cl−, the cation, apart from the methyl groups, is almost planar, with a maximum deviation of 0.040 (1) Å; the methyl C atoms deviate by 0.389 (2) and −1.247 (1) Å, from the mean plane. In the crystal, cations and anions associate through C—H⋯Cl hydrogen bonds, forming a helical arrangement. In addition, intermolecular O—H⋯Cl, N—H⋯Cl and C—H⋯N interactions are observed.
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Abstract
Biodiesel involves the mixture of fatty acyl methyl/ethyl esters, produced from transesterification neutral lipids and if the origin of the source is from oleaginous micro organisms, then it is termed as micro diesel. In the present work, aiming to exploit fungi for biodiesel production, 12 fungal isolates were screened for lipid content by Sudan Black B staining method. Among 12 isolates, lipid rich five species viz, Mortierella alpina , M.ramanianna, M.vinancea, M.hyalina and M.verticella have been taken for fatty acids analysis by spectrophotometry, which revealed that the amount of free fatty acids were ranged from highest in M.alpina 35 ?moles of Oleic acid , 25 ?moles of Palmitic acid and 14 ?moles of Myristic acids to lower as much as 21 ?moles of Oleic acid , 18 ?moles of Palmitic acid and 16 ?moles of Myristic acids respectively in M.ramanianna. DOI: http://dx.doi.org/10.3126/ijls.v6i1.5721
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Venkati M, Reddy SS, Swamy GYSK, Ravikumar K, Krupadanam GLD. Synthesis of 5-aryl-2-piperidino-5H-chromeno[3,4-c]pyridine-1-carbonitriles. ARKIVOC 2012. [DOI: 10.3998/ark.5550190.0013.632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Sridhar B, Nanubolu JB, Ravikumar K. Competition between the two-point and three-point synthon in cytosine–carboxylic acid complexes. CrystEngComm 2012. [DOI: 10.1039/c2ce26076j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nanubolu JB, Sridhar B, Babu VSP, Jagadeesh B, Ravikumar K. Sixth polymorph of aripiprazole - an antipsychotic drug. CrystEngComm 2012. [DOI: 10.1039/c2ce25306b] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Avasthi K, Kumar A, Aswal S, Kant R, Raghunandan R, Maulik PR, Khanna RS, Ravikumar K. Role of arene interactions and substituent effects in conformational (syn/anti) control of 1,2-diarylethanes. CrystEngComm 2012. [DOI: 10.1039/c1ce06001e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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59
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Nanubolu JB, Sridhar B, Ravikumar K. Resonance-assisted amide protonation in dutasteride hydrochloride salt. CrystEngComm 2012. [DOI: 10.1039/c2ce06421a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Animashawun AM, Bhattee G, Ravikumar K. Bilateral tibial stress fractures: a case report. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2011; 22 Suppl 1:189-91. [PMID: 26662776 DOI: 10.1007/s00590-011-0918-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Accepted: 11/22/2011] [Indexed: 10/15/2022]
Abstract
A stress fracture can be defined as a fracture of a bone caused by repeated (rather than sudden) mechanical stress. They have been reported in almost all bones of the body, with the lower extremity weight bearing bones, especially the tibia, tarsals and metatarsals, being affected most often. These injuries have a broad spectrum of severity and prognosis. Although the pathology of this injury is understood, the aetiology is less agreed upon. This can make it difficult for clinicians to diagnose and treat this common injury. Stress fractures of the proximal tibiae are common in elderly patients with osteoarthritis, and they are also reported in children. Here, we report an unusual case of an otherwise fit, young, adult male who presented with bilateral insufficiency stress fractures occurring simultaneously in both proximal tibiae. Stress fractures should be a differential diagnosis in any young, fit adult who presents with spontaneous knee pain.
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Satish K, Vishnuvardhan M, Lakshma Nayak V, Srihari G, Subrahamanyam M, Prabhakar Rao T, Ramakrishna S, Ravikumar K, Sridhar B, Marthanda Murthy M. Cytotoxic diterpenoid quinonemethides from the roots of Pygmacopremna herbacea. Bioorg Med Chem Lett 2011; 21:4581-4. [DOI: 10.1016/j.bmcl.2011.05.109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 05/26/2011] [Accepted: 05/27/2011] [Indexed: 12/01/2022]
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Selvanayagam S, Ravikumar K, Saravanan P, Raghunathan R. 1',1''-Dimethyl-4'-(naphthalen-1-yl)-1,2,3,4-tetra-hydro-naphthalene-2-spiro-3'-pyrrolidine-2'-spiro-3''-indoline-1,2''-dione. Acta Crystallogr Sect E Struct Rep Online 2011; 67:o751. [PMID: 21754048 PMCID: PMC3099991 DOI: 10.1107/s1600536811007124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 02/24/2011] [Indexed: 11/12/2022]
Abstract
In the title compound, C32H28N2O2, the pyrrolidine ring adopts an envelope conformation, whereas the cyclohexanone ring in the tetrahydronaphthalene fused-ring system adopts a half-chair conformation. The oxindole ring system is oriented at an angle of 48.2 (1)° with respect to the naphthyl ring system. An intramolecular C—H⋯O close contact is observed. In the crystal, molecules associate via two C—H⋯O hydrogen bonds, forming R22(14) and R22(10) dimers.
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Dubey R, Tewari AK, Ravikumar K, Sridhar B. Weak interactions: Potency for stabilization of molecule in solid state. J Heterocycl Chem 2011. [DOI: 10.1002/jhet.601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sridhar B, Ravikumar K. Multiple hydrogen bonds in cytosinium zoledronate trihydrate. Acta Crystallogr C 2011; 67:o115-9. [DOI: 10.1107/s0108270111005191] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 02/11/2011] [Indexed: 11/10/2022] Open
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Selvanayagam S, Sridhar B, Ravikumar K, Saravanan P, Raghunathan R. 1'-Methyl-4'-(1-naphth-yl)-1'',2'',3'',4''-tetra-hydro-indane-2-spiro-2'-pyrrolidine-3'-spiro-2''-naphthalene-1,3,1''-trione. Acta Crystallogr Sect E Struct Rep Online 2011; 67:o629. [PMID: 21522383 PMCID: PMC3052033 DOI: 10.1107/s1600536811004880] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 12/03/2022]
Abstract
In the title compound, C32H25NO3, the pyrrolidine ring adopts an envelope conformation, whereas the cyclohexanone ring in the tetrahydronaphthalene fused-ring system adopts a half-chair conformation. The indanedione unit is oriented at an angle of 58.9 (1)° with respect to the naphthyl ring system. Three intramolecular C—H⋯O close contacts and an intramolecular C—H⋯π interaction are observed. In the crystal, molecules associate via C—H⋯O hydrogen bonds, forming a helical chain with a C(10) motif along the b axis.
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Ravikumar K, Sridhar B, Pradhan N, Khunt M. Four stereoisomers of the novel μ-opioid receptor agonist tapentadol hydrochloride. Acta Crystallogr C 2011; 67:o71-6. [DOI: 10.1107/s0108270111001727] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 01/12/2011] [Indexed: 11/10/2022] Open
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Avasthi K, Ansari A, Kant R, Maulik PR, Ravikumar K, Chattopadhyay P, Adhikary ND. An alternative to ‘propylene/Leonard linker’ for studying arene interactions in flexible pyrazolo[3,4-d]pyrimidine core based models both at molecular and supramolecular levels. CrystEngComm 2011. [DOI: 10.1039/c0ce00336k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ravikumar K, Sridhar B, Bhujanga Rao AKS, Pulla Reddy M. Sorafenib and its tosylate salt: a multikinase inhibitor for treating cancer. Acta Crystallogr C 2010; 67:o29-32. [PMID: 21206080 DOI: 10.1107/s0108270110047451] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 11/16/2010] [Indexed: 11/10/2022] Open
Abstract
Sorafenib, a drug that targets malignant cancer cells and cuts off the blood supply feeding the tumour, has been crystallized as the free base, 4-(4-{3-[4-chloro-3-(trifluoromethyl)phenyl]ureido}phenoxy)-N-methylpyridine-2-carboxamide, C(21)H(16)ClF(3)N(4)O(3), (I), and as a tosylate salt, 4-(4-{3-[4-chloro-3-(trifluoromethyl)phenyl]ureido}phenoxy)-2-(N-methylcarbamoyl)pyridinium 4-methylbenzenesulfonate, C(21)H(17)ClF(3)N(4)O(3)(+)·C(7)H(7)O(3)S(-), (II). In both structures, the sorafenib molecule is in an extended conformation. The pyridine-2-carboxamide group exhibits a syn conformation of the N atoms in (I), whereas an almost anti orientation is present in (II). In both crystal structures, the two terminal groups, viz. pyridine-2-carboxamide and the trifluorophenyl ring, are oriented differently to the conformations found in enzyme-bound sorafenib. The sorafenib molecules in (I) are linked into zigzag chains by N-H···O hydrogen bonds, whereas in (II) the presence of the additional tosylate anion results in the formation of chains of fused hydrogen-bonded rings. This study reveals the variations in the solid-state conformation of the sorafenib molecule in different crystalline environments.
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Selvanayagam S, Sridhar B, Ravikumar K, Kathiravan S, Raghunathan R. Methyl 3-[(1 H-benzimidazol-1-yl)methyl]-1-methyl-4-(4-methylphenyl)-2′-oxopyrrolidine-2-spiro-3′-1-benzimidazole-3-carboxylate. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o2508-9. [PMID: 21587504 PMCID: PMC2983424 DOI: 10.1107/s1600536810035312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 09/01/2010] [Indexed: 11/10/2022]
Abstract
In the title compound, C29H28N4O3, the pyrrolidine ring adopts a twist conformation whereas the oxindole and benzimidazole residues are approximately planar with maximum deviations of 0.159 (1) and 0.011 (1) Å, respectively. The oxindole residue is almost perpendicular to the benzimidazole residue, making a dihedral angle of 89.2 (1)°. The methyl-substituted benzene ring is oriented at angles of 47.7 (1) and 71.0 (1)°, respectively, with respect to the oxindole and benzimidazole residues. An intramolecular C—H⋯O hydrogen bond is observed. In the crystal, molecules associate via N—H⋯N hydrogen bonds, forming R22(9) dimers.
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Selvanayagam S, Sridhar B, Ravikumar K, Kathiravan S, Raghunathan R. Methyl 4-(4-chlorophenyl)-3,3a,4,4a,5,12c-hexahydro-2-thianaphtho[1′,2′:3,2]furo[5,4- b]pyrrolizine-4a-carboxylate. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o2098. [PMID: 21588391 PMCID: PMC3007469 DOI: 10.1107/s1600536810028746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 07/19/2010] [Indexed: 11/10/2022]
Abstract
In the title compound, C25H22ClNO3S, both the pyrrolidinyl and thiazolyl rings adopt envelope conformations whereas the dihydropyran ring adopts a half-chair conformation. The chlorophenyl and naphthalenyl ring systems are oriented at a dihedral angle of 59.7 (1)°. The crystal packing is stabilized by an intramolecular C—H⋯N hydrogen bond and weak intermolecular C—H⋯π interactions.
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Sridhar B, Ravikumar K. Supramolecular hydrogen-bonded networks in cytosinium nicotinate monohydrate and cytosinium isonicotinate cytosine dihydrate. Acta Crystallogr C 2010; 66:o414-7. [DOI: 10.1107/s0108270110026430] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 07/05/2010] [Indexed: 11/11/2022] Open
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Ravikumar K, Sridhar B. Two polymorphs of safinamide, a selective and reversible inhibitor of monoamine oxidase B. Acta Crystallogr C 2010; 66:o317-20. [DOI: 10.1107/s0108270110019384] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 05/24/2010] [Indexed: 11/10/2022] Open
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Dubey R, Tewari AK, Ravikumar K, Sridhar B. Studies of Inter/intramolecular Weak Interactions with CH⋯S and S⋯arene Interaction in Symmetrical and Dissymmetrical Models. B KOREAN CHEM SOC 2010. [DOI: 10.5012/bkcs.2010.31.5.1326] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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75
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Selvanayagam S, Sridhar B, Ravikumar K, Kathiravan S, Raghunathan R. Methyl 4-phenyl-1,2,3,3a,4,4a,5,12c-octa-hydronaphtho[1',2':3,2]furo[5,4-b]pyrrolizine-4a-carboxyl-ate. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1345. [PMID: 21579434 PMCID: PMC2979659 DOI: 10.1107/s1600536810017307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 05/11/2010] [Indexed: 11/25/2022]
Abstract
In the title compound, C26H25NO3, both pyrrolidine rings adopt envelope conformations, whereas the dihydropyran ring adopts a half-chair conformation. The phenyl ring is oriented at an angle of 27.9 (1)° with respect to the naphthalene ring system. An intramolecular C—H⋯O hydrogen bond is observed. The crystal packing is stabilized by weak intermolecular C—H⋯π interactions.
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