Characterization Of Wy 14,643 And Its Complex With Aldose Reductase, Michael R. Sawaya, Malkhey Verma, Vaishnavi Balendiran, Nigam P. Rath, Duilio Cascio, Ganesaratnam K. Balendiran
Nov 2016
Characterization Of Wy 14,643 And Its Complex With Aldose Reductase, Michael R. Sawaya, Malkhey Verma, Vaishnavi Balendiran, Nigam P. Rath, Duilio Cascio, Ganesaratnam K. Balendiran
Nigam Rath
The peroxisome proliferator, WY 14,643 exhibits a pure non-competitive inhibition pattern in the aldehyde reduction and in alcohol oxidation activities of human Aldose reductase (hAR). Fluorescence emission measurements of the equilibrium dissociation constants, Kd, of oxidized (hAR•NADP+) and reduced (hAR•NADPH) holoenzyme complexes display a 2-fold difference between them. Kd values for the dissociation of WY 14,643 from the oxidized (hAR•NADP+•WY 14,643) and reduced (hAR•NADPH•WY 14,643) ternary complexes are comparable to each other. The ternary complex structure of hAR•NADP+•WY 14,643 reveals the first structural evidence of a fibrate class drug binding to hAR. These observations demonstrate how fibrate molecules such as …
A Generator-Produced Gallium-68 Radiopharmaceutical For Pet Imaging Of Myocardial Perfusion, Nigam Rath, Vijay Sharma, Jothilingam Sivapackiam, Scott E. Harpstrite, Julie L. Prior, Hannah Gu, David Piwnica-Worms
Oct 2014
A Generator-Produced Gallium-68 Radiopharmaceutical For Pet Imaging Of Myocardial Perfusion, Nigam Rath, Vijay Sharma, Jothilingam Sivapackiam, Scott E. Harpstrite, Julie L. Prior, Hannah Gu, David Piwnica-Worms
Nigam Rath
Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of producing high quality 68Ga, an isotope with excellent emission characteristics for clinical PET imaging, have emerged. Herein, we report a novel 68Ga-complex identified through mechanism-based cell screening that holds promise as a generator-produced radiopharmaceutical for PET MPI.
New Bis(Imino)Pyridine Complexes Of Iron(Ii) And Iron(Iii), And Their Catalytic Activity In The Mukaiyama Aldol Reaction, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Nov 2013
New Bis(Imino)Pyridine Complexes Of Iron(Ii) And Iron(Iii), And Their Catalytic Activity In The Mukaiyama Aldol Reaction, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Nigam Rath
New iron(II) and iron(III) complexes bearing bis(imino)pyridine ligands were synthesized and successfully applied to the Mukaiyama aldol reaction. The two complexes [FeCl2 L] (L = bis(imino)pyridine ligand, 55% isolated yield) and [LFe(μCl)3FeCl3] (76%) were obtained employing FeCl2 and FeCl3 iron sources, respectively, and characterized by elemental analyses, mass spectrometry, IR spectroscopy and, one example, by X-ray diffraction. The two new iron complexes were subsequently employed as catalysts in the Mukaiyama aldol reaction after abstraction of two chlorides by AgSbF6 to obtain the aldol products in 43% to virtually quantitative yield (CH2Cl2 solvent, room temperature, 3.5 to 16 h reaction time). …
Dicarbonyldichloridobis(Trimethylphosphane)Iron(Ii)–Carbonyldichloridotris(Trimethylphosphane)Iron(Ii)–Tetrahydrofuran (1/1/2), Nigam P. Rath, Meghan Stouffer, Matthew K. Janssen, John R. Bleeke
Apr 2011
Dicarbonyldichloridobis(Trimethylphosphane)Iron(Ii)–Carbonyldichloridotris(Trimethylphosphane)Iron(Ii)–Tetrahydrofuran (1/1/2), Nigam P. Rath, Meghan Stouffer, Matthew K. Janssen, John R. Bleeke
Nigam Rath
The asymmetric unit of the title crystal, [FeCl2(C3H9P)3(CO)]·[FeCl2(C3H9P)2(CO)2]·2C4H8O, contains half molecules of the two closely related FeII complexes lying on mirror planes and a tetrahydrofuran solvent molecule, one C atom of which is disordered over two sets of sites with site occupancy factors 0.633 (9) and 0.367 (9). In both FeII complex molecules, a distorted octahedral coordination geometry has been observed around the Fe atoms. Weak intermolecular C-H...O interactions are observed in the crystal structure.
(1e,3e)-1,4-Bis(4-Methoxyphenyl)Buta1,3-Diene, Gopinathan Narayan, Nigam P. Rath, Suresh Das
Oct 2010
(1e,3e)-1,4-Bis(4-Methoxyphenyl)Buta1,3-Diene, Gopinathan Narayan, Nigam P. Rath, Suresh Das
Nigam Rath
The title compound, C18H18O2, which exhibits blue emission in the solid state, is an intermediate in the preparation of liquid crystals and polymers. The molecule is located on an inversion centre. In the crystal, molecules are arranged in a herringbone motif.
2,2′,5,5′-TetraChloroBenzidine, Onome Ugono, Marcel Douglas, Nigam P. Rath, Alicia M. Beatty
Sep 2010
2,2′,5,5′-TetraChloroBenzidine, Onome Ugono, Marcel Douglas, Nigam P. Rath, Alicia M. Beatty
Nigam Rath
In the crystal structure of the title compound, C12H8Cl4N2, molecules lie on crystallographic twofold axes at the centre of the C-C bonds linking the benzene rings, such that the asymmetric unit consists of a half-molecule. The individual molecules participate in intermolecular N-H...N, N-H...Cl, C-H...Cl and Cl...Cl [3.4503 (3) Å] interactions.
New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Apr 2010
New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer
Nigam Rath
New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the …
Catena-Poly[[(Pyridine-Κn)Copper(Ii)]-Μ3-Pyridine-2,6-Dicarboxylato-Κ3o2:O2′,N,O6:O6′], Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath
Mar 2009
Catena-Poly[[(Pyridine-Κn)Copper(Ii)]-Μ3-Pyridine-2,6-Dicarboxylato-Κ3o2:O2′,N,O6:O6′], Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath
Nigam Rath
In the title compound, [Cu(C7H3NO4)(C5H5N)]n, the CuII atom is in a slightly distorted octahedral coordination environment. Each CuII atom is bound to two N atoms and one O atom of the pyridinedicarboxylate (PDA) ligand in a tridentate manner, one N atom of the pyridine molecule and two bridging carboxylate O atoms of adjacent PDA ligands, leading to a linear one-dimensional chain running along the c axis. These chains are further assembled via weak C-H...O and [pi]-[pi] interactions into a three-dimensional supramolecular network structure. The centroid-centroid distance between the [pi]-[pi] interacting pyridine rings is 3.9104 (13) Å. The two N atoms …
Dioxidobis(2-Oxo-1,2-Dihydropyridin-3-Olato)Molybdenum(Vi), Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath
Apr 2008
Dioxidobis(2-Oxo-1,2-Dihydropyridin-3-Olato)Molybdenum(Vi), Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath
Nigam Rath
In the title compound, [Mo(C5H4NO2)2O2], the MoVI atom exhibits a distorted octahedral coordination geometry formed by two terminal oxo ligands and two monoanionic O,O-bidentate pyridinone ligands. The two terminal oxo ligands lie in a cis arrangement, the ketonic O atoms of the pyridinone ligands are coordinated trans to the oxo ligands and the deprotonated hydroxyl O atoms are located trans to each other. The crystal structure contains intermolecular N-H...O hydrogen bonds, C-H...O contacts and face-to-face [pi]-[pi] stacking interactions with an interplanar separation of 3.25 (1) Å.
Diethyl 2-[(4-NitroPhenYl)(4-Phenyl-1,2,3-Selenadiazol-5-Yl)MethYl]Malonate, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath
Apr 2008
Diethyl 2-[(4-NitroPhenYl)(4-Phenyl-1,2,3-Selenadiazol-5-Yl)MethYl]Malonate, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath
Nigam Rath
In the title compound, C22H21N3O6Se, the heterocyclic ring makes dihedral angles of 50.03 (11) and 67.75 (11)°, respectively, with the benzene and phenyl rings. The terminal C atoms of the ester groups are disordered over two positions: the site occupancies for the C atoms are 0.62 (3)/0.38 (3) and 0.48 (3)/0.52 (3). In the crystal structure, weak intra- and intermolecular C-H...O interactions are observed.
4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath
Feb 2008
4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath
Nigam Rath
In the title compound, C18H15Cl2N3O2Se, the selenadiazole ring makes dihedral angles of 49.87 (3) and 55.70 (3)° with the two benzene rings. The dihedral angle between the two benzene rings is 11.90 (5)°. In the crystal structure, intramolecular C-H...O and C-H...Se interactions and intermolecular C-H...O, C-H...Cl and C-H...N interactions are observed.
Reactions Of Boranes And Metallaboranes With Phosphines, Lawrence Barton, Oleg Volkov, Mitsuhiro Hata, Paul Mcquade, Nigam P. Rath
Dec 2002
Reactions Of Boranes And Metallaboranes With Phosphines, Lawrence Barton, Oleg Volkov, Mitsuhiro Hata, Paul Mcquade, Nigam P. Rath
Nigam Rath
This paper reports extensions of the well-established field of phosphine–borane chemistry. Linked clusters, for example, {[(PPh3)2(CO)OsB4H7-3-BH2-PPh2]2 [(Fe(C5H4)2]}, are formed in reactions of rigid backboned bidentate phosphines with {2,2,2-(PPh3)2(CO)-nido-2-OsB5H9]. Reaction of bidentate phosphines with the unsaturated clusters [8,8-PPh3)2-nido-8,7-RhSB9H10] and [9,9-(PPh3)2-nido-9,7,8-RhC2B8 H11] leads to the isolation of novel species such as {1-(PPh3)[1,3-(µ-dppm)]-closo -1,2-RhSB9H8},with a dppm molecule bridging adjacent metal and boron vertices in the cage, [1,1-(ç2-dppe)-3-(ç1-dppm)-closo-1,2-RhSB 9H8], a mixed ligand system, and {9,9-ç2-[(ç2-BH3)PPh2PCH2 PPh2]-nido- 9,7,8-RhC2B8H11} which contains a bidentate dppm BH3 moiety. The formation of bidentate phosphine-linked main group transition-metal moieties such as [BH3PPh2(CH)nPPh2IrCp*Cl2] is also described as is an example of …
2-Phenyl-3-(5,6,7,7a-Tetrahydro-1h,3h-Pyrrolo[1,2-C]Oxazol-3-Ylidene)-1-Propene-1,1-Dicarbonitrile And 4-(4-Methoxyphenyl)-2,6-Bis(Methylthio)Pyridine-3-Carbonitrile, M. George, S. Das, C.V. Ashokan, N.P. Rath, M.V. George
Jul 1998
2-Phenyl-3-(5,6,7,7a-Tetrahydro-1h,3h-Pyrrolo[1,2-C]Oxazol-3-Ylidene)-1-Propene-1,1-Dicarbonitrile And 4-(4-Methoxyphenyl)-2,6-Bis(Methylthio)Pyridine-3-Carbonitrile, M. George, S. Das, C.V. Ashokan, N.P. Rath, M.V. George
Nigam Rath
The reaction of 3-aryl-2-cyano-5,5-bis(methylthio)penta-2,4-dienenitrile, (1), with (L)-(-)-2-hydroxymethylpyrrolidine, (2), gave two types of product, the normal substitution product, (3), and a pyridine derivative, (4). The structures of two representative examples, 2-phenyl-3-(5,6,7,7a-tetrahydro1H,3H-pyrrolo[1,2-c]oxazol-3-ylidene)-1-propene-1,1-dicarbonitrile, (3a), as its hemibenzene solvate, C17H14N3O.0.5C6H6, and 4-(4-methoxyphenyl)-2,6-bis(methylthio)pyridine-3-carbonitrile, (4b), C15H14N2OS2, have been unambiguously established by X-ray crystallographic analysis. The molecular packing of (4b) involves loosly held dimers with S1...S1' distances of 3.424 (1) Å.
Exo- And Endo-Tricarbonyl[(4b,5,6,7,8,8a-Η)-Cis-N-Methyl-2,3,4,4a,9,9a-Hexahydro-1h- Carbazole]Chromium(0), Nigam Rath, F. Christopher Pigge, Shiyue Fang
Dec 1997
Exo- And Endo-Tricarbonyl[(4b,5,6,7,8,8a-Η)-Cis-N-Methyl-2,3,4,4a,9,9a-Hexahydro-1h- Carbazole]Chromium(0), Nigam Rath, F. Christopher Pigge, Shiyue Fang
Nigam Rath
Acid-mediated hydride reduction of tricarbonyl([eta]6-N-methyl-1,2,3,4-tetrahydrocarbazole)chromium(0) affords either the cis-fused exo-hexahydrocarbazole chromium(0) complex {[Cr(C13H17N)(CO)3], (I)} exclusively, or a separable mixture of (I) and the endo-isomer {[Cr(C13H17N)(CO)3], (II)}, depending upon the choice of hydride donor. The conformations of the hexahydrocarbazole systems differ in the orientation of the indoline moiety with respect to the saturated hexahydrocarbazole rings. The isolation of the exo isomer is unusual, as this complex arises via reaction at the sterically more hindered endo face of the coordinated ligand.
Dimethyl (±)-(1s*,2r*,3s*)-[3-Phenyl-1-(N-Phenylcarbamoyloxy)-2, 3-Epoxypropyl]-Phosphonate, T. Boehlow, A. De La Cruz, Nigam P. Rath, C. D. Spilling
Dec 1997
Dimethyl (±)-(1s*,2r*,3s*)-[3-Phenyl-1-(N-Phenylcarbamoyloxy)-2, 3-Epoxypropyl]-Phosphonate, T. Boehlow, A. De La Cruz, Nigam P. Rath, C. D. Spilling
Nigam Rath
The crystal structure of the racemic title compound, C18H20NO6P, m.p. 428-431 K, has been determined by X-ray diffraction. The title compound consists of a tetrahedral P atom bonded to two methoxy groups, and an alkyl chain. The alkyl chain was substituted at position 1 with a carbamate and with an epoxide at positions 2 and 3. The relative configuration of the 1-carbamate and 2,3-epoxide substituents was confirmed as anti (1S,2R,3S). The crystal structure contains an enantiomeric pair with two intermolecular hydrogen bonds in a 14-membered ring. The hydrogen bonds are formed between the P=O of one enantiomer and the N-H …
[(Co)H(Pph3)2-Arachno-Osb3h8], Nigam Rath, J. Bould, L. Barton
Dec 1995
[(Co)H(Pph3)2-Arachno-Osb3h8], Nigam Rath, J. Bould, L. Barton
Nigam Rath
A single-crystal X-ray diffraction study of the species 2-carbonyl2-hydrido-trans-2,2-bis(triphenylphosphine)-2-osma-arachno-tetraborane confirms the structure as a tetraborane(10) butterfly with a trans-[(CO)H(PPh3)2Os] group replacing a BH2 group at a wing-tip or 2-position. It is compared with the previously reported ruthenaborane analogue (CO)H(PPh3)2-arachno-RuB3H8.
