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Kumar S, Sharma A, Mahala S, Gaatha K, Reddy SR, Rom T, Paul AK, Roy P, Joshi H. Macrocyclic Sulfur Ligand Stabilized Trans-Palladium Dichloride Complex: Syntheses, Structure, Chlorine Rotation, and Application in α-Olefination of Nitriles by Primary Alcohols. Chem Asian J 2024; 19:e202300935. [PMID: 38116906 DOI: 10.1002/asia.202300935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/05/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Herein, we have reported the synthesis of a macrocyclic organosulfur ligand (L1) having a seventeen-membered macrocyclic ring. Subsequently, the corresponding trans-palladium complex (C1) of bulky macrocyclic organosulfur ligand (L1) was synthesized by reacting it with PdCl2 (CH3 CN)2 salt. The newly synthesized ligand and complex were characterized using various analytical and spectroscopic techniques. The complex showed a square planar geometry with trans orientation of two ligands around the palladium center. The complex possesses intramolecular SCH…Cl interactions of 2.648 Å between the macrocyclic ligand and palladium dichloride. The potential energy surface (PES) for the rotational process of C1 suggested a barrier of ~23.81 kcal/mol for chlorine rotation. Furthermore, the bulky macrocyclic organosulfur ligand stabilized palladium complex (C1) was used as a catalyst (2.5 mol %) for α-olefination of nitriles by primary alcohols. The α,β-unsaturated nitrile compounds were found to be the major product of the reaction (57-78 % yield) with broad substrate scope and large functional group tolerance. Notably, the saturated nitrile product was not observed during the reaction. The mechanistic studies suggested the formation of H2 and H2 O as only by-products of the reaction, thereby making the protocol greener and sustainable.
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Affiliation(s)
- Sunil Kumar
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Ashutosh Sharma
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Suman Mahala
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - K Gaatha
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - S Rajagopala Reddy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Tanmay Rom
- Department of Chemistry, National Institute of Technology Kurukshetra, Kurukshetra, 136119, India
| | - Avijit Kumar Paul
- Department of Chemistry, National Institute of Technology Kurukshetra, Kurukshetra, 136119, India
| | - Partha Roy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Hemant Joshi
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan, 305817, India
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Kumar S, Singh S, Mahala S, Janjani P, Rajagopala Reddy S, Rom T, Paul AK, Roy P, Joshi H. A palladium complex of a macrocyclic selenium ligand: catalyst for the dehydroxymethylation of dihydroxy compounds. Dalton Trans 2023; 52:5110-5118. [PMID: 36960760 DOI: 10.1039/d3dt00375b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
This report describes the synthesis of a seventeen-membered macrocyclic ring containing ligand (L1) by the reaction of 1,8-bis(2-(chloromethyl)phenoxy)octane with selenium powder. The trans-palladium dichloride complex (C1) of the macrocyclic selenium ligand was synthesized from its reaction with the Pd(CH3CN)2Cl2 precursor. The formation of the ligand and complex was authenticated with the help of various analytical techniques like 1H and 13C{1H} NMR, HRMS, FTIR, UV-visible spectroscopy, and elemental analysis. The structure of the ligand and its coordination mode with the palladium precursor were authenticated with the help of single crystal X-ray diffraction. The complex possesses a distorted square planar geometry around the palladium center. The new ligand and complex are air and moisture insensitive and stable at room temperature for over three months. The variable temperature NMR data and computational studies suggest selenium inversion in the palladium complex (C1) with an inversion barrier of ∼22.6 kcal mol-1. The palladium complex C1 was used as a catalyst for the dehydroxymethylation of long alkyl chain containing dihydroxy compounds. Generally, two separate catalysts are used for dehydroxymethylation (one for the oxidation of the alcohol and the other for the decarbonylation of the aldehyde). Here a single catalyst shows the dual action of dehydroxymethylation with up to 91% yield under only 5.0 mol% catalyst loading. A broad substrate scope can be achieved with good functional group tolerance. The PPh3 and Hg poisoning tests suggest the homogeneous nature of the reaction. Interestingly, the same long alkyl chain containing dihydroxy compounds were reported to undergo macrolactonization when reacted with a ruthenium catalyst.
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Affiliation(s)
- Sunil Kumar
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India.
| | - Sohan Singh
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India.
| | - Suman Mahala
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India.
| | - Prachi Janjani
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - S Rajagopala Reddy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Tanmay Rom
- Department of Chemistry, National Institute of Technology Kurukshetra, Kurukshetra-136119, India
| | - Avijit Kumar Paul
- Department of Chemistry, National Institute of Technology Kurukshetra, Kurukshetra-136119, India
| | - Partha Roy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Hemant Joshi
- ISC Laboratory, Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India.
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Kumari R, Jha AK, Goyal S, Maan R, Reddy SR, Easwar S. Acyl Transfer-Driven Rauhut-Currier Dimerization of Morita-Baylis-Hillman Ketones. J Org Chem 2023; 88:2023-2033. [PMID: 36753536 DOI: 10.1021/acs.joc.2c02244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A serendipitous Rauhut-Currier dimerization of 1,1-disubstituted activated olefins derived from Morita-Baylis-Hillman adducts was observed in the presence of DABCO. The reaction is driven by the migration of an acyl group and produces multifunctionalized enol esters in yields greater than 90% in most cases, without necessitating column chromatographic purification. The acyl transfer is thought to proceed via a transition state typical of a Morita-Baylis-Hillman (MBH) reaction, supported by a brief mechanistic study involving computational calculations.
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Affiliation(s)
- Rajkiran Kumari
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer 305817, Rajasthan, India
| | - Ajit Kumar Jha
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer 305817, Rajasthan, India
| | - Sophiya Goyal
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer 305817, Rajasthan, India
| | - Reena Maan
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer 305817, Rajasthan, India
| | - S Rajagopala Reddy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer 305817, Rajasthan, India
| | - Srinivasan Easwar
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer 305817, Rajasthan, India
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Papadopoulos I, Reddy SR, Coto PB, Lehnherr D, Thiel D, Thoss M, Tykwinski RR, Guldi DM. Parallel versus Twisted Pentacenes: Conformational Impact on Singlet Fission. J Phys Chem Lett 2022; 13:5094-5100. [PMID: 35653702 DOI: 10.1021/acs.jpclett.2c01395] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We placed two pentacene chromophores at the termini of a diacetylene linker to investigate the impact of excitation wavelength, conformational flexibility, and vibronic coupling on singlet fission. Photoexcitation of the low-energy absorption results in a superposed mixture of states, which transform on an ultrafast time-scale into a spin-correlated and vibronically coupled/hot delocalized triplet pair 1(T1T1)deloc. Regardless of temperature, the lifetime for 1(T1T1)deloc is less than 2 ps. In contrast, photoexcitation of the high-energy absorption results in the formation of 1(T1T1)deloc lasting 1.0 ps, which then decays at room temperature within 4 ps via triplet-triplet annihilation. Lowering the temperature enables 1(T1T1)deloc to delocalize and vibronically decouple, in turn affording 1(T1T1)loc. In addition, our results suggest that the quasi-free rotation at the diacetylene spacer may lead to twisted conformations with very low SF quantum yields, highlighting the need of controlling this structural aspect in the design of new singlet fission active molecules.
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Affiliation(s)
- Ilias Papadopoulos
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - S Rajagopala Reddy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Pedro B Coto
- Materials Physics Center (CFM), CSIC and Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 5, 20018 Donostia - San Sebastián, Spain
| | - Dan Lehnherr
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Dominik Thiel
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Michael Thoss
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Rik R Tykwinski
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
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Joshi H, Meena N, Kumar S, Shinde VN, Reddy SR, Bhuvanesh N, Kumar A. Bulky selenium ligand stabilized trans-palladium dichloride complexes as catalyst for silver-free decarboxylative coupling of coumarin-3-carboxylic acids. Chem Asian J 2021; 17:e202101199. [PMID: 34919329 DOI: 10.1002/asia.202101199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/14/2021] [Indexed: 11/06/2022]
Abstract
This report describes synthesis of three new trans -palladium dichloride complexes of bulky selenium ligands. These complexes possess a Cl-Pd-Cl rotor spoke attached to a Se-Pd-Se axle. The new ligands and palladium complexes ( C1 - C3 ) were characterized with the help of NMR, HRMS, UV-Vis., IR, and elemental analysis. The single crystal structure of metal complex C2 confirmed a square planer geometry of complex with trans -orientation. The X-ray structure revealed intramolecular secondary interactions (SeCH---Cl) between chlorine of PdCl 2 and CH 2 proton of selenium ligand. Variable temperature NMR data shows coalescence of diastereotopic protons, which indicates pyramidal inversion of selenium atom at elevated temperature. The relaxed potential energy scan of C2 suggests a rotational barrier of ~12.5 kcal/mol for rotation of chlorine atom through Cl-Pd-Cl rotor. The complex C3 possess dual intramolecular secondary interactions (OCH 2 ---Cl and SeCH 2 ---Cl) with stator ligand. Molecular rotor C2 was found to be most efficient catalyst for the decarboxylative Heck-coupling under mild reaction conditions. The protocol is applicable to a broad range of substrates with large functional group tolerance and low catalyst loading (2.5 mol %). The mechanism of decarboxylative Heck-coupling reaction was investigated through experimental and computational studies. Importantly the reaction works under silver-free conditions which reduces the cost of overall protocol. Further, the catalyst also worked for decarboxylative arylation and decarboxylative Suzuki-Miyaura coupling reactions with good yields of the coupled products.
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Affiliation(s)
- Hemant Joshi
- Central University of Rajasthan, Ajmer, Chemistry, Department of Chemistry, Central University of Rajasthan, 305817, Bandarsindri, Ajmer, INDIA
| | - Neha Meena
- BITS Pilani: Birla Institute of Technology and Science, Chemistry, INDIA
| | - Sunil Kumar
- Central University of Rajasthan, Chemistry, INDIA
| | - Vikki N Shinde
- BITS: Birla Institute of Technology and Science Pilani, Chemistry, INDIA
| | | | - Nattamai Bhuvanesh
- Texas A&M University College Station: Texas A&M University, Chemistry, UNITED STATES
| | - Anil Kumar
- BITS: Birla Institute of Technology and Science Pilani, Chemistry, INDIA
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Mukherjee A, Ansari AJ, Rajagopala Reddy S, Kanti Das G, Singh R. Mechanistic Investigations for the Formation of Active Hexafluoroisopropyl Benzoates Involving Aza‐Oxyallyl Cation and Anthranils. ASIAN J ORG CHEM 2020. [DOI: 10.1002/ajoc.202000424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Anirban Mukherjee
- National Institute of Pharmaceutical Education and Research (NIPER) Raebareli, Uttar Pradesh 229010 India
| | - Arshad J. Ansari
- School of Chemical Sciences and Pharmacy Central University of Rajasthan Bandarsindri, Kishangarh 305817, Rajasthan India
| | - S. Rajagopala Reddy
- School of Chemical Sciences and Pharmacy Central University of Rajasthan Bandarsindri, Kishangarh 305817, Rajasthan India
| | - Gourab Kanti Das
- Department of Chemistry Institute of Science (Siksha Bhavana) Visva-Bharati, Santiniketan 731235, West Bengal India
| | - Ritesh Singh
- School of Chemical Sciences and Pharmacy Central University of Rajasthan Bandarsindri, Kishangarh 305817, Rajasthan India
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Reddy SR, Yoshida S, Bhattacharjee T, Sake N, Lozinko A, Guo S, Bhattacharjee PP, Tsuji N. Nanostructuring with Structural-Compositional Dual Heterogeneities Enhances Strength-Ductility Synergy in Eutectic High Entropy Alloy. Sci Rep 2019; 9:11505. [PMID: 31395929 PMCID: PMC6687781 DOI: 10.1038/s41598-019-47983-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/23/2019] [Indexed: 11/30/2022] Open
Abstract
A lamellar (L12 + B2) AlCoCrFeNi2.1 eutectic high entropy alloy (EHEA) was severely deformed by a novel hybrid-rolling process. During hybrid-rolling, the deformation was carried out in two stages, namely cryo-rolling followed by warm-rolling at 600 °C. The strain (ε) imparted in each of these steps was identical ~1.2, resulting in a total strain of ε~2.4 (corresponding to 90% reduction in thickness). The novel processing strategy resulted in an extremely heterogeneous microstructure consisting of retained lamellar and transformed nanocrystalline regions. Each of these regions consisted of different phases having different crystal structures and chemical compositions. The novel structure-composition dual heterogeneous microstructure originated from the stored energy of the cryo-rolling which accelerated transformations during subsequent low temperature warm-rolling. The dual heterogeneous microstructure yielded an unprecedented combination of strength (~2000 MPa) and ductility (~8%). The present study for the first time demonstrated that dual structure-composition heterogeneities can be a novel microstructural design strategy for achieving outstanding strength-ductility combination in multiphase high entropy alloys.
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Affiliation(s)
- S R Reddy
- Department of Materials Science and Metallurgical Engineering, IIT Hyderabad, Hyderabad, India
| | - S Yoshida
- Department of Materials Science and Engineering, Kyoto University, Kyoto, Japan
| | - T Bhattacharjee
- Department of Materials Science and Engineering, Kyoto University, Kyoto, Japan.,Elements Strategy Initiative for Structural Materials (ESISM), Kyoto University, Kyoto, Japan
| | - N Sake
- Department of Materials Science and Metallurgical Engineering, IIT Hyderabad, Hyderabad, India
| | - A Lozinko
- Industrial and Materials Science, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - S Guo
- Industrial and Materials Science, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - P P Bhattacharjee
- Department of Materials Science and Metallurgical Engineering, IIT Hyderabad, Hyderabad, India.
| | - N Tsuji
- Department of Materials Science and Engineering, Kyoto University, Kyoto, Japan.,Elements Strategy Initiative for Structural Materials (ESISM), Kyoto University, Kyoto, Japan
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Ghosh A, Reddy SR, Mahapatra S. Electronic spectroscopy of carbon chains (C 2n+1, n = 7–10) of astrophysical importance. II. Quantum dynamics. J Chem Phys 2019. [DOI: 10.1063/1.5108726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Arpita Ghosh
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| | | | - Susanta Mahapatra
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
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Reddy SR, Ghosh A, Mahapatra S. Electronic spectroscopy of carbon chains (C 2n+1, n = 7–10) of astrophysical importance. I. Quantum chemistry. J Chem Phys 2019. [DOI: 10.1063/1.5108725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Arpita Ghosh
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| | - S. Mahapatra
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
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Reddy SR, Coto PB, Thoss M. Quantum dynamical simulation of intramolecular singlet fission in covalently coupled pentacene dimers. J Chem Phys 2019; 151:044307. [DOI: 10.1063/1.5109897] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- S. Rajagopala Reddy
- Institute of Physics, Albert-Ludwigs University Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Pedro B. Coto
- Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julián Clavería 8, 33006, Oviedo, Spain
| | - Michael Thoss
- Institute of Physics, Albert-Ludwigs University Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
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Abstract
We investigate the dynamics of intramolecular singlet fission in a dimer consisting of two pentacene-based chromophores covalently bonded to a phenylene spacer using an approach that combines high-level ab initio multireference perturbation theory methods and quantum dynamical simulations. The results show that the population of the multiexcitonic state, corresponding to the first step of singlet fission, is facilitated by the existence of higher-lying doubly excited and charge transfer states that participate in a superexchange-like way. The important role played by high-frequency ring-breathing molecular vibrations in the process is also discussed.
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Affiliation(s)
- S Rajagopala Reddy
- Institute of Theoretical Physics and Interdisciplinary Center for Molecular Materials , Friedrich-Alexander University Erlangen-Nürnberg , 91058 Erlangen , Germany
| | - Pedro B Coto
- Institute of Theoretical Physics , Friedrich-Alexander-University Erlangen-Nürnberg , 91058 Erlangen , Germany
| | - Michael Thoss
- Institute of Physics , Albert-Ludwigs University Freiburg , 79104 Freiburg , Germany
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Basel BS, Zirzlmeier J, Hetzer C, Reddy SR, Phelan BT, Krzyaniak MD, Volland MK, Coto PB, Young RM, Clark T, Thoss M, Tykwinski RR, Wasielewski MR, Guldi DM. Evidence for Charge-Transfer Mediation in the Primary Events of Singlet Fission in a Weakly Coupled Pentacene Dimer. Chem 2018. [DOI: 10.1016/j.chempr.2018.04.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Dalton BG, Gonzalez KW, Reddy SR, Hendrickson RJ, Iqbal CW. Improved outcomes for inborn babies with uncomplicated gastroschisis. J Pediatr Surg 2017; 52:1132-1134. [PMID: 28017414 DOI: 10.1016/j.jpedsurg.2016.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/16/2016] [Accepted: 12/09/2016] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Gastroschisis (GS) is a common abdominal wall defect necessitating neonatal surgery and intensive care. We hypothesized that inborn patients had improved outcomes compared to patients born at an outside hospital (outborn) and transferred for definitive treatment. METHODS A single center, retrospective chart review at a pediatric tertiary care center was performed from 2010 to 2015. All patients whose primary surgical treatment of GS was performed at this center were included. We compared patients delivered within our center (inborn) to patients delivered outside of our center and transferred for surgical care (outborn). Babies with complicated gastroschisis were excluded. RESULTS During the study period 79 patients with GS were identified. Of these, 53 were inborn and 26 were outborn. Sixteen patients were excluded for complicated GS. The rate of complicated GS was higher in the outborn group (32%) compared to the inborn population (11%) (p=0.03). Duration of stay, readmission rate and time on TPN were all significantly decreased for inborn patients, while time to definitive closure was similar. Mortality was 0% for both inborn and outborn patients. CONCLUSION Patients with uncomplicated GS seem to benefit from delivery with immediate pediatric surgical care available eliminating the need for transfer. LEVEL OF EVIDENCE III.
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Affiliation(s)
- B G Dalton
- Children's Mercy Hospital Kansas City, MO
| | | | - S R Reddy
- Children's Mercy Hospital Kansas City, MO
| | | | - C W Iqbal
- Children's Mercy Hospital Kansas City, MO.
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Affiliation(s)
- Arpita Ghosh
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| | | | | | - S. Mahapatra
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
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Zirzlmeier J, Casillas R, Reddy SR, Coto PB, Lehnherr D, Chernick ET, Papadopoulos I, Thoss M, Tykwinski RR, Guldi DM. Solution-based intramolecular singlet fission in cross-conjugated pentacene dimers. Nanoscale 2016; 8:10113-23. [PMID: 27122097 DOI: 10.1039/c6nr02493a] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We show unambiguous and compelling evidence by means of pump-probe experiments, which are complemented by calculations using ab initio multireference perturbation theory, for intramolecular singlet fission (SF) within two synthetically tailored pentacene dimers with cross-conjugation, namely XC1 and XC2. The two pentacene dimers differ in terms of electronic interactions as evidenced by perturbation of the ground state absorption spectra stemming from stronger through-bond contributions in XC1 as confirmed by theory. Multiwavelength analysis, on one hand, and global analysis, on the other hand, confirm that the rapid singlet excited state decay and triplet excited state growth relate to SF. SF rate constants and quantum yields increase with solvent polarity. For example, XC2 reveals triplet quantum yields and rate constants as high as 162 ± 10% and (0.7 ± 0.1) × 10(12) s(-1), respectively, in room temperature solutions.
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Affiliation(s)
- Johannes Zirzlmeier
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Engineering of Advanced Materials (EAM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstrasse 3, 91058 Erlangen, Germany.
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Krishna SG, Stroehlein JR, Foo WC, Suzuki R, Reddy SR, Bhutani MS. Iatrogenic infection of a colonic cystic lymphangioma following cold-forceps biopsy. Endoscopy 2012; 44 Suppl 2 UCTN:E104-5. [PMID: 22477167 DOI: 10.1055/s-0031-1291568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- S G Krishna
- Department of Gastroenterology, Hepatology and Nutrition, University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4008, USA
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Rajagopala Reddy S, Mahapatra S. Theoretical study of photodetachment processes of anionic boron clusters. I. Structure. J Chem Phys 2012; 136:024322. [DOI: 10.1063/1.3675165] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [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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Reddy SR, Mahapatra S. Theoretical study of photodetachment processes of anionic boron clusters. II. Dynamics. J Chem Phys 2012; 136:024323. [DOI: 10.1063/1.3675166] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [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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Singh S, Reddy SR, Sud A, Wanchu A, Bambery P, Gill KD. Subacute arsenical neuropathy leading to Gullian-Barre-like syndrome and respiratory failure. J Assoc Physicians India 2002; 50:853-4. [PMID: 12240865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Affiliation(s)
- S Singh
- Department of Internal Medicine and Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh
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Abstract
The present study investigates enzyme activities of the urea cycle, transamidinase and ornithine-proline inter-conversion in the hypertrophied kidney after unilateral nephrectomy in mice. Surgical removal of the left kidney in mice led to compensatory enlargement of the right kidney after 1 and 14 days. This renal growth was associated with an increase in glomerular volume (but not number) and enlargement of the proximal convoluted tubules. The total renal protein content increased in proportion to the increase in kidney weight, but the protein per gram weight of kidney did not change. The specific activity of only ornithine aminotransferase (OAT), the rate-limiting enzyme in the conversion of ornithine to proline, increased in 2 weeks of hypertrophy. The specific activity of all other enzymes was unchanged. However, the total enzyme activity per kidney of all the enzymes, without exception, was elevated in the hypertrophied kidney. While the increase in total OAT activity was much more than the increase in kidney weight, all other enzymes increased more or less in proportion to the increase in renal mass. The results suggest that compensation in OAT activity to chronic reduction in renal mass was complete, but only partial in the case of other enzymes.
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Affiliation(s)
- S Natesan
- Department of Zoology, University of Pune, Pune - 411 007, Maharashtra, India.
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Kumar VP, Reddy SR. Medialisation laryngoplasty: a new surgical frontier in the management of vocal cord paralysis. J Indian Med Assoc 2001; 99:638-9. [PMID: 12022206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Patients who are victims of vocal cord paralysis usually suffer from husky or hoarse voice which is very much jeopardising their future particularly in professional voice users like singers, priests, teachers, etc. Phonosurgical techniques like medialisation laryngoplasty has opened a new horizon in the management of dysphonia with unilateral vocal cord paralysis. Medialisation laryngoplasty is sometimes described under the heading of laryngoplastic phonosurgery or thyroplasty. A report of 10 cases of unilateral vocal cord paralysis with dysphonia subjected to medialisation laryngoplasty from March 1996 to March 1998 with 90% success is presented. Only one patient developed inspiratory stridor as a complication.
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Affiliation(s)
- V P Kumar
- Department of ENT, Guntur Medical College
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Kumar VP, Reddy SR, Das MH. Medialization laryngoplasty with silastic implant in unilateral vocal cord paralysis. Indian J Otolaryngol Head Neck Surg 1997; 49:262-4. [PMID: 23119305 PMCID: PMC3450587 DOI: 10.1007/bf02991287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The state of art of Laryngoplastic surgery gaining day to day importance where Rhinoplasty stood almost a century ago. Medialization Laryngoplasty using Silastic Implant for the correction of symptomatic unilateral vocal cord paralysis is discussed.
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Abstract
OBJECTIVE The purpose of this study was to evaluate the interaction of a linoleic acid enriched diet with NaCl on the development of hypertension in Dahl salt sensitive (Dahl-S) rats and in two-kidney, one-clip Sprague Dawley rats. METHODS In both experimental models, separate groups of animals were fed either linoleic acid enriched (provided as safflower oil) or control (containing coconut oil) diets for 5 weeks. Diets were further subdivided on the basis of either a low NaCl (0.3%) or a high NaCl (3.0%) content. Tail systolic blood pressure, direct mean intra-arterial pressure, and cardiac output were measured in chronically instrumented, conscious rats. RESULTS In Dahl-S, on both NaCl intakes, and in two-kidney, one-clip rats on a high NaCl diet, safflower oil had no effect on arterial pressure. In contrast, in two-kidney, one-clip rats fed the low NaCl diet, both indirect tail systolic blood pressures and direct mean arterial pressure were lower (p<0.01) in animals on the linoleic acid enriched diet; total peripheral resistance was also decreased (p<0.01). CONCLUSION Safflower oil has a hypotensive effect only in the two-kidney, one-clip rat on a low NaCl, but not on a high NaCl intake, and not in Dahl-S rats. Additional studies are required to identify the mechanism(s) for the hypotensive effect of safflower oil and to define the relationship of this animal study to human hypertension.
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Affiliation(s)
- S R Reddy
- Department of Medicine, Medical College of Wisconsin, Milwaukee 53226, USA
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Abstract
Hypertension is often associated with insulin resistance, and several chemically diverse agents that increase insulin sensitivity attenuate the development of experimental hypertension. We undertook the present study to determine whether attenuation of hypertension by pioglitazone, a thiazolidinedione derivative that increases insulin sensitivity without increasing insulin secretion, is specifically related to its effect on insulin-mediated glucose uptake. Pioglitazone administered daily by oral gavage (20 mg/kg per day) for 3 weeks attenuated the development of hypertension in both the Dahl salt-sensitive (DS) rat (an insulin-resistant model of hypertension) and the one-kidney, one clip rat (a model of hypertension not associated with insulin resistance). Based on euglycemic insulin clamp studies in conscious animals, the glucose clearance rate was increased (P < .05) in pioglitazone-treated DS rats (36 +/- 3 mg/kg per minute) compared with control DS rats (27 +/- 1 mg/kg per minute). However, pioglitazone did not affect the glucose clearance rate in one-kidney, one clip hypertensive rats. Metformin, an unrelated agent that also improves glucose tolerance, had no significant effect on blood pressure or glucose clearance rate in either DS or one-kidney, one clip rats. Thus, the hypotensive effect of pioglitazone is not invariably associated with its capacity to improve insulin-induced glucose utilization.
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Affiliation(s)
- H Y Zhang
- Department of Medicine, Medical College of Wisconsin, Milwaukee 53226
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Reddy SR, Watts DC. Hybridization of matrix-bound MM-creatine kinase with BB-creatine kinase and arginine kinase. Comp Biochem Physiol Biochem Mol Biol 1994; 108:73-8. [PMID: 8205393 DOI: 10.1016/0305-0491(94)90167-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Dimeric rabbit muscle creatine kinase (MM-CK) was bound to CNBr-activated Sepharose 4B by one of its subunits (MM-CKA). Treatment of MM-CKA with guanidine hydrochloride released the unbound subunit to yield the matrix-bound monomer (M-CKB). M-CKB recombined with dissociated MM-CK soluble subunits to reconstitute a matrix-bound dimer (MM-CKC). M-CKB also associated with dissociated subunits of BB-CK from crude extracts of rabbit brain and of arginine kinase from sea cucumber muscle (MM-AK) to form the matrix-bound heterohybrids MB-CKC and M-CK/M-AKC, respectively. Guanidine hydrochloride gradient elution studies showed that MM-CKA, MM-CKC and MB-CKC were all dissociated at the same concentration of the denaturant (0.96 M), while the M-CK/M-AKC heterohybrid was less stable, dissociating at 0.5 M. The specific interaction between subunits of echinoderm and mammalian phosphagen kinases to form a hybrid enzyme of dual substrate specificity supports the view that these enzymes had a common evolutionary origin.
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Affiliation(s)
- S R Reddy
- Department of Biochemistry, Guy's Hospital Medical School, London, U.K
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Dubey RK, Zhang HY, Reddy SR, Boegehold MA, Kotchen TA. Pioglitazone attenuates hypertension and inhibits growth of renal arteriolar smooth muscle in rats. Am J Physiol 1993; 265:R726-32. [PMID: 8238439 DOI: 10.1152/ajpregu.1993.265.4.r726] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hypertension is frequently associated with insulin resistance. We evaluated the effects of pioglitazone, an agent that increases insulin sensitivity, on the development of hypertension in the Dahl salt-sensitive (Dahl-S) rat and in the one-kidney, one-clip Sprague-Dawley rat. We also evaluated the effects of pioglitazone on growth of cultured preglomerular renal arteriolar smooth muscle cells. In Dahl-S rats fed a 3% NaCl diet, tail systolic blood pressures and direct arterial pressures were lower (P < 0.05) in pioglitazone-treated (20 mg/kg daily by gavage for 3 wk) than in control rats (n = 10 rats/group). In one-kidney, one-clip Sprague-Dawley rats, systolic blood pressures were also lower in pioglitazone-treated animals (P < 0.0001). In vitro, proliferation of arteriolar smooth muscle cells was stimulated (P < 0.01) by insulin, epidermal growth factor (EGF), and fetal calf serum (FCS); pioglitazone (5 microM) reversibly inhibited (P < 0.01) insulin-, EGF-, and FCS-induced proliferation. Pioglitazone (0.01-100 microM) also inhibited insulin- (1 mU/ml), EGF- (100 ng/ml), and 5% FCS-induced [3H]thymidine incorporation in a concentration-dependent manner (P < 0.01). Thus pioglitazone attenuated the development of hypertension in the Dahl-S rat and the one-kidney, one-clip rat. The ability of pioglitazone to inhibit growth of vascular smooth muscle may contribute to its hypotensive effect.
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Affiliation(s)
- R K Dubey
- Department of Medicine, School of Medicine, West Virginia University, Morgantown 26506
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Srikanth R, Rao AM, Khanum A, Reddy SR. Mercury contamination of groundwater around Hussain Sagar Lake. Bull Environ Contam Toxicol 1993; 51:96-98. [PMID: 8318780 DOI: 10.1007/bf00201006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- R Srikanth
- Department of Botany, Osmania University, Hyderabad, India
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Abstract
The molecular weight of arginase, determined by gel filtration of frog (Rana tigerina) liver and kidney extracts, varied with the protein concentration. It increased from about 25-27 KDa in dilute solutions to about 92-96 KDA in concentrated extracts. In addition, an arginase with a molecular weight of 45-49 KDA appeared at intermediate concentrations. The results suggest the probable aggregation of arginase monomers to yield the dimeric and tetrameric forms of the enzyme at high protein concentration in extracts.
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Abstract
In the rat, elevated arterial pressure is not consistently associated with obesity. The purpose of this study was to compare measurements of blood pressure, cardiac output, and total peripheral resistance in obese and lean Zucker rats on different NaCl intakes. Obese and lean rats drank either water or isotonic NaCl for 18 days. Tail systolic blood pressures of saline-drinking obese rats were higher than all other groups (p less than 0.05). NaCl intake did not affect blood pressure in lean rats, and blood pressures of water-drinking obese rats did not differ from those of lean controls. In a subsequent experiment, direct arterial pressures and cardiac outputs (thermodilution) were measured in separate groups of conscious rats that had been maintained on a 1% or 4% NaCl intake for 12 weeks. Arterial pressure was higher (p less than 0.01) in obese rats fed 4% NaCl (130 +/- 4 mm Hg) than in obese rats fed 1% NaCl (118 +/- 2 mm Hg) or than in lean rats fed either NaCl intake (118 +/- 3 mm Hg and 116 +/- 3 mm Hg, respectively). Cardiac output of obese rats was higher than that of lean rats (p less than 0.01); however, the NaCl-induced increase of blood pressure was accounted for by an increase of peripheral resistance (p less than 0.01). Thus, in contrast to the lean Zucker rat, arterial pressure of the obese Zucker rat is increased by a high dietary intake of NaCl.
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Affiliation(s)
- S R Reddy
- Department of Medicine, West Virginia University, School of Medicine, Morgantown
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Reddy SR, Kotchen TA. Hemodynamic effects of high dietary intakes of sodium or chloride in the Dahl salt-sensitive rat. J Lab Clin Med 1992; 120:476-82. [PMID: 1517694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the Dahl salt-sensitive (Dahl-S) rat, a high sodium without chloride diet (NaAA) and a chloride without sodium diet ("X"Cl) do not increase arterial pressure to the same extent as a high NaCl diet. To explain these differences, hemodynamic responses to acute volume expansion were compared in conscious Dahl-S and Dahl salt-resistant (Dahl-R) rats fed either 7% NaCl, NaAA, or "X"Cl diets for 5 weeks. Before acute volume expansion, on each of the three diets, mean arterial pressures and total peripheral resistances were higher (p less than 0.01) in Dahl-S than in Dahl-R rats, and in Dahl-S, arterial pressure was higher (p less than 0.05 or less) on the 7% NaCl intake than on the other two diets. No group differences were found in cardiac index (thermodilution). Right atrial pressure was also elevated (p less than 0.01) in Dahl-S rats on the 7% NaCl diet. In response to acute volume expansion, arterial pressure did not change, and the decrement of total peripheral resistance was greater in Dahl-S rats than in Dahl-R rats on each of the three diets (p less than 0.05 or less). Assuming that reductions of peripheral resistance in response to acute volume expansion reflect withdrawal of sympathetic tone, these results suggest that sympathetic tone is increased comparably on each of the diets in Dahl-S rats. As suggested by the increased right atrial pressure, higher arterial pressure induced by 7% NaCl may be related to an expanded intravascular volume in conjunction with increased neural activity.
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Affiliation(s)
- S R Reddy
- Department of Medicine, West Virginia University School of Medicine, Morgantown
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Abstract
Ornithine carbamoyltransferase (OCT) and arginase, but not arginine synthetase (AS), were detected in the body wall and gut tissues of the leech. The activities of these enzymes were not altered by starvation. The high activity of arginase in body wall is probably due to the association of the latter with botryoidal tissue. Hirudineans, which evolved from oligochaete ancestors, appear to have lost the citrulline-arginine segment of the urea cycle due to their ammonotelic mode of nitrogen excretion.
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Affiliation(s)
- S Natesan
- Department of Zoology, University of Poona, Pune, India
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Abstract
Scallop muscle arginine kinase binds to F-actin from mollusc and rabbit muscle in vitro. One site of interaction appears to be located in residues 305-325 of a C-terminal fragment (residues 285-375) of actin. The binding is hindered in the presence of arginine, Mg(2+)-ADP and NO3-, which form a dead-end complex with the enzyme. F-actin inhibits the enzyme activity non-competitively with respect to Mg(2+)-ATP. As a function of arginine concentration, the inhibition is of the mixed type, where Km is affected more than Vmax.
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Affiliation(s)
- S R Reddy
- Department of Zoology, University of Poona, Pune, India
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Abstract
We believe this is the first reported case of seminoma in a patient with the 48,XXYY variant form of Klinefelter's syndrome. Moreover, the seminoma in this patient occurred in a normally descended testis. We report this case because patients with 48,XXYY Klinefelter's syndrome are often confined to institutions, where the diagnosis of testicular tumor may not be recognized as readily.
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Affiliation(s)
- S R Reddy
- Department of Medicine, Louisiana State University School of Medicine, New Orleans 70112
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Kotchen TA, Blehschmidt NG, Reddy SR. Effect of dietary NaCl on norepinephrine turnover in the Dahl rat. J Lab Clin Med 1991; 117:383-9. [PMID: 2019793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To evaluate neural mechanisms in salt-sensitive hypertension, norepinephrine turnover rates were measured in peripheral tissues and selected brain areas of Dahl salt-sensitive and salt-resistant rats receiving either 1% or 7% NaCl diets for 5 weeks. Norepinephrine turnover was determined by measuring tissue norepinephrine in untreated animals or in separate groups killed 2, 4, 6, and 10 hours after alpha-methyl-tyrosine. Plasma volume (radiolabeled albumin) was also measured. Arterial pressure of Dahl S rats receiving 7% NaCl (167 +/- 4 mm Hg) was higher (p less than 0.001) than that of Dahl S rats receiving 1% NaCl (141 +/- 3mm Hg), which was higher (p less than 0.001) than that of Dahl R rats receiving both NaCl intakes. Norepinephrine turnover was increased (p less than 0.01) by 7% NaCl in both heart and brown adipose tissue in Dahl S rats, whereas norepinephrine turnover in Dahl R rats was decreased (p less than 0.01) by the 7% NaCl intake in the heart and kidney. On the high NaCl intake, norepinephrine turnover in heart and adipose tissue was lower (p less than 0.05) in Dahl R rats than in Dahl S rats. In brain stem tissue, with the 1% NaCl diet, norepinephrine turnover was higher (p less than 0.001) in Dahl S rats than in Dahl R rats, and norepinephrine turnover was inhibited (p less than 0.001) by the high NaCl intake in Dahl S rats but not in Dahl R rats. In posterior hypothalamus, norepinephrine turnover was inhibited (p less than 0.01) by the high NaCl intake in Dahl R rats but not in Dahl S rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T A Kotchen
- Department of Medicine, West Virginia University School of Medicine, Morgantown 26506
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Reddy SR, Roustan C, Benyamin Y. Purification and properties of two molecular forms of arginine kinase from the adductor muscle of the scallop, Pecten maximus. Comp Biochem Physiol B 1991; 99:387-94. [PMID: 1764917 DOI: 10.1016/0305-0491(91)90059-m] [Citation(s) in RCA: 8] [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] [Indexed: 12/28/2022]
Abstract
1. Two molecular forms of arginine kinase, AK1 and AK2 have been purified from the adductor muscle of the scallop, Pecten maximus. AK2 was retained on a DEAE-cellulose column at pH 7.5, but AK1 was not. 2. Both forms were monomeric (mol. wt. approximately 42,000) and showed the same pH optimum (7.5-8.0) in the direction of phosphoarginine synthesis. 3. AK1 had slower electrophoretic mobility at pH 8.3 towards the anode, higher lysine content, lower glutamate content, lower Km for L-arginine and higher Km for Mg(2+)-ATP than AK2. Unlike AK1, AK2 was strongly inhibited at high concentrations of Mg(2+)-ATP. 4. Both molecular forms cross-reacted with antisera raised against native as well as performic acid-oxidized lobster muscle arginine kinase. However, AK1 showed a greater affinity than AK2 to anti-lobster arginine kinase antibodies, particularly to those raised against the native enzyme.
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Affiliation(s)
- S R Reddy
- UPR 8402 Centre de Recherches de Biochimie Macromoléculaire (CNRS), U 249 INSERM, Université de Montpellier I, France
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Ghegadmal CK, Natesan S, Reddy SR. Allantoin excretion in snakes. Indian J Exp Biol 1989; 27:1008-9. [PMID: 2620928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Allantoin, which is generally regarded as absent in the excreta of snakes, has been demonstrated in the urinary deposits of 7 species of snakes by a sensitive paper chromatographic method. It appears that allantoin is the end product of purine catabolism in these animals.
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Abstract
High dietary intake of linoleic acid lowers arterial pressure, and, in vitro, linoleic acid inhibits the enzymatic activity of renin. The purpose of the present study was 1) to evaluate the effect of intravenous infusion of linoleic acid on blood pressure in normotensive and hypertensive Sprague-Dawley rats and 2) to determine whether the hypotensive response to linoleic acid infusion is caused by inhibition of circulating renin. Blood pressure was decreased (P less than 0.01) by linoleic acid infusion in normotensive sodium chloride-deprived animals and in animals with two-kidney, one-clip hypertension. In contrast, linoleic acid infusion did not affect blood pressure in normotensive rats on a "normal" or high sodium chloride intake, in rats with deoxycorticosterone acetate (DOCA)-salt hypertension, and in anephric rats. In sodium chloride-deprived rats, the reduction of blood pressure by linoleic acid infusion was associated with increased plasma renin activity (P less than 0.05); serum angiotensin-converting enzyme activity was unchanged. The in vitro enzymatic activity of exogenous renin in plasma of anephric rats was not affected by linoleic acid infusion. In two-kidney, one-clip hypertensive animals, pretreatment with indomethacin did not alter the hypotensive response to linoleic acid. Thus, although linoleic acid infusion lowered blood pressure in high renin but not in low renin states, the reduction of blood pressure was not related to inhibition of circulating renin or to alterations of endogenous prostaglandin biosynthesis.
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Affiliation(s)
- S R Reddy
- Department of Medicine, West Virginia University School of Medicine, Morgantown 26506
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Abstract
The in vitro and in vivo effects of aldrin, dieldrin, and endrin on calmodulin regulated Ca2+-pump activity in rat brain synaptosomes and heart sarcoplasmic reticulum were investigated. All the 3 cyclodiene compounds inhibited both brain synaptosomal and heart sarcoplasmic reticulum Ca2+-pump activity in vitro in a concentration dependent manner. Calmodulin depleted Ca2+-pump activity was insensitive to the action of toxic compounds. Oral administration of pesticides (0.5-10 mg/kg) to rats similarly decreased the Ca2+-pump activity, in addition to decreasing the levels of calmodulin of both brain and heart thus indicating disruption in membrane Ca2+ transport mechanisms. Exogenous addition of calmodulin (1-20 micrograms) could effectively reverse the pesticide induced inhibition. Ca2+-pump activity is more sensitive to the 3 cyclodiene compounds in brain than in heart. The results of the present study indicate that the cyclodiene compounds may produce neurotoxic effects by altering calmodulin regulated calcium dependent events in neurons.
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Affiliation(s)
- B D Mehrotra
- Department of Chemistry, Tougaloo College, MS 39174
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Genain CP, Reddy SR, Ott CE, Van Loon GR, Kotchen TA. Failure of salt loading to inhibit tissue norepinephrine turnover in prehypertensive Dahl salt-sensitive rats. Hypertension 1988; 12:568-73. [PMID: 3203961 DOI: 10.1161/01.hyp.12.6.568] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To determine if alterations of electrolyte balance or sympathetic nervous system activity are present in Dahl salt-sensitive rats (DS) before the onset of hypertension, we compared electrolyte balances, extracellular fluid volume (inulin space), plasma volume (radiolabeled albumin), and norepinephrine turnover in peripheral tissues (heart and interscapular brown fat) in prehypertensive DS and Dahl salt-resistant rats (DR). Animals were maintained for 5 to 7 days on either a "normal" or high NaCl diet. Tissue norepinephrine turnover was evaluated by measuring the rate at which norepinephrine content decreased following tyrosine hydroxylase inhibition with alpha-methyl-p-tyrosine. Blood pressure was higher (p less than 0.05) in DS (135 +/- 2 [SE] mm Hg) than in DR (129 +/- 2 mm Hg) and was not affected by the diets. Extracellular fluid volume and net Na+ and Cl- balances did not differ between DS and DR. However, plasma volume was greater in DS than in DR (p less than 0.05). In both fat and heart, norepinephrine turnover was decreased by dietary NaCl loading in DR (p less than 0.01), but not in DS. Thus, the tendency of the DS to become hypertensive with high NaCl intake may be related to the combined effects of an increased plasma volume and the failure of high dietary NaCl to inhibit peripheral sympathetic nervous system activity.
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Affiliation(s)
- C P Genain
- Department of Medicine, University of Kentucky School of Medicine, Lexington
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Subrahmanyam TS, Reddy SR. L-ornithine and L-lysine need their alpha-carboxyl groups for effective inhibition of bovine liver arginase. Indian J Biochem Biophys 1986; 23:359-61. [PMID: 3110050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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45
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Abstract
Kidney transamidinase activity in the lizard (Calotes versicolor), like that in the mouse, showed the pH optimum at 7.4. The lizard enzyme was inhibited to a greater degree than the mouse enzyme at high concentrations (greater than 20 mM) of L-arginine and glycine. Kidney and liver in the lizard and kidney and pancreas in the mouse were the tissues with high transamidinase activity. While transamidinase activity was widely distributed in mouse tissues, the enzyme was found to be restricted only to a few tissues in the lizard. Hydrocortisone administration into male lizards did not significantly alter the transamidinase levels in kidney and liver.
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Reddy SR, Reddy SM. Laboratory evaluation of aureofungin against some phytopathogenic fungi. Hindustan Antibiot Bull 1984; 26:105-6. [PMID: 6533136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Venkatakrishnan G, Reddy SR. A comparative polyacrylamide gel electrophoretic study of arginase in vertebrate tissues. Enzyme 1983; 29:145-52. [PMID: 6851990 DOI: 10.1159/000469626] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The electrophoretic behaviour of arginase in the tissue extracts of rat, beef, lizard and frog was studied by bidirectional polyacrylamide gel electrophoresis. The enzyme from rat liver and submaxillary gland migrated to the cathode with the activity concentrated in a single peak. Arginase from beef liver emerged as a single peak of anodal migration with a significant shoulder in the sample gel. Frog liver and kidney enzymes also appeared as single peaks with a distinct anodal movement. The activity in mammalian kidney and lizard liver and kidney resolved into two peaks of anodal migration suggesting the presence of two isoenzymes of arginase in these tissues.
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Reddy SR, Watts DC. Inhibition of creatine kinase by iodoalkanes. Further appraisal of the essential nature of the reactive thiol group. Biochim Biophys Acta 1979; 569:109-13. [PMID: 37913 DOI: 10.1016/0005-2744(79)90086-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Creating kinase (ATP: creatine N-phosphotransferase) is completely inhibited by low molecular weight iodoalkanes in a pseudo first order reaction. Analysis of this and other data suggests that covalent modification per se is not a sufficient criterion to establish whether or not an enzyme group is essential for catalysis.
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