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Rajput S, Sahoo RK, Sarkar N, Nembenna S. Gallium Hydride-Catalyzed Selective Hydroboration of Unsaturated Organic Substrates. Chempluschem 2024:e202300737. [PMID: 38437065 DOI: 10.1002/cplu.202300737] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/04/2024] [Accepted: 03/04/2024] [Indexed: 03/06/2024]
Abstract
The first examples of tetrasubstituted conjugated bis-guanidinate (CBG) supported monomeric and thermally stable gallium dihalides [LGaX2], (X=Cl (Ga-Cl), I (Ga-I)) and dihydride (Ga-H) [LGaH2] (where L={(ArHN)(ArN)-C=N-C=(NAr)(NHAr)}; Ar=2,6-Et2-C6H3) compounds are reported. The reaction of in situ generated LLi with 1.0 equiv. GaX3 (X=Cl, I) afforded compounds Ga-Cl and Ga-I. The reaction between Ga-Cl and Li[HBEt3] in benzene yielded the dihydride compound Ga-H. All reported compounds (Ga-Cl, Ga-I, and Ga-H) were characterized by NMR, HRMS, and single-crystal X-ray diffraction studies. Ga-H was probed for the hydroboration of carbodiimides (CDI), isocyanates, and isothiocyanates with HBpin. Compound Ga-H was also found effective for the catalytic hydroboration of imines, nitriles, alkynes, esters, and formates, affording the corresponding products in quantitative yields. Stoichiometric reactions with a CDI were performed to establish the catalytic cycle.
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Affiliation(s)
- Sagrika Rajput
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
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2
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Patro AG, Sahoo RK, Nembenna S. Zinc hydride catalyzed hydroboration of esters. Dalton Trans 2024; 53:3621-3628. [PMID: 38289250 DOI: 10.1039/d3dt04084d] [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: 02/21/2024]
Abstract
The conjugated bis-guanidinate (CBG)-supported zinc hydride {LZnH}2; L = {(ArHN)(ArN)-CN-C(NAr)(NHAr); Ar = 2,6-Et2-C6H3} (I) is utilized as a catalyst for the hydroboration of esters with pinacolborane (HBpin) under mild reaction conditions. Various aryl and alkyl substrates containing electron-donating, withdrawing, and cyclic groups of esters are effectively converted into alkoxy boronate esters as products upon hydroboration. Furthermore, stoichiometric experiments have been performed to understand the plausible reaction mechanism for the hydroboration of esters. Additionally, complex (I) was used for the hydroboration of carbonate, carboxylic acid, and anhydride substrates to showcase the broad substrate scope.
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Affiliation(s)
- A Ganesh Patro
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI) Bhubaneswar, 752050, India.
| | - Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI) Bhubaneswar, 752050, India.
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI) Bhubaneswar, 752050, India.
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Sahoo RK, Nembenna S. Zinc-Catalyzed Chemoselective Reduction of Nitriles to N-Silylimines through Hydrosilylation: Insights into the Reaction Mechanism. Inorg Chem 2023. [PMID: 37481732 DOI: 10.1021/acs.inorgchem.3c00309] [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: 07/25/2023]
Abstract
The N,N'-chelated conjugated bis-guanidinate (CBG) supported zinc hydride (Zn-1) pre-catalyzed highly challenging chemoselective mono-hydrosilylation of a wide range of nitriles to exclusive N-silylimines and/or N,N'-silyldiimines is reported. Furthermore, the effectiveness of pre-catalyst Zn-1 is compared with another pre-catalyst analogue, i.e., DiethylNacNac zinc hydride (Zn-2), to know the ligand effect. We observed that pre-catalyst Zn-1 shows high efficiency and better selectivity than pre-catalyst Zn-2 for reducing nitriles to N-silylimines. Mechanistic studies indicate the insertion of the C≡N bond of nitrile into Zn-H to form the zinc vinylidenamido complexes (Zn-1' and Zn-2'). The active catalysts Zn-1' and Zn-2' are confirmed by NMR, mass spectrometry, and single-crystal X-ray diffraction analyses. A most plausible catalytic cycle has been explored depending on stoichiometric experiments, active catalysts isolation, and in situ studies. Moreover, the synthetic utility of this protocol was demonstrated.
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Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
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4
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Sahoo RK, Patro AG, Sarkar N, Nembenna S. Zinc Catalyzed Hydroelementation (HE; E = B, C, N, and O) of Carbodiimides: Intermediates Isolation and Mechanistic Insights. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Arukela Ganesh Patro
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
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Sarkar N, Kumar Sahoo R, Nembenna S. Aluminium-Catalyzed Selective Hydroboration of Esters and Epoxides to Alcohols: C-O Bond Activation. Chemistry 2023; 29:e202203023. [PMID: 36226774 DOI: 10.1002/chem.202203023] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Indexed: 11/07/2022]
Abstract
In this work, the molecular aluminium dihydride complex bearing an N, N'-chelated conjugated bis-guanidinate (CBG) ligand is used as a catalyst for reducing a wide range of aryl and alkyl esters with good tolerance of alkene (C=C), alkyne (C≡C), halides (Cl, Br, I and F), nitrile (C≡N), and nitro (NO2 ) functionalities. Further, we investigated the catalytic application of aluminium dihydride in the C-O bond cleavage of alkyl and aryl epoxides into corresponding branched Markovnikov ring-opening products. In addition, the chemoselective intermolecular reduction of esters over other reducible functional groups, such as amides and alkenes, has been established. Intermediates are isolated and characterized by NMR and HRMS studies, which confirm the probable catalytic cycles for the hydroboration of esters and epoxides.
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Affiliation(s)
- Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
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6
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Sahoo RK, Sarkar N, Nembenna S. Intermediates, Isolation and Mechanistic Insights into Zinc Hydride-Catalyzed 1,2-Regioselective Hydrofunctionalization of N-Heteroarenes. Inorg Chem 2023; 62:304-317. [PMID: 36571301 DOI: 10.1021/acs.inorgchem.2c03389] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The conjugated bis-guanidinate-supported zinc hydride [{LZnH}2; L = {(ArHN) (ArN)-C═N-C═(NAr) (NHAr); Ar = 2,6-Et2-C6H3}] (I)-catalyzed highly demanding exclusive 1,2-regioselective hydroboration and hydrosilylation of N-heteroarenes is demonstrated with excellent yields. This protocol is compatible with many pyridines and N-heteroarene derivatives, including electron-donating and -withdrawing substituents. Catalytic intermediates, such as [(LZnH) (4-methylpyridine)] IIA, [(L'ZnH) (4-methylpyridine) IIA', where L' = CH{(CMe) (2,6-Et2C6H3N)}2)], LZn(1,2-DhiQ) (isoquinoline) III, [L'Zn(1,2-DhiQ) (isoquinoline)] III', and LZn(1,2-(3-MeDHQ)) (3-methylquinoline) V, were isolated and thoroughly characterized by NMR, HRMS, and IR analyses. Furthermore, X-ray single-crystal diffraction studies confirmed the molecular structures of compounds IIA', III, and III'. The NMR data proved that the intermediate III or III' reacted with HBpin and gave a selective 1,2-addition hydroborated product. Stoichiometric experiments suggest that V and III independently reacted with silane, yielding selective 1,2-addition of mono- and bis-hydrosilylated products, respectively. Based on the isolation of intermediates and a series of stoichiometric experiments, plausible catalytic cycles were established. Furthermore, the intermolecular chemoselective hydroboration reaction over other reducible functionalities was studied.
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Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, Odisha 752 050, India
| | - Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, Odisha 752 050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, Odisha 752 050, India
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Sarkar N, Sahoo RK, Nembenna S. Aluminum‐Catalyzed Selective Reduction of Heteroallenes Through Hydroboration: Amide/Thioamide/Selenoamide Bond Construction and C=X (X= O, S, Se) Bond Activation. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Nabin Sarkar
- NISER: National Institute of Science Education and Research School of Chemical Sciences INDIA
| | - Rajata Kumar Sahoo
- NISER: National Institute of Science Education and Research School of Chemical Sciences INDIA
| | - Sharanappa Nembenna
- National Institute of Science Education and Research (NISER) School of Chemical Sciences Jatni CampusNISER, BhubaneswarINDIA 752050 Bhubaneswar INDIA
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8
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Nayak DK, Sarkar N, Sampath CM, Sahoo RK, Nembenna S. Organoaluminum Catalyzed Guanylation and Hydroboration Reactions of Carbodiimides. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Deepak Kumar Nayak
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Nabin Sarkar
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Chabathula Manoj Sampath
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Rajata Kumar Sahoo
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Sharanappa Nembenna
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
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9
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Khuntia AP, Sarkar N, Patro AG, Sahoo RK, Nembenna S. Germanium Hydride Catalyzed Selective Hydroboration and Cyanosilylation of Ketones. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anwesh Prasad Khuntia
- National Institute of Science Education and Research School of Chemical Sciences SCS NISERbhubaneswar 752050 bhubaneswar INDIA
| | - Nabin Sarkar
- National Institute of Science Education and Research School of Chemical Sciences INDIA
| | - A Ganesh Patro
- National Institute of Science Education and Research School of Chemical Sciences SCS NISERbhubaneswar 752050 bhubaneswar INDIA
| | - Rajata Kumar Sahoo
- National Institute of Science Education and Research School of Chemical Sciences SCS NISERbhubaneswar 752050 bhubaneswar INDIA
| | - Sharanappa Nembenna
- National Institute of Science Education and Research (NISER) School of Chemical Sciences Jatni CampusNISER, BhubaneswarINDIA 752050 Bhubaneswar INDIA
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10
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Sarkar N, Kumar Sahoo R, Ganesh Patro A, Nembenna S. Aluminum-Catalyzed Selective Hydroboration of Carbonyls and Dehydrocoupling of Alcohols, Phenols, Amines, Thiol, Selenol, Silanols with HBpin. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Sarkar N, Sahoo RK, Mukhopadhyay S, Nembenna S. Organoaluminum Cation Catalyzed Selective Hydrosilylation of Carbonyls, Alkenes, and Alkyne. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202101030] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nabin Sarkar
- National Institute of Science Education and Research School of Chemical Sciences SCS NISERbhubaneswar 752050 bhubaneswar INDIA
| | - Rajata Kumar Sahoo
- National Institute of Science Education and Research School of Chemical Sciences SCS NISERbhubaneswar 752050 bhubaneswar INDIA
| | - Sayantan Mukhopadhyay
- National Institute of Science Education and Research School of Chemical Sciences SCS NISERbhubaneswar 752050 bhubaneswar INDIA
| | - Sharanappa Nembenna
- National Institute of Science Education and Research (NISER) School of Chemical Sciences Jatni CampusNISER, BhubaneswarINDIA 752050 Bhubaneswar INDIA
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12
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Sahoo RK, Rajput S, Patro AG, Nembenna S. Synthesis of low oxidation state zinc(I) complexes and their catalytic studies in dehydroborylation of terminal alkynes. Dalton Trans 2022; 51:16009-16016. [DOI: 10.1039/d2dt02846h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new example of structurally characterized conjugated bis-guanidinate (CBG) supported zinc (I) dimer, i.e., LZnZnL (3) (L = {(ArNH)(ArN)–C=N–C=(NAr)(NHAr)}; Ar = 2,6-Et2-C6H3)) with a Zn-Zn bond is reported. Moreover, homoleptic...
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Sahoo RK, Sarkar N, Nembenna S. Zinc Hydride Catalyzed Chemoselective Hydroboration of Isocyanates: Amide Bond Formation and C=O Bond Cleavage. Angew Chem Int Ed Engl 2021; 60:11991-12000. [PMID: 33638314 DOI: 10.1002/anie.202100375] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [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: 01/09/2021] [Revised: 02/16/2021] [Indexed: 12/15/2022]
Abstract
Herein, a remarkable conjugated bis-guanidinate (CBG) supported zinc hydride, [{LZnH}2 ; L={(ArHN)(ArN)-C=N-C=(NAr)(NHAr); Ar=2,6-Et2 -C6 H3 }] (I) catalyzed partial reduction of heteroallenes via hydroboration is reported. A large number of aryl and alkyl isocyanates, including electron-donating and withdrawing groups, undergo reduction to obtain selectively N-boryl formamide, bis(boryl) hemiaminal and N-boryl methyl amine products. The compound I effectively catalyzes the chemoselective reduction of various isocyanates, in which the construction of the amide bond occurs. Isocyanates undergo a deoxygenation hydroboration reaction, in which the C=O bond cleaves, leading to N-boryl methyl amines. Several functionalities such as nitro, cyano, halide, and alkene groups are well-tolerated. Furthermore, a series of kinetic, control experiments and structurally characterized intermediates suggest that the zinc hydride species are responsible for all reduction steps and breaking the C=O bond.
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Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
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14
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Abstract
Three new dimeric bis-guanidinate zinc(II) alkyl, halide, and hydride complexes [LZnEt]2 (1), [LZnI]2 (2) and [LZnH]2 (3) were prepared. Compound 3 was successfully employed for the hydrosilylation and hydroboration of a vast number of ketones. The catalytic performance of 3 in the hydroboration of acetophenone exhibits a turnover frequency, reaching up to 5800 h-1, outperforming that of reported zinc hydride catalysts. Notably, both intra- and intermolecular chemoselective hydrosilylation and hydroboration reactions have been investigated.
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Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Mamata Mahato
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Achintya Jana
- Undergraduate Programme, Indian Institute of Science, Bangalore 560 012, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
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Abstract
Plantar fasciitis (PF) is a distressing condition experienced by many patients. Although self-limiting, it tends to become a chronic ailment if the precipitating factors are not addressed. One of the modality of treating PF is intra-lesional corticosteroid injection. This was done using palpation technique earlier but nowadays many specialists use ultrasound (US) imaging as a guide to give injection accurately instead of inadvertently damaging the plantar fascia or injecting into surrounding soft tissue, both of which can have serious implications. We did a literature search in Medline, Scopus, and Embase databases to find out articles describing US-guided corticosteroid injection for treating PF and whether guided injection was effective than injection given by palpation.
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Affiliation(s)
- A S Nair
- Department of Anesthesiology and Pain Management, Citizens Hospital, Hyderabad, Telangana, India
| | - R K Sahoo
- Department of Anesthesiology and Pain Management, Citizens Hospital, Hyderabad, Telangana, India
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Sarangi GS, Sahoo RK, Mohanty S, Mohapatra D. Resolution of tubercular abscess with antitubercular treatment. Indian J Tuberc 2014; 61:336-339. [PMID: 25675698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Tubercular brain abscess is a rare manifestation of neurotuberculosis. Large brain absceses are usually surgically treated. We report a case of tubercular brain abscesses in left cerebellar hemisphere and right parietal lobe in a child who was treated surgically for the cerebellar abscess and conservatively with antitubercular drug for parietal abscess. The patient showed significant clinical improvement and healing of brain abscess on follow up imaging. The resolution of relatively large abscess by conservative management with antitubercular treatment is very rare.
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Sahoo RK, Jacob C. The effect of growth temperature variation on partially bismuth filled carbon nanotubes synthesis using a soft semi-metallic template. J Nanosci Nanotechnol 2014; 14:4595-4601. [PMID: 24738435 DOI: 10.1166/jnn.2014.8246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The dewetting of a low melting point metal thin film deposited on silicon substrates was studied. The experimental results suggest that the change in the growth temperature affects the nanostructures that form. Based on the experimental results, the temperature which yielded the smallest features for the growth of nanotubes is determined. The mechanism by which these nano-templates become an efficient seeds for the growth of the carbon nanotubes is discussed. The partial bismuth filling inside the CNTs was optimized. Based on the results, a schematic growth model for better understanding of the process parameters has also been proposed.
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Sahoo RK, Subudhi E, Kumar M. Quantitative approach to track lipase producing Pseudomonas sp. S1 in nonsterilized solid state fermentation. Lett Appl Microbiol 2014; 58:610-6. [PMID: 24527988 DOI: 10.1111/lam.12235] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [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: 10/17/2013] [Revised: 02/10/2014] [Accepted: 02/10/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED Proliferation of the inoculated Pseudomonas sp. S1 is quantitatively evaluated using ERIC-PCR during the production of lipase in nonsterile solid state fermentation an approach to reduce the cost of enzyme production. Under nonsterile solid state fermentation with olive oil cake, Pseudomonas sp. S1 produced 57·9 IU g(-1) of lipase. DNA fingerprints of unknown bacterial isolates obtained on Bushnell Haas agar (BHA) + tributyrin exactly matched with that of Pseudomonas sp. S1. Using PCR-based enumeration, population of Pseudomonas sp. S1 was proliferated from 7·6 × 10(4) CFU g(-1) after 24 h to 4·6 × 10(8) CFU g(-1) after 96 h, which tallied with the maximum lipase activity as compared to control. Under submerged fermentation (SmF), Pseudomonas sp. S1 produced maximum lipase (49 IU ml(-1) ) using olive oil as substrate, while lipase production was 9·754 IU ml(-1) when Pseudomonas sp. S1 was grown on tributyrin. Optimum pH and temperature of the crude lipase was 7·0 and 50°C. Crude enzyme activity was 71·2% stable at 50°C for 360 min. Pseudomonas sp. S1 lipase was also stable in methanol showing 91·6% activity in the presence of 15% methanol, whereas 75·5 and 51·1% of activity were retained in the presence of 20 and 30% methanol, respectively. Thus, lipase produced by Pseudomonas sp. S1 is suitable for the production of biodiesel as well as treatment of oily waste water. SIGNIFICANCE AND IMPACT OF STUDY This study presents the first report on the production of thermophilic organic solvent tolerant lipase using agro-industry waste in nonsterile solid state fermentation. Positive correlation between survival of Pseudomonas sp. S1 and lipase production under nonsterile solid state fermentation was established, which may emphasize the need to combine molecular tools and solid state fermentation in future studies. Our study brings new insights into the lipase production in cost-effective manner, which is an industrially relevant approach.
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Affiliation(s)
- R K Sahoo
- Centre of Biotechnology, Siksha O Anusandhan University, Bhubaneswar, India
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19
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Dutta TK, Sujatha S, Sahoo RK. Anthrax--update on diagnosis and management. J Assoc Physicians India 2011; 59:573-578. [PMID: 22334971] [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: 05/31/2023]
Abstract
Human anthrax is difficult to contain. This is primarily because it is a zoonotic disease and the disease has never been contained in the livestock of India due to lack of adequate vaccination facilities. Animal anthrax is very common in many parts of India. The problem of anthrax is further compounded by lack of awareness on the part of village folk who unwittingly handle the hide and share the dead animal meat and this causes cutaneous and gastrointestinal forms of anthrax respectively. Hemorrhagic meningitis and pulmonary anthrax, the other forms of anthrax, carry a risk of nearly cent percent mortality. Characteristic gram positive rods abundantly found in the smear of the cerebrospinal fluid, blood etc. make diagnosis certain in most of the cases. Resistance to penicillin, the drug of choice, now being occasionally reported, may become a confounding factor while attempting successful control of the disease. Other antibiotics which are found to be very effective are doxycycline and ciprofloxacin. Fear of use of anthrax spores as a biological weapon has also given a new dimension to the problem.
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Affiliation(s)
- T K Dutta
- Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry 605006
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20
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Abstract
Analyses of calcium, magnesium, sulphur, potassium and phosphorus content of the eggshell, yolk-albumen and embryos of olive ridley turtle, Lepidochelys olivacea, have been carried out at various stages of embryonic development. Calcium is the major inorganic constituent in the egg (shell and yolk-albumen) and embryos. Other elements are present either in trace or in minute trace amounts. The egg contents (yolk and albumen) provide only 40% of the embryonic calcium requirement of the hatchling. The remaining 60% is provided by the eggshell. The eggshell also undergoes a similar reduction in its calcium content from laying to hatching. Elements other than calcium present in the yolk-albumen are sufficient for normal embryonic development. The movement of calcium from the eggshell to the embryo starts at about the 40th day of development at 29.5 degrees C. Birds, turtles and crocodiles use their eggshell as the secondary source of embryonic calcium requirement. This dependence on the eggshell varies in different groups which is highest in birds and lowest in crocodiles.
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Affiliation(s)
- G Sahoo
- Regional Research Laboratory, Bhubaneswar, India
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Sahoo G, Mohapatra BK, Sahoo RK, Mohanty-Hejmadi P. Ultrastructure and characteristics of eggshells of the olive ridley turtle (Lepidochelys olivacea) from Gahirmatha, India. Acta Anat (Basel) 1996; 156:261-7. [PMID: 9078397 DOI: 10.1159/000147854] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The structure of a chelonian eggshell is of prime importance for the developing embryo. It acts as a protective covering as well as mediator in the exchange of heat and water. The fresh eggshell of the olive ridley (Lepidochelys olivacea) turtle displays a variety of structural forms in their aragonite framework. Its netted substrate, loose texture and poorly organised crystallites favour the easy exchange of air and water during its development. The shell consists mostly of calcium in carbonate form and K, Mg, Fe, Ni, Pb, Zn, Co, Cr, Cu, Mn and Cd in traces. Ba and Sr in traces are also a feature of the thermal analysis graph. Phosphorous was not detected in the shell and its absence eliminates an earlier suggestion of it being a key factor in the development of aragonite crystals in the inorganic structure of marine turtle eggshells. Its combustion characteristics, which have not been previously reported, are recorded.
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Affiliation(s)
- G Sahoo
- Regional Research Laboratory, Bhubaneswar, India
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Sahoo RK, Panda AR, Nath A. Magnetic moments and charge radii of decuplet baryons in a field-theoretic quark model. Int J Clin Exp Med 1995; 52:4099-4105. [PMID: 10019634 DOI: 10.1103/physrevd.52.4099] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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