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Uddandrao VVS, Brahma Naidu P, Chandrasekaran P, Saravanan G. Pathophysiology of obesity-related infertility and its prevention and treatment by potential phytotherapeutics. Int J Obes (Lond) 2024; 48:147-165. [PMID: 37963998 DOI: 10.1038/s41366-023-01411-4] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND Obesity is a complex multifactorial disease in which the accumulation of excess body fat has adverse health effects, as it can increase the risk of several problems, including infertility, in both men and women. Obesity and infertility have risen together in recent years. Against this background, the present review aims to highlight the impact of obesity on infertility and the underlying pathophysiology of obesity-related infertility (ORI) in men and women, and to provide readers with knowledge of current trends in the effective development of phytotherapeutics for its treatment. METHODS We thoroughly searched in PubMed, MEDLINE, Scopus, EMBASE, and Google Scholar to find all relevant papers on ORI and the therapeutic effects of phytotherapeutics on ORI in men and women. RESULTS The extensive search of the available literature revealed that obesity affects reproductive function through several complex mechanisms such as hyperlipidaemia, hyperinsulinaemia, hyperandrogenism, increased body mass index, disruption of the hormonal milieu, systemic inflammation, oxidative stress, alterations in epigenetics and dysbiosis. On the other hand, several studies reported that phytotherapeutics has a broad therapeutic spectrum of action by improving sex hormone homeostasis, ovarian dysfunction, menstrual cycle and inhibiting ovarian hyperplasia, as well as down-regulating ovarian apoptosis, inflammation and oxidative stress, and controlling metabolic dysfunction in obese women. Male infertility is also addressed by phytotherapeutics by suppressing lipogenesis, increasing testosterone, 3β-HSD and 17β-HSD levels, improving sperm parameters and attenuating testicular dyslipidaemia, oxidative stress, inflammation and germ cell apoptosis. CONCLUSIONS In the present review, we discussed the effects of obesity on reproductive dysfunction in men and women and the underlying pathophysiology of ORI. In addition, the therapeutic effect of phytotherapeutics against ORI was highlighted.
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Affiliation(s)
- V V Sathibabu Uddandrao
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Namakkal District, 637215, Tamilnadu, India.
| | - Parim Brahma Naidu
- Department of Animal Physiology and Biochemistry, National Animal Resource Facility for Biomedical Research (ICMR-NARFBR), Hyderabad, Telangana, 500078, India
| | - P Chandrasekaran
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Namakkal District, 637215, Tamilnadu, India
| | - G Saravanan
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Namakkal District, 637215, Tamilnadu, India
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Tamilmani P, Sathibabu Uddandrao VV, Chandrasekaran P, Saravanan G, Brahma Naidu P, Sengottuvelu S, Vadivukkarasi S. Linalool attenuates lipid accumulation and oxidative stress in metabolic dysfunction-associated steatotic liver disease via Sirt1/Akt/PPRA-α/AMPK and Nrf-2/HO-1 signaling pathways. Clin Res Hepatol Gastroenterol 2023; 47:102231. [PMID: 37865226 DOI: 10.1016/j.clinre.2023.102231] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
INTRODUCTION Linalool is a monoterpene that occurs naturally in various aromatic plants and is identified in our previous study as a potential candidate for protection against high-fat diet (HFD)-induced metabolic dysfunction-associated steatotic liver disease (MASLD). However, little is known about its direct effects on hepatic lipid metabolism and oxidative stress. Therefore, this study aims to investigate the therapeutic effect of linalool against MASLD and the underlying mechanism. METHODS To establish a rat model of MASLD, male Wistar rats were fed HFD for 16 weeks and orally administered linalool (100 mg/kg body weight) for 45 days starting from week 14. RESULTS Linalool significantly reduced HFD-induced liver lipid accumulation and restored altered adipokine levels. Mechanistically, linalool downregulated the mRNA expression of sterol regulatory element binding protein 1 and its lipogenesis target genes fatty acid synthase and acetyl-CoA carboxylase, and upregulated the mRNA expression of genes involved in fatty acid oxidation (peroxisome proliferator-activated receptor (PPAR)-alpha [PPAR-α], lipoprotein lipase and protein kinase B [Akt]) as well as the upstream mediators sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK) in the liver of MASLD rats. In addition, linalool also curbed oxidative stress by increasing antioxidant enzymes and activating nuclear erythroid-2-related factor 2 (Nrf-2) and its downstream target genes involved in antioxidant properties. CONCLUSION Therefore, this study concludes that linalool attenuates lipid accumulation in the liver by inhibiting de novo lipogenesis, promoting fatty acid oxidation, and attenuating oxidative stress by regulating Sirt1/Akt/PPRA-α/AMPK and Nrf-2/ HO-1 signaling pathways.
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Affiliation(s)
- P Tamilmani
- Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Namakkal District, Tiruchengode, Tamil Nadu 637215, India; Department of Biochemistry, PGP College of Arts and Science, Namakkal, Tamil Nadu 637207, India; Department of Biochemistry, Muthayammal College of Arts and Science, Rasipuram, Tamil Nadu 637408, India
| | - V V Sathibabu Uddandrao
- Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Namakkal District, Tiruchengode, Tamil Nadu 637215, India
| | - P Chandrasekaran
- Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Namakkal District, Tiruchengode, Tamil Nadu 637215, India
| | - G Saravanan
- Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Namakkal District, Tiruchengode, Tamil Nadu 637215, India
| | - Parim Brahma Naidu
- Animal Physiology and Biochemistry Laboratory, ICMR-National Animal Resource Facility for Biomedical Research (ICMR-NARFBR), Hyderabad 500078, India
| | - S Sengottuvelu
- Department of Pharmacology, Nandha College of Pharmacy, Erode, Tamil Nadu 638052, India
| | - S Vadivukkarasi
- Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Namakkal District, Tiruchengode, Tamil Nadu 637215, India.
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Han B, Li Q, Wang C, Chandrasekaran P, Zhou Y, Qin L, Liu XS, Enomoto-Iwamoto M, Kong D, Iozzo RV, Birk DE, Han L. Differentiated activities of decorin and biglycan in the progression of post-traumatic osteoarthritis. Osteoarthritis Cartilage 2021; 29:1181-1192. [PMID: 33915295 PMCID: PMC8319061 DOI: 10.1016/j.joca.2021.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/01/2021] [Accepted: 03/19/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To delineate the activities of decorin and biglycan in the progression of post-traumatic osteoarthritis (PTOA). DESIGN Three-month-old inducible biglycan (BgniKO) and decorin/biglycan compound (Dcn/BgniKO) knockout mice were subjected to the destabilization of the medial meniscus (DMM) surgery to induce PTOA. The OA phenotype was evaluated by assessing joint structure and sulfated glycosaminoglycan (sGAG) staining via histology, surface collagen fibril nanostructure and calcium content via scanning electron microscopy, tissue modulus via atomic force microscopy-nanoindentation, as well as subchondral bone structure and meniscus ossification via micro-computed tomography. Outcomes were compared with previous findings in the inducible decorin (DcniKO) knockout mice. RESULTS In the DMM model, BgniKO mice developed similar degree of OA as the control (0.44 [-0.18 1.05] difference in modified Mankin score), different from the more severe OA phenotype observed in DcniKO mice (1.38 [0.91 1.85] difference). Dcn/BgniKO mice exhibited similar histological OA phenotype as DcniKO mice (1.51 [0.97 2.04] difference vs control), including aggravated loss of sGAGs, salient surface fibrillation and formation of osteophyte. Meanwhile, Dcn/BgniKO mice showed further cartilage thinning than DcniKO mice, resulting in the exposure of underlying calcified tissues and aberrantly high surface modulus. BgniKO and Dcn/BgniKO mice developed altered subchondral trabecular bone structure in both Sham and DMM groups, while DcniKO and control mice did not. CONCLUSION In PTOA, decorin plays a more crucial role than biglycan in regulating cartilage degeneration, while biglycan is more important in regulating subchondral bone structure. The two have distinct activities and modest synergy in the pathogenesis of PTOA.
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Affiliation(s)
- B Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, 19104, United States
| | - Q Li
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, 19104, United States
| | - C Wang
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, 19104, United States
| | - P Chandrasekaran
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, 19104, United States
| | - Y Zhou
- Department of Statistical Sciences, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - L Qin
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - X S Liu
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - M Enomoto-Iwamoto
- Department of Orthopaedics, School of Medicine, University of Maryland, Baltimore, MD, 21201, United States
| | - D Kong
- Department of Statistical Sciences, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - R V Iozzo
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, United States
| | - D E Birk
- Department of Molecular Pharmacology and Physiology, Morsani School of Medicine, University of South Florida, Tampa, FL, 33612, United States
| | - L Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, 19104, United States.
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Suryavanshi N, Sane M, Gaikwad S, Paradkar M, Mave V, Chandrasekaran P, Shivakumar SVBY, Gupta A, Gupte N, Thomas B. Assessment of persistent depression among TB patients. Int J Tuberc Lung Dis 2020; 24:1208-1211. [PMID: 33172530 DOI: 10.5588/ijtld.20.0231] [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: 11/10/2022] Open
Affiliation(s)
- N Suryavanshi
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research Site, Pune, India
| | - M Sane
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research Site, Pune, India
| | - S Gaikwad
- Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - M Paradkar
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research Site, Pune, India
| | - V Mave
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research Site, Pune, India, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - P Chandrasekaran
- National Institute for Research in Tuberculosis, Indian Council of Medical Research, Chennai, India
| | - S V B Y Shivakumar
- Johns Hopkins University, Center for Clinical Global Health Education, India Office, Pune, India
| | - A Gupta
- Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - N Gupte
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research Site, Pune, India, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - B Thomas
- National Institute for Research in Tuberculosis, Indian Council of Medical Research, Chennai, India
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Arul V, Chandrasekaran P, Sethuraman M. Reduction of Congo red using nitrogen doped fluorescent carbon nanodots obtained from sprout extract of Borassus flabellifer. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137646] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Pavithra K, Sathibabu Uddandrao VV, Chandrasekaran P, Brahmanaidu P, Sengottuvelu S, Vadivukkarasi S, Saravanan G. Phenolic fraction extracted from Kedrostis foetidissima leaves ameliorated isoproterenol-induced cardiotoxicity in rats through restoration of cardiac antioxidant status. J Food Biochem 2020; 44:e13450. [PMID: 32839989 DOI: 10.1111/jfbc.13450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 05/21/2020] [Revised: 07/25/2020] [Accepted: 08/07/2020] [Indexed: 12/17/2022]
Abstract
In this study, the cardioprotective effects of partially purified phenolic fraction of Kedrostis foetidissima leaves (PFK) were evaluated in isoproterenol (ISO)-induced myocardial infarction rat model. ISO induction to experimental rats for two consecutive days significantly increased the levels of triglycerides, cholesterol, phospholipids, free fatty acids, low-density lipoproteins, and cardiac biomarker enzymes, and decreased the levels of high-density lipoproteins and antioxidant enzyme activity. Pretreatment of experimental rats with PFK for 45 days led to a significant elevation in antioxidant enzyme activity. PFK-pretreated rats exhibited significantly reduced levels of circulating lipids and cardiac-specific biomarker enzymes compared to ISO-treated rats. Thus, the present study demonstrated that PFK ameliorated ISO-induced cardiotoxicity through the augmentation of the endogenous cardiac antioxidant system, thereby modulating the lipid peroxidation caused by ISO-induced free radicals, and prevented the myocardial damage, which was confirmed through histopathological analysis. PRACTICAL APPLICATIONS: Kedrostis foetidissima is edible medicinal plant and phenolic fraction extracted from the leaves of this plant may help the common man in the protection of heart. The phenolic fraction shows significant antioxidant activity, so this might be referred to as dietary supplement and also helps to develop new pharmaceutical formulations.
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Affiliation(s)
- K Pavithra
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Tamilnadu, India
| | - V V Sathibabu Uddandrao
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Tamilnadu, India
| | - P Chandrasekaran
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Tamilnadu, India
| | - P Brahmanaidu
- Animal Physiology and Biochemistry Laboratory, ICMR-National Animal Resource Facility for Biomedical Research (ICMR-NARFBR), Hyderabad, India
| | - S Sengottuvelu
- Department of Pharmacology, Nandha College of Pharmacy, Erode, India
| | - S Vadivukkarasi
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Tamilnadu, India
| | - G Saravanan
- Centre for Biological Sciences, Department of Biochemistry, K.S. Rangasamy College of Arts and Science (Autonomous), Tiruchengode, Tamilnadu, India
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Gupte AN, Selvaraju S, Paradkar M, Danasekaran K, Shivakumar SVBY, Thiruvengadam K, Dolla C, Shivaramakrishnan G, Pradhan N, Kohli R, John S, Raskar S, Jain D, Momin A, Subramanian B, Gaikwad A, Lokhande R, Suryavanshi N, Gupte N, Salvi S, Murali L, Checkley W, Golub JE, Bollinger R, Chandrasekaran P, Mave V, Gupta A. Respiratory health status is associated with treatment outcomes in pulmonary tuberculosis. Int J Tuberc Lung Dis 2020; 23:450-457. [PMID: 31064624 DOI: 10.5588/ijtld.18.0551] [Citation(s) in RCA: 6] [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: 11/10/2022] Open
Abstract
<sec id="st1"> <title>BACKGROUND</title> The association between respiratory impairment and tuberculosis (TB) treatment outcomes is not clear. </sec> <sec id="st2"> <title>METHODS</title> We prospectively evaluated respiratory health status, measured using the Saint George's Respiratory Questionnaire (SGRQ), in a cohort of new adult pulmonary TB cases during and up to 18 months following treatment in India. Associations between total SGRQ scores and poor treatment outcomes of failure, recurrence and all-cause death were measured using multivariable Poisson regression. </sec> <sec id="st3"> <title>RESULTS</title> We enrolled 455 participants contributing 619 person-years at risk; 39 failed treatment, 23 had recurrence and 16 died. The median age was 38 years (interquartile range 26-49); 147 (32%) ever smoked. SGRQ scores at treatment initiation were predictive of death during treatment (14% higher risk per 4-point increase in baseline SGRQ scores, 95%CI 2-28, P = 0.01). Improvement in SGRQ scores during treatment was associated with a lower risk of failure (1% lower risk for every per cent improvement during treatment, 95%CI 1-2, P = 0.05). Clinically relevant worsening in SGRQ scores following successful treatment was associated with a higher risk of recurrence (15% higher risk per 4-point increase scores, 95%CI 4-27, P = 0.004). </sec> <sec id="st4"> <title>CONCLUSION</title> Impaired respiratory health status was associated with poor TB treatment outcomes. The SGRQ may be used to monitor treatment response and predict the risk of death in pulmonary TB. </sec>.
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Affiliation(s)
- A N Gupte
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - S Selvaraju
- National Institute for Research in Tuberculosis, Chennai
| | - M Paradkar
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - K Danasekaran
- National Institute for Research in Tuberculosis, Chennai
| | | | | | - C Dolla
- National Institute for Research in Tuberculosis, Chennai
| | | | - N Pradhan
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - R Kohli
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - S John
- National Institute for Research in Tuberculosis, Chennai
| | - S Raskar
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - D Jain
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - A Momin
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - B Subramanian
- National Institute for Research in Tuberculosis, Chennai
| | - A Gaikwad
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - R Lokhande
- Byramjee Jeejeebhoy Government Medical College and Sassoon General Hospitals, Pune
| | - N Suryavanshi
- Byramjee Jeejeebhoy Government Medical College-Johns Hopkins University Clinical Research Site, Pune
| | - N Gupte
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - S Salvi
- Chest Research Foundation, Pune, India
| | - L Murali
- National Institute for Research in Tuberculosis, Chennai
| | - W Checkley
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - J E Golub
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - R Bollinger
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - V Mave
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - A Gupta
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Chandrasekaran P, Santosh Kumar C, Rangachari K, Sekar K. Disassociation of β1-α1-β2 from the α2-α3 domain of prion protein (PrP) is a prerequisite for the conformational conversion of PrPC into PrPSc: Driven by the free energy landscape. Int J Biol Macromol 2019; 136:368-376. [DOI: 10.1016/j.ijbiomac.2019.06.099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/29/2019] [Accepted: 06/13/2019] [Indexed: 12/16/2022]
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Santhosh R, Chandrasekaran P, Michael D, Rangachari K, Bankoti N, Jeyakanthan J, Sekar K. ACMS: a database of alternate conformations found in the atoms of main and side chains of protein structures. J Appl Crystallogr 2019. [DOI: 10.1107/s1600576719006447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
Proteins are usually dynamic biological macromolecules, thereby exhibiting a large number of conformational ensembles which influence the association with their neighbours and interacting partners. Most of the side-chain atoms and a few main-chain atoms of the high-resolution crystal structures deposited in the Protein Data Bank adopt alternate conformations. This kind of conformational behaviour prompted the authors to explore the relationship, if any, between the alternate conformations and the function of the protein molecule. Thus, a knowledge base of the alternate conformations of the main- and side-chain atoms of protein structures has been developed. It provides a detailed description of the alternate conformations of various residues for more than 60 000 high-resolution crystal structures. The proposed knowledge base is very user friendly and has various flexible options. The knowledge base will be updated periodically and can be accessed at http://iris.physics.iisc.ac.in/acms.
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Shivakumar SVBY, Chandrasekaran P, Kumar AMV, Paradkar M, Dhanasekaran K, Suryavarshini N, Thomas B, Kohli R, Thiruvengadam K, Kulkarni V, Hannah LE, Sivaramakrishnan GN, Pradhan N, Dolla C, Gupte A, Ramachandran G, DeLuca A, Meshram S, Bhardawaj R, Bollinger RC, Golub J, Selvaraj K, Gupte N, Swaminathan S, Mave V, Gupta A. Diabetes and pre-diabetes among household contacts of tuberculosis patients in India: is it time to screen them all? Int J Tuberc Lung Dis 2019; 22:686-694. [PMID: 29862955 DOI: 10.5588/ijtld.17.0598] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Pre-diabetes mellitus (pre-DM) and DM increase the risk of developing tuberculosis (TB). Screening contacts of TB patients for pre-DM/DM and linking them to care may mitigate the risk of developing TB and improve DM management. OBJECTIVE To measure the prevalence of pre-DM/DM and associated factors among the adult household contacts (HHCs) of pulmonary TB patients. METHODS Between August 2014 and May 2017, adult HHCs of newly diagnosed adult PTB patients in Pune and Chennai, India, had single blood samples tested for glycosylated haemoglobin (HbA1c) at enrolment. DM was defined as previously diagnosed, self-reported DM or HbA1c 6.5%, and pre-DM as HbA1c between 5.7% and 6.4%. Latent tuberculous infection (LTBI) was defined as a positive tuberculin skin test (5 mm induration) or QuantiFERON® Gold In-Tube (0.35 international units/ml). RESULTS Of 652 adult HHCs, 175 (27%) had pre-DM and 64 (10%) had DM. Forty (64%) HHCs were newly diagnosed with DM and 48 (75%) had poor glycaemic control (HbA1c 7.0%). Sixty-eight (22%) pre-DM cases were aged 18-34 years. Age 35 years, body mass index 25 kg/m2, chronic disease and current tobacco smoking were significantly associated with DM among HHCs. CONCLUSIONS Adult HHCs of TB patients in India have a high prevalence of undiagnosed DM, pre-DM and LTBI, putting them at high risk for developing TB. Routine DM screening should be considered among all adult HHCs of TB.
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Affiliation(s)
| | - P Chandrasekaran
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - A M V Kumar
- International Union Against Tuberculosis and Lung Disease, Paris, France
| | - M Paradkar
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - K Dhanasekaran
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - N Suryavarshini
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - B Thomas
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - R Kohli
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - K Thiruvengadam
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - V Kulkarni
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - L E Hannah
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | | | - N Pradhan
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India
| | - C Dolla
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - A Gupte
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - G Ramachandran
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - A DeLuca
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - S Meshram
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - R Bhardawaj
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Byramjee Jeejeebhoy Government Medical College, Pune, India
| | - R C Bollinger
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - J Golub
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - K Selvaraj
- Pondicherry Institute of Medical Sciences (PIMS), Puducherry
| | - N Gupte
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - S Swaminathan
- Indian Council of Medical Research, New Delhi, India
| | - V Mave
- Byramjee Jeejeebhoy Government Medical College, Johns Hopkins University Clinical Research site, Pune, Maharashtra, India, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - A Gupta
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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Cardona A, Ning X, Smart S, Chandrasekaran P, Wei C, Mccarthy B, Lee D, Raman SV. 528Left ventricular dysfunction, not myocardial injury, drives use of cardioprotective medications in acute myocarditis: insights from machine learning. Eur Heart J Cardiovasc Imaging 2019. [DOI: 10.1093/ehjci/jez115.004] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- A Cardona
- The Ohio State University, Division of Cardiovascular Medicine, Columbus, United States of America
| | - X Ning
- The Ohio State University, Biomedical Informatics, Columbus, United States of America
| | - S Smart
- The Ohio State University, Division of Cardiovascular Medicine, Columbus, United States of America
| | - P Chandrasekaran
- Davis Heart & Lung Research Institute, Columbus, United States of America
| | - C Wei
- The Ohio State University, Biomedical Informatics, Columbus, United States of America
| | - B Mccarthy
- Davis Heart & Lung Research Institute, Columbus, United States of America
| | - D Lee
- Northwestern University, Chicago, United States of America
| | - S V Raman
- The Ohio State University, Division of Cardiovascular Medicine, Columbus, United States of America
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Rangachari K, Bankoti N, Shyamala N, Michael D, Sameer Ahmed Z, Chandrasekaran P, Sekar K. Glaucoma Pred: Glaucoma prediction based on Myocilin genotype and phenotype information. Genomics 2018; 111:696-699. [PMID: 29665417 DOI: 10.1016/j.ygeno.2018.04.006] [Citation(s) in RCA: 6] [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: 02/08/2018] [Revised: 04/02/2018] [Accepted: 04/09/2018] [Indexed: 11/28/2022]
Abstract
Glaucoma is the second leading cause of blindness after cataract and is heterogeneous in nature. Employing a genetic approach for the detection of the diseased condition provides an advantage that the gene responsible for the disease can be identified by genetic test. The availability of predictive tests based on the published literature would provide a mechanism for early detection and treatment. The genotype and phenotype information could be a valuable source for predicting the risk of the disease. To this end, a web server has been developed, based on the genotype and phenotype of myocilin mutation, which were identified by familial linkage analysis and case studies. The proposed web server provides clinical data and severity index for a given mutation. The server has several useful options to help clinicians and researchers to identify individuals at a risk of developing the disease. Glaucoma Pred server is available at http://bioserver1.physics.iisc.ac.in/myocilin.
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Affiliation(s)
- K Rangachari
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India
| | - Namrata Bankoti
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India
| | - N Shyamala
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India
| | - Daliah Michael
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India
| | - Z Sameer Ahmed
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India
| | - P Chandrasekaran
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India
| | - K Sekar
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore 560 012, India.
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Mugundhan K, Chandrasekaran P, Sivakumar S, Sundaresan N, Senthilkumar P. Megalencephalic Leucoencephalopathy [Van Der Knaap Disease] in a Non Agarwal Family. J Assoc Physicians India 2018; 66:80. [PMID: 30341876] [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: 06/08/2023]
Affiliation(s)
| | | | | | - N Sundaresan
- Asst. Professor, Dept. of Radiology, Govt. Mohan Kumaramangalam Medical College Hospital, Salem, Tamil Nadu
| | - P Senthilkumar
- Asst. Professor, Dept. of Radiology, Govt. Mohan Kumaramangalam Medical College Hospital, Salem, Tamil Nadu
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Chandrasekaran P, Kandasamy R. Solid Oral Flexible Formulations for Pediatric and Geriatric patients: Age-appropriate Formulation Platforms. Indian J Pharm Sci 2018. [DOI: 10.4172/pharmaceutical-sciences.1000326] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Selby-Karney T, Grossie DA, Arumugam K, Wright E, Chandrasekaran P. Structural and spectroscopic characterization of five coordinate iron and cobalt bis(dithiolene)-trimethylphosphine complexes. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.03.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Mugundhan K, Arasi KV, Balamurugan N, Chandrasekaran P, Thiruvarutchelvan K, Sivakumar S. Carcinoma Prostate Presenting as Multiple Cranial Nerve Palsy. J Assoc Physicians India 2017; 65:92-93. [PMID: 28457045] [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: 06/07/2023]
Abstract
Metastatic prostatic carcinoma commonly involves bones and extra pelvic lymph nodes. CNS involvement is unusual and particularly the occurence of leptomeningeal metastasis is extremely rare, with few cases described in the literature.1 The reported incidence at autopsy vary from 0.6 to 4.4 percent.2 We report a 65 year old male who presented with multiple cranial nerve palsies due to leptomeningeal metastasis in carcinoma prostate treated with orchidectomy and planned for radiotherapy and antiandrogen therapy.
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Affiliation(s)
| | - K V Arasi
- Senior Assistant Professor of Urology
| | | | | | | | - S Sivakumar
- Head of the Dept., Dept. of Neurology, Govt. Mohan Kumaramangalam Medical College Hospital, Salem, Tamil Nadu
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Chandrasekaran P, Rajasekaran R. Detailed computational analysis revealed mutation V210I on PrP induced conformational conversion on β2–α2 loop and α2–α3. Mol BioSyst 2016; 12:3223-33. [DOI: 10.1039/c6mb00342g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of fatal transmissible spongiform encephalopathies (TSE) is associated with the conformational conversion of the normal cellular prion protein, PrPC, into its pathogenic isoform, PrPSc.
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Affiliation(s)
- P. Chandrasekaran
- Computational Biology Lab
- Department of Biotechnology
- School of Biosciences and Technology
- VIT University
- Vellore 632 014
| | - R. Rajasekaran
- Computational Biology Lab
- Department of Biotechnology
- School of Biosciences and Technology
- VIT University
- Vellore 632 014
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Mugundhan K, Chandrasekaran P, Sivakumar S, Kumar P, Senthilkumar P. Haemorrhage in Posterior Reversible Encephalopathy Syndrome (PRES). J Assoc Physicians India 2015; 63:56. [PMID: 26591171] [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: 06/05/2023]
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Jayaprakash J, Srinivasan N, Chandrasekaran P, Girija EK. Synthesis and characterization of cluster of grapes like pure and Zinc-doped CuO nanoparticles by sol-gel method. Spectrochim Acta A Mol Biomol Spectrosc 2015; 136 Pt C:1803-1806. [PMID: 25467673 DOI: 10.1016/j.saa.2014.10.087] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/28/2014] [Accepted: 10/23/2014] [Indexed: 06/04/2023]
Abstract
Pure CuO and Zn-doped CuO nanoparticles were synthesized from sol-gel process by reacting copper acetate monohydrate with a urea in distilled water at 80°C. The synthesized Samples were different concentrations but same annealing temperature at 400°C. The obtained samples were characterized by means of UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM) and Energy dispersive X-ray spectroscopy (EDS). UV-visible technique used to measure the band gap of the synthesized samples. The XRD spectra of the synthesized samples confirmed the CuO nanoparticles with monoclinic structure. All the functional groups of the pure and doped synthesized samples were investigated by FT-IR analysis. The morphological and elemental estimation of the pure and Zn-doped synthesized samples were examined by FE-SEM with EDS.
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Affiliation(s)
- J Jayaprakash
- Department of Physics, Annamalai University, Annamalai Nagar 608 002, India
| | - N Srinivasan
- Department of Engineering Physics (FEAT), Annamalai University, Annamalai Nagar 608 002, India.
| | - P Chandrasekaran
- Department of Physics, Annamalai University, Annamalai Nagar 608 002, India
| | - E K Girija
- Department of Physics, Periyar University, Periyar Palkalai Nagar 636 011, India
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Chandrasekaran P, Greene AF, Lillich K, Capone S, Mague JT, DeBeer S, Donahue JP. A Structural and Spectroscopic Investigation of Octahedral Platinum Bis(dithiolene)phosphine Complexes: Platinum Dithiolene Internal Redox Chemistry Induced by Phosphine Association. Inorg Chem 2014; 53:9192-205. [DOI: 10.1021/ic501273b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- P. Chandrasekaran
- Department of Chemistry and Biochemistry, Lamar University, Beaumont, Texas 77710, United States
| | - Angelique F. Greene
- Department of Chemistry, Tulane University, 6400
Freret Street, New Orleans, Louisiana 70118, United States
| | - Karen Lillich
- Department of Chemistry, Tulane University, 6400
Freret Street, New Orleans, Louisiana 70118, United States
| | - Stephen Capone
- Department of Chemistry, Tulane University, 6400
Freret Street, New Orleans, Louisiana 70118, United States
| | - Joel T. Mague
- Department of Chemistry, Tulane University, 6400
Freret Street, New Orleans, Louisiana 70118, United States
| | - Serena DeBeer
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse
34−36, D-45470 Mülheim an der Ruhr, Germany
| | - James P. Donahue
- Department of Chemistry, Tulane University, 6400
Freret Street, New Orleans, Louisiana 70118, United States
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Jayaprakash J, Srinivasan N, Chandrasekaran P. Surface modifications of CuO nanoparticles using Ethylene diamine tetra acetic acid as a capping agent by sol-gel routine. Spectrochim Acta A Mol Biomol Spectrosc 2014; 123:363-368. [PMID: 24412789 DOI: 10.1016/j.saa.2013.12.080] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/08/2013] [Accepted: 12/11/2013] [Indexed: 06/03/2023]
Abstract
The uncapped and capped CuO nanoparticles were synthesized by sol-gel process. Ethylene diamine tetra acetic acid (EDTA) used as a capping agent to control the size and morphology of the CuO nanoparticles. Control the nanostructure and optical properties of CuO nanoparticles are deliberate by using capping agent. The obtained samples were characterized by means of UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDS). UV-Visible technique used to measure the band gap of the synthesized samples. The XRD spectra of the synthesized samples confirmed the CuO nanoparticles with monoclinic structure. The occurrences of capping agent have been analyzed by Fourier transform-infrared spectroscopy (FT-IR). The FT-IR study revealed that the transmittance peaks at 501cm(-1) and 592cm(-1) were CuO stretching mode, and 677cm(-1) was CuO monoclinic phase of the uncapped CuO nanoparticles. Further, SEM study find out the morphology of the synthesized samples, where the surface morphology changes occurred with an addition of capping agent. Moreover, the capping mechanism has been discussed based on the chemical reaction between the CuO nanoparticles and the functional groups of the capping agent.
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Affiliation(s)
- J Jayaprakash
- Department of Physics, Annamalai University, Annamalai Nagar 608 002, India
| | - N Srinivasan
- Department of Engineering Physics (FEAT), Annamalai University, Annamalai Nagar 608 002, India.
| | - P Chandrasekaran
- Department of Physics, Annamalai University, Annamalai Nagar 608 002, India
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Greene AF, Chandrasekaran P, Yan Y, Mague JT, Donahue JP. Element misidentification in X-ray crystallography: a reassessment of the [MCl2(diazadiene)] (M = Cr, Mo, W) series. Inorg Chem 2014; 53:308-17. [PMID: 24320788 DOI: 10.1021/ic402246d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of reports describing the syntheses and structures of [MCl2(diazadiene)] (M = Cr, Mo, W) complexes is reassessed in the context of known chemistry of low-valent Group VI metal complexes, crystallographic trends such as M-Cl bond lengths and unit cell volumes, and calculated metal-ligand bond lengths. Crystallographic data and computational results are inconsistent with any of these species being second or third row transition metal complexes. A review of the crystallographic information files accompanying the [MCl2(diazadiene)] (M = Mo, W) published structures reveals that the metal atoms were inappropriately treated with partial site occupancy factors (0.775 for Mo; 0.4005 and 0.417 for W), the effect of which was to manifest lighter-element behavior and better refinement in accord with the metal atoms' correct identity. A deliberate synthesis and characterization by X-ray diffraction of [ZnCl2((Mes)dad(Me))] ((Mes)dad(Me) = 1,4-bis(2,4,6-trimethylphenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene) are reported. Refinement of this structure with the same combination of second or third row metal and offsetting partial site occupancy is shown to provide final refinement statistics essentially the same as with the correct model employing M = Zn at site occupancy 1.00. Use of the published method for synthesis of [WCl2(diazadiene)] with (Mes)dad(Me) and [WBr4(MeCN)2] in lieu of [WCl4(MeCN)2] is shown to produce [ZnBr2((Mes)dad(Me))], which has also been characterized by X-ray diffraction. It is concluded that the unusual putative 12-electron [MCl2(diazadiene)] (M = Cr, Mo, W) complexes are in all cases the corresponding [ZnCl2(diazadiene)] complexes, Zn having been commonly employed as reducing agent in their synthesis.
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Affiliation(s)
- Angelique F Greene
- Department of Chemistry, Tulane University , 6400 Freret Street, New Orleans, Louisiana 70118-5698, United States
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Chandrasekaran P, Rajasekaran R. Structural characterization of disease-causing mutations on SAP and the functional impact on the SLAM peptide: a molecular dynamics approach. Mol BioSyst 2014; 10:1869-80. [DOI: 10.1039/c4mb00177j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Chandrasekaran P, Anandan P, Srinivasan N. Structural and optical properties of sol-gel synthesised Zn(1-x)Mg(x)O nanocrystals. Spectrochim Acta A Mol Biomol Spectrosc 2013; 116:311-316. [PMID: 23973572 DOI: 10.1016/j.saa.2013.07.031] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 07/11/2013] [Accepted: 07/21/2013] [Indexed: 06/02/2023]
Abstract
Zn(1-x)Mg(x)O nanocrystals with various compositions (x = 0-0.1) were synthesised by sol-gel process using tri ethanol amine (TEA) as a capping agent. The structural properties of the prepared materials were studied by X-ray diffraction analysis. Un-agglomerated nanocrystals with spherical morphology were observed by scanning electron microscope (SEM). The presence of Mg in the Zn(1-x)Mg(x)O was confirmed by X-ray photoelectron spectroscopy (XPS). Moreover, the Mg composition relatively increases in the synthesised nanocrystals as it increases in the precursor solution. The optical absorption studies of the Zn(1-x)Mg(x)O samples show the blue shift from the pure ZnO due to the incorporation of Mg in ZnO lattice. The photoluminescence studies demonstrated that the intensity of defect related deep level emission increases drastically with increasing the x value from 0.02 to 0.08 and decreases sharply on further increase of Mg from 0.08 to 0.1. The mechanism for the enhanced green emission was explained based on the structural properties of the Zn(1-x)Mg(x)O samples.
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Affiliation(s)
- P Chandrasekaran
- Department of Physics, Annamalai University, Annamalai Nagar, Chidambaram, India
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Chandrasekaran P, Chiang KP, Nordlund D, Bergmann U, Holland PL, DeBeer S. Sensitivity of X-ray core spectroscopy to changes in metal ligation: a systematic study of low-coordinate, high-spin ferrous complexes. Inorg Chem 2013; 52:6286-98. [PMID: 23662855 DOI: 10.1021/ic3021723] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to assess the sensitivity and complementarity of X-ray absorption and emission spectroscopies for determining changes in the metal ligation sphere, a systematic experimental and theoretical study of iron model complexes has been carried out. A series of high-spin ferrous complexes, in which the ligation sphere has been varied from a three-coordinate complex, [L(tBu)Fe(SPh)] (1) (where L(tBu) = bulky β-diketiminate ligand; SPh = phenyl thiolate) to four-coordinate complexes [L(tBu)Fe(SPh)(X)] (where X = CN(t)Bu (2); 1-methylimidazole (3); or N,N-dimethylformamide (DMF) (4)), has been investigated using a combination of Fe K-edge X-ray absorption (XAS) and Kβ X-ray emission (XES) spectroscopies. The Fe K XAS pre-edge and edge of all four complexes are consistent with a high-spin ferrous assignment, with the largest differences in the pre-edge intensities attributed to changes in covalency of the fourth coordination site. The X-ray emission spectra show pronounced changes in the valence to core region (V2C) as the identity of the coordinated ligand is varied. The experimental results have been correlated to density functional theory (DFT) calculations, to understand key molecular orbital contributions to the observed absorption and emission features. The calculations also have been extended to a series of hypothetical high-spin iron complexes to understand the sensitivity of XAS and XES techniques to different ligand protonation states ([L(tBu)Fe(II)(SPh)(NHn)](3-n) (n = 3, 2, 1, 0)), metal oxidation states [L(tBu)Fe(SPh)(N)](n-) (n = 3, 2, 1), and changes in the ligand identity [L(tBu)Fe(IV)(SPh)(X)](n-) (X = C(4-), N(3-), O(2-); n = 2, 1, 0). This study demonstrates that XAS pre-edge data have greater sensitivity to changes in oxidation state, while valence to core (V2C) XES data provide a more sensitive probe of ligand identity and protonation state. The combination of multiple X-ray spectroscopic methods with DFT results thus has the potential to provide for detailed characterization of complex inorganic systems in both chemical and biological catalysis.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
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Chandrasekaran P, Doss CGP, Nisha J, Sethumadhavan R, Shanthi V, Ramanathan K, Rajasekaran R. In silico analysis of detrimental mutations in ADD domain of chromatin remodeling protein ATRX that cause ATR-X syndrome: X-linked disorder. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s13721-013-0031-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sreevishnupriya K, Chandrasekaran P, Senthilkumar A, Sethumadhavan R, Shanthi V, Daisy P, Nisha J, Ramanathan K, Rajasekaran R. Computational analysis of deleterious missense mutations in aspartoacylase that cause Canavan's disease. Sci China Life Sci 2012; 55:1109-19. [PMID: 23233226 DOI: 10.1007/s11427-012-4406-8] [Citation(s) in RCA: 5] [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] [Received: 08/08/2012] [Accepted: 11/06/2012] [Indexed: 01/09/2023]
Abstract
In this work, the most detrimental missense mutations of aspartoacylase that cause Canavan's disease were identified computationally and the substrate binding efficiencies of those missense mutations were analyzed. Out of 30 missense mutations, I-Mutant 2.0, SIFT and PolyPhen programs identified 22 variants that were less stable, deleterious and damaging respectively. Subsequently, modeling of these 22 variants was performed to understand the change in their conformations with respect to the native aspartoacylase by computing their root mean squared deviation (RMSD). Furthermore, the native protein and the 22 mutants were docked with the substrate NAA (N-Acetyl-Aspartic acid) to explain the substrate binding efficiencies of those detrimental missense mutations. Among the 22 mutants, the docking studies identified that 15 mutants caused lower binding affinity for NAA than the native protein. Finally, normal mode analysis determined that the loss of binding affinity of these 15 mutants was caused by altered flexibility in the amino acids that bind to NAA compared with the native protein. Thus, the present study showed that the majority of the substrate-binding amino acids in those 15 mutants displayed loss of flexibility, which could be the theoretical explanation of decreased binding affinity between the mutant aspartoacylases and NAA.
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Affiliation(s)
- K Sreevishnupriya
- Bioinformatics Division, School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India
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Chandrasekaran P, Stieber SCE, Collins TJ, Que L, Neese F, DeBeer S. Prediction of high-valent iron K-edge absorption spectra by time-dependent density functional theory. Dalton Trans 2011; 40:11070-9. [PMID: 21956429 DOI: 10.1039/c1dt11331c] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In recent years, a number of high-valent iron intermediates have been identified as reactive species in iron-containing metalloproteins. Inspired by the interest in these highly reactive species, chemists have synthesized Fe(IV) and Fe(V) model complexes with terminal oxo or nitrido groups, as well as a rare example of an Fe(VI)-nitrido species. In all these cases, X-ray absorption spectroscopy has played a key role in the identification and characterization of these species, with both the energy and intensity of the pre-edge features providing spectroscopic signatures for both the oxidation state and the local site geometry. Here we build on a time-dependent DFT methodology for the prediction of Fe K- pre-edge features, previously applied to ferrous and ferric complexes, and extend it to a range of Fe(IV), Fe(V) and Fe(VI) complexes. The contributions of oxidation state, coordination environment and spin state to the spectral features are discussed. These methods are then extended to calculate the spectra of the heme active site of P450 Compound II and the non-heme active site of TauD. The potential for using these methods in a predictive manner is highlighted.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
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Chandrasekaran P, Mague JT, Balakrishna MS. Synthesis and Derivatization of the Bis(amido)-λ3-cyclodiphosphazanes cis-[R′(H)NP(μ-NR)]2, Including a Rare Example, trans-[tBu(H)N(Se)P(μ-NCy)]2, Showing Intermolecular Se···H-O Hydrogen Bonding. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201001348] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [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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Arumugam K, Shaw MC, Chandrasekaran P, Villagrán D, Gray TG, Mague JT, Donahue JP. Synthesis, structures, and properties of 1,2,4,5-benzenetetrathiolate linked group 10 metal complexes. Inorg Chem 2010; 48:10591-607. [PMID: 19831407 DOI: 10.1021/ic901257s] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dimetallic compounds [(P-P)M(S(2)C(6)H(2)S(2))M(P-P)] (M = Ni, Pd; P-P = chelating bis(phosphine), 3a-3f) are prepared from O=CS(2)C(6)H(2)S(2)C=O or (n)Bu(2)SnS(2)C(6)H(2)S(2)Sn(n)Bu(2), which are protected forms of 1,2,4,5-benzenetetrathiolate. Selective monodeprotections of O=CS(2)C(6)H(2)S(2)C=O or (n)Bu(2)SnS(2)C(6)H(2)S(2)Sn(n)Bu(2) lead to [(P-P)Ni(S(2)C(6)H(2)S(2)C=O)] or [(P-P)Ni(S(2)C(6)H(2)S(2)Sn(n)Bu(2))]; the former is used to prepare trimetallic compounds [(dcpe)Ni(S(2)C(6)H(2)S(2))M(S(2)C(6)H(2)S(2))Ni(dcpe)] (M = Ni (6a) or Pt (6b); dcpe = 1,2-bis(dicyclohexylphosphino)ethane). Compounds 3a-3f are redox active and display two oxidation processes, of which the first is generally reversible. Dinickel compound [(dcpe)Ni(S(2)C(6)H(2)S(2))Ni(dcpe)] (3d) reveals two reversible oxidation waves with DeltaE(1/2) = 0.66 V, corresponding to K(c) of 1.6 x 10(11) for the mixed valence species. Electrochemical behavior is unstable to repeated scanning in the presence of [Bu(4)N][PF(6)] electrolyte but indefinitely stable with Na[BArF(24)] (BArF(24) = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate), suggesting that the radical cation generated by oxidation is vulnerable to reaction with PF(6)(-). Chemical oxidation of 3d with [Cp(2)Fe][BArF(24)] leads to formation of [3d][BArF(24)]. Structural identification of [3d][BArF(24)] reveals appreciable shortening and lengthening of C-S and C-C bond distances, respectively, within the tetrathioarene fragment compared to charge-neutral 3d, indicating this to be the redox active moiety. Attempted oxidation of [(dppb)Ni(S(2)C(6)H(2)S(2))Ni(dppb)] (3c) (dppb = 1,2-bis(diphenylphosphino)benzene) with AgBArF(24) produces [[(dppb)Ni(S(2)C(6)H(2)S(2))Ni(dppb)](2)(mu-Ag(2))][BArF(24)](2), [4c][BArF(24)](2), in which no redox chemistry has occurred. Crystal structures of bis(disulfide)-linked compounds [(P-P)Ni(S(2)C(6)H(2)(mu-S(2))(2)C(6)H(2)S(2))Ni(P-P)] are reported. Near IR spectroscopy upon cationic [3d](+) and neutral 6a reveals multiple intense absorptions in the 950-1400 nm region. Time-dependent density functional theory (DFT) calculations on a 6a model compound indicate that these absorptions are transitions between ligand-based pi-type orbitals that have significant contributions from the sulfur p orbitals.
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Affiliation(s)
- Kuppuswamy Arumugam
- Department of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118-5698, USA
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Chandrasekaran P, Arumugam K, Jayarathne U, Pérez LM, Mague JT, Donahue JP. Synthesis, structures, and properties of mixed dithiolene-carbonyl and dithiolene-phosphine complexes of tungsten. Inorg Chem 2009; 48:2103-13. [PMID: 19235970 DOI: 10.1021/ic802016b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new, high yield synthesis of [Ni(S(2)C(2)Me(2))(2)] (3) is described using 4,5-dimethyl-1,3-dithiol-2-one, Me(2)C(2)S(2)CO (1), as dithiolene ligand precursor. Reaction of (Me(2)C(2)S(2))Sn(n)Bu(2), 2, with WCl(6) produces tris(dithiolene) [W(S(2)C(2)Me(2))(3)] (6) and demonstrates the potential synthetic utility of this compound in metallodithiolene synthesis. The series of compounds [W(S(2)C(2)Me(2))(x)(CO)(6-2x)] (x = 1-3), obtained as a mixture via the reaction of [Ni(S(2)C(2)Me(2))(2)] with [W(MeCN)(3)(CO)(3)], has been characterized structurally. A trigonal prismatic geometry is observed for [W(S(2)C(2)Me(2))(CO)(4)] (4) and confirmed by a DFT geometry optimization to be lower in energy than an octahedron by 5.1 kcal/mol. The tris(dithiolene) compound [W(S(2)C(2)Me(2))(3)] crystallizes in disordered fashion upon a 2-fold axis in C2/c, a different space group than that observed for its molybdenum homologue (P1), which is attributed to a slightly smaller chelate fold angle, alpha, in the former. The reactivity of 4 and [W(S(2)C(2)Me(2))(2)(CO)(2)] (5) toward PMe(3) has been examined. Compound 4 yields only [W(S(2)C(2)Me(2))(CO)(2)(PMe(3))(2)] (7), while 5 produces either [W(S(2)C(2)Me(2))(2)(CO)(PMe(3))] (8) or [W(S(2)C(2)Me(2))(2)(PMe(3))(2)] (9) depending upon reaction conditions. Crystallographic characterization of 5, 8, and 9 reveals a trend toward greater reduction of the dithiolene ligand (i.e., more ene-1,2-dithiolate character) across the series, as manifested by C-C and C-S bond lengths. These structural data indicate a profound effect exerted by the pi-acidic CO ligands upon the apparent state of reduction of the dithiolene ligand in compounds with ostensibly the same oxidation state.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118-5698, USA
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Chandrasekaran P, Mague JT, Balakrishna MS. Gold(i) complexes of cyclodiphosphazanes cis-{RP(μ-NtBu)}2: structure of a novel tetranuclear gold(i) macrocycle, [{Au{(o-MeOC6H4O)P(μ-NtBu)}2}4](ClO4)4. Dalton Trans 2009:5478-86. [DOI: 10.1039/b903075a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Chandrasekaran P, Mague JT, Balakrishna MS. Synthesis and characterization of RuII/AuI, PdII/AuI, PdII/2AuI, PtII/2AuI and CuI/2AuI heterometallic complexes of cyclodiphosphazane cis-{(o-MeOC6H4O)P(μ-NtBu)}2. Polyhedron 2008. [DOI: 10.1016/j.poly.2007.08.024] [Citation(s) in RCA: 11] [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: 10/22/2022]
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Chandrasekaran P, Mague JT, Venkateswaran R, Balakrishna MS. Cyclodiphosphazanecis-{(o-MeOC6H4O)P(μ-NtBu)}2 as a Bridging Bidentate Ligand: Synthesis, Structures of Heterometallic Complexes, and Halogen Exchange Between Rh–Cl and Cu–X (X = Br, I). Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700554] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Chandrasekaran P, Mague JT, Balakrishna MS. Intramolecular amine-induced [1,3]-sigmatropic rearrangement in the reactions of aminophosphinites or phosphites with elemental sulfur or selenium. Inorg Chem 2007; 45:5893-7. [PMID: 16841994 DOI: 10.1021/ic060413m] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ether- and thioether-functionalized cyclodiphosphazanes cis-[tBuNP(OCH2CH2EMe)]2 (E = O, 1; E = S, 2) react with 2 equiv of elemental sulfur or selenium to produce dichalcogenides cis-[tBuNP(E)(OCH2CH2EMe)]2 (4-6), whereas the similar reaction of amine-functionalized cyclodiphosphazane cis-[tBuNP(OCH2CH2NMe2)]2 (3) with elemental chalcogen results in the formation of thio- or selenophosphates trans-[tBuNP(O)(ECH2CH2NMe2)]2 (E = S, 7; E = Se, 8) through [1,3]-sigmatropic rearrangement. The X-ray crystal structure of 8 confirms the rearranged product as the trans isomer with a planar P2N2 ring. The equimolar reaction of P(OCH2CH2OMe)3 (9) with elemental sulfur or selenium produces the simple sulfide and selenide E=P(OCH2CH2OMe)3 (E = S, 11; E = Se, 12) derivatives, respectively. In contrast, the reaction between P(OCH2CH2NMe2)3 (10) and S or Se furnishes the rearranged products (13 and 14). The rearrangement reaction was monitored by (31)PNMR spectroscopy, which confirms the formation of selenophosphinic acid as the first step of the rearrangement. The [1,3]-sigmatropic rearrangement presumably takes place through chalcogen-nitrogen interactions.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, India
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Walkup M, Wright N, Chandrasekaran P, Samuelson L, Gerber D. P106. J Surg Res 2007. [DOI: 10.1016/j.jss.2006.12.337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chandrasekaran P, Mague JT, Balakrishna MS. One-dimensional silver(i) coordination polymers containing cyclodiphosphazane, cis-{(o-MeOC6H4O)P(µ-NtBu)}2. Dalton Trans 2007:2957-62. [PMID: 17607411 DOI: 10.1039/b704303a] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The 1:1 reaction between the cyclodiphosphazane cis-{(o-MeOC(6)H(4)O)P(mu-N(t)Bu)}(2) (1) and AgOTf afforded one-dimensional Ag(I) coordination polymer [Ag{mu-OTf-kappaO,kappaO}{mu-(o-MeOC(6)H(4)O)P(mu-N(t)Bu)-kappaP,kappaP}(2)](infinity) (2) containing bridging cyclodiphosphazane and trifluoromethanesulfonate (OTf) ligands. The 2:1 reaction of and AgOTf leads to the formation of simple mononuclear complex [Ag{OTf-kappaO,kappaO}({(o-MeOC(6)H(4)O)P(mu-N(t)Bu)-kappaP}(2))(2)] (3) in quantitative yield. Reaction of 1 with AgCN produces a strain-free zig-zag coordination polymer [({(o-MeOC(6)H(4)O)P(mu-N(t)Bu)-kappaP,kappaP}(2))(2)Ag(NCAgCN)](infinity) (4) irrespective of reaction stoichiometry and conditions. In complexes 3 and 4 cyclodiphosphazanes coordinate to Ag(I) centers in a monodentate fashion. Single crystal structures were established for the Ag(I) polymers 2 and 4.
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Affiliation(s)
- P Chandrasekaran
- Phosphorus Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
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Chandrasekaran P, Mague JT, Balakrishna MS. Copper(I) Coordination Polymers [{Cu(μ-X)}2{RP(μ-NtBu)}2]n (R = OC6H4OMe-o; X = Cl, Br, and I) and Their Reversible Conversion into Mononuclear Complexes [CuX{(RP(μ-NtBu))2}2]: Synthesis and Structural Characterization. Inorg Chem 2006; 45:6678-83. [PMID: 16903722 DOI: 10.1021/ic060464j] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reactions of cyclodiphosphazane cis-[tBuNP(OC6H4OMe-o)]2 (1) with 2 equiv of CuX in acetonitrile afforded one-dimensional Cu(I) coordination polymers [Cu2X2{tBuNP(OC6H4OMe-o)}2]n (2, X = Cl; 3, X = Br; 4, X = I). The crystal structures of 2 and 4 reveal a zigzag arrangement of [P(mu-N)(2)P] and [Cu(mu-X)(2)Cu] units in an alternating manner to form one-dimensional Cu(I) coordination polymers. The reaction between 1 and CuX in a 2:1 ratio afforded mononuclear tricoordinated copper(I) complexes of the type [CuX{(tBuNP(OC6H4OMe-o))2}2] (5, X = Cl; 6, X = Br; 7, X = I). The single-crystal structures were established for the mononuclear copper(I) complexes 5 and 6. When the reactant ratios are 1:1, the formation of a mixture of polymeric and mononuclear products was observed. The Cu(I) polymers (2-4) were converted into the mononuclear complexes (5-7) by reacting with 3 equiv of 1 in dimethyl sulfoxide. Similarly, the mononuclear complexes (5-7) were converted into the corresponding polymeric complexes (2-4) by reacting with 3 equiv of copper(I) halide under mild reaction conditions.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry, Indian Institute of Technology, Bombay, Mumbai 400 076, India
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Chandrasekaran P, Mague JT, Balakrishna MS. Cyclodiphosphazanes with Hemilabile Ponytails: Synthesis, Transition Metal Chemistry (Ru(II), Rh(I), Pd(II), Pt(II)), and Crystal and Molecular Structures of Mononuclear (Pd(II), Rh(I)) and Bi- and Tetranuclear Rhodium(I) Complexes. Inorg Chem 2005; 44:7925-32. [PMID: 16241142 DOI: 10.1021/ic0509478] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cyclodiphosphazanes having hemilabile ponytails such as cis-[(t)()BuNP(OC(6)H(4)OMe-o)](2) (2), cis-[(t)()BuNP(OCH(2)CH(2)OMe)](2) (3), cis-[(t)BuNP(OCH(2)CH(2)SMe)](2) (4), and cis-[(t)BuNP(OCH(2)CH(2)NMe(2))](2) (5) were synthesized by reacting cis-[(t)()BuNPCl](2) (1) with corresponding nucleophiles. The reaction of 2 with [M(COD)Cl(2)] afforded cis-[MCl(2)(2)(2)] derivatives (M = Pd (6), Pt (7)), whereas, with [Pd(NCPh)(2)Cl(2)], trans-[MCl(2)(2)(2)] (8) was obtained. The reaction of 2 with [Pd(PEt(3))Cl(2)](2), [{Ru(eta(6)-p-cymene)Cl(2)](2), and [M(COD)Cl](2) (M = Rh, Ir) afforded mononuclear complexes of Pd(II) (9), Ru(II) (11), Rh(I) (12), and Ir(I) (13) irrespective of the stoichiometry of the reactants and the reaction condition. In the above complexes the cyclodiphosphazane acts as a monodentate ligand. The reaction of 2 with [PdCl(eta(3)-C(3)H(5))](2) afforded binuclear complex [(PdCl(eta(3)-C(3)H(5)))(2){((t)BuNP(OC(6)H(4)OMe-o))(2)-kappaP}] (10). The reaction of ligand 3 with [Rh(CO)(2)Cl](2) in 1:1 ratio in CH(3)CN under reflux condition afforded tetranuclear rhodium(I) metallamacrocycle (14), whereas the ligands 4 and 5 afforded bischelated binuclear complexes 15 and 16, respectively. The crystal structures of 8, 9, 12, 14, and 16 are reported.
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Affiliation(s)
- P Chandrasekaran
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai
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Chandrasekaran P, Mague JT, Balakrishna MS. Tetranuclear Rhodium(I) Macrocycle Containing Cyclodiphosphazane [Rh2(μ-Cl)2(CO)2{(tBuNP(OC6H4OMe-o))2-κP]2 and Its Reversible Conversion into trans-[Rh(CO)Cl{(tBuNP(OC6H4OMe-o))2-κP}2]. Organometallics 2005. [DOI: 10.1021/om0502537] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. Chandrasekaran
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Joel T. Mague
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Maravanji S. Balakrishna
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
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Simko V, Chandrasekaran P, Gillon S, De Soto F. Enteroenteric fistula of the duodenum in a patient with AIDS and Mycobacterium avium-intracellulare infection. J Assoc Acad Minor Phys 1993; 4:138-142. [PMID: 8251709] [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: 05/22/2023]
Abstract
Upper gastrointestinal endoscopy revealed a double lumen in the second portion of the duodenum in a 39-year-old man with advanced acquired immunodeficiency syndrome (AIDS). The lesion was not lined with an epithelium and improved with antituberculous therapy. These findings, as well as both an extensive transmural inflammation with foamy macrophages laden with acid-fast microorganisms and the destruction of the bowel wall, were consistent with Mycobacterium avium-intracellulare infection, but not with congenital duplication. An upper gastrointestinal series was falsely negative. Deep, penetrating lesions and double-barreled lumen are not infrequent in AIDS-related esophageal disease. We propose that similar lesions related to M avium-intracellulare occur in the bowel, especially when immune impairment and mycobacterial infection are severe. Awareness of mycobacterial infections of the gut is important in the era of AIDS.
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Affiliation(s)
- V Simko
- Section of Gastroenterology, Brooklyn Veterans Administration Medical Center, NY 11209
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Chandrasekaran P, Aruldhas MM, Govindarajulu P. Effect of testosterone propionate on subcellular distribution pattern of monoacyl glycerol in different regions of brain of castrated pubertal male rats. Indian J Exp Biol 1987; 25:211-2. [PMID: 3666822] [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: 01/06/2023]
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Andrews J, Chandrasekaran P, McSwiggan D. Lower respiratory tract infections in an acute geriatric male ward: a one-year prospective surveillance. Gerontology 1984; 30:290-6. [PMID: 6333374 DOI: 10.1159/000212648] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A prospective study of 340 patients admitted to an acute geriatric male ward for a 12-month period was carried out to determine the aetiology and incidence of lower respiratory tract infection (LRTI) acquired either prior or after admission to the hospital. Over the year, 120 patients (35%) were found to have LRTI; a specific aetiology was found in 44 (37%) patients. The pathogens most frequently isolated were Haemophilus influenzae (11 patients), Streptococcus pneumoniae (9 patients) and influenza A (4 patients). A further 8 (7%) patients had antibody titres sufficiently raised to indicate a recent infection (influenza A6, Chlamydia psittaci 2). A marked difference in the aetiology between community- and hospital-acquired infection was demonstrated. Cross-infection was not found, although patients with influenza A infection were admitted to the ward. Mortality showed a high correlation with current and ex-smokers.
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