Boron-Catalyzed Hydrogenative Reduction of Substituted Quinolines to Tetrahydroquinolines with Hydrosilanes

Gandhamsetty, Narasimhulu,Park, Sehoon,Chang, Sukbok Georg Thieme Verlag KG 2017 Synlett Vol.28 No.18

<P>A metal-free procedure for the hydrogenative reduction of substituted N-heteroaromatics has been developed by using hydrosilanes as reducing agents. The optimized conditions were successfully applied to the reactions of quinolines, quinoxalines, and quinoline N-oxides. They were also effective for the reduction of quinolines bearing amino or hydroxy groups, where H2 was evolved through dehydrogenative silylation of the amine or hydroxy moieties. Preliminary mechanistic studies revealed that the initial step in the catalytic cycle involves 1,4-addition of the hydrosilane to the quinoline to give a 1,4-dihydroquinoline; this is followed by (transfer) hydrogenation to deliver the tetrahydroquinoline as the final product.</P>

Boron-Catalyzed Silylative Reduction of Nitriles in Accessing Primary Amines and Imines

Gandhamsetty, Narasimhulu,Jeong, Jinseong,Park, Juhyeon,Park, Sehoon,Chang, Sukbok American Chemical Society 2015 Journal of organic chemistry Vol.80 No.14

<P>Silylative reduction of nitriles was studied under transition metal-free conditions by using B(C<SUB>6</SUB>F<SUB>5</SUB>)<SUB>3</SUB> as a catalyst with hydrosilanes as a reductant. Alkyl and (hetero)aryl nitriles were efficiently converted to primary amines or imines under mild conditions. The choice of silanes was found to determine the selectivity: while a full reduction of nitriles was highly facile, the use of sterically bulky silanes allowed for the partial reduction leading to <I>N</I>-silylimines.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/joceah/2015/joceah.2015.80.issue-14/acs.joc.5b00941/production/images/medium/jo-2015-00941q_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jo5b00941'>ACS Electronic Supporting Info</A></P>

Boron-Catalyzed Silylative Reduction of Quinolines: Selective sp³ C–Si Bond Formation

Gandhamsetty, Narasimhulu,Joung, Seewon,Park, Sung-Woo,Park, Sehoon,Chang, Sukbok American Chemical Society 2014 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.136 No.48

<P>A silylative reduction of quinolines to synthetically versatile tetrahydroquinoline molecules involving the formation of a C(sp<SUP>3</SUP>)–Si bond exclusively β to nitrogen is described. Triarylborane is a highly efficient catalyst (up to 1000 turnovers), and silanes serve as both a silyl source and a reducing reagent. The present procedure is convenient to perform even on a large scale with excellent stereoselectivity. Mechanistic studies revealed that the formation of a 1,4-addition adduct is rate-limiting while the subsequent C(sp<SUP>3</SUP>)–Si bond-forming step from the 1,4-adduct is facile.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2014/jacsat.2014.136.issue-48/ja510674u/production/images/medium/ja-2014-10674u_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja510674u'>ACS Electronic Supporting Info</A></P>

LWT Based ANN with Ant Lion Optimizer for Detection and Classifcation of High Impedance Faults in Distribution System

N. Narasimhulu,D. V. Ashok Kumar,M. Vijay Kumar 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

In this paper, the proposed wavelet-based methodology is developed to identify and classify the High Impedance Fault (HIF) in the Power Distribution System (PDS). The planned technique is based on the combination of Ant Lion Optimizer (ALO) and Artifcial Neural Network (ANN), which is performed to accurately isolate the HIF. The change in phase current waveforms caused by faults and normal switching events has been used in this methodology. In order to develop the method to detect high impedance arcing faults under the linear conditions. The faults are identifed through the computation of the basic electric descriptions of current and voltage signals. From the voltage and current signals, the harmonic components also computed. From the voltage, current signals, the fault are identifed and classifed in the system which can be able to solve the problem in the system. The harmonics level also analyzed which also detected and able to correct it for enabling the stable operation in the system. ANN is an Artifcial Intelligence (AI) method that applied for optimizing precise generation limits as blocking happened. The neural network contains two stages: training stage and testing stage. Here, the ALO algorithm is utilized to improve the performance of the ANN training process. ALO is a new nature-inspired algorithm mimicking the hunting behavior of ant lions. The design of Lifting Wavelet Transform (LWT) is suitable for the classifcation process. The main objective of ANN with the aid of the ALO algorithm is the detection and classifcation of the HIF in PDS and analyzed the delay time of diferent locations. From the evaluation of the proposed technique, the inputs and their corresponding outputs are noted. The performance of the work is implemented in MATLAB/Simulink platform and the presentation of this model is investigated on the basis of the two cases of analysis. The results show that the projected algorithm detects the HIFs accurately and compared with the existing methods ALO, GSA and ANN, and GA and Fuzzy, respectively.

Selective Silylative Reduction of Pyridines Leading to Structurally Diverse Azacyclic Compounds with the Formation of sp³ C–Si Bonds

Gandhamsetty, Narasimhulu,Park, Sehoon,Chang, Sukbok American Chemical Society 2015 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.137 No.48

<P>Tris(pentafluorophenyl)borane-catalyzed silylative reduction of pyridines has been developed giving rise to the formation of sp<SUP>3</SUP> C–Si bonds selectively beta to the nitrogen atom of azacyclic products. Depending on the position and nature of pyridine substituents, structurally diverse azacycles are obtained with high selectivity under the borane catalysis. Mechanistic studies elucidated the sequence of hydrosilylation in this multiple reduction cascade: 1,2- or 1,4-hydrosilylation as an initial step depending on the substituent position, followed by selective hydrosilylation of enamine double bonds eventually affording β-silylated azacyclic compounds.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2015/jacsat.2015.137.issue-48/jacs.5b09209/production/images/medium/ja-2015-09209p_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja5b09209'>ACS Electronic Supporting Info</A></P>

Therapeutic Potential of Ocimum tenuiflorum as MPO Inhibitor with Implications for Atherosclerosis Prevention

Chandrakala Aluganti Narasimhulu,Sangamithra Vardhan 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.5

Current experimental studies show that Ocimum tenuiflorum (commonly known as basil or Tulsi) possesses many health benefits. Ocimum is suggested to be antioxidative and anti-inflammatory. Eugenol, an orthomethoxyphenol, and ursolic acid have been identified as important components of basil. Myeloperoxidase (MPO), an oxidative enzyme, has been implicated in the pathogenesis of atherosclerosis. MPO-dependent oxidation of lipoproteins has been implicated in foam cell formation, dysfunctional HDL, and abnormalities in reverse cholesterol transport. Whole leaf extract of O. tenuiflorum and its major components, eugenol and ursolic acid, inhibit the oxidation of lipoproteins by myeloperoxidase/copper as measured by conjugated diene formation as well as by the thiobarbituric acid reactive substance (TBARS) assay. Whole basil leaf extract is able to attenuate the lipopolysaccharide-induced inflammation in RAW 264.7 cells compared with its components. In addition, whole basil leaf extract and eugenol inhibited MPO enzyme activity against synthetic substrates. Based on these results, we conclude that basil extract could act as an inhibitor of MPO and may serve as a nonpharmacological therapeutic agent for atherosclerosis.

Anti-Atherosclerotic and Anti-Inflammatory Actions of Sesame Oil

Chandrakala Aluganti Narasimhulu,Krithika Selvarajan,Dmitry Litvinov,Sampath Parthasarathy 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.1

Atherosclerosis, a major form of cardiovascular disease, has now been recognized as a chronic inflammatory disease. Nonpharmacological means of treating chronic diseases have gained attention recently. We previously reported that sesame oil has anti-atherosclerotic properties. In this study, we have determined the mechanisms by which sesame oil might modulate atherosclerosis by identifying genes and inflammatory markers. Low-density lipoprotein receptor knockout (LDLR- / - ) female mice were fed with either an atherogenic diet or an atherogenic diet reformulated with sesame oil (sesame oil diet). Plasma lipids and atherosclerotic lesions were quantified after 3 months of feeding. Plasma samples were used for cytokine analysis. RNA was extracted from the liver tissue and used for global gene arrays. The sesame oil diet significantly reduced atherosclerotic lesions, plasma cholesterol, triglyceride, and LDL cholesterol levels in LDLR- / - mice. Plasma inflammatory cytokines, such as MCP-1, RANTES, IL-1α, IL-6, and CXCL-16, were significantly reduced, demonstrating an anti-inflammatory property of sesame oil. Gene array analysis showed that sesame oil induced many genes, including ABCA1, ABCA2, APOE, LCAT, and CYP7A1, which are involved in cholesterol metabolism and reverse cholesterol transport. In conclusion, our studies suggest that a sesame oil-enriched diet could be an effective nonpharmacological treatment for atherosclerosis by controlling inflammation and regulating lipid metabolism.

Water-Soluble Components of Sesame Oil Reduce Inflammation and Atherosclerosis

Chandrakala Aluganti Narasimhulu,Krithika Selvarajan,Kathryn Young Burge,Dmitry Litvinov,Bhaswati Sengupta,Sampath Parthasarathy 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.7

Atherosclerosis, a major form of cardiovascular disease, is now recognized as a chronic inflammatory disease. Nonpharmacological means of treating chronic diseases have gained attention recently. We previously reported that sesame oil aqueous extract (SOAE) has anti-inflammatory properties, both in vitro and in vivo. In this study, we have investigated the antiatherosclerotic properties of SOAE, and the mechanisms, through genes and inflammatory markers, by which SOAE might modulate atherosclerosis. Low-density lipoprotein receptor (LDL-R) knockout female mice were fed with either a high-fat (HF) diet or an HF diet supplemented with SOAE. Plasma lipids and atherosclerotic lesions were quantified after 3 months of feeding. Plasma samples were used for global cytokine array. RNA was extracted from both liver tissue and the aorta, and used for gene analysis. The high-fat diet supplemented with SOAE significantly reduced atherosclerotic lesions, plasma cholesterol, and LDL cholesterol levels in LDL-R−/− mice. Plasma inflammatory cytokines were reduced in the SOAE diet-fed animals, but not significantly, demonstrating potential anti-inflammatory properties of SOAE. Gene analysis showed the HF diet supplemented with SOAE reduced gene expression involved in inflammation and induced genes involved in cholesterol metabolism and reverse cholesterol transport, an anti-inflammatory process. Our studies suggest that a SOAE-enriched diet could be an effective nonpharmacological treatment for atherosclerosis by controlling inflammation and regulating lipid metabolism.

Sesame Oil and an Aqueous Extract Derived from Sesame Oil Enhance Regression of Preexisting Atherosclerotic Lesions in Low-Density Lipoprotein Receptor Knockout Mice

Chandrakala Aluganti Narasimhulu,Aladdin Riad,Sampath Parthasarathy 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.7

Diet and exercise are recommended both as a prophylactic and as a therapeutic approach for patients with established coronary artery disease. We previously reported that sesame oil (SESO) and its aqueous extract (SOAE) showed antiatherosclerotic and anti-inflammatory properties. We also observed that genes involved in reverse cholesterol transport (RCT) might be activated. In this study, we tested whether post-treatment with SESO or SOAE would reduce preexisting atherosclerosis by enhancing RCT. Female low-density lipoprotein receptor knockout (LDL-R−/−) mice were fed an atherogenic diet for 3 months, followed by post-treatment with either control or SESO or SOAE for 1 month. Plasma lipids and atherosclerotic lesions were quantified at the end of the study. RNA was extracted from the aortic tissues and used for real-time polymerase chain reaction analysis. SESO and SOAE post-treatment significantly reduced atherosclerotic lesions in LDL-R−/− mice compared to controls. No significant change in plasma cholesterol, triglyceride, or LDL cholesterol levels was observed. Aortic gene analysis showed that the SESO/SOAE post-treatment reduced inflammatory gene expression and induced genes involved in cholesterol metabolism and RCT. This is the first study that demonstrates that post-treatment with SESO and SOAE could be an effective treatment for preexisting atherosclerosis and inflammation. The study also may suggest that reducing inflammation might be conducive to an accelerated regression of lesions.

New Synthetic Routes to Biologically Interesting Geranylated Acetophenones from Melicope Semecarpifolia and Their Unnatural Prenylated and Farnesylated Derivatives

Xia, Likai,Narasimhulu, Manchala,Li, Xin,Shim, Jae-Jin,Lee, Yong-Rok Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.3

This paper describes a new synthetic approach for biologically interesting geranylated acetophenones. The first total syntheses of 1-(5-geranyloxy-7-hydroxy-2,2-dimethyl-2H-chromen-8-yl)ethanone and 1-[5-geranyloxy-7-hydroxy-2-methyl-2-(4-methylpent-3-enyl)-2H-chromen-8-yl]ethanone, isolated from Melicope semecarpifolia, were carried out starting from commercially available 2,4,6-trihydroxyacetophenone.