List ofpuBRcations

List of papers published/communicated

[1] Synthesis of P-amino carbonyl derivatives of coumarin and benzofuran and

Evaluation of tiieir biological activity. Kenchappa.R. Yadav D. Bodke, S. K.

Peethambar, Sandeep Telkar, Venkatesh K. Bhovi; Medicinal Chemistry Research,

(2013)22:4787-4797.

[2] Synthesis of some 2, 6-bis (l-coumarin-2-yl)-4-(4-substituted phenyl) Pyridine

derivatives as Potent biological agents. Kenchappa.R Yadav D. Bodke, A.

Chandrashekar, Sandeep Telkar S. Manjunatha M. Aruna Sindhe; Arabian Journal

o/CAem/s/rv>doi.org/10.1016/j.arabjc.20I3.03.020.

[3] Synthesis antimicrobial and antioxidant activity of benzofiiran barbitone and

benzofUran thiobarbitone derivatives. Kenchappa.R. Yadav D. Bodke, Asha B,

Sandeep Telkar, Aruna Sindhe M; Medicinal Chemistry Research, DOI

10.1007/s00044-013-0892-x.

[4] Synthesis of coumarin derivatives fused with pyrazole and indenone rings as potent

antioxidant and antihyperglycemic agents. Kenchappa.R. Yadav D. Bodke, A.

Chandrashekar, M. Aruna Sindhe, S. K. Peethambar; Arab J Chem (Under review).

[5] Synthesis, antifungal, anthelmentic and molecular docking studies of novel

benzofuran derivatives containing thiazolo benzimidazole nucleus. Kenchappa.R,

Yadav D.Bodke, Asha B, Sharath pattar, Talavara Venkatesh, Sandeep Telkar;

European Journal of Medicinal Chemistry (communicated).

[6] Synthesis, analgesic and anti-inflammatory activity of some new substituted

benzofuran pyrazole derivatives. Kenchappa.R, Yadav D.Bodke, A. Chandrashekar,

Talavara Venkatesh, Nibin joy; Archiv der Pharmazie (communicated).

Articles (co-author)

[1] Synthesis of 6-arylimidazo [2, 1-6] [1, 3] thiazole and 2-aryl-7-methoxy imidazo

[2, 1-6] [1, 3] benzothiazole derivatives as potent biological agents. Yadav D. Bodke,

Shankarappa A Biradar, Kenchappa.R; Inventi Rapid: Med Chem, 2014(1): 1-7,

2013.

[2] Synthesis, characterization, antibacterial and analgesic activities of some coumarin

derivatives containing pyrazole and isoxazole moiety.Yadav.D.Bodke,

Kenchappa. R and Ramganesh C.K; Kuvempu University Science Journal

List of research papers presented at National/International Conferences

[1] Synthesis of some 3-(5-amino-l, 3, 4-oxadiazol-2-yl)-2i/-Chromen-2-one derivatives

as Antimicrobial Agents. Kenchappa R. Yadav D. Bodke and Venkatesh. K. Bhovi;

"International symposium on challenging in Drug Discovery Programe-2011",

(Febl6,17 2011) Kamataka state Open University, Manasagangothri, Mysore.

[2] Cerric Ammonium Nitrate (CAN) catalyzed one pot synthesis of P-amino

Benzofliran carbonyl derivatives by Mannich type reaction as potent antimicrobial

and antioxidant agents. Kenchappa. R Yadav D. Bodke and Chandrashekar

Aswathanarayanappa; "International Conference on Synthetic and Structural

Chemistry" (08-10*''Dec, 2011) Mangalore University, Mangalore.

[3] One pot Synthesis and Biological Evaluation of 2, 6-bis (l-coumarin-2-yl)-4-(4-

subtituted phenyl) pyridine derivatives. Kenchappa. R. Yadav D Bodke, Peethambar

S. K; Two day national conference on ''Impact of Chemical Biology on Society'

(NCIBS-2012, April 26,27), Kuvempu University Shankaraghatta.

[4] Synthesis, characterization and biological studies on novel 3-(2-oxo-2h-chromen-3-

yl)-l-phenyl-lH-pyrazole-4-carbaldehyde derivatives. Kenchappa.R, Yadav D

Bodke, Peethambar S. K; "e*"* International meeting on halogen Chemistry"

(HALCHEM, DEC 8-11, 2012), Indian Institute of science Bangalore.

[5] Synthesis, Characterization of some P-amino carbonyl derivatives of coumarin and

Evaluation of their biological activity. Kenchappa. R. Yadav D Bodke; Two day

State level conference on "5*" Annual KSTA conferene-2012 (DEC, 19-20 2012)"

Organized by Kamataka science and technology academy (KSTA), Bangalore.

[6] Synthesis of some thiazolo [3, 2-a] benzimidazole derivatives containing benzofuran

nucleus as potent biological agents. Yadav D. Bodke, Kenchappa.R; Two day

national conference on "Frontiers and challenges in biological organometallic

compounds" (FCBOM-2013, June 20-21) organized by M.S Ramaiah Institute of

technology Bangalore.

[7] Synthesis antimicrobial and antioxidant activity of benzofuran phenyl methylidene

pyrimidine 2, 4, 6(1 H, 3H, 5H)-trione, 2, 2-dimethyl-l, 3dioxane- 4, 6-dione and 2-

thioxodihydropyrimidine-4, 6 (IH, 5H)-diones.Yadav D. Bodke, Kenchappa.R;

"CRSI-Mid-year symposium" (July 12-13, 2013).Organized by Department of

Chemistry, NITK Suratkal, Mangalore.

[8] Synthesis, analgesic and anti-inflammatory activities of benzofuran derivatives fused

with pyrazole and indenone rings. Kenchappa.R. Yadav D.Bodke, Talavara

Venkatesh. Two day State level conference on "6"" Annual KSTA cconferene-2012

(DEC, 20-21 2013)". Organized by Kamataka science and technology academy

(KSTA), Bangalore.

Conferences, Seminars and Symposium (attended)

[1] National conference on "Emerging areas in Chemical and Biological Sciences",

during 23 & 24" March, 2007. Organized by the Dept. of Chemistry and Industrial

Chemistry, Kuvempu University, Shankaraghatta, Shimoga, Kamataka, India.

[2] National conference on "Chemistry and molecular nanotechnology for industry

and society" (Jan 16, 17, 2009). Kuvempu University Janna Sahydri,

Shankaraghatta, Shimoga.

[3] UGC sponsored national conference on "Recent Trends in Analytical Techniques"

2011 (19* Feb 2011) D.R.M Science College, Davanagere.

[4] Three day workshop on "Research Methodology" (26, 27 and 28"" 2011), Kuvempu

University Janna Sahydri, Shankaraghatta, Shimoga.

[5] National workshop on "Usage of instruments for Nanotechnology

appIications":@Dept. of Nano science and Technology, Kuvempu University, Janna

Sahyadri, Shankaraghatta, Shimoga.(April 25*, 2011).

[6] Two days National conference on 'Progress in Biomedical Research and its

impact on human health (01, 02. April, 2012)' organized by Dept. of

Biochemistry, Kuvempu University, Shankaraghatta.

Arabian Journal of Chemistry (20) 3) xxx, xxx-xxx

King Saud University

Arabian Journal of Chemistry

www.lcsu.edu,sa www.sciencedircct.com

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^Y^ CHEMICAL f

ORIGINAL ARTICLE

Synthesis of some 2, 6-bis (l-coumarin-2-yl)-4-(4-substituted phenyl) pyridine derivatives as potent biological agents

R. Kenchappa ^ Yadav D. Bodke ^'% A. Chandrashekar '*''', Sandeep Telkar ^ K.S. Manjunatha •", M. Aruna Sindhe ^

^ Department of P.O. Studies and Research in Industrial Chemistry, School of Chemical Science. JnanaSahyadri, Kuvempu University, Shankaraghatta, 577 451 Shivamogga. Karnataka. India ^ Biocon Ltd., 20th KM, Hosur Road, Electronic City, Bangalore 560 100. Karnataka, India '^ Department of P.O. Studies and Research in Biotechnology and Bioinjormatics, Jnanasahyadri, Kuvempu University, Shankaraghatta 577 451, Karnataka, India

Department of P.O. Studies and Research in Pharmaceutical Cliemistry, Kuvempu University, P.O. Centre, Kadur, 577 548 Chikkamagaluru Dt., Karnataka. India

Received 27 September 2012; accepted 29 March 2013

KEYWORDS ,

Coumarin; Dicoumarinyl pyridines; Chichibabin; Antimicrobial; Glucosamine-6-phosphate synthase; Antioxidant

Abstract A convenient one-pot, three-component synthesis of 2, 6-bis (i-coumarin-2-yl)-4-(4-substituted phenyl) pyridine derivatives (3a-k) by Chichibabin reaction has been reported. These compounds were synthesized by the reaction of 3-acetyl coumarin (la) or 5-bromo 3-acetyl couma­rin (lb) with substituted aromatic aldehydes (2a-k) and ammonium acetate under acidic conditions and the structure was confirmed by FT-IR, ' H N M R , ' ^C N M R and Mass spectroscopic methods. The newly synthesized compounds (3a-k) were evaluated for antimicrobial activity, DPPH free rad­ical scavenging activity and ferrous lon-chelating ability. The mode of action of these active com­pounds was carried out by docking receptor GlcN6P synthase. Compounds 3a, 3b, 3c, and 3d have displayed potential antimicrobial activity and some of the compounds have shown promising anti­oxidant properties.

© 2013 Production and hostmg by Elsevier B.V. on behalf of King Saud University.

Corresponding author. Tel.: +91 8282256228; fax: +91 8282256225.

E-mail addresses: ydbodkc(njgmail.com, yd_bodkccaiyahoo.co.in (Y.D. Bodkc). Peer review under responsibility of King Saud University.

Production and hosting by Eisevier

1. Introduction

Coumar in derivatives conta in ing pyridine heterocycle (Brahmbhatt and Pandya, 2001, 2003; Brahmbhatt et al., 2004, 2005, Brahmbhatt et al., 2007; Niraj et al., 2010) are known to exhibit anticoagulant, antibacterial and antifungal activities (Brahmbhatt et al., 2010). Pyridine scaffolds have been found in numerous naturally occurring compounds and are also frequently used in functional materials (Muller and Bunz, 2007; McKillop and Boulton. 1984; Jones, 1996; Spitzner, 2004). Pyridine-diol derivatives are of particular interest as building

1878-5352 © 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University. http;//dx.doi.org/10.1016/j.arabjc.20I3.03.020

Please cite this article in press as: Kenchappa, R. et al., Synthesis of some 2, 6-bis (l-coumarin-2-yl)-4-(4-substituted phenyl) pyridine derivatives as potent biological agents. Arabian Journal of Chemistry (2013), http://dx.doi.Org/10.1016/j.arabjc.2013.03.020

Med Chem Res (2013) 22 4787^797 DOI 10 1007/s00044-On-0494-7

MEDIQNAL CHEMISTRY RESEARCH

ORIGINAL RESEARCH

Synthesis of P-amino carbonyl derivatives of coumarin and benzofuran and evaluation of their biological activity

R. Kenchappa • Yadav D. Bodke • S. K. Peethambar Sandeep Telkar • Venkatesh K. Bhovi

Received 1 September 2012/Accepted 11 January 2013/Published online 25 January 2013 © Spnnger Science+Business Media New York 2013

Abstract A series of p-ammo carbonyl compounds con­taining coumann (4a-h) and benzofuran (6a-i) moieties was synthesized by a three component Mannich reaction of 3-acetyl-2//-chromen-2-one (1) or l-(l-benzofuran-2-yl) ethanone (5) with p-substjiuied aromatic aldehydes (2a-g) and aromatic amines (3a-b) in the presence of cerric ammonium nitrate as a catalyst The newly synthesized compounds were screened for antimicrobial and antioxi­dant activities Compounds 4b, 4e, 4f, 6f, 6g, and 6i showed microbial inhibition with minimal inhibition con­centration ranging between 0 040 and 0 500 mg/mL, compounds 4b, 4c, 6e, 6e, and 6i showed promising free radical scavenging activity and compounds 4b, 4f, 6c, 6d, and 6h showed good chelating ability with Fe "*" ions The synthesized compounds were studied for docking on the enzyme, glucosamine-6-phosphate synthase to predict the binding atfinity and orientation at the active site of the receptor.

R Kenchappa Y D Bodke (EI) V K Bhovi Deparlmeni of P G Studies and Research in Industrial Chemistry, Jnana Sahyadn, Kuvempu University Shankaraghatta, Shivamogga 577451, Karnataka, India e-mail yd_bodke@yahoo co in, ydbodke@gmail com

S K Peethambar Department of P G Studies and Research in Biochemistry, Jnana Sahyadn, Kuvempu University, Shankaraghatta, Shivamogga 577451, Karnataka, India

S Telkar Department of P G Studies and Research in Biotechnology, Jnana Sahyadn, Kuvempu University, Shankaraghatta, Shivamogga 577451, Karnataka, India

Keywords Cerric ammonium nitrate P-amino ketones Antimicrobial Antioxidant Glucosamine-6-phosphate synthase

Introduction

Derivatives of coumarin and benzofuran have been found to exhibit a variety of biological and pharmacological activities and have raised considerable interest because of their potential effects on human health (Kennedy and Thomes, 1997, Hoult and Paya, 1996) Coumann, the potent basic pharmacodynamic nucleus, has been reported to possess a wide variety of biological properties, viz, antibacterial, antifungal, antioxidant (Melagraki et al., 2009), anti­inflammatory, analgesic, anticancer, anthelmintic, and anti­convulsant (Sandhya et al, 2011) Benzo[b]furan deriva­tives have been an important class of organic compounds which are known to be present in many natural products and possess physiological activity (Venkatesh e/a/ ,2010) Most of the compounds prepared from 2-acetylbenzofurans have antimicrobial, antitumor, anti-inflammatory, fungicidal, weed-killing activity, and were used for treatment of cardiac arrhythmias (Basawaraj et al, 2001, Abdel-Wahab et al., 2009, Dawood e r a / , 2006)

In recent years, cerium ammonium nitrate has been employed as a multipurpose promoter for a wide range of synthetically useful reactions (Hong-Juan Wang et al, 2011) However, most examples require stoichiometric quantities of CAN (Sridharan and Menendez, 2010) Cenc ammonium nitrate has emerged as an important reagent for the construction of carbon-carbon and carbon-heteroatom bonds In addition, many advantages such as solubility in water, cost-effectiveness, eco-fnendly nature, easy han­dling, high reactivity, and facile work-up procedures made

^ Springer

Med Chem Res

DOI 10 1007/S00044-013-0892-X

MEDIQNAL CHEMISTRY RESEARCH

ORIGINAL RESEARCH

Synthesis, antimicrobial, and antioxidant activity of benzofuran barbitone and benzofuran thiobarbitone derivatives

R. Kenchappa • Yadav D. Bodke • B. Asha • Sandeep Telkar • M. Aruna Sindhe

Received 5 October 2013/Accepted 12 December 2013 © Spnnger Science+Business Media New York 2013

Abstract The synthesis of novel series of benzofuran derivatives, containing barbitone moiety, 5-[(2/4-substi-tutedphenyl)(5-substituted-1 -benzofuran-2-y 1) methyhdene] pynmidm-2,4,6(lH,3H,5//)-tnone (4a-i) and thiobarbitone moiety, 5-[(2/4-substitutedphenyl)(5-substituted-l-benzo furan-2-yl)methyhdene] 2-thioxodihydropynmidin-4,6(l//, 5//)-dione (5a-i) have been reported The target com­pounds (4a-i) and (5a-i) were synthesized by the Knoe-venagel condensation of (5-substituted-l-benzofuran-2 yl) (2/4-substitutedphenyl) methanone (3a-i) with barbitunc acid and thiobarbitunc acid, respectively, in acid medium These compounds were screened for the antimicrobial and antioxidant activities From antimicrobial activity results it was found that compounds 4a, 5a, 4c, and 5c displayed good antibacterial and antifungal activity against all tested strains Further, the synthesized compounds were studied for docking on the enzyme, Glucosamine-6-phosphate synthase and the compounds 4c and 5c have emerged has an active antimicrobial agent with least binding energy (-5 27 and - 4 85 kJ moP') Compounds 4e, 4f, 5e, and 5f showed promising free radical scavenging activity and

R Kenchappa Y D Bodke ( S ) M Aruna Sindhe Department of P G Studies and Research m Industrial Chemistry, Jnana Sahyadri Kuvempu University, Shankaraghatta, Shivamogga 577451, Karnataka, India e-mail yd_bodke@yahoo co in, ydbodke@gmail in

B Asha Department of P G Studies and Research in Applied Botany, Jnana Sahyadri Kuvempu University Shankaraghatta, Shivamogga 577451, Karnataka, India

S Telkar Department of PG Studies and Research m Biotechnology, Jnana Sahyadn, Kuvempu University, Shankaraghatta Shivamogga 577451, Karnataka, India

compounds 5a and 5b showed good chelating ability with Fe "*" ions

Keywords Benzofuran Barbiturates Knoevenagel condensation Antimicrobial Antioxidant Docking

Introduction

The resistance of pathogenic bacteria toward available antibiotics is rapidly becoming a major worldwide prob­lem On the other hand, primary and opportunistic fungal infections continue to grow rapidly because of the increased number of immune compromised patients (Grange and Zumla, 2002, Guzeldemirci and Kucukb-asmaci, 2010) In order to combat this new problem, novel, structurally diverse antibiotic compounds are required (Francesca, 2011)

Benzofuran heterocycles exhibit a broad range of bio­logical activities Recently, compounds containing metha­none linkage between the benzofuran at C-2 position and aromatic rings have been investigated and reported as antimicrobials (Koca el al, 2005, Kinlmis et al, 2008, Bondock et al,20\\, Jiang et al, 2011, Liu et al, 2012, Rajanarendar et al, 2013), novel SIRTl inhibitors (Wu et al, 2013), anticancer (Parekh et a/, 2011), and antiox­idant agents (Karatas et al, 2006) Also, benzofuran-2-yl(phenyl)methanone analogs displayed anti tumor (Agat-suma et al, 2004), antitubercular (Manna and Agrawal, 2010, 2011), dnti-inflammatory, analgesic (Rajanarendar et al, 2013), CYP19 inhibitory activity, molecular docking (Saberi et al, 2006), and cytotoxicity properties (Bigler et al, 2007, Saberi et al, 2006) Cloridarol, a 2-substituted benzofuran is used for treatment of lipidemia and has

Published online 27 December 2013 & Springer

RESEARCH ARTICLE inVCrXllI Knowledge

Synthesis of 6-Arylimidazo [2,1-b] [1, 3] Thiazole and 2-Aryl"7-Methoxy Imidazo [2, l-b][l, 3] Benzothiazole Derivatives as Potent Biological Agents

Yadav D Bodkei*, S A Biradar^ R Kenchappai

Abstract: In the present investigation, new antimicrobial agents, arylimidazo [2,1 b] [1,3] thiazoles C3a e) and imidazo [2,1 b] [1,3] benzothiazoles (5a-h), have been synthesized The structure of newly synthesized compounds was characterized by NMR, mass spectral data and elemental analyses The antimicrobial activity was carried out against various Gram positive. Gram-negative bacteria and fungi Some of the compounds exhibited moderate to good activity as compared to the standard drugs Preliminary structure activity observations revealed that the presence of fluoro, chloro, cyano or nitro functional groups in the synthesized compounds enhanced the antimicrobial activity significantly compared to other substituents Further, the synthesized compounds were screened for antioxidant (DPPH method) property and compounds 3a and 5a showed promising scavenging activity with DPPH free radicals

INTRODUCTION Human beings have been in constant exposure to pathogenic bacteria for many decades Although several antibacterial agents are currently available, there is clearly a critical need for the development of new specific antibacterial agents 11 The widespread use of antifungal and antibacterial drugs and the fast development of pathogen resistance to most of the known antibiotics is becoming a serious problem 11 So, it has become quite difficult to eradicate these microbial infections l l Nitrogen containing heterocyclic compounds are reported to be effective against many of these pathogens '''1

During recent years, there have been intense investigations on imidazo [2, 1-b] [1, 3] thiazole moiety which has been used extensively in medicinal chemistry The imidazo[2,l b][l,3] thiazole derivatives possess versatile biological properties such as diuretic, antitumor, (51 anti-inflammatory, 1*1 immunosuppressive, I' i antimicrobial, antitubercular I'l and analgesic activity H" m Benzothiazole moieties have diverse biological activities and are of great scientific interest nowadays They have been widely studied in the areas of bioorganic and medicinal chemistry with numerous applications in drug discoveries. Drugs containing benzothiazole moiety are reported to possess numerable biological activities such as antimicrobial, (' is) anticancer, ['<> '^i anti helmentic f'J antidiabetic, I "! anti tuberculosis, l i 221 antiviral, 1" z-*! as well as antitumor l s 26] Predominantly, imidazo [2,1 b] [1, 3] benzothiazoles are known to possess anti-infiammatory, antimicrobial properties and also used as diuretic agents [27 30]

Therefore, it is envisaged that chemical entities with imidazo [2, 1-b] thiazoles and imidazo [2, 1-b] [1, 3] benzothiazoles moieties would result in compounds of interesting biological activities In view of these findings, we have synthesized the title compounds containing both imidazo [2, 1-b] thiazoles and imidazo [2, 1-b] [1, 3]

'Department of Post Graduate Studies and Research 1 Chemistry Kuvempu University Shankaraghatta 577451 India E mail ydbodke@gmail com •Corresponding author

Industrial Karnataka

benzothiazole heterocyclic ring systems in order to investigate the effect of such molecular variation on the antimicrobial and antioxidant activities

METHODS Melting points were determined on a Buchi Melting Point B 545 apparatus and are uncorrected Reactions were monitored and purity of the products was checked by TLC performed on Merck 60 F 254 silica gel plates with visualization by UV-light using ethyl acetate and n-hexane as solvent system 'H NMR spectra were recorded on Bruker (400 MHz) spectrometer instrument in DMSO-rfe and chemical shifts [6} weie recorded in parts per million downfield from tetramethylsilane Mass spectra were recorded on LC-MS Agilent 1100 series with MSD (ion trap) using 0 1% aqueous TFA in acetonitrile system on C18-BDS column for 10 mm duration and elemental analyses were performed on Thermo Finningan FLASH EA 1112 CHN analyzer Analysis results were within + 0 5% of the calculated value Column chromatography was performed on silica gel (230-400 mesh) supplied by Acme Chemical Co (India)

Synthesis of 6-{3, 4-Disubstitutedphenyl) Imidazo [2,1-b] [1, 3] Thiazole Derivatives (3a-e) The mixture of 1, 3 thiazol-2-amine (2) (0 001 mol) and 2-bromo 1 (3,4 disubstituted phenyl)ethanone (la e) (0 001 mol) m dry ethanol was refluxed at 85-95°C for about 6-B h the completion of the reaction was monitored by TLC and the products were isolated and recrystallized using ethanol

6-(3, 4-Dichlorophenyl) Imidazo [2, l b ] [1, 3] Thiazole (3a) Yield 62%, mp 296 298°C, 'H NMR (DMSG-de) 6 9 52(lH,s), 8 48(lH,s), 8 10-8 07(2H, d, 7=10), 7 84-7 81(2H, d,y=10 4), 7 71-7 69 (lH,d,/=8 4), 7 43-7 42(1H, d, 7=4 4), 13C NMR(DMSO de] 6 149 8 142 4, 133 8, 132 1, 131 5, 130 2, 126 9, 125 4, 120 9, 115 5, 111 6, MS, m/z = 270 (M-), 272 (M+2), 274 (M+4), Anal Cald. for C11H6CI2N2S C, 49 09, H, 2.25, N, 10 4 1 % Found: C, 49.11, H, 2 29, N, 10 44%.

Invent! Rapid Med Chem Vol 2014 Issue 4 [ISSN 0976 3821]

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