@article { ISI:000328864800072, title = {First total synthesis of hunanamycin A}, journal = {Organic Letters}, volume = {15}, number = {17}, year = {2013}, month = {SEP}, pages = {4556-4559}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The first total synthesis of hunanamycin A, an antibiotic natural product with a pyrido[1,2,3-de]quinoxaline-2,3-dione core from a marine-derived Bacillus hunanensis, is disclosed. The present effort provides access to sufficient amounts of scarce hunanamycin A for further biological evaluation and confirmation of the assigned absolute configuration. In addition, four new analogues of the natural product are reported.

}, issn = {1523-7060}, doi = {10.1021/ol402110e}, author = {Shingare, Rahul D. and Velayudham, R. and Gawade, Jalindar R. and Reddy, D. Srinivasa} } @article { ISI:000339493400008, title = {General approach to N-heterocyclic carbenes with a fused tetracyclic core: ligands for suzuki-miyaura cross-coupling reaction}, journal = {European Journal of Organic Chemistry}, number = {21}, year = {2014}, month = {JUL}, pages = {4482-4486}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading.

}, keywords = {C-C coupling, carbenes, Homogeneous catalysis, N ligands, synthetic methods}, issn = {1434-193X}, doi = {10.1002/ejoc.201402378}, author = {Sutar, Revannath L. and Kumar, Vinod and Shingare, Rahul D. and Thorat, Shridhar and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article { ISI:000380599800018, title = {Multi-gram scale synthesis of hunanamycin A, an antibiotic natural product from the marine source}, journal = {Tetrahedron Letters}, volume = {57}, number = {32}, year = {2016}, month = {AUG}, pages = {3662-3663}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A simple, practical, and biomimetic approach to access antibiotic natural product hunanamycin A starting from readily available inexpensive material Riboflavin is disclosed here. The present synthesis consists of three operationally simple, protecting group free steps and it is far superior when compared with the previous route. Using this route one can make multi-gram quantities of the natural product which will help in further biological assays, in particular exploring the potential of treating food infections. (C) 2016 Elsevier Ltd. All rights reserved.

}, keywords = {Antibacterial, Biomimetic synthesis, Gram scale synthesis, Natural product, Riboflavin}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2016.07.003}, author = {Shingare, Rahul D. and Farhana, Sa Ada and Reddy, D. Srinivasa} } @article {42900, title = {Repurposing of a drug scaffold: identification of novel sila analogues of rimonabant as potent antitubercular agents}, journal = {European Journal of Medicinal Chemistry}, volume = {122}, year = {2016}, month = {OCT}, pages = {723-730}, abstract = {

The structural similarity between an MmpL3 inhibitor BM212, and a cannabinoid receptor modulator rimonabant, prompted us to investigate the anti-tubercular activity of rimonabant and its analogues. Further optimization, particularly through incorporation of silicon into the scaffold, resulted in new compounds with significant improvement in anti-tubercular activity against Mycobacterium tuberculosis (H37Rv). The sila analogue 18a was found to be the most potent antimycobacterial compound (MIC, 31 ng/mL) from this series with an excellent selectivity index. (C) 2016 Elsevier Masson SAS. All rights reserved.

}, doi = {10.1016/j.ejmech.2016.07.009}, author = {Ramesh, Remya and Shingare, Rahul D. and Kumar, Vinod and Anand, Amitesh and Swetha, B. and Veeraraghavan, Sridhar and Viswanadha, Srikant and Ummanni, Ramesh and Gokhale, Rajesh S. and Reddy, D. Srinivasa} } @article {45690, title = {Route to benzimidazol-2-ones via decarbonylative ring contraction of quinoxalinediones: application to the synthesis of flibanserin, A drug for treating hypoactive sexual desire disorder in women and marine natural product hunanamycin analogue}, journal = {ACS Omega}, volume = { 2 }, year = {2017}, month = {AUG}, pages = {5137-5141}, type = {Article}, abstract = {

A simple and practical method to access a variety of benzimidazol-2-ones is reported here. A series of N-alkylsubstituted benzimidazol-2-ones were synthesized by decarbonylative ring contraction starting from corresponding quinoxalinediones for the first time. The utility of the method has been demonstrated by synthesizing recently approved controversial drug flibanserin (Addyi) and a urea analogue of marine antibiotic natural product hunanamycin-A.

}, doi = {10.1021/acsomega.7b00819}, author = {Shingare, Rahul D. and Kulkarni, Akshay S. and Sutar, Revannath L. and Reddy, D. Srinivasa} } @article {45380, title = {Total synthesis of an anticancer natural product (+/-)-peharmaline A and its analogues}, journal = { European Journal of Organic Chemistry}, year = {2018}, month = {DEC}, pages = {6453-6456}, type = {Article}, abstract = {

First total synthesis of a rare beta-carboline-vasicinone hybrid alkaloid (+/-)-peharmaline A has been accomplished in just 3 steps starting from known compounds. Stereoselective Pictet-Spengler reaction to nitrogenated tertiary carbon center and one-pot construction of the tricyclic skeleton of vasicinone are the highlights of present synthesis. We have also synthesized structurally close analogues of the natural product by following the developed route.

}, issn = {1434-193X}, doi = {10.1002/ejoc.201800949}, author = {Kulkarni, Akshay S. and Shingare, Rahul D. and Dandela, Rambabu and Reddy, D. Srinivasa} } @article {48411, title = {Antibiotic natural product hunanamycin A: Lead identification towards anti-Salmonella agents}, journal = {European Journal of Medicinal Chemistry}, volume = {236}, year = {2022}, month = {JUN}, pages = {114245}, type = {Article}, abstract = {

Design and synthesis of library of compounds around the antibiotic natural product hunanamycin A scaffold and their biological evaluation are disclosed here. These efforts resulted in identification of a lead compound 36, which is a structurally simplified analogue of original hunanamycin A with impressive activity against Salmonella enterica and possesses other druggable properties. In addition, no acute oral toxicity was observed for compound 36 in Swiss albino mice dosed up to 2 g/kg. It has the potential to be developed for the treatment of food infections caused by Salmonella. (c) 2022 Published by Elsevier Masson SAS.

}, keywords = {Antibiotic natural product, Hunanamycin A, Riboflavin synthase, Salmonella, Structure activity relationship}, issn = {0223-5234}, doi = {10.1016/j.ejmech.2022.114245}, author = {Shingare, Rahul D. and MacMillan, John B. and Reddy, D. Srinivasa} } @article {48761, title = {Identification of new modulator of DNA repairing pathways based on natural product ({\textpm})-peharmaline A}, journal = {Bioorganic \& Medicinal Chemistry}, volume = {91}, year = {2023}, month = {AUG}, pages = {117365}, type = {Article}, abstract = {

The complex heterogenic environment of tumour mass often leads to drug resistance and facilitate chemo insensitivity triggering more malignant phenotypes among cancer patients. Major DNA-damaging cancer drugs have been consistently proven unsuccessful in terms of elevating chemo-resistance. (\& PLUSMN;)-peharmaline A, a hybrid natural product isolated from seeds of Peganum harmala L. possesses significant cytotoxic activities. Herein, we have described the design, and synthesis of a novel library of close and simplified analogues around the anticancer natural product (\& PLUSMN;)-peharmaline A and investigated their cytotoxic activities, which led to the identification of three structurally simplified lead compounds exhibiting better potency than parent natural product. Among them, demethoxy analogue of peharmaline A was further investigated for its anticancer potential eliciting demethoxy analogue as potent DNA-damage inducing agent attenuating the expression of the proteins responsible for the DNA damage repair. Therefore, this demethoxy analogue warrants detailed investigations for the confirmations of the molecular mechanism-based studies responsible for its anticancer activity.

}, keywords = {DNA damage, EMT, Pictet, Spengler reaction, Structure-activity relationship, Total synthesis}, issn = {0968-0896}, doi = {10.1016/j.bmc.2023.117365}, author = {Kulkarni, Akshay S. and Dash, Anshurekha and Shingare, Rahul D. and Chand, Jagdish and Manhas, Diksha and Singh, Aman and Nandi, Utpal and Goswami, Anindya and Reddy, D. Srinivasa} } @article {48826, title = {Synthesis, biological evaluation and docking studies of silicon incorporated diarylpyrroles as MmpL3 inhibitors: an effective strategy towards development of potent anti-tubercular agents}, journal = {European Journal of Medicinal Chemistry}, volume = {259}, year = {2023}, month = {NOV }, pages = {115633}, type = {Article}, abstract = {

Growing global demand for new molecules to treat tuberculosis has created an urgent need to develop novel strategies to combat the menace. BM212 related compounds were found to be potent anti-TB agents and they inhibit mycolic acid transporter, MmpL3, a known potent drug target from Mycobacterium tuberculosis. In order to enhance their inhibitory potency, several silicon analogues of diarylpyrroles related to BM212 were designed, synthesized, and evaluated for anti-tubercular activities. In Alamar blue assay, most of the silicon-incorporated compounds were found to be more potent than the parent compound (BM212), against Mycobacterium tuberculosis (MIC = 1.7 \& mu;M, H37Rv). Docking results from the crystal structure of MmpL3 and silicon analogues as pharmacophore model also strongly correlate with the biological assays and suggest that the incorporation of silicon in the inhibitor scaffold could enhance their potency by stabilizing the hydrophobic residues at the binding pocket. The best docking hit, compound 12 showed an MIC of 0.1 \& mu;M against H37Rv with an acceptable in vitro ADME profile and excellent selectivity index. Overall, the present study indicates that, the designed silicon analogues, especially compound 12 could be a good inhibitor for an intrinsically flexible drug-binding pocket of MmpL3 and has potential for further development as anti-tubercular agents.

}, keywords = {antibiotic, BM212, docking studies, MmpL3 inhibitor, Silicon analogue, tuberculosis}, issn = {0223-5234}, doi = {10.1016/j.ejmech.2023.115633}, author = {Vasudevan, N. and Motiwala, Zenia and Ramesh, Remya and Wagh, Sachin B. and Shingare, Rahul D. and Katte, Revansiddha and Anand, Amitesh and Choudhary, Sushil and Kumar, Ajay and Gokhale, Rajesh S. and Kulkarni, Kiran A. and Reddy, D. Srinivasa} }