@article {43219, title = {Simple procedure for the synthesis of gamma-hydroxy-alpha,beta-(E)-alkenoic esters: formal synthesis of (+)-macrosphelides A and B}, journal = {Tetrahedron Letters}, volume = {46}, year = {2005}, month = {MAR}, pages = {2287-2290}, abstract = {A highly trans-selective conjugate reduction of 7-hydroxy-alpha,beta-alkynoic esters to produce gamma-hydroxy-alpha,beta-(E)-alkenoic esters using LiAlH4 is reported. The application of this methodology is demonstrated by a formal synthesis of the potent cell-cell adhesion inhibitors (+)-macrosphelides A and B. (c) 2005 Elsevier Ltd. All rights reserved.}, author = {Rao, K. Srinivasa and Mukkanti, K. and Reddy, D. Srinivasa and Pal, Manojit and Lqbal, Javed} } @article {43221, title = {Synthesis of small cyclic peptides constrained with 3-(3-aminomethylphenyl)propionic acid linkers using free radical-mediated macrocyclization}, journal = {Tetrahedron Letters}, volume = {46}, year = {2005}, month = {AUG}, pages = {5207-5210}, abstract = {In this letter, we report that small peptides (di- and tri-) having a 3-bromobenzyl group at the C-termini and an acryloyl group at the N-termini undergo an efficient Bu3SnH-AlBN mediated intramolecular free radical cyclization to afford cyclic peptides in good yields. We also propose that these cyclizations are occurring via a pre-organized acyclic structure dictated by a reverse turn (gamma/beta-turn). (c) 2005 Published by Elsevier Ltd.}, doi = {10.1016/j.tetlet.2005.05.115}, author = {Balraju, V. and Reddy, D. Srinivasa and Periasamy, M. and Iqbal, Javed} } @article {43213, title = {Synthesis of cyclic peptides using a palladium-catalyzed enyne cycloisomerization}, journal = {Tetrahedron Letters}, volume = {47}, year = {2006}, month = {MAY}, pages = {3569-3571}, abstract = {In this letter, we report a palladium-catalyzed enyne cycloisomerization of linear peptides to generate small cyclic peptides embedded with a conjugated 1,3-diene. The utility of these resulting macrocyclic dienes is demonstrated by carrying out [4+2] cycloadditions with dienophiles to generate constrained cyclic peptides with cyclic linkers. (c) 2006 Elsevier Ltd. All rights reserved.}, doi = {10.1016/j.tetlet.2006.03.053}, author = {Balraju, V. and Dev, R. Vasu and Reddy, D. Srinivasa and Iqbal, Javed} } @article { ISI:000286577400023, title = {Synthesis of molluscicidal agent cyanolide a macrolactone from D-(-)-pantolactone}, journal = {Journal of Organic Chemistry}, volume = {76}, number = {3}, year = {2011}, month = {FEB}, pages = {963-966}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

An efficient synthesis of potent molluscicidal agent cyanolide A, a glycosidic 16-membered macrolide, starting from D-(-)-pantolactone is reported. Highly stereoselective aldol, oxa-Michael addition, and Yamaguchi macrolactonization are the key steps in the present synthesis.

}, issn = {0022-3263}, doi = {10.1021/jo101782q}, author = {Hajare, Atul K. and Ravikumar, Velayutham and Khaleel, Shaik and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000293436100018, title = {Synthesis of novel dihydrooxazine and oxazoline based sugar hybrids from sugar azides}, journal = {Tetrahedron Letters}, volume = {52}, number = {33}, year = {2011}, month = {AUG}, pages = {4313-4315}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A convenient one-step method for the synthesis of novel dihydrooxazine and oxazoline based sugar hybrids is reported starting from the readily accessible sugar azides and aldehydes. We have used Aube{\textquoteright}s protocol to achieve this transformation. The resulting glycoconjugates could be used to increase the diversity on the sugar backbone and may find applications as potential glycomimetics and in drug discovery. (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Dihydrooxazine, Glycoconjugate, Hydroxy azide, Oxazoline, Sugar azide, Sugar hybrids}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2011.06.035}, author = {Kurhade, Suresh E. and Ravula, Sudhir and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000312564500027, title = {Studies toward the synthesis of potent anti-inflammatory peptides solomonamides A and B: synthesis of a macrocyclic skeleton and key fragment 4-amino-6-(2 {\textquoteleft}-amino-4 {\textquoteleft}-hydroxyphenyl)-3-hydroxy-2-methyl-6-oxohexanoic acid (AHMOA)}, journal = {Organic Letters}, volume = {14}, number = {24}, year = {2012}, month = {DEC}, pages = {6222-6225}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A first synthetic effort toward total synthesis of highly potent solomonamides is disclosed. An efficient strategy to synthesize this class of compounds, along with the synthesis of a core macrocycle (shown in red) and the key fragment AHMOA, is described.

}, issn = {1523-7060}, doi = {10.1021/ol303149k}, author = {Kashinath, K. and Vasudevan, N. and Reddy, D. Srinivasa} } @article { ISI:000310947900007, title = {Synthesis of isomeric corniculatolides}, journal = {Tetrahedron Letters}, volume = {53}, number = {47}, year = {2012}, month = {NOV}, pages = {6343-6346}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Synthesis of three natural macrolides 11-O-methylcorniculatolide A, 11-O-methylisocorniculatolide A and isocorniculatolide A is reported using a simple, straight forward and high-yielding route. The present synthesis confirms the assigned molecular structures and provides an access to sufficient quantities of the natural products for the biological evaluation. In addition, we have determined the anti-TB potential of the three natural compounds using Alamar-Blue assay (H(37)Rv) and found no significant inhibitory activity at 100 mu g/ml. Excellent yields, short sequence and useful SAR information are the highlights of the present work. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Diaryl ether, Isocorniculatolide, Macrocyclization, Mitsunobu reaction, Total synthesis}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2012.09.010}, author = {Raut, Gajanan N. and Chakraborty, Kasturi and Verma, Priyanka and Gokhale, Rajesh S. and Reddy, D. Srinivasa} } @article { ISI:000320979500046, title = {Syntheses and determination of absolute configurations and biological activities of the enantiomers of the longtailed mealybug pheromone}, journal = {Journal of Organic Chemistry}, volume = {78}, number = {12}, year = {2013}, month = {JUN}, pages = {6281-6284}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (S)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (R)-(-)-enantiomer was benign, being neither attractive nor inhibitory.

}, issn = {0022-3263}, doi = {10.1021/jo400491n}, author = {Ramesh, Remya and Swaroop, Pandrangi Siva and Gonnade, Rajesh G. and Thirupath, Choppari and Waterworth, Rebeccah A. and Millar, Jocelyn G. and Reddy, D. Srinivasa} } @article { ISI:000321490900014, title = {Synthesis of a sex pheromone of the longtailed mealybug, pseudococcus longispinus}, journal = {Synthesis-Stuttgart}, volume = {45}, number = {12}, year = {2013}, month = {JUN}, pages = {1689-1692}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

The synthesis of a recently identified and highly active sex pheromone of the longtailed mealybug, Pseudococcus longispinus is reported. A concise synthetic route, use of the under explored Meyer-Schuster rearrangement, Claisen rearrangement, and ring-closing metathesis are the highlights of this work.

}, keywords = {Acylation, Metathesis, pheromones, rearrangement, Total synthesis}, issn = {0039-7881}, doi = {10.1055/s-0033-1338450}, author = {Kurhade, Suresh E. and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000316693100020, title = {Synthesis of palmyrolide A and its cis-isomer and mechanistic insight into trans-cis isomerisation of the enamide macrocycle}, journal = {Chemical Communications}, volume = {49}, number = {32}, year = {2013}, month = {MAR}, pages = {3342-3344}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Concise and protecting-group free synthesis of ent-palmyrolide A and (-)-cis-palmyrolide A were achieved starting from commercially available (S)-citronellal. The key fragment of palmyrolide A, {\textquoteleft}{\textquoteleft}(5S,7S)-7-hydroxy-5,8,8-trimethylnonanamide{\textquoteright}{\textquoteright}, which makes up the most challenging part of the target molecule, was prepared in just three steps. A plausible mechanism for the trans-cis isomerization of the double bond in the macrocycle has been investigated.

}, issn = {1359-7345}, doi = {10.1039/c3cc40541a}, author = {Philkhana, Satish Chandra and Seetharamsingh, B. and Dangat, Yuvraj B. and Vanka, Kumar and Reddy, D. Srinivasa} } @article { ISI:000364803200006, title = {Silicon incorporated morpholine antifungals: design, synthesis, and biological evaluation}, journal = {ACS Medicinal Chemistry Letters}, volume = {6}, number = {11}, year = {2015}, month = {NOV}, pages = {1111-1116}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Known morpholine class antifungals (fenpropimorph, fenpropidin, and amorolfine) were synthetically modified through silicon incorporation to have 15 sila-analogues. Twelve sila-analogues exhibited potent antifungal activity against different human fungal pathogens such as Candida albicans, Candida glabrata, Candida tropicalis, Cryptococcus neoformans, and Aspergillus niger. Si la-analogue 24 (fenpropimorph analogue) was the best in our hands, which showed superior fungicidal potential than fenpropidin, fenpropimorph, and amorolfine. The mode of action of sila-analogues was similar to morpholines, i.e., inhibition of sterol reductase and sterol isomerase enzymes of ergosterol synthesis pathway.

}, keywords = {Antifungal drugs, Candida albicans, ergosterol biosynthesis, morpholines, sila-analogues}, issn = {1948-5875}, doi = {10.1021/acsmedchemlett.5b00245}, author = {Jachak, Gorakhnath R. and Ramesh, Remya and Sant, Duhita G. and Jorwekar, Shweta U. and Jadhav, Manjusha R. and Tupe, Santosh G. and Deshpande, Mukund V. and Reddy, D. Srinivasa} } @article { ISI:000356927800001, title = {Synthesis of novel N-cyclopentenyl-lactams using the aube reaction}, journal = {Beilstein Journal of Organic Chemistry}, volume = {11}, year = {2015}, month = {JUN}, pages = {1060-1067}, publisher = {BEILSTEIN-INSTITUT}, address = {TRAKEHNER STRASSE 7-9, FRANKFURT AM MAIN, 60487, GERMANY}, abstract = {

A novel and convenient method utilizing the Aube reaction to access a new class of compounds that are similar to carbocyclic nucleosides is reported. The azido alcohol derived from Vince lactam undergoes the Aube reaction with various cyclic ketones to give cyclopentenyl-substituted lactams. Upon dihydroxylation, this affords the N-cyclopentenyl-lactam compounds in racemic form. Given the numerous uses of nucleosides and related compounds, we were interested in the synthesis of carbocylic nucleoside mimics. The attempts and results are described herein.

}, keywords = {Aube reaction, Biological activity, carbocyclic nucleosides, cyclopentenylated lactams, cyclopentylated lactams}, issn = {1860-5397}, doi = {10.3762/bjoc.11.119}, author = {Shinde, Madhuri V. and Ople, Rohini S. and Sangtani, Ekta and Gonnade, Rajesh G. and Reddy, D. Srinivasa} } @article {42897, title = {Solution-phase synthesis of the macrocyclic core of teixobactin}, journal = {European Journal of Organic Chemistry}, volume = {25}, year = {2016}, month = {SEP}, pages = {4289-4293}, abstract = {

Towards the total chemical synthesis of the exceptionally potent antibiotic teixobactin, we synthesized the macrocyclic core of a natural product by using a solution-phase approach. The gramscale synthesis of L-allo-enduracididine and Shiina macrolactonization are highlights of the present disclosure.

}, author = {Dhara, Santu and Gunjal, Vidya B. and Handore, Kishor L. and Reddy, D. Srinivasa} } @article {42896, title = {Synthesis and biological evaluation of palmyrolide a macrocycles as sodium channel blockers towards neuroprotection}, journal = {Organic \& Biomolecular Chemistry}, volume = {14}, year = {2016}, month = {AUG}, pages = {8457-8473}, abstract = {

Palmyrolide A is a neuroprotective macrolide isolated by Gerwick and coworkers in 2010. This natural product is known to suppress neuronal spontaneous calcium ion oscillations through its voltage-gated sodium channel blocking ability which is of significant interest in CNS drug discovery. Herein, we give a detailed account on total synthesis of (+)-palmyrolide A and synthesis of a focused library of macrocycles around the scaffold, followed by their biological evaluation. Use of the chiral pool approach, Zhu{\textquoteright}s oxidative homologation, access to unnatural cis-palmyrolide A, preparation of 18 new analogues and identification of macrolides with improved sodium channel blocking activity are the important features of the present paper. As a measure of potency as voltage-gated sodium channel blockers, all the synthesized analogues were profiled for their ability to inhibit the veratridine-stimulated Na+ influx in murine primary neuronal cultures. Four macrocycles were found to be more potent or comparable to that of the natural product (-)-palmyrolide A. The most potent compound from this series 20 was structurally simplified and readily accessible in good quantities for further biological profiling.

}, author = {Philkhana, Satish Chandra and Mehrotra, Suneet and Murray, Thomas F. and Reddy, D. Srinivasa} } @article { ISI:000377612300008, title = {Synthesis of revised structure of klaivanolide (acetylmelodorinol)}, journal = {Arkivoc}, number = {2}, year = {2016}, month = {OCT}, pages = {116-122}, publisher = {ARKAT USA INC}, address = {C/O ALAN R KATRITZKY, UNIV FLORIDA, DEPT CHEMISTRY, PO BOX 117200, GAINESVILLE, FL 32611 USA}, abstract = {

Klaivanolide (acetylmelodorinol) is an anti-leishmanial/anti-trypanosomal agent isolated from Uvaria klaineana and the structure was originally assigned as a 7-membered lactone with extended conjugation and S-configuration at the lactone junction. Very recently, the structure of klaivanolide was revised as previously known compound acetylmelodorinol. Now, we have synthesized the revised structure in racemic form using a short route.

}, keywords = {acetylmelodorinol, Klaivanolide, leishmaniasis, Natural product}, issn = {1551-7004}, doi = {10.3998/ark.5550190.p009.231}, author = {Raut, Gajanan N. and Wagh, Sachin B. and Reddy, D. Srinivasa} } @article {44618, title = {Specific stereoisomeric conformations determine the drug potency of cladosporin scaffold against malarial parasite}, journal = {Journal of Medicinal Chemistry}, volume = {61}, year = {2018}, month = {JUL}, pages = {5664-5678}, abstract = {

The dependence of drug potency on diastereomeric configurations is a key facet. Using a novel general divergent synthetic route for a three-chiral center antimalarial natural product cladosporin, we built its complete library of stereoisomers (cladologs) and assessed their inhibitory potential using parasite-, enzyme-, and structure-based assays. We show that potency is manifest via tetrahyropyran ring conformations that are housed in the ribose binding pocket of parasite lysyl tRNA synthetase (KRS). Strikingly, drug potency between top and worst enantiomers varied 500-fold, and structures of KRS-cladolog complexes reveal that alterations at C3 and C10 are detrimental to drug potency whereas changes at C3 are sensed by rotameric flipping of glutamate 332. Given that scores of antimalarial and anti-infective drugs contain chiral centers, this work provides a new foundation for focusing on inhibitor stereochemistry as a facet of antimicrobial drug development.

}, issn = {0022-2623}, doi = {10.1021/acs.jmedchem.8b00565}, author = {Das, Pronay and Babbar, Palak and Malhotra, Nipun and Sharma, Manmohan and Jachak, Goraknath R. and Gonnade, Rajesh G. and Shanmugam, Dhanasekaran and Harlos, Karl and Yogavel, Manickam and Sharma, Amit and Reddy, D. Srinivasa} } @article {46163, title = {Scalable synthesis of cladosporin}, journal = {Tetrahedron Letters}, volume = {60}, year = {2019}, month = {MAR }, pages = {831-833}, type = {Article}, abstract = {

Cladosporin, a secondary metabolite isolated from fungal sources like Cladosporium cladosporioides and Aspergillus flavus was found to exhibit selective nano-molar activity against malarial parasite Plasmodium falciparum by inhibiting parasitic protein biosynthesis. In addition, this natural product has a broad range of bioactivities including, antiparasitic, antifungal, antibacterial as well as plant growth inhibition. However, it has limited availability from the natural sources for further development. Herein, we report a modified and improved synthetic route which led us to produce this potent natural product in a gram scale. Conversion of the undesired diastereomer to desired one via Mitsunobu inversion of secondary alcohol and carbon monoxide insertion reaction towards the construction of isocoumarin unit are the key features of the present synthesis. (C) 2019 Elsevier Ltd. All rights reserved.

}, keywords = {Anti-malarials, Cladosporin, Mitsunobu, Total synthesis}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2019.02.012}, author = {Das, Pronay and Mankad, Yash and Reddy, D. Srinivasa} } @article {46212, title = {Synthesis of chiral tetrahydrofuran building blocks from pantolactones: application in the synthesis of empagliflozin and amprenavir analogs}, journal = {Europen Journal of Organic Chemistry}, year = {2019}, month = {JUL}, type = {Article}, abstract = {

Chiral 4,4-dimethyl tetrahydrofuran (THF) derivatives were synthesized from commercially available D-(-)/ l-(+) pantolactones, which can serve as chiral building blocks in medicinal chemistry. In addition, two of the synthesized building blocks were utilized for the synthesis of new amprenavir (HIV protease inhibitor) and empagliflozin (anti-diabetic) analogs. The synthesized analogs may have beneficial effects in terms of pharmacokinetics and modulation of bioactivity.

}, doi = {10.1002/ejoc.201900718}, author = {Athawale, Paresh R and Kumari, Neeta and Kashinath, K and Reddy, D. Srinivasa} } @article {46820, title = {Synthesis of alpha-ketoamides using potassium superoxide (KO2) as an oxidizing agent}, journal = {Tetrahedron}, volume = {76}, year = {2020}, month = {JUN }, pages = {131262}, type = {Article}, abstract = {

A simple and convenient method for the synthesis of alpha-ketoamides by the oxidation of aryl acetamides using potassium superoxide (KO2) as an oxidizing agent is disclosed here. The scope of the developed method is successfully tested with fifteen substrates. In addition, the utility of method has been demonstrated by synthesizing an orexin receptor antagonist, a medicinally interesting compound. (C) 2020 Published by Elsevier Ltd.

}, keywords = {alpha-Ketoamide, Orexin receptor, Oxidation, Potassium superoxide (KO2)}, issn = {0040-4020}, doi = {10.1016/j.tet.2020.131262}, author = {Vasudevan, N. and Routholla, Ganesh and Illa, Giri Teja and Reddy, D. Srinivasa} } @article {47423, title = {Scalable, sustainable and catalyst-free continuous flow ozonolysis of fatty acids}, journal = {Green Chemistry}, volume = {23}, year = {2021}, month = {MAR}, pages = {2391-2396}, type = {Article}, abstract = {

A simple and efficient catalyst-free protocol for continuous flow synthesis of azelaic acid is developed from the renewable feedstock oleic acid. An ozone and oxygen mixture was used as the reagent for oxidative cleavage of double bond without using any metal catalyst or terminal oxidant. The target product was scaled up to more than 100 g with 86\% yield in a white powder form. Complete recycling and reuse of the solvent were established making it a green method. The approach is significantly energy efficient and also has a very small chemical footprint. The methodology has been successfully tested with four fatty acids making it a versatile platform that gives value addition from renewable resources.

}, issn = {1463-9262}, doi = {10.1039/d0gc04021e}, author = {Atapalkar, Ranjit S. and Athawale, Paresh R. and Reddy, D. Srinivasa and Kulkarni, Amol A.} } @article {47691, title = {Separation of a diastereomeric diol pair using the mechanical properties of crystals}, journal = {Crystengcomm}, volume = {23}, year = {2021}, month = {OCT}, pages = {7056-7060}, type = {Article}, abstract = {We report the separation of a (2S,3R/S)-3-ethyl-1-phenylhex-5-ene-2,3-diol (ephd) diastereomeric pair with visually indistinguishable acicular morphologies based on their mechanical responses, which is found to be more efficient than conventional separation methods. Furthermore, the molecular crystals of (2S,3R)-ephd show elastic deformation, while (2S,3S)-ephd fractures in a brittle manner under similar conditions.}, doi = {10.1039/d1ce01055g}, author = {Gamidi, Rama Krishna and Dandawate, Monica and Choudhury, Rahul and Tothadi, Srinu and Nangia, Ashwini and Reddy, D. Srinivasa} } @article {47699, title = {Synthesis and biological evaluation of hoshionolactam-based compounds}, journal = {European Journal of Organic Chemistry}, volume = {2021}, year = {2021}, month = {APR }, pages = {2212-2218}, type = {Article}, abstract = {In search of novel antitrypanosomal agents based on hoshinolactam (IC50=3.9 nM), we disclose the synthesis and biological evaluations of 14 different analogues of the natural product using combinations of different acids and lactams. Antitrypanosomal activity assays revealed that the synthesized analogues were less potent than the parent natural product.}, keywords = {Hoshinolactam, Ozonolysis, Parasitic diseases, Trypanosoma}, issn = {1434-193X}, doi = {10.1002/ejoc.202001588}, author = {Jachak, Gorakhnath R. and Elizebath, Drishya and Shukla, Anurag and Shanmugam, Dhanasekaran and Reddy, D. Srinivasa} } @article {48764, title = {Scalable synthesis of silacyclohexanones and ready access to silicon building blocks}, journal = {Organic Letters}, volume = {25}, year = {2023}, month = {SEP }, pages = {6881-6885}, type = {Article}, abstract = {

A simple and efficient two-step method for the synthesis of silacyclohexanones starting from bis(bromoethylsilanes) using TosMIC is presented. The prepared silacyclohexanones were transformed to nine different heterocycles with silicon incorporation. In addition, the developed methodology was used for the synthesis of a sila analogue of the HDAC6 inhibitor tubastatin A.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.3c02561}, author = {Ramesh, Eagala and Nandawadekar, Laxman D. and Rao, Ramana Sreenivasa 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} } @article {49277, title = {Synthesis of benzofuran-6-carboxylic acid, an intermediate of lifitegrast with low-carbon footprints}, journal = {ACS SUSTAINABLE CHEMISTRY \& ENGINEERING}, volume = {12}, year = {2024}, month = {OCT}, pages = {15671-15681}, type = {Journal Article}, keywords = {benzofuran-6-carboxylicacid, dry eye disease, life cycle, lifitegrast, process development}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.4c06361}, author = {Zade, Vishal M. and Athawale, Paresh R. and Kopperi, Harishankar and Mohan, S. Venkata and Reddy, D. Srinivasa} } @article {49723, title = {Scalable and sustainable reductive amidation of nitroarenes, nitroalkenes, and nitroalkyls with acyl saccharins in aqueous media}, journal = {Communications Chemistry}, volume = {8}, year = {2025}, month = {JUN}, pages = {184}, type = {Article}, abstract = {

Amide bond formation is essential in both organic and medicinal chemistry, however, most existing methods present poor ecological efficiency. Here, we report a scalable and sustainable method for synthesizing N-substituted amides from nitroarenes, nitroalkenes, nitroalkyls, and acyl saccharin in aqueous media. This atom-efficient approach avoids column chromatography, offers high yield, and is compatible with various functional groups. It is applicable to synthesize Dispyrin, a bromopyrrole alkaloid, amide-based drugs, and agrochemicals, including paracetamol, with solvent and saccharin recycling. A comprehensive Life Cycle Assessment (LCA; ISO 14044) was conducted to evaluate the environmental impacts and sustainability of nine Active Pharmaceutical Ingredients (APIs) produced via Amidation Route (AR) and Saccharin Amidation Route (SAR). The study shows SAR methods reduce carbon footprints and environmental impacts compared to AR methods, being carbon-negative and resource-efficient. Additional reductions can be achieved through saccharin recycling and the integration of renewable energy sources, demonstrating saccharin-based processes potential to minimize environmental burdens in pharmaceutical synthesis.

}, issn = {2399-3669}, doi = {10.1038/s42004-025-01464-8}, author = {Khamkar, Sunil L. and Mohan, Rayala and Santhosh, J. and Shinde, Harish M. and Handore, Kishor L. and Mohan, S. Venkata and Reddy, D. Srinivasa} } @article {49727, title = {Silicon incorporated tacrine: design, synthesis, and evaluation of biological and pharmacokinetic parameters}, journal = {RSC Medicinal Chemistry}, volume = {16}, year = {2025}, month = {JUN}, pages = {2603-2614}, type = {Article}, abstract = {

Tacrine, an orally bioavailable cholinesterase inhibitor, was previously used to treat Alzheimer{\textquoteright}s disease but was withdrawn due to hepatotoxicity. The unique structural features of tacrine have once again captured the interest of medicinal chemists. However, the blood-brain barrier (BBB) permeability hampered the development of the majority of its new analogs. Herein, we employed a silicon switch approach for improving the BBB permeability of CNS drugs with tacrine as a tool compound. The replacement of C2 methylene of tacrine with dimethyl silicon yielded {\textquoteleft}sila-tacrine{\textquoteright} that inhibits acetylcholinesterase as well as butyrylcholinesterase with IC50 values of 3.18 and 6.09 mu M, respectively. Sila-tacrine competitively inhibits acetylcholinesterase while it is a non-competitive inhibitor of butyrylcholinesterase. The molecular docking results corroborated with the in vitro cholinesterase inhibition activity of tacrine vs. sila-tacrine. Sila-tacrine demonstrated metabolic stability in HLM and MLM and exhibited superior plasma exposure in an oral pharmacokinetic study in Swiss albino mice. However, tissue distribution studies revealed lower-than-expected brain levels due to efflux pump-mediated transport. This study offers a proof-of-concept for the silicon switch approach in improving the BBB permeability of CNS-active compounds.

}, doi = {10.1039/d5md00019j}, author = {Kulkarni, Akshay S. and Ramana, Sreenivasa Rao and Nuthakki, Vijay K. and Bhatt, Shipra and Jamwal, Ashiya and Nandawadekar, Laxman D. and Jotshi, Anshika and Kumar, Ajay and Nandi, Utpal and Bharate, Sandip B. and Reddy, D. Srinivasa} }