@article {46429, title = {Efficient and convenient route for the synthesis of thiophene-2-carboxamidines as potential inhibitors of nitric oxide synthase (NOS)}, journal = {Tetrahedron Letters}, volume = {60}, year = {2019}, month = {NOV}, pages = {151254}, type = {Article}, abstract = {

A mild and efficient synthesis of substituted thiophene-2-carboxamidines which are potent inhibitors of nitric oxide synthase (NOS) is reported herein. The key step involves reaction of a BOC-protected imidazolyl thiophene-2-carboxamidine reactive intermediate with various primary amines to form BOC-thio-phene-2-carboxamidines which could be readily deprotected using TFA to furnish free carboxamidines. The method is very mild and tolerates diverse substituents including sensitive peptide and amino acid fragments. This new methodology represents a substantial improvement to the literature method owing to its simplicity and hassle-free purification procedures. (C) 2019 Elsevier Ltd. All rights reserved.

}, keywords = {Amidines, Nitric oxide synthase (NOS), Nitric oxide synthase inhibitors, Thiophene-2-carboxamidines}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2019.151254}, author = {Rashid, P. P. and Singh, Dharmendra and Sanjayan, Gangadhar J.} } @article {46894, title = {Novel cilengitide-based cyclic RGD peptides as alpha nu beta(3) integrin inhibitors}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {30}, year = {2020}, month = {APR}, pages = {127039}, type = {Article}, abstract = {

In this letter, we report a series of five new RGD-containing cyclic peptides as potent inhibitors to alpha nu beta(3) integrin protein. We have incorporated various unnatural lipophilic amino acids into the cyclic RGD framework of cilengitide, which is selective for alpha nu beta(3) integrin. All the newly synthesized cyclic peptides were evaluated in vitro solid phase binding assay and investigated for their binding behaviour towards integrin subtypes. All the cyclic peptides were synthesized in excellent yield following solution-phase coupling strategy. The cyclic RGD peptides 1a-e exhibited IC50 of 9.9, 5.5, 72, 11 and 3.3 nM, respectively, towards a alpha nu beta(3) integrin protein. This finding offers further opportunities for the introduction unusual amino acids into the cyclic peptide framework of cilengitide.

}, keywords = {Anticancer drugs, Cilengitide, Integrins, RGD cyclicpeptides}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2020.127039}, author = {Meena, Chhuttan L. and Singh, Dharmendra and Weinmueller, Michael and Reichart, Florian and Dangi, Abha and Marelli, Udaya Kiran and Zahler, Stefan and Sanjayan, Gangadhar J.} } @article {47064, title = {Triazine-based janus G-C nucleobase as a building block for self-assembly, peptide nucleic acids, and smart polymers}, journal = {Journal of Organic Chemistry}, volume = {86}, year = {2021}, month = {FEB }, pages = {3186-3195}, type = {Article}, abstract = {

This communication reports on the utility of a triazine-based self-assembling system, reminiscent of a Janus G-C nucleobase, as a building block for developing (1) supramolecular polymers, (2) peptide nucleic acids (PNAs), and (3) smart polymers. The strategically positioned self-complementary triple H-bonding arrays DDA and AAD facilitate efficient self-assembly, leading to a linear supramolecular polymer.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.0c02530}, author = {Meena, Chhuttan L. and Singh, Dharmendra and Kizhakeetil, Bhavya and Prasad, Manasa and George, Malini and Tothadi, Srinu and Sanjayan, Gangadhar J.} } @article {48922, title = {Carbamate-Protected (BOC and O-NB) 2-Aminopyrimidinedione-based janus G-C nucleobase motifs as building blocks for supramolecular assembly and smart polymers}, journal = {Journal of organic chemistry }, volume = {88}, year = {2023}, month = {OCT }, pages = {14953-14959}, type = {Article}, abstract = {

In this paper, we report {\textquoteleft}{\textquoteleft}carbamate protected{\textquoteright}{\textquoteright} 2-aminopyrimidinedione-based Janus G-C nucleobases (2-APD Janus G-C nucleobases) featuring polymerizable groups and self-complementary triple H-bonding motifs DDA and AAD as building blocks for developing smart polymers and self-healing materials. The carbamate-masked H-bonding motif, cleavable under acidic (BOC group) or photocleavable (O-nitrobenzyl group) conditions, would facilitate the synthesis of smart polymers by alleviating aggregation during polymerization which in turn would exclude self-assembly-assisted solubility issues. Ready accessibility in excellent yields coupled with the possibility for facile introduction of polymerizable groups would make these building blocks excellent candidates for diverse polymerization applications.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.3c01318}, author = {Singh, Dharmendra and Lakshmi, Durga and Meena, Chhuttan L. and Krishna, Gamidi Rama and Sanjayan, Gangadhar J.} } @article {49445, title = {Block copolymer self-assembly: exploitation of hydrogen bonding for nanoparticle morphology control via incorporation of triazine based comonomers by RAFT polymerization}, journal = {Small}, volume = {20}, year = {2024}, month = {OCT}, pages = {2401129}, type = {Article}, abstract = {

Synthesis of polymeric nanoparticles of controlled non-spherical morphology is of profound interest for a wide variety of potential applications. Self-assembly of amphiphilic diblock copolymers is an attractive bottom-up approach to prepare such nanoparticles. In the present work, RAFT polymerization is employed to synthesize a variety of poly(N,N-dimethylacrylamide)-b-poly[butyl acrylate-stat-GCB] copolymers, where GCB represents vinyl monomer containing triazine based Janus guanine-cytosine nucleobase motifs featuring multiple hydrogen bonding arrays. Hydrogen bonding between the hydrophobic blocks exert significant influence on the morphology of the resulting nanoparticles self-assembled in water. The Janus feature of the GCB moieties makes it possible to use a single polymer type in self-assembly, unlike previous work exploiting, e.g., thymine-containing polymer and adenine-containing polymer. Moreover, the strength of the hydrogen bonding interactions enables use of a low molar fraction of GCB units, thereby rendering it possible to use the present approach for copolymers based on common vinyl monomers for the development of advanced nanomaterials.

}, doi = { https://doi.org/10.1002/smll.202401129}, author = {Haque, Farah and Thompson, Steven W. and Ishizuka, Fumi and Kuchel, Rhiannon P. and Singh, Dharmendra and Sanjayan, Gangadhar J. and Zetterlund, Per B.} } @article {49287, title = {Synthesis and film formation of aqueous emulsion polymer latexes featuring hydrogen bonding via a janus guanine-cytosine base monomer}, journal = {ACS APPLIED POLYMER MATERIALS}, volume = {6}, year = {2024}, month = {MAY }, pages = {6495-6507}, type = {Journal Article}, keywords = {Emulsion polymerization, Film formation, Hydrogenbonding, Supramolecular networks}, issn = {2637-6105}, doi = {10.1021/acsapm.4c00738}, author = {Thompson, Steven W. and Li, Joanna and Singh, Dharmendra and Sanjayan, Gangadhar J. and Zetterlund, Per B.} }