01176nas a2200205   4500008004100000022001400041245009800055210006900153260011000222300001400332490000700346520034900353100002200702700002200724700002700746700001600773700002400789700002800813856012900841       2012                        eng d  a1477-052000aConformational modulation of Ant-Pro oligomers using chirality alteration of proline residues0 aConformational modulation of AntPro oligomers using chirality al  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a8426-84330 v103 a<p>Structural modulation of Ant-Pro (anthranilic acid-proline) oligomers has been carried out by chirality alteration of the proline residues. The results suggest that the chirality altered oligomers show well-defined helical conformation featuring nine-membered hydrogen bonding interactions - without compromising conformational rigidity.</p>1 aKale, Sangram, S.1 aKotmale, Amol, S.1 aDutta, Achintya, Kumar1 aPal, Sourav1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/conformational-modulation-ant-pro-oligomers-using-chirality-alteration-proline-residues-001336nas a2200229   4500008004100000022001400041245009600055210006900151260011000220300001400330490000700344520043900351100001700790700002200807700002300829700001900852700001600871700002600887700003500913700002800948856013000976       2012                        eng d  a1359-734500aHelical folding in heterogeneous foldamers without inter-residual backbone hydrogen-bonding0 aHelical folding in heterogeneous foldamers without interresidual  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL  a8922-89240 v483 a<p>This communication describes a set of hybrid foldamers that do not feature inter-residual, but intra-residual backbone hydrogen-bonding, yet adopt a preferentially folded conformation displaying right-handed helical architecture. Conformational ordering is apparently due to the combined conformational restrictions imposed by the conformationally restricted individual amino acid residues with which the oligomers are made of.</p>1 aPriya, Gowri1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aMishra, Deepti1 aPal, Sourav1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/helical-folding-heterogeneous-foldamers-without-inter-residual-backbone-hydrogen-bonding-001283nas a2200205   4500008004100000022001400041245007400055210006900129260011000198300001600308490000700324520048900331100002500820700001700845700002200862700002400884700003500908700002800943856010600971       2012                        eng d  a1359-734500aMultifaceted folding in a foldamer featuring highly cooperative folds0 aMultifaceted folding in a foldamer featuring highly cooperative   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a11205-112070 v483 a<p>Herein, we report on the folding pattern observed in a synthetic peptide featuring two highly mutually dependent, yet strikingly dissimilar, closed networks of hydrogen-bonded rings that work in a cumulative fashion to stabilize the entire folded architecture of the peptide. Structural studies unequivocally suggest that disruption of any one of these mutually-dependent hydrogen-bonded networks is deleterious to the stability of the fully folded conformation of the peptide.</p>1 aRamesh, Veera, V. E.1 aPriya, Gowri1 aKotmale, Amol, S.1 aGonnade, Rajesh, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/multifaceted-folding-foldamer-featuring-highly-cooperative-folds-001208nas a2200217   4500008004100000022001400041245011300055210006900168260011000237300001400347490000700361520030300368100003300671700002100704700002200725700002300747700002600770700003500796700002800831856013100859       2012                        eng d  a1359-734500aUnusual conformational similarity of two peptide folds featuring sulfonamide and carboxamide on the backbone0 aUnusual conformational similarity of two peptide folds featuring  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a9747-97490 v483 a<p>Two folded peptides featuring carboxamide and sulfonamide at the core of the peptide fold have been shown to possess almost similar conformational features, despite the well-known fact that carboxamides and sulfonamides have strikingly different hydrogen-bonding and geometrical preferences.</p>1 aVijayadas, Kuruppanthara, N.1 aDavis, Hilda, C.1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/unusual-conformational-similarity-two-peptide-folds-featuring-sulfonamide-and-carboxamide-001158nas a2200217   4500008004100000022001400041245010000055210006900155260007100224300001400295490000700309520033000316100002500646700002200671700002200693700002300715700002600738700002400764700002800788856012400816       2013                        eng d  a1523-706000aCarboxamide versus sulfonamide in peptide backbone folding: a case study with a hetero foldamer0 aCarboxamide versus sulfonamide in peptide backbone folding a cas  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR  a1504-15070 v153 a<p>Strikingly dissimilar hydrogen-bonding patterns have been observed for two sets of closely similar hetero foldamers containing carboxamide and sulfonamides at regular intervals. Although both foldamers maintain conformational ordering, the hydrogen-bonding pattern and backbone helical handedness differ diametrically.</p>1 aRamesh, Veera, V. E.1 aKale, Sangram, S.1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/carboxamide-versus-sulfonamide-peptide-backbone-folding-case-study-hetero-foldamer-002114nas a2200241   4500008004100000022001400041245008000055210006900135260011000204300001400314490000700328520119600335100003301531700002101564700002301585700002201608700002601630700002401656700002601680700003501706700002801741856010301769       2013                        eng d  a1477-052000aEster vs. amide on folding: a case study with a 2-residue synthetic peptide0 aEster vs amide on folding a case study with a 2residue synthetic  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a8348-83560 v113 a<p>Although known for their inferiority as hydrogen-bonding acceptors when compared to amides, esters are often found at the C-terminus of peptides and synthetic oligomers (foldamers), presumably due to the synthetic readiness with which they are obtained using protected peptide coupling, deploying amino acid esters at the C-terminus. When the H-bonding interactions deviate from regularity at the termini, peptide chains tend to ``fray apart''. However, the individual contributions of C-terminal esters in causing peptide chain end-fraying goes often unnoticed, particularly due to diverse competing effects emanating from large peptide chains. Herein, we describe a striking case of a comparison of the individual contributions of C-terminal ester vs. amide carbonyl as a H-bonding acceptor in the folding of a peptide. A simple two-residue peptide fold has been used as a testing case to demonstrate that amide carbonyl is far superior to ester carbonyl in promoting peptide folding, alienating end-fraying. This finding would have a bearing on the fundamental understanding of the individual contributions of stabilizing/destabilizing non-covalent interactions in peptide folding.</p>1 aVijayadas, Kuruppanthara, N.1 aNair, Roshna, V.1 aGawade, Rupesh, L.1 aKotmale, Amol, S.1 aPrabhakaran, Panchami1 aGonnade, Rajesh, G.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/ester-vs-amide-folding-case-study-2-residue-synthetic-peptide-001185nas a2200217   4500008004100000022001400041245006400055210006300119260011000182300001400292490000700306520039400313100002200707700001700729700002200746700002300768700002600791700002400817700002800841856009800869       2013                        eng d  a1359-734500aOrthanilic acid-promoted reverse turn formation in peptides0 aOrthanilic acidpromoted reverse turn formation in peptides  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a2222-22240 v493 a<p>Orthanilic acid (2-aminobenzenesulfonic acid, (S)Ant), an aromatic beta-amino acid, has been shown to be highly useful in inducing a folded conformation in peptides. When incorporated into peptide sequences (Xaa-(S)Ant-Yaa), this rigid aromatic beta-amino acid strongly imparts a reverse-turn conformation to the peptide backbone, featuring robust 11-membered-ring hydrogen-bonding.</p>1 aKale, Sangram, S.1 aPriya, Gowri1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/orthanilic-acid-promoted-reverse-turn-formation-peptides-001793nas a2200241   4500008004100000022001400041245013800055210006900193260007100262300001600333490000800349520084600357100002101203700002001224700002301244700002201267700002401289700002401313700002601337700003501363700002801398856012501426       2013                        eng d  a0002-786300aSynthetic zipper peptide motif orchestrated via co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality0 aSynthetic zipper peptide motif orchestrated via cooperative inte  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a11477-114800 v1353 a<p>Here, we report on a new class of synthetic zipper peptide which assumes its three-dimensional zipper-like structure via a co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality. Structural studies carried out in both solid- and solution-state confirmed the zipper-like structural architecture assumed by the synthetic peptide which makes use of unusually remote inter-residual hydrogen-bonding and aromatic stacking interactions to attain its shape. The effect of chirality modulation and the extent of noncovalent forces in the structure stabilization have also been comprehensively explored via single-crystal X-ray diffraction and solution-state NMR studies. The results highlight the utility of noncovalent forces in engineering complex synthetic molecules with intriguing structural architectures.</p>1 aNair, Roshna, V.1 aKheria, Sanjeev1 aRayavarapu, Suresh1 aKotmale, Amol, S.1 aJagadeesh, Bharatam1 aGonnade, Rajesh, G.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/synthetic-zipper-peptide-motif-orchestrated-co-operative-interplay-hydrogen-bonding-001408nas a2200217   4500008004100000022001400041245012300055210006900178260011000247300001200357490000700369520051400376100002100890700002200911700002400933700002300957700002600980700003501006700002801041856012101069       2014                        eng d  a1477-052000aFormation of a pseudo-beta-hairpin motif utilizing the Ant-Pro reverse turn: consequences of stereochemical reordering0 aFormation of a pseudobetahairpin motif utilizing the AntPro reve  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a774-7820 v123 a<p>Herein, we report a special case of pseudo-beta-hairpin formation by tetrapetide sequences featuring a two-membered Ant Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region. These folded structures uniquely feature the presence of C9- and C17-H-bonding patterns at reverse turn and interstrand regions, respectively. Their hairpin nucleation and folding propensities have been expounded using solution and solid state studies of distinct stereochemically altered sequences.</p>1 aNair, Roshna, V.1 aKotmale, Amol, S.1 aDhokale, Snehal, A.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/formation-pseudo-beta-hairpin-motif-utilizing-ant-pro-reverse-turn-consequences-001445nas a2200205   4500008004100000022001400041245009200055210006900147260011000216300001600326490000600342520063800348100001400986700002201000700002301022700002601045700002401071700002801095856011601123       2014                        eng d  a2046-206900aProbing the folding induction ability of orthanilic acid in peptides: some observations0 aProbing the folding induction ability of orthanilic acid in pept  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a13018-130250 v43 a<p>This paper describes the ability of orthanilic acid (2-aminobenzenesulfonic acid, (S)Ant) to promote folding when introduced in a peptide sequence. Three peptide sequences, containing orthanilic acid (SAnt) with a sulfonamide moiety in the turn segment, have been synthesized in the solution phase using suitable coupling agents, and their structural aspects investigated using NMR and X-ray crystallographic studies. Solid- and solution-state conformational analyses reveal that the peptide sequences containing orthanilic acid in their backbone exist in a folded conformation featuring long-range 15-membered ring H-bonding.</p>1 aRoy, Arup1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aPuranik, Vedavati, G.1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/probing-folding-induction-ability-orthanilic-acid-peptides-some-observations01662nas a2200193   4500008004100000022001400041245008600055210006900141260011000210300001200320490000700332520089000339100002201229700002401251700002701275700002401302700002201326856012001348       2015                        eng d  a1144-054600aBile acid hydrazides: gelation, structural, physical and spectroscopic properties0 aBile acid hydrazides gelation structural physical and spectrosco  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a453-4600 v393 a<p>Synthesis and gelation properties of a series of novel bile acid hydrazides are presented. These compounds are found to undergo self-assembly leading to organogelation in certain organic solvents. Compound 1 was found to be the most ``effective'' gelator in this series. The properties of this gel have been thoroughly investigated by conventional methods typical for molecular gel studies. Sol gel transition temperature (T-g) of chloroform gels of compounds 1 and 3 was found to increase with increase in the chain length. Sol-gel transition was probed using the isothermal time test and results show that there is instantaneous increase in both the moduli after shear melting, which suggests that the kinetics of formation of the network was very fast. IR and NMR studies revealed hydrogen bonding between amidic carbonyl in the side chain and hydroxyl groups of cholic acid.</p>1 aPore, Vandana, S.1 aAgalave, Sandip, G.1 aPharande, Shrikant, G.1 aPatil, Prashant, A.1 aKotmale, Amol, S.  uhttps://library.ncl.res.in/content/bile-acid-hydrazides-gelation-structural-physical-and-spectroscopic-properties-001228nas a2200205   4500008004100000022001400041245008900055210006900144260011000213300001400323490000700337520040000344100001700744700002200761700003100783700002600814700003500840700002800875856011900903       2015                        eng d  a1477-052000aConformational modulation of peptides using beta-amino benzenesulfonic acid ((S)Ant)0 aConformational modulation of peptides using betaamino benzenesul  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a2087-20910 v133 a<p>This communication describes the utility of a conformationally restricted aromatic beta-amino acid (2-aminobenzenesulfonic acid, (S)Ant) inducing various folding interactions in short peptides. Sandwiching (S)Ant between diverse amino acid residues was shown to form robust folded architectures featuring a variety of H-bonded networks, suggesting its utility in inducing peptide folding.</p>1 aPriya, Gowri1 aKotmale, Amol, S.1 aChakravarty, Debamitra, K.1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/conformational-modulation-peptides-using-beta-amino-benzenesulfonic-acid-sant-001314nas a2200217   4500008004100000022001400041245009500055210006900150260011000219300001400329490000700343520043700350100003300787700002200820700002500842700002400867700002100891700003500912700002800947856012100975       2015                        eng d  a1477-052000aReversal of H-bonding direction by N-sulfonation in a synthetic reverse-turn peptide motif0 aReversal of Hbonding direction by Nsulfonation in a synthetic re  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a3064-30690 v133 a<p>This communication depicts an intriguing example of hydrogen-bonding reversal upon introduction of a sulfonamide linkage at the N-terminus of a synthetic reverse-turn peptide motif. The ready availability of two sulfonyl oxygen atoms, as hydrogen-bonding acceptors, combined with the inherent twisted conformation of sulfonamides are seen to act as switches that engage/disengage the hydrogen-bond at the sticky ends/termini.</p>1 aVijayadas, Kuruppanthara, N.1 aKotmale, Amol, S.1 aThorat, Shridhar, H.1 aGonnade, Rajesh, G.1 aNair, Roshna, V.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/reversal-h-bonding-direction-n-sulfonation-synthetic-reverse-turn-peptide-motif-001978nas a2200193   4500008004100000022001400041245007100055210006900126260011000195300001400305490000700319520123400326100002001560700002101580700002201601700003501623700002801658856009801686       2015                        eng d  a1144-054600aRole of N-terminal proline in stabilizing the Ant-Pro zipper motif0 aRole of Nterminal proline in stabilizing the AntPro zipper motif  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a3327-33320 v393 a<p>Hetero-chiral hybrid peptides of the general sequence (L)alpha beta(D)(n)alpha beta(n) featuring proline (Pro, a constrained alpha-amino acid) and anthranilic acid (Ant, a constrained beta-amino acid) as building blocks, where n = 2, 4 etc., form a three-dimensional zipper-like architecture. These zipper peptides attain stable conformation by balancing the co-operative contribution of two competing non-covalent forces, namely hydrogen bonding and aromatic stacking. However, the selection of the N-terminal residue also stands to be one of the key contributors in stabilising the unusually long-range intramolecular hydrogen bond, featuring 26 atoms in the H-bonded ring observed at the termini. This article deals with the substitution alterations at the N-terminus of the zipper motif and their consequent influences on its structure and stability. In this study, the N-terminal Pro residue of the zipper motif was substituted with a flexible amino acid, alanine, and a constrained acyclic amino acid, 2-aminoisobutyric acid, to investigate the role of N-terminal proline in stabilizing the Ant-Pro zipper motif, and its stabilities were assessed by employing solution-state NMR and restrained MD simulation studies.</p>1 aKheria, Sanjeev1 aNair, Roshna, V.1 aKotmale, Amol, S.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/role-n-terminal-proline-stabilizing-ant-pro-zipper-motif-001551nas a2200193   4500008004100000245007200041210006700113260000800180300001400188490000700202520089000209100002401099700002201123700002301145700002401168700003501192700002801227856010201255       2016                        eng d00a3-Aminothiophenecarboxylic acid (3-Atc)-induced folding in peptides0 a3Aminothiophenecarboxylic acid 3Atcinduced folding in peptides  cSEP  a9205-92100 v403 aThis paper describes the consequences of incorporating a constrained heterocyclic aromatic b-amino acid 3-aminothiophenecarboxylic acid (3-Atc) into peptides containing beta-turn forming elements such as Pro-Gly motif and the effect on the secondary structural architecture of the entire peptide backbone. Conformational investigations of oligomers comprising an alpha,beta,alpha peptide sequence were carried out by single-crystal X-ray diffraction, solution-state NMR, nOe-restrained MD simulation and circular dichroism studies. The results suggested that these peptide sequences assume helical architecture. The helical folding in the oligomers was found to be devoid of inter-residual H-bonding, instead found to be stabilized by a co-operative effect of 6-membered H-bonding within the 3-Atc unit and conformational restrictions of individual amino acids in the peptide backbone.1 aIngole, Tukaram, S.1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aGonnade, Rajesh, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/3-aminothiophenecarboxylic-acid-3-atc-induced-folding-peptides01208nas a2200193   4500008004100000022001400041245012100055210006900176260011000245300001400355490000700369520038400376100002200760700002200782700003500804700001900839700002800858856012800886       2016                        eng d  a1359-734500aAngiotensin II analogs comprised of pro-amb (gamma-turn scaffold) as angiotensin II type 2 (AT(2)) receptor agonists0 aAngiotensin II analogs comprised of proamb gammaturn scaffold as  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a1645-16480 v523 a<p>We describe herein the design, synthesis and conformational investigation of Pro-Amb (proline-3-amino-2-methoxybenzoic acid) incorporated Angiotensin II and its truncated analogues. Solution-state NMR and CD studies suggest gamma-turn-like conformation in Pro-Amb analogs in aqueous solution. Furthermore, Pro-Amb analogs have been shown to act as AT(2) receptor agonists.</p>1 aJedhe, Ganesh, S.1 aKotmale, Amol, S.1 aRajamohanan, Pattuparambil, R.1 aPasha, Santosh1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/angiotensin-ii-analogs-comprised-pro-amb-gamma-turn-scaffold-angiotensin-ii-type-2-at2-001968nas a2200253   4500008004100000022001400041245017900055210006900234260007500303300001400378520096100392653001601353653002301369653001601392653002301408653002601431100001901457700002501476700001801501700001801519700002201537700002401559856013101583       2016                        eng d  a1434-193X00aBronsted-acid-mediated divergent reactions of betti bases with indoles: an approach to chromeno[2,3-b]indoles through intramolecular dehydrogenative C2-alkoxylation of indole0 aBronstedacidmediated divergent reactions of betti bases with ind  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJUL  a3441-34483 a<p>Divergent reactions of various 1-(aminoalkyl) naphthols and 2-(aminoalkyl) phenols (commonly known as Betti bases) with indoles under Bronsted acid catalysis is reported. With the reaction strategies, one can efficiently synthesize important indole derivatives such as 3-(alpha,alpha-diarylmethyl)indoles and chromeno[2,3-b]indoles. Furthermore, we disclose here a new C-C bond-cleavage reaction, in which naphthol and phenol behave as leaving groups to produce diarylmethanes. Inexpensive reagents such as p-toluenesulfonic acid monohydrate and molecular iodine are used to catalyze the reactions. No metal catalyst is required. The starting material of the reactions, Betti bases, are easily prepared from a three-component reaction of naphthol/phenol, aldehydes, and secondary amines. The mechanisms for the reactions are established through some control experiments. Quinone methide is the key intermediate for all the reactions reported herein.</p>10aBetti bases10aC-O bond formation10aDearylation10aFused-ring systems10anitrogen heterocycles1 aDeb, Mohit, L.1 aPegu, Choitanya, Dev1 aDeka, Bhaskar1 aDutta, Prantu1 aKotmale, Amol, S.1 aBaruah, Pranjal, K.  uhttps://library.ncl.res.in/content/bronsted-acid-mediated-divergent-reactions-betti-bases-indoles-approach-chromeno23-bindoles01813nas a2200265   4500008004100000022001400041245013800055210006900193260007500262300001400337520077500351653002601126653001901152653002001171653002601191100002401217700003301241700002201274700002201296700002301318700002401341700002401365700002801389856013001417       2016                        eng d  a1434-193X00aDisruption of native beta-turns: consequence of folding competition between native and orthanilic acid proline-based pseudo beta-turn0 aDisruption of native betaturns consequence of folding competitio  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAR  a1380-13883 a<p>Five tetrapeptides comprising beta-turn-forming elements and a pseudo beta-turn (C9 H-bonding) based on an SAntPro (orthanilic acid - proline) motif were designed and synthesized. Their extensive conformational investigation by single-crystal X-ray crystallography, solution-state 2D NMR spectroscopic, and nOe-restrained MD simulation studies revealed the formation of C14 or C9 folding and disruption of the native beta-turn (C10 H-bonding) architecture. The striking difference between the psi(psi(2)) angle of ``i + 2'' residues of native beta-turn and designed peptides suggest that formation of the native beta-turn is not favored. The results suggest that other turn-forming motifs can dramatically modulate the stability of the native beta-turn structure.</p>10aConformation analysis10ahydrogen bonds10aPeptidomimetics10astructure elucidation1 aIngole, Tukaram, S.1 aVijayadas, Kuruppanthara, N.1 aChaitanya, K., N.1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aGonnade, Rajesh, G.1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/disruption-native-beta-turns-consequence-folding-competition-between-native-and-orthanilic01436nas a2200229   4500008004100000022001400041245010700055210006900162260011000231300001600341490000600357520050500363100002200868700003300890700002200923700001900945700002300964700002400987700003501011700002801046856013201074       2016                        eng d  a2046-206900aResidue dependent hydrogen-bonding preferences in orthanilic acid-based short peptide beta-turn motifs0 aResidue dependent hydrogenbonding preferences in orthanilic acid  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a35328-353310 v63 a<p>This communication describes the competition between native beta-turn (C10) and 2-aminobenzenesulfonic acid (SAnt)( orthanilic acid)-based pseudo beta-turn (C11) in their hybrid peptides. Solid-state crystal structure and solution-state NMR studies revealed that C10 and C11 can be simultaneously observed under appropriate conditions. The variable temperature NMR coefficient data suggest that the isolated C11/C14 hydrogen bond is weaker in comparison with the consecutive C10 and C11 turns.</p>1 aJedhe, Ganesh, S.1 aVijayadas, Kuruppanthara, N.1 aKotmale, Amol, S.1 aSangtani, Ekta1 aShinde, Dinesh, R.1 aGonnade, Rajesh, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/residue-dependent-hydrogen-bonding-preferences-orthanilic-acid-based-short-peptide-beta-turn01184nas a2200193   4500008004100000245010500041210006900146260000800215300001400223490000700237520047500244100002000719700002300739700002200762700002300784700002400807700002800831856013100859       2017                        eng d00aCoumarin-appended stable fluorescent self-complementary quadruple-hydrogen-bonded molecular duplexes0 aCoumarinappended stable fluorescent selfcomplementary quadrupleh  cJUN  a6403-64080 v823 aIn this paper we report a coumarin-conjugated self-assembling system adorned with valuable features such as high duplex stability and a built-in fluorophore, which would augment its application potential. This system forms a highly :stalik molecular duplex in a nonpolar solvent (K-dim > 1.9 X 10(7) M-1 in CDCl3). Due to the fluorescent property of coumarin, these new structural motifs may find potential application in material chemistry and supramolecular chemistry.1 aKheria, Sanjeev1 aRayavarapu, Suresh1 aKotmale, Amol, S.1 aShinde, Dinesh, R.1 aGonnade, Rajesh, G.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/coumarin-appended-stable-fluorescent-self-complementary-quadruple-hydrogen-bonded-molecular01256nas a2200169   4500008004100000245010300041210006900144260000800213300001600221520059600237100002500833700002200858700002100880700003100901700002800932856012600960       2017                        eng d00aStructural insights into the hydrogen-bonding and folding pattern in ant-ant-pro-gly tetrapeptides0 aStructural insights into the hydrogenbonding and folding pattern  cMAY  a2944–29493 aIn this paper, we provide structural insights into the hydrogen-bonding and folding pattern in Ant-Ant-Pro-Gly tetrapeptides (Ant: anthranilic acid; Pro: proline; and Gly: glycine). Comparison of the C-terminal esters and their amide analogs revealed strikingly different H-bonding networks. Whereas the ester analogs displayed an open structure without terminal H-bonding interactions, the amide analogs showed a completely folded structure. Structural details were revealed by using a combination of X-ray crystal structure studies and NOE-based molecular dynamics (MD) simulation studies.1 aBaravkar, Sachin, B.1 aKotmale, Amol, S.1 aMobin, Samir, R.1 aGonnade, Rajesh, Ghanshyam1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/structural-insights-hydrogen-bonding-and-folding-pattern-ant-ant-pro-gly-tetrapeptides01395nas a2200157   4500008004100000245014800041210006900189260000800258490000700266520074400273100002001017700002301037700002201060700002801082856012701110       2017                        eng d00aThree in one: prototropy-free highly stable AADD-type self-complementary quadruple hydrogen-bonded molecular duplexes with built-in fluorophore0 aThree in one prototropyfree highly stable AADDtype selfcomplemen  cFEB0 v533 aThis communication reports an effective approach for addressing the prototropy-related problems in heterocycle-based AADD-type self-assembling systems by freezing their hydrogen-bonding codes, by utilizing intramolecular bifurcated hydrogen bonding interactions. Using this strategy, we have also developed a hydroquinone-conjugated AADD-type self-assembling system adorned with three valuable features such as prototropy-free dimerization yielding single duplexes, high duplex stability and a built-in fluorophore, which would augment its application potential. The rational approach used herein to arrest prototropic shift may also find application elsewhere, wherein proton shift-mediated structural changes become a detrimental factor.1 aKheria, Sanjeev1 aRayavarapu, Suresh1 aKotmale, Amol, S.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/three-one-prototropy-free-highly-stable-aadd-type-self-complementary-quadruple-hydrogen01064nas a2200181   4500008004100000245011700041210006900158260000800227300001200235490000700247520038000254100002000634700002300654700002200677700002400699700002800723856013100751       2017                        eng d00aTriazine-based highly stable AADD-type self-complementary quadruple hydrogen-bonded systems devoid of prototropy0 aTriazinebased highly stable AADDtype selfcomplementary quadruple  cJAN  a783-7870 v233 a<p>A new class of 1,3,5-triazine-based quadruple hydrogen-bonded system featuring AADD-type self-complementary arrays has been developed and characterized. This system forms highly stable molecular duplex in non-polar solvent (K-dim &gt; 1.9 x 10(7) M-1 in CDCl3) without prototropy-related issues, raising its prospects for application in supramolecular polymer science.</p>1 aKheria, Sanjeev1 aRayavarapu, Suresh1 aKotmale, Amol, S.1 aGonnade, Rajesh, G.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/triazine-based-highly-stable-aadd-type-self-complementary-quadruple-hydrogen-bonded-systems01323nas a2200205   4500008004100000245010100041210006900142260000800211300001400219490000700233520057900240100002200819700001900841700002400860700001900884700001900903700003500922700002800957856013200985       2018                        eng d00aConformational studies of Ant-Pro motif-incorporated cyclic peptides: gramicidin S and avellanin0 aConformational studies of AntPro motifincorporated cyclic peptid  cJAN  a1197-12010 v423 aThis paper reports conformational changes observed in cyclic bioactive peptides such as gramicidin S and avellanin upon incorporation of a pseudo-beta (C9) Ant-(D)Pro turn motif in their structural frameworks. Solution-state studies suggested that a synthetic gramicidin S analog exhibits a beta-sheet conformation with C9 and C17 intramolecular hydrogen bonding patterns, while its truncated analog disturbs the beta-sheet conformation. Structural details were obtained using a combination of CD studies, X-ray crystal structure studies and nOe-based MD simulation studies.1 aKotmale, Amol, S.1 aSangtani, Ekta1 aGonnade, Rajesh, G.1 aSarkar, Dhiman1 aBurade, Sachin1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/conformational-studies-ant-pro-motif-incorporated-cyclic-peptides-gramicidin-s-and-avellanin01217nas a2200181   4500008004100000245010000041210006900141260000800210300001400218490000600232520053900238100002800777700002600805700002200831700002400853700002800877856013000905       2018                        eng d00aHelically structured peptide architecture engineered using dimedone as a rigid organic scaffold0 aHelically structured peptide architecture engineered using dimed  cMAR  a2776-27800 v33 aThis communication reports the use of a rigid organic scaffold to attach two unsymmetrical peptide chains on a single carbon atom. The approach describes the step-by-step attachment of peptide chains to the rigid dimedone template (5,5-dimethyl-1,3-cyclohexanedione) - a molecular scaffold that directs orientation of the peptide helices in a well-defined arrangement via intra-molecular hydrogen bonding. The overall topology of the final molecules was studied using CD spectroscopy which suggested existence of helical architecture.1 aNadimpally, Krishna, C.1 aMadica, Krishnaprasad1 aKotmale, Amol, S.1 aGonnade, Rajesh, G.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/helically-structured-peptide-architecture-engineered-using-dimedone-rigid-organic-scaffold