@article { ISI:000255774700006, title = {Rigid bicyclo[3.3.0]octane (octahydropentalene): a heavily constrained novel aliphatic template for molecular self-assembly}, journal = {Tetrahedron Letters}, volume = {49}, number = {19}, year = {2008}, month = {MAY}, pages = {3056-3059}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

This Letter reports the utility of a heavily constrained cis-fused bicyclo[3.3.0]octane (octahydropentalene) aliphatic template for effecting molecular self-assembly. An attractive feature of this system is its heavily constrained alicyclic backbone that would allow for the exploration of self-assembling systems with conformationally ordered features. (C) 2008 Elsevier Ltd. All rights reserved.

}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2008.03.062}, author = {Kendhale, Amol M. and Gonnade, Rajesh G. and Rajamohanan, P. R. and Sanjayan, Gangadhar J.} } @article { ISI:000350674400031, title = {Reversal of H-bonding direction by N-sulfonation in a synthetic reverse-turn peptide motif}, journal = {Organic \& Biomolecular Chemistry}, volume = {13}, number = {10}, year = {2015}, month = {MAR}, pages = {3064-3069}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

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.

}, issn = {1477-0520}, doi = {10.1039/c4ob02438a}, author = {Vijayadas, Kuruppanthara N. and Kotmale, Amol S. and Thorat, Shridhar H. and Gonnade, Rajesh G. and Nair, Roshna V. and Rajamohanan, Pattuparambil R. and Sanjayan, Gangadhar J.} } @article { ISI:000354199900018, title = {Role of N-terminal proline in stabilizing the Ant-Pro zipper motif}, journal = {New Journal of Chemistry}, volume = {39}, number = {5}, year = {2015}, month = {MAR}, pages = {3327-3332}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

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.

}, issn = {1144-0546}, doi = {10.1039/c4nj02151g}, author = {Kheria, Sanjeev and Nair, Roshna V. and Kotmale, Amol S. and Rajamohanan, Pattuparambil R. and Sanjayan, Gangadhar J.} } @article { ISI:000374349600022, title = {Residue dependent hydrogen-bonding preferences in orthanilic acid-based short peptide beta-turn motifs}, journal = {RSC Advances}, volume = {6}, number = {42}, year = {2016}, month = {MAR}, pages = {35328-35331}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

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.

}, issn = {2046-2069}, doi = {10.1039/c6ra05684a}, author = {Jedhe, Ganesh S. and Vijayadas, Kuruppanthara N. and Kotmale, Amol S. and Sangtani, Ekta and Shinde, Dinesh R. and Gonnade, Rajesh G. and Rajamohanan, Pattuparambil R. and Sanjayan, Gangadhar J.} } @article {43725, title = {Rigid peptide scaffold-incorporated structural analogs of the potent antidepressant peptide drug rapastinel (GLYX-13)}, journal = {Chemistryselect}, volume = {2}, year = {2017}, month = {APR}, pages = {3594-3596}, type = {Article}, abstract = {

Rapastinel (GLYX-13) is a natural amidated tetrapeptide (Thr-Pro-Pro-Thr-NH2)endowed with strong antidepressant property. Rapastinel shows considerable promise for treating drug-resistant major depressive disorder (MDD), and is under clinical phase III development. Herein, we report the synthesis of a novel class of analogues of the potent antidepressant peptide drug rapastinel featuring rigid dipeptide scaffolds comprising proline (L/D) and amino thiophene carboxylates (Atc). Amino thiophene carboxylate is a conformationally constrained aromatic beta-amino acid, known to rigidify peptide backbones thereby limiting the conformational flexibility of peptides and improving proteolytic stability.

}, doi = {10.1002/slct.201700605}, author = {Nadimpally, Krishna Chaitanya and Chakrapani, Aswathi and Prabhu, Priyanka J. and Madica, Krishnaprasad and Sanjayan, Gangadhar J.} }