02283nas a2200229   4500008004100000022001400041245008800055210006900143260007100212300001600283490000800299520143600307100002601743700002201769700002601791700002401817700001801841700002601859700002401885700002801909856011601937       2008                        eng d  a0002-786300aSequence-specific unusual (1 -> 2)-type helical turns in alpha/beta-hybrid peptides0 aSequencespecific unusual 1 2type helical turns in alphabetahybri  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC  a17743-177540 v1303 a<p>This article describes novel conformationally ordered (alpha/beta-hybrid peptides consisting of repeating L-proline-anthranilic acid building blocks. These oligomers adopt a compact, right-handed helical architecture determined by the intrinsic conformational preferences of the individual amino acid residues. The striking feature of these oligomers is their ability to display an unusual periodic pseudo beta-turn network of nine-membered hydrogen-bonded rings formed in the forward direction of the sequence by 1–&gt;2 amino acid interactions both in solid-state and in solution. Conformational investigations of several of these oligomers by single-crystal X-ray diffraction, solution-state NMR, and ab initio MO theory suggest that the characteristic steric and dihedral angle restraints exerted by proline are essential for stabilizing the unusual pseudo beta-turn network found in these oligomers. Replacing proline by the conformationally flexible analogue alanine (Ala) or by the conformationally more constrained alpha-amino isobutyric acid (Aib) had an adverse effect on the stabilization of this structural architecture. These findings increase the potential to design novel secondary structure elements profiting from the steric and dihedral angle constraints of the amino acid constituents and help to augment the conformational space available for synthetic oligomer design with diverse backbone structures.</p>1 aPrabhakaran, Panchami1 aKale, Sangram, S.1 aPuranik, Vedavati, G.1 aRajamohanan, P., R.1 aChetina, Olga1 aHoward, Judith, A. K.1 aHofmann, Hans-Joerg1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/sequence-specific-unusual-1-2-type-helical-turns-alphabeta-hybrid-peptides-001020nas a2200181   4500008004100000022001400041245008400055210006900139260011000208300001600318490000700334520028000341100002400621700002200645700003000667700002800697856011300725       2016                        eng d  a1359-734500aSelf-assembled vesicles of urea-tethered foldamers as hydrophobic drug carriers0 aSelfassembled vesicles of ureatethered foldamers as hydrophobic   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a10771-107740 v523 a<p>Molecular self-assembly of nonamphiphilic alpha,beta-hybrid foldamers based on urea-tethered anthranilic acid-proline (Ant-Pro) foldamers is reported. These self-assembled hollow vesicular architectures can take up and release the anticancer hydrophobic drug curcumin.</p>1 aIngole, Tukaram, S.1 aKale, Sangram, S.1 aSukumaran, Santhosh, Babu1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/self-assembled-vesicles-urea-tethered-foldamers-hydrophobic-drug-carriers