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1.
Marius Bruvoll Selma Dizdarevic Nina Fimland Jasmina Hafizovic Carl Henrik Grbitz Helen Therese Kalfjs Kristian Vestli Alexander Krivokapic 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(1):o22-o25
The structures of the title dipeptides, C9H18N2O4·0.33H2O, C12H16N2O4 and C8H16N2O4S·0.34H2O, complete a series of investigations focused on l ‐Xaa‐l ‐serine peptides, where Xaa is a hydrophobic residue. All three structures are divided into hydrophilic and hydrophobic layers. The hydrophilic layers are thin for l ‐phenylalanyl‐l ‐serine, rendered possible by an unusual peptide conformation, and thick for l ‐isoleucyl‐l ‐serine and l ‐methionyl‐l ‐serine, which include cocrystallized water molecules on the twofold axes. 相似文献
2.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o533-o536
The crystal structure of N‐(l ‐2‐aminobutyryl)‐l ‐alanine, C7H14N2O3, is closely related to the structure of l ‐alanyl‐l ‐alanine, both being tetragonal, while the retro‐analogue 2‐(l ‐alanylamino)‐l ‐butyric acid 0.33‐hydrate, C7H14N2O3·0.33H2O, forms a new type of molecular columnar structure with three peptide molecules in the asymmetric unit. 相似文献
3.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o730-o732
The side chains of l ‐alanyl‐l ‐methionine hemihydrate, C8H16N2O3S·0.5H2O, form hydrophobic columns within a three‐dimensional hydrogen‐bond network that includes extended polymers of cocrystallized water molecules and Cα—H⋯S interactions. 相似文献
4.
Ina Hydal Helle Camilla Victoria Lkken Carl Henrik Grbitz Bjrn Dalhus 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):o771-o772
The peptide bond in the crystal structure of the title compound, C8H16N2O4, deviates substantially from planarity in the same manner as in other l ‐Ser‐l ‐Xaa dipeptides, where Xaa is a hydrophobic residue. 相似文献
5.
Lilianna Chciska Diana Frster Wolfgang Morgenroth Peter Luger 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):o454-o457
The low‐temperature crystal and molecular structure analyses of two modifications of l ‐alanyl‐l ‐tyrosyl‐l ‐alanine with water, C15H21N3O5·2.63H2O [(I), at 9 K], and ethanol, C15H21N3O5·C2H5O [(II), at 20 K], solvent molecules in the crystal lattice show that the overall conformations of both modifications of the title tripeptide are practically the same. Moreover, despite the presence of different solvent molecules in the crystal lattice, the specific intermolecular interactions characteristic for individual tripeptide molecules of (I) and (II) are conserved. The crystal packing of the two modifications of Ala‐Tyr‐Ala differ from each other only in the solvent region. The tight arrangements of tripeptide molecules seem to be responsible for similar displacement parameters for all non‐H atoms, despite the different distances from the molecular centre of mass. Comparison of the displacement parameters between the room‐ and low‐temperature structures shows that an average Ueq value decrease of about 80% takes place at 9 K [for (I)] and 20 K [for (II)] with respect to room temperature. 相似文献
6.
Carl Henrik Grbitz Lars Male Hartviksen 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(3):o171-o176
The crystal structures of the four dipeptides l ‐seryl‐l ‐asparagine monohydrate, C7H13N3O5·H2O, l ‐seryl‐l ‐tyrosine monohydrate, C12H16N2O5·H2O, l ‐tryptophanyl‐l ‐serine monohydrate, C14H17N3O4·H2O, and l ‐tyrosyl‐l ‐tryptophan monohydrate, C20H21N3O4·H2O, are dominated by extensive hydrogen‐bonding networks that include cocrystallized solvent water molecules. Side‐chain conformations are discussed on the basis of previous observations in dipeptides. These four dipeptide structures greatly expand our knowledge on dipeptides incorporating polar residues such as serine, asparagine, threonine, tyrosine and tryptophan. 相似文献
7.
Jan Janczak Genivaldo Julio Perptuo 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):o117-o119
Crystals of l ‐leucinium perchlorate, C6H14NO2+·ClO4−, are built up from protonated l ‐leucinium cations and perchlorate anions. l ‐Leucinium cations related by a twofold screw axis are interconnected by N—H⋯O hydrogen bonds into zigzag chains parallel to [010]. The O atoms of the perchlorate anions act as acceptors of hydrogen bonds that link the l ‐leucinium chains into separated but interacting two‐dimensional layers parallel to (001). Since the title compound crystallizes in a non‐centrosymmetric space group, it can be useful as a material for non‐linear optics. The efficiency of second harmonic generation is about twice that of K2[HPO4]. 相似文献
8.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o589-o592
The crystal structure of l ‐methionyl‐l ‐alanine, C8H16N2O3S, is very similar to that of l ‐valyl‐l ‐alanine [Görbitz & Gundersen (1996). Acta Cryst. C 52 , 1764–1767] and other related dipeptides in space group P61, but there are seven molecules in the asymmetric unit. The Z value of 42 is the highest ever observed for a chiral molecule. 相似文献
9.
Maksymilian Chruszcz Marcin Cymborowski Anna Gawlicka‐Chruszcz Shoichi Yasukawa Joseph D. Ferrara Wladek Minor 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o868-o871
The crystal structures of the title compounds, (S)‐1‐carboxy‐3‐(methylsulfanyl)propanaminium chloride, C5H12NO2S+·Cl−, and (S)‐1‐carboxy‐3‐(methylselanyl)propanaminium chloride, C5H12NO2Se+·Cl−, are isomorphous. The protonated l ‐methionine and l ‐selenomethionine molecules have almost identical conformations and create very similar contacts with the Cl− anions in the crystal structures of both compounds. The amino acid cations and the Cl− anions are linked viaN—H⋯Cl− and O—H⋯Cl− hydrogen bonds. 相似文献
10.
V. H. Rodrigues M. M. R. R. Costa E. de Matos Gomes E. Nogueira M. S. Belslsey 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):o699-o701
In the 1:1 adduct formed between l ‐phenylalanine and 4‐nitrophenol [alternative IUPAC name: (2S)‐2‐ammonio‐3‐phenylpropanoate–4‐nitrophenol (1/1)], C9H11NO2·C6H5NO3, the l ‐phenylalanine molecule is in the zwitterionic state. The overall structure is stabilized via strong hydrogen bonding between polar zones and van der Waals interactions between non‐polar zones, which alternate with the polar zones. 相似文献
11.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1496-1498
One of the amino H atoms of l ‐phenylalanyl‐l ‐valine, C14H20N2O3, participates in a rare secondary interaction in being accepted by the aromatic ring of the phenylalanine side chain. The phenyl group is also a donor in a weak hydrogen bond to the peptide carbonyl group. 相似文献
12.
Claude Didierjean Guy Boussard Andr Aubry 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o394-o396
The title dipeptide, 1‐(tert‐butoxycarbonyl‐d ‐alanyl)‐N‐isopropyl‐l ‐pipecolamide or Boc‐d ‐Ala‐l ‐Pip‐NHiPr (H‐Pip‐OH is pipecolic acid or piperidine‐2‐carboxylic acid), C17H31N3O4, with a d –l heterochiral sequence, adopts a type II′β‐turn conformation, with all‐trans amide functions, where the C‐terminal amide NH group interacts with the Boc carbonyl O atom to form a classical i+3 i intramolecular hydrogen bond. The Cα substituent takes an axial position [Hα (Pip) equatorial] and the trans pipecolamide function is nearly planar. 相似文献
13.
Raffaella Puliti Carlo Andrea Mattia 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):496-499
Ammonium N‐acetyl‐l ‐threoninate, NH4+·C6H10NO4?, and methylammonium N‐acetyl‐l ‐threoninate, CH6N+·C6H10NO4?, crystallize in the orthorhombic P212121 and monoclinic P21 space groups, respectively. The two crystals present the same packing features consisting of infinite ribbons of screw‐related N‐acetyl‐l ‐threoninate anions linked together through pairs of hydrogen bonds. The cations interconnect neighbouring ribbons of anions involving all the nitrogen‐H atoms in three‐dimensional networks of hydrogen bonds. The hydrogen‐bond patterns include asymmetric `three‐centred' systems. In both structures, the Thr side chain is in the favoured (g?g+) conformation. 相似文献
14.
Birger Dittrich Parthapratim Munshi Mark A. Spackman 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):o633-o635
The structure of l ‐valinol [(S)‐(+)‐2‐amino‐3‐methylbutan‐1‐ol or hydroxylated l ‐valine], C5H13NO, has been determined at 100 K by single‐crystal X‐ray diffraction. The independent atom model geometry, Flack parameter and figures of merit are compared with results from an invariom structure refinement. The latter provides H‐atom positions free of independent atom model bias and therefore yields a more accurate hydrogen‐bond pattern, and the geometry from invariom refinement shows an improved agreement with results from a quantum chemical geometry optimization. 相似文献
15.
R. Chitra Vijay Thiruvenkatam R. R. Choudhury M. V. Hosur T. N. Guru Row 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(1):o11-o13
The title bis(glycyl‐l ‐aspartic acid) oxalate complex {systematic name: bis[2‐(2‐ammonioacetamido)butanedioic acid] oxalate 0.4‐hydrate}, 2C6H11N2O5+·C2O42−·4H2O, crystallizes in a triclinic space group with the planar peptide unit in a trans conformation. The asymmetric unit consists of two glycyl‐l ‐aspartic acid molecules with positively charged amino groups and neutral carboxyl groups, and an oxalate dianion. The twist around the C—Cα bond indicates that both the peptide molecules adopt extended conformations, while the twist around the N—Cα bond shows that one has a folded and the other a semi‐extended state. The present complex can be described as an inclusion compound with the dipeptide molecule as the host and the oxalate anion as the guest. The usual head‐to‐tail sequence of aggregation is not observed in this complex, as is also the case with the glycyl‐l ‐aspartic acid dihydrate molecule. The study of aggregation and interaction patterns in binary systems is the first step towards understanding more complex phenomena. This further leads to results that are of general interest in bimolecular aggregation. 相似文献
16.
Jyoti Makker Sharmistha Dey Pravindra Kumar Tej P. Singh 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):o212-o214
The title peptide N‐benzyloxycarbonyl–ΔLeu–l ‐Ala–l ‐Leu–OCH3 [methyl N‐(benzyloxycarbonyl)‐α,β‐dehydroleucyl‐l ‐alanyl‐l ‐leucinate], C24H35N3O6, was synthesized in the solution phase. The peptide adopts a type II′β‐turn conformation which is stabilized by an intramolecular 4 1 N—H?O hydrogen bond. The crystal packing is stabilized by two intermolecular N—H?O hydrogen bonds. 相似文献
17.
Tsonko Kolev Michael Spiteller William S. Sheldrick Heike Mayer‐Figge 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o299-o300
Cations and anions of the title compound {systematic name: 1‐[4‐(aminocarbonyl)butyl]guanidinium bis(hydrogensquarate)}, C6H17N5O2+·2C4HO4−, are connected into a three‐dimensional network by intermolecular N—H⋯O hydrogen bonds between the l ‐argininamidium ammonium, amide and guanidinium functions and the hydrogensquarate carbonyl O atoms. The independent hydrogensquarate monoanions are linked into dimers by pairs of O—H⋯O′ hydrogen bonds. 相似文献
18.
Lars Eriksson Roland Stenutz Gran Widmalm 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):702-704
The crystal structure of methyl 4‐O‐β‐l ‐fucopyranosyl α‐d ‐glucopyranoside hemihydrate C13H24O10·0.5H2O is organized in sheets with antiparallel strands, where hydrophobic interaction accounts for partial stabilization. Infinite hydrogen‐bonding networks are observed within each layer as well as between layers; some of these hydrogen bonds are mediated by water molecules. The conformation of the disaccharide is described by the glycosidic torsion angles: ?H = ?6.1° and ψH = 34.3°. The global energy minimum conformation as calculated by molecular mechanics in vacuo has ?H = ?58° and ψH = ?20°. Thus, quite substantial changes are observed between the in vacuo structure and the crystal structure with its infinite hydrogen‐bonding networks. 相似文献
19.
Alvaro B. Onofrio Eliezer Jger Tiago A. S. Brando Adailton J. Bortoluzzi Faruk Nome 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o237-o239
The title compound (with the systematic name 2‐{[(1S)‐1‐(methoxycarbonyl)‐3‐methylbutyl]aminocarbonyl}benzoic acid), C15H19NO5, crystallizes in the monoclinic space group P21, with two independent molecules per asymmetric unit. The most notable difference between the two molecules is in the dihedral angles between the planes of the carboxyl group and the benzene ring, which are 3.5 (3) and 25.7 (1)°. This difference may account for the fact that two competing reactions are observed in aqueous solution, namely cyclization to form the imide N‐phthaloylleucine and hydrolysis of N‐(2‐carboxybenzoyl)‐l ‐leucine methyl ester to phthalic acid and leucine. 相似文献
20.
Graham Smith Urs D. Wermuth Jonathan M. White 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):o694-o698
The structures of two compounds of l ‐tartaric acid with quinoline, viz. the proton‐transfer compound quinolinium hydrogen (2R,3R)‐tartrate monohydrate, C9H8N+·C4H5O6−·H2O, (I), and the anhydrous non‐proton‐transfer adduct with quinaldic acid, bis(quinolinium‐2‐carboxylate) (2R,3R)‐tartaric acid, 2C10H7NO2·C4H6O6, (II), have been determined at 130 K. Compound (I) has a three‐dimensional honeycomb substructure formed from head‐to‐tail hydrogen‐bonded hydrogen tartrate anions and water molecules. The stacks of π‐bonded quinolinium cations are accommodated within the channels and are hydrogen bonded to it peripherally. Compound (II) has a two‐dimensional network structure based on pseudo‐centrosymmetric head‐to‐tail hydrogen‐bonded cyclic dimers comprising zwitterionic quinaldic acid species which are interlinked by tartaric acid molecules. 相似文献