0000000001299711
AUTHOR
Tadeusz Lis
N-[Glycyl-(Z)-α,β-dehydrophenylalanylglycyl-(Z)-α,β-dehydrophenylalanyl]glycine trifluoroacetate methanol solvate
The molecular conformation of the title dehydropeptide, H+-Gly1–ΔZPhe2–Gly3–ΔZPhe4–Gly5-OH·CF3COO−·CH3OH or C24H26N5O6+·CF3COO−·CH3OH, is characterized by the presence of two intramolecular N—H⋯O hydrogen bonds that stabilize two type III β-turns, at the ΔZPhe2 (ΔZPhe is the Z isomer of the α,β-dehydrophenylalanine residue) and Gly3, and Gly3 and ΔZPhe4 residues. As a result, the pentapeptide adopts a right-handed 310-helical conformation. All peptide units are linked trans to each other.
Two phosphonodehydrotripeptides: Boc0–Gly1–Δ(Z)Phe2–α‐Abu3PO3Me2 and Boc0–Gly1–Δ(Z)Phe2–α‐Nva3PO3Et2
The present paper reports the crystal structures of two short phosphonotripeptides (one in two crystal forms) containing one ΔPhe (dehydrophenylalanine) residue, namely dimethyl (3-{[tert-butoxycarbonylglycyl-α,β-(Z)-dehydrophenylalanyl]amino}propyl)phosphonate, Boc0–Gly1–Δ(Z)Phe2–α-Abu3PO3Me2, C21H32N3O7P, (I), and diethyl (4-{[tert-butoxycarbonylglycyl-α,β-(Z)-dehydrophenylalanyl]amino}butyl)phosphonate, Boc0–Gly1–Δ(Z)Phe2–α-Nva3PO3Et2, as the propan-2-ol monosolvate 0.122-hydrate, C24H38N3O7P·C3H8O·0.122H2O, (II), and the ethanol monosolvate 0.076-hydrate, C24H38N3O7P·C2H6O·0.076H2O, (III). The crystals of (II) and (III) are isomorphous but differ in the type of solvent. The phosphono gr…
Ethyl 1-acetyl-3-amino-1H-pyrazole-4-carboxylate, a tetragonal structure with Z′ = 4
The title compound, C8H11N3O3, crystallizes with Z' = 4. One pyrazole N atom is substituted and excluded from intermolecular contacts. The amine N, acetyl O and an ester O atom are involved in the formation of nearly planar molecular layers. The layers are perpendicular to the c axis, with an interlayer distance of 3.333 Å. The hydrogen-bonding patterns are similar for each molecule, i.e. intramolecular N-H...O, as well as intermolecular N-H...O and C-H...N(pyrazole), bonds are present.
The conformational properties of dehydrobutyrine and dehydrovaline: theoretical and solid-state conformational studies
Dehydrobutyrine is the most naturally occurring dehydroamino acid. It is also the simplest dehydroamino acid having the geometrical isomers E/Z. To investigate its conformational properties, a theoretical analysis was performed on N-acetyl-α,β-dehydrobutyrine N′-methylamides, Ac-(E)-ΔAbu-NHMe and Ac-(Z)-ΔAbu-NHMe, as well as the dehydrovaline derivative Ac-ΔVal-NHMe. The ϕ, ψ potential energy surfaces and the localised conformers were calculated at the B3LYP/6-311 + + G(d,p) level of theory both in vacuo and with inclusion of the solvent (chloroform, water) effect (SCRF method). The X-ray crystal structures of Ac-(Z)-ΔAbu-NHMe and Ac-ΔVal-NHMe were determined at 85 and 100 K, respectively. …
Thecis-transisomerization ofN-methyl-α,β-dehydroamino acids
Dehydroamino acids with the methylated N-terminal peptide group occur in natural small cyclic peptides. The structural analysis was used to investigate the cis-trans isomerization of the N-terminal tertiary amide group of diamides: Ac-(Z)-Δ(Me)Abu-NHMe (1), Ac-(Z)-Δ(Me)Phe-NHMe (2), Ac-(E)-Δ(Me)Phe-NHMe (3), Ac-Δ(Me)Ala-NHMe (4), and Ac-(Me)Ala-NHMe (5). The compounds were analyzed in the solid state by an X-ray crystallography (1-3), and in the solution by FTIR (MeCN and CHCl(3) ) and NMR (DMSO-d6 and CDCl(3) ) methods (1-5). In the solid state, the studied compounds adopt the cis configuration of N-terminal amide. In solution, this configuration also prevails for the dehydroamino acids 1-…
Orthometallation reactions of tris(p-methoxyphenyl)phosphine with dirhodium(II) tetraacetate
Abstract Reactions of dirhodium(II)tetraacetate [Rh2(OAc)4] with tris(p-methoxyphenyl)phosphine (PMP) at 1:1 and 1:2 molar ratios yield, first appropriate adducts: [Rh2(OAc)4P(p-CH3OC6H4)3] (1a) and [Rh2(OAc)4{P(p-CH3OC6H4)3}2] (2a), and then orthometallated [Rh2(OAc)3{μ-(p-CH3OC6H3)P(p-CH3OC6H4)2}(HOAc)2] (1) and [Rh2(OAc)2{μ-(p-CH3OC6H3)P(p-CH3OC6H4)2}2(HOAc)2] (2) complexes, respectively. They have been characterized by spectroscopic methods. The molecular structure of 1 has been determined by the X-ray methods. Crystal data: space group P1, a=11.085(5), b=11.387(5), c=13.900(6) A, α=97.29(3), β=105.23(3), γ=91.93(3)°. In this compound The Rh–Rh distance is 2.421(1), Rh–P bond length 2.1…
4-Nitrophenyl phosphoric acid and its four different potassium salts: a solid state structure and kinetic study
The structures of 4-nitrophenyl phosphoric acid, H2NPP (1), and its four different potassium salts, K(H2NPP)(HNPP) (2), K(HNPP)·CH3OH (3), K(HNPP)·2H2O (4), and K2(NPP)·4H2O (5), were determined by X-ray diffraction methods. These investigations, together with the study of the role of potassium ions in the hydrolysis of 4-nitrophenyl phosphate, provided information about interactions between the acid, monoanionic and dianionic forms of 4-nitrophenyl phosphate and the potassium cations. In the crystalline state, the H2NPP molecules form one-dimensional chains of bifurcated O–H⋯O hydrogen bonds between phosphate groups. A different network, derived from ladder-like chains of the O–H⋯O hydroge…
Two pentadehydropeptides with different configurations of the ΔPhe residues
Comparison of the crystal structures of two pentadehydropeptides containing DeltaPhe residues, namely (Z,Z)-N-(tert-butoxycarbonyl)glycyl-alpha,beta-phenylalanylglycyl-alpha,beta-phenylalanylglycine (or Boc(0)-Gly(1)-Delta(Z)Phe(2)-Gly(3)-Delta(Z)Phe(4)-Gly(5)-OH) methanol solvate, C(29)H(33)N(5)O(8) x CH(4)O, (I), and (E,E)-N-(tert-butoxycarbonyl)glycyl-alpha,beta-phenylalanylglycyl-alpha,beta-phenylalanylglycine (or Boc(0)-Gly(1)-Delta(E)Phe(2)-Gly(3)-Delta(E)Phe(4)-Gly(5)-OH), C(29)H(33)N(5)O(8), (II), indicates that the Delta(Z)Phe residue is a more effective inducer of folded structures than the Delta(E)Phe residue. The values of the torsion angles phi and psi show the presence of two …
A [Cr2Ni] coordination polymer: slow relaxation of magnetization in quasi-one-dimensional ferromagnetic chains
The reaction of [Cr3IIIO(OAc)6(H2O)3]NO3·AcOH with 2-hydroxynaphthaldehyde, 2-amino-isobutyric acid and NiCl2·6H2O in MeOH, under basic and solvothermal conditions, led to the formation of the quasi-1D coordination polymer {[CrIII2NiII(L)4(MeOH)2]}n (where L = the dianion of the Schiff base between 2-hydroxynaphthaldehyde and 2-amino-isobutyric acid), which behaves as a ferromagnetic chain, displaying slow relaxation of magnetization.
N-[tert-Butoxycarbonylglycyl-(Z)-α,β-dehydrophenylalanylglycyl-(E)-α,β-dehydrophenylalanylphenylalanyl]-4-nitroaniline ethanol solvate
The alpha,beta-dehydrophenylalanine residues influence the conformation of the title pentapeptide Boc0-Gly1-Delta(Z)Phe2-Gly3-Delta(E)Phe4-L-Phe5-p-NA ethanol solvate, C42H43N7O9.C2H5OH. The first unsaturated phenylalanyl (Delta(Z)Phe2) and the third glycyl (Gly3) residues form a type I beta turn, while the second unsaturated phenylalanyl (Delta(E)Phe4) and the last phenylalanyl (L-Phe5) residues are part of a type II beta turn. All the amino acids in the peptide are linked trans to one another. The crystal structure is stabilized by intra- and intermolecular hydrogen bonds.
N‐[tert‐Butoxycarbonylglycyl‐(E)‐α,β‐dehydrophenylalanylglycylglycyl‐(E)‐α,β‐dehydrophenylalanyl]glycine
In the molecule of the title hexapeptide, Boc0–Gly1–ΔEPhe2–Gly3–Gly4–ΔEPhe5–Gly6–OH, C31H36N6O9, there are two overlapping β-turns, one of type II on the ΔEPhe2 (ΔEPhe is isomer E of the α,β-dehydrophenylalanine residue) and Gly3 residues and the second of type III′ on the Gly3 and Gly4 residues. All amino acids in the peptide are linked trans to each other. Three relatively strong intramolecular N—H⋯O hydrogen bonds stabilize the crystal structure. Two of them, of the 4→1 type, are responsible for two β-turns in the peptide.
N‐[tert‐Butoxycarbonylglycyl‐(Z)‐α,β‐dehydrophenylalanylglycyl‐(E)‐α,β‐dehydrophenylalanyl]glycine methyl ester dihydrate
The title pentapeptide, Boc0—Gly1–ΔZPhe2—Gly3–ΔEPhe4—Gly5—OMe, C30H35N5O8·2H2O, adopts the type I β-turn conformation for the ΔZPhe2—Gly3 residues. It is stabilized by a 4\rightarrow1 intramolecular hydrogen bond between the ΔEPhe4 NH and Gly1 CO groups. All the amino acid residues in the pentapeptide sequence are linked trans to each other. The crystal structure is stabilized by intra- and intermolecular hydrogen bonds.
Synthesis, spectral and magnetic properties of two different 2-nitrobenzoatocopper(II) complexes containing N,N-diethylnicotinamide
Abstract Two structurally different complexes, [Cu2(2-NO2Bz)4(denia)1]n (1) and [Cu(2-NO2Bz)2(denia)2(H2O)2] (2), were prepared from the same reaction (where 2-NO2Bz = 2-nitrobenzoate, denia = N,N-diethylnicotinamide) and they are reported together with [Cu2(2-NO2Bz)4(DMF)2] (3) (DMF = N,N-dimethylformamide). The compounds under study were characterized by elemental analysis, electronic, IR and EPR spectra, magnetic measurements over the temperature range of 1.8–300 K and X-ray analysis. The molecular structure of (1) is polymeric, (2) is monomeric and (3) is dimeric. In the polymeric chain of (1), the denia molecules serve as bridges between dimeric Cu2(2-NO2bz)4 units. Each Cu(II) atom ha…
Conformational Properties of Oxazole-Amino Acids: Effect of the Intramolecular N–H···N Hydrogen Bond
Oxazole ring occurs in numerous natural peptides, but conformational properties of the amino acid residue containing the oxazole ring in place of the C-terminal amide bond are poorly recognized. A series of model compounds constituted by the oxazole-amino acids occurring in nature, that is, oxazole-alanine (L-Ala-Ozl), oxazole-dehydroalanine (ΔAla-Ozl), and oxazole-dehydrobutyrine ((Z)-ΔAbu-Ozl), was investigated using theoretical calculations supported by FTIR and NMR spectra and single-crystal X-ray diffraction. It was found that the main feature of the studied oxazole-amino acids is the stable conformation β2 with the torsion angles φ and ψ of -150°, -10° for L-Ala-Ozl, -180°, 0° for ΔAl…
An Open-Shell Coronoid with Hybrid Chichibabin-Schlenk Conjugation.
A hexaradicaloid molecule with alternating Kekule and non-Kekule connectivities between adjacent spin centers was obtained by fusing two conjugation motifs in Chichibabin and Schlenk hydrocarbons into a coronoid structure. 1 H NMR, ESR, and SQUID experiments and computational analyses show that the system has a singlet ground state with a significant hexaradicaloid character (γ0 =0.826, γ1 =γ2 =0.773). It has multiple thermally accessible high-spin states (up to the septet), with uniform energy gaps of ca 1.0 kcal mol-1 between consecutive multiplicities. In line with its open-shell character, the coronoid has a small electronic band gap (ca. 0.8 eV) and undergoes two consecutive one-electr…
Self-assembled hydrogen-bonded coordination networks in two copper(II) carboxylates with 4-pyridylmethanol
AbstractThe crystal and molecular structure of [Cu(nif)2(4-PM)2]·CH3OH (1) and [Cu(2-Clbz)2(4-PM)2(H2O)] (2), (where nif = niflumate anion, 2-Clbz = 2-chlorobenzoate anion and 4-PM is the 4-pyridylmethanol), have been determinated by X-ray crystallography. The Cu2+ cation in (1), is coordinated by two pairs of oxygen atoms from asymmetric bidentate niflumate anions and by a pair of pyridine nitrogen atoms from monodentate 4-pyridylmethanol ligands in trans position forming an extremely elongated bipyramid. The Cu2+ cation in (2), is coordinated by a pair of oxygen atoms from monodentate 2-chlorobenzoate anions, further by a pair of pyridine nitrogen atoms from monodentate 4-pyridylmethanol …
Combined effect of the DeltaPhe or DeltaAla residue and the p-nitroanilide group on a didehydropeptides conformation.
Two series of dehydropeptides of the general formulae Boc-Gly-X-Phe-p-NA, Boc-Gly-Gly-X-Phe-p-NA, Gly-X-Gly-Phe-p-NA·TFA, and Boc-Gly-X-Gly-Phe-p-NA, with X = ΔZPhe and ΔAla, were studied with NMR in DMSO and CDCl3-DMSO, and with CD in MeOH, MeCN, and TFE. The NMR spectra measured in DMSO suggest that peptides with the ΔPhe residue next to Phe are folded whereas peptides with Gly between ΔPhe and Phe are less ordered. NMR spectra of ΔAla-containing peptides indicate that these peptides are flexible and their conformational equilibria are populated by many different conformations. The CD spectra show that conformational properties of the peptides studied are distinctly influenced by a mutual…
CCDC 2087056: Experimental Crystal Structure Determination
Related Article: Bibek Prajapati, Duy-Khoi Dang, Piotr J. Chmielewski, Marcin A. Majewski, Tadeusz Lis, Carlos J. Gómez-García, Paul M. Zimmerman, Marcin Stępień|2021|Angew.Chem.,Int.Ed.|60|22496|doi:10.1002/anie.202109273
CCDC 862034: Experimental Crystal Structure Determination
Related Article: Dawid Siodłak, Agnieszka Macedowska-Capiga, Małgorzata A. Broda, Anna E. Kozioł, Tadeusz Lis|2012|Biopolymers|98|466|doi:10.1002/bip.22082
CCDC 862033: Experimental Crystal Structure Determination
Related Article: Dawid Siodłak, Agnieszka Macedowska-Capiga, Małgorzata A. Broda, Anna E. Kozioł, Tadeusz Lis|2012|Biopolymers|98|466|doi:10.1002/bip.22082
CCDC 976532: Experimental Crystal Structure Determination
Related Article: Dawid Siodlak, Monika Stas,Malgorzata A. Broda, Maciej Bujak, Tadeusz Lis|2014|J.Phys.Chem.B|118|2340|doi:10.1021/jp4121673
CCDC 862035: Experimental Crystal Structure Determination
Related Article: Dawid Siodłak, Agnieszka Macedowska-Capiga, Małgorzata A. Broda, Anna E. Kozioł, Tadeusz Lis|2012|Biopolymers|98|466|doi:10.1002/bip.22082
CCDC 2087057: Experimental Crystal Structure Determination
Related Article: Bibek Prajapati, Duy-Khoi Dang, Piotr J. Chmielewski, Marcin A. Majewski, Tadeusz Lis, Carlos J. Gómez-García, Paul M. Zimmerman, Marcin Stępień|2021|Angew.Chem.,Int.Ed.|60|22496|doi:10.1002/anie.202109273
CCDC 1833818: Experimental Crystal Structure Determination
Related Article: Eirini Fotopoulou, Jose Martínez-Lillo, Milosz Siczek, Tadeusz Lis, Vassilis Tangoulis, Marco Evangelisti, Euan K. Brechin, Constantinos J. Milios|2018|Chem.Commun.|54|6153|doi:10.1039/C8CC02583E
CCDC 976533: Experimental Crystal Structure Determination
Related Article: Dawid Siodlak, Monika Stas,Malgorzata A. Broda, Maciej Bujak, Tadeusz Lis|2014|J.Phys.Chem.B|118|2340|doi:10.1021/jp4121673