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Soliman SM, Barakat A, Islam MS, Ghabbour HA. Synthesis, Crystal Structure and DFT Studies of a New Dinuclear Ag(I)-Malonamide Complex. MOLECULES (BASEL, SWITZERLAND) 2018; 23:molecules23040888. [PMID: 29641507 PMCID: PMC6017368 DOI: 10.3390/molecules23040888] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 03/27/2018] [Accepted: 04/06/2018] [Indexed: 12/17/2022]
Abstract
The synthesis and structural aspects of a new dinuclear silver (I) complex with malonamide type ligand (L) is reported. Each Ag ion in the [Ag2L2(NO3)2]·H2O complex is coordinated to two ligands, L, each acting as a bridged ligand via its two pyridine arms; Ag(I) acts as a connector between them. Two types of Ag-ligands close contacts were detected: Ag–N1, Ag–N4 from the two L units, and Ag–O5, Ag—O6 from the two nitrate anions, wherein both the nitrate ions are inside the cage formed by the [Ag2L2] unit. The coordination geometry around each Ag(I) is a distorted tetrahedron. The [Ag2L2(NO3)2] complex units are connected by weak intermolecular C—H…O interactions. The different intermolecular interactions were quantified using Hirshfeld surface analysis. Using two DFT methods (B3LYP and WB97XD), the nature and strength of the Ag–N and Ag–O interactions were described using atoms in molecules (AIM) and natural bond orbital (NBO) analyses. Topological parameters indicated that the strength of the two Ag–N bonds was similar, while that of the two Ag–O interactions were significantly different. Moreover, the Ag–N interactions have a predominant covalent character, while the Ag–O interactions are mainly ionic. The NBO analysis indicated that the most important anti-bonding Ag-orbital in these interactions has an s-orbital character.
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Affiliation(s)
- Saied M Soliman
- Department of Chemistry, Rabigh College of Science and Art, King Abdulaziz University, P. O. Box 344, Rabigh 21911, Saudi Arabia.
- Department of Chemistry, Faculty of Science, Alexandria University, P. O. Box 426, Ibrahimia 21321, Alexandria, Egypt.
| | - Assem Barakat
- Department of Chemistry, Faculty of Science, Alexandria University, P. O. Box 426, Ibrahimia 21321, Alexandria, Egypt.
- Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh-11451, Saudi Arabia.
| | - Mohammad Shahidul Islam
- Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh-11451, Saudi Arabia.
| | - Hazem A Ghabbour
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P. O. Box 2457, Riyadh 11451, Saudi Arabia.
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt.
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Synthesis, molecular structure, spectral analysis, and biological activity of new malonamide derivatives as α-glucosidase inhibitors. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.12.093] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Islam MS, Barakat A, Al-Majid AM, Ghabbour HA, Rahman AFMM, Javaid K, Imad R, Yousuf S, Choudhary MI. A concise synthesis and evaluation of new malonamide derivatives as potential α-glucosidase inhibitors. Bioorg Med Chem 2016; 24:1675-82. [PMID: 26972921 DOI: 10.1016/j.bmc.2016.02.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/26/2016] [Accepted: 02/27/2016] [Indexed: 11/28/2022]
Abstract
A series of new malonamide derivatives were synthesized by Michael addition reaction of N(1),N(3)-di(pyridin-2-yl)malonamide into α,β-unsaturated ketones mediated by DBU in DCM at ambient temperature. The inhibitory potential of these compounds in vitro, against α-glucosidase enzyme was evaluated. Result showed that most of malonamide derivatives were identified as a potent inhibitors of α-glucosidase enzyme. Among all the compounds, 4K (IC50=11.7 ± 0.5 μM) was found out as the most active one compared to standard drug acarbose (IC50=840 ± 1.73 μM). Further cytotoxicity of 4a-4m were also evaluated against a number of cancer and normal cell lines and interesting results were obtained.
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Affiliation(s)
- Mohammad Shahidul Islam
- Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Assem Barakat
- Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia; Department of Chemistry, Faculty of Science, Alexandria University, PO Box 426, Ibrahimia, 21321 Alexandria, Egypt.
| | - Abdullah M Al-Majid
- Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - Hazem A Ghabbour
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia; Department of Medicinal Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - A F M Motiur Rahman
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia
| | - Kulsoom Javaid
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Rehan Imad
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - Sammer Yousuf
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
| | - M Iqbal Choudhary
- Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia; H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
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Computational and spectroscopic data correlation study of N,N'-bisarylmalonamides (Part II). J Mol Model 2015; 21:239. [PMID: 26289037 DOI: 10.1007/s00894-015-2777-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/28/2015] [Indexed: 10/23/2022]
Abstract
To complement a previous UV study, we present a quantitative evaluation of substituent effects on spectroscopic data ((1)H and (13)C NMR chemical shifts as well as FT-IR absorption frequency) applied to N,N'-bisarylmalonamides, using simple and extended Hammett equations as well as the Swain-Lupton equation. Furthermore, the DFT CAM-B3LYP/6-311+G(d,p) method was applied to study the impact of different solvents on the geometry of the molecules and their spectral data. Additionally, experimental data are correlated with theoretical results; excellent linear dependence was obtained. The overall results presented in this paper show that N,N'-bisarylmalonamides are prominent candidates for model molecules.
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Arsovski VM, Božić BĐ, Mirković JM, Vitnik VD, Vitnik ZJ, Fabian WMF, Petrović SD, Mijin DZ. Spectroscopic and quantum mechanical investigation of N,N'-bisarylmalonamides: solvent and structural effects. J Mol Model 2014; 20:2384. [PMID: 25116150 DOI: 10.1007/s00894-014-2384-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/17/2014] [Indexed: 11/26/2022]
Abstract
The UV absorption spectra of ten N,N'-bisarylmalonamides have been recorded in the range 200-400 nm in a set of selected solvents. The solute-solvent interactions have been analyzed on the basis of the linear solvation energy relationship (LSER) concept proposed by Kamlet and Taft. The effects of substituents on the absorption spectra have been interpreted by correlating absorption frequencies with Hammett substituent constants. Furthermore, the experimental findings have been interpreted using the DFT CAM-B3LYP/6-311+G(d,p) method. Electronic energies have been calculated using the same method in combination with the implicit solvation model (conductor-like polarizable continuum model, CPCM) as well as with the explicit addition of two molecules of solvent.
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van Marsenille M, Gysen C, Tourwé D, van Binst G. Synthesis of a Protected Acetylene Dipeptide Isostere. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19860950209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Basavaprabhu, Narendra N, Lamani RS, Sureshbabu VV. T3P® (propylphosphonic anhydride) mediated conversion of carboxylic acids into acid azides and one-pot synthesis of ureidopeptides. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sureshbabu VV, Lalithamba HS, Narendra N, Hemantha HP. New and simple synthesis of acid azides, ureas and carbamates from carboxylic acids: application of peptide coupling agents EDC and HBTU. Org Biomol Chem 2010; 8:835-40. [DOI: 10.1039/b920290k] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sureshbabu VV, Narendra N. Synthesis of N-Z, N′-Formyl α-Amino Acid Derived Gem-Diamines. Int J Pept Res Ther 2008. [DOI: 10.1007/s10989-008-9127-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Alemán C, Bella J. Chain conformation in polyretropeptides: Quantum mechanical and empirical force field calculations on 2,6,8-trioxo-3,5,9-triazadecane, a model compound for poly(retro-glycine). Biopolymers 2004. [DOI: 10.1002/bip.360350302] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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11
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Schiavoni MM, Mack HG, Ulic SE, Della Védova CO. Tautomers and conformers of malonamide, NH2-C(O)-CH2-C(O)-NH2: vibrational analysis, NMR spectra and ab initio calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2000; 56A:1533-1541. [PMID: 10907882 DOI: 10.1016/s1386-1425(99)00276-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The conformational and tautomeric compositions of malonamide, NH2-C(O)-CH2-C(O)-NH2 were determined by vibrational spectroscopy and theoretical calculations (HF/6-31G*, B3PW91/6-31G*). Solid state Fourier transform infrared and Raman spectra were analysed. They reveal the existence of a diketo tautomer. Theoretical calculations predict a diketo structure belonging to the C1 symmetry group. No enol form is present in the molecule in the solid. 13C-NMR studies show only signals of a diketo tautomer.
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Affiliation(s)
- M M Schiavoni
- LADECOR, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina
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Sowemimo V, Scanlon D, Jones P, Craik DJ. Synthesis of cyclic penta- and hexapeptides: a general synthetic strategy on DAS resin. JOURNAL OF PROTEIN CHEMISTRY 1994; 13:339-46. [PMID: 7945797 DOI: 10.1007/bf01901567] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The active part or receptor-binding sequence of peptide hormones can usually be defined by a span of 4-8 amino acids. Cyclic penta- and hexapeptides are excellent model systems for performing conformational and structure-function studies on this class of bioactive molecules. A synthetic scheme has been devised comprising solid-phase Fmoc chemistry followed by resin cleavage, cyclization in solution, and, finally, side-chain deprotection. A new resin, DAS, cleaved under weak acid conditions, is an excellent solid-phase synthesis support, and HBTU or PyBOP are the activation reagents of choice, not only during synthesis, but also for the cyclization reaction. Three cyclic peptides were synthesized using this method, one requiring extensive side-chain protection, and this method has general applicability for any cyclic pentapeptide or hexapeptide, giving good yields and high purity.
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Affiliation(s)
- V Sowemimo
- Victorian College of Pharmacy, Monash University, Parkville, Australia
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Parkinson GN, Wu Y, Fan P, Kohn J, Baum J, Berman HM. Crystal structure and NMR conformation of a cyclic pseudotetrapeptide containing urethane backbone linkages. Biopolymers 1994; 34:403-14. [PMID: 8161712 DOI: 10.1002/bip.360340312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Urethane bonds, derived from the hydroxyl group of the tyrosine side chain, have been investigated as a new type of amide bond mimetic in the design of pseudopeptides. The structure of a representative cyclic pseudotetrapeptide that consists of an -Ala-Tyr(urethane)Ala-Tyr(urethane) sequence fused into a rigid ring has been studied in the solid state by x-ray crystallography and in solution by two-dimensional nmr techniques. The cyclic pseudotetrapeptide has an oblong shape. The backbone urethane bonds assume a trans-trans conformation. The carbonyl groups in the ring have an alternating pattern of down, up, down, up with respect to the average ring plane. Solution nmr studies give observed nuclear Overhauser effects and coupling constants largely in agreement with the crystal structure. However, in solution the observed structure is likely to be conformationally averaged, and in the averaged structure, the urethane bond is perpendicular to the plane of the aromatic ring of the tyrosine, while in the crystal it is close to this plane. These differences may be explained by intermolecular hydrogen-bonding interactions. Four aspects of the conformation of the cyclic pseudotetrapeptide were investigated in detail: the tyrosine residue with the attached side-chain urethane bond (the tyrosine-urethane unit), the conformation of the two urethane backbone linkages, the conformation of the two conventional peptide bonds within this unusual ring structure, and the tight turns within the cyclic pseudotetrapeptide. The conformation of the tight turns present in the cyclic pseudotetrapeptide is very similar to that of a beta-bend of type II. Intermolecular hydrogen bonding, joining adjacent layers of the cyclic pseudotetrapeptide in the solid state, resemble a parallel beta-pleated sheet. The presence of these structural motifs in the cyclic pseudotetrapeptide indicates that the tyrosine urethane unit may find applications in peptide and protein engineering.
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Affiliation(s)
- G N Parkinson
- Department of Chemistry, Rutgers, State University of New Jersey, New Brunswick 08903
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Alemán C, Perez JJ. Conformational study of alanine and alpha-aminoisobutyric psi [NHCO]-retroamide peptide analogues. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1994; 43:258-63. [PMID: 8005748 DOI: 10.1111/j.1399-3011.1994.tb00388.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The minimum-energy conformations of N,N'-dimethyl-2-methylmalondiamide (2mMA) and N,N'-dimethyl-2-dimethylmalondiamide (2dmMA) have been computed using the AM1 method. The results show that molecules tend to form an intramolecular six-membered ring hydrogen-bond system. The same trend is observed in crystals of malonamide derivatives substituted in the central carbon atom. The results are also compared with previous molecular-mechanics calculations. The conformational trends of 2mMA and 2dmMA are very similar to those showed by N,N'-dimethylmalondiamide. Details of the computed conformational energy maps for 2mMA and 2dmMA compounds are given.
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Affiliation(s)
- C Alemán
- Department of Chemical Engineering, Technical College for Industrial Engineers, Polytechnic University of Catalunya, Barcelona, Spain
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Alemán C, Pérez JJ. SCF-MO study of the preferred conformation of a symmetric malonamide derivative: N,N' -dimethyl malonamide. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0166-1280(93)87037-e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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Jung G, Beck-Sickinger AG. Methoden der multiplen Peptidsynthese und ihre Anwendungen. Angew Chem Int Ed Engl 1992. [DOI: 10.1002/ange.19921040404] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Said-Nejad OE, Felder ER, Mierke DF, Yamazaki T, Schiller PW, Goodman M. 14-membered cyclic opioids related to dermorphin and their partially retro-inverso modified analogues. I. Synthesis and biological activity. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1992; 39:145-60. [PMID: 1517014 DOI: 10.1111/j.1399-3011.1992.tb00784.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As a continuation of our program to study structure-activity relationships of opiate peptides, we report the syntheses and biological activities of a series of 14-membered cyclic dermorphin analogues closely related to enkephalin analogue Tyr-c[D-A2bu-Gly-Phe-Leu] incorporating a phenylalanine at the third position in place of glycine. In addition to two parent dermorphin analogues Tyr-c[D-A2bu-Phe-Phe-(L and D)-Leu], four stereoisomeric retro-inverso modified analogues Tyr-c[D-A2bu-Phe-gPhe-(S and R)-mLeu] with a reversed amide bond between residues four and five, and Tyr-c[D-Glu-Phe-gPhe-(L and D)-rLeu] with two reversed amide bonds between residues four and five, and between residue five and the side chain of residue two have been synthesized. The results from the guinea pig ileum (GPI) and mouse vas deferens (MVD) assays show that all analogues are superactive at either one or both opiate receptors and in general display higher activities as compared to the corresponding enkephalin analogues with a glycine at the third position. Results from the in vitro biological assays and conformational analysis using 1H-NMR spectroscopy (adjoining paper) will provide useful information to understand the role of the Phe3 aromatic side chain in dermorphin, and that of the Phe4 aromatic side chain in enkephalin, on opiate activity since these cyclic dermorphin analogues contain two Phe residues at both the third and fourth positions.
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Affiliation(s)
- O E Said-Nejad
- Department of Chemistry, University of California, San Diego, La Jolla
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Nunami K, Yamazaki T, Goodman M. Cyclic retro-inverso dipeptides with two aromatic side chains. I. Synthesis. Biopolymers 1991; 31:1503-12. [PMID: 1814500 DOI: 10.1002/bip.360311307] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A series of cyclic retro-inverso dipeptides--2-[(4-hydroxy)benzyl]-5-benzyl-4,6(1H,2H,3H,5H)-pyrimidinedi one (c[mPhe-gTyr]), 2-benzyl-5-[(4-hydroxy)benzyl]-4,6(1H,2H,3H,5H)-pyrimidinedione (c[mTyr-gPhe]), and 2-benzyl-5-amino-5-[(4-hydroxy)benzyl]-4,6(1H,2H,3H,5H)-pyrimidinedione (c[(alpha-amino)mTyr-gPhe])--were synthesized in order to define the minimum structural requirements for binding affinity with opiate receptors and biological activity. Although the first two compounds lack a free amine proposed to be necessary for receptor recognition, the c[mPhe-gTyr] and c[mTyr-gPhe] analogues serve as model molecules in conformational studies of the target analogue, c[(alpha-amino)mTyr-gPhe]. The cis- and trans-c[(alpha-amino)mTyr-gPhe] contain all the functional groups such as the amine and phenolic groups in the tyrosine, and the aromatic group in the phenylalanine, necessary for opiate activity. In addition, the c[(alpha-amino)mTyr-gPhe] analogues possess similar geometries to the Tyr-Pro part of morphiceptin (Tyr-Pro-Phe-Pro-NH2) whose high mu-receptor activity is attributed to conformations with the Tyr-Pro amide bond in a cis conformation because the peptide bonds assume a cis conformation. However, both analogues are inactive in the guinea pig ileum and the mouse vas deferens assays. This may result from wrong orientation of the benzyl group of the gPhe residue with respect to the (alpha-amino)mTyr residue. Conformational studies of these molecules using 1H-nmr spectroscopy and molecular mechanics calculations will be reported in the following paper. Results of conformational analysis should provide information about backbone-side-chain interactions in the retro-inverso peptide chains since all the fundamental structural elements of the retro-inverso peptides are included in these model systems even though the peptide bonds must assume a cis conformation.
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Affiliation(s)
- K Nunami
- Department of Chemistry, University of California, San Diego, La Jolla 92093-0343
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Mierke DF, Said-Nejad OE, Schiller PW, Goodman M. Enkephalin analogues containing beta-naphthylalanine at the fourth position. Biopolymers 1990; 29:179-96. [PMID: 2158358 DOI: 10.1002/bip.360290123] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To examine the importance of the aromatic side chains of enkephalin on opiate activity, we report the synthesis and conformational analysis of a series of analogues related to enkephalin with beta-naphthylalanine in place of phenylalanine at the fourth position. Three linear analogues (Tyr-D-Ala-Gly-(L and D)-beta Nal(1)-Leu-NH2 and Tyr-D-Ala-Gly-beta Nal(2)-Leu-NH2) were initially synthesized to examine the effect of the substitution on biological activity. The increased activity of these peptides at the mu-opiate receptor, compared to native Leu-enkephalin, prompted us to examine the more conformational constrained analogues, Tyr-c[D-A2bu-Gly-(L and D)-beta Nal(1)-Leu], incorporating a alpha, gamma-diaminobutyric acid at the second position and cyclization to the carboxylic end of the leucine. These two cyclic analogues provide insight into the necessity for the L chirality of the aromatic residue at position 4. The Tyr-c[D-A2bu-Gly-L-beta Nal(1)-Leu] analogue is highly potent and displays a slight preference for the mu receptor. The conformational analysis indicates that despite the high flexibility of the tyrosine side chain, the aromatic rings of the tyrosine and naphthylalanine are relatively distant from each other. The presence of two intramolecular hydrogen bonds help maintain the conformation of the 14-membered backbone ring that keeps the side chains directed away from each other. These findings are in agreement with our model of an extended structure required for mu selectivity and a folded form with close aromatic ring placement for delta selectivity.
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Affiliation(s)
- D F Mierke
- Department of Chemistry, University of California, San Diego, La Jolla 92093
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Gomez EJ, Vitoux B, Marraud M, Sakarellos C, el Masdouri L, Aubry A. Conformational perturbations in retro-analogs of the tBuCO-Ala-Gly-NHiPr dipeptide. Crystal structure of the retro-dipeptide with a reversed Ala-Gly amide bond. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1989; 34:480-6. [PMID: 2635694 DOI: 10.1111/j.1399-3011.1989.tb01397.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The three retro-analogs of the tBuCO-Ala-Gly-NHiPr dipeptide, in which each amide bond had been successively reversed, were studied in solution by 1H-n.m.r. and i.r. spectroscopy with reference to the conformational properties of their parent dipeptide. Reversal of the Ala-Gly amide bond proved to perturb the folding tendency of the backbone less than the inversion of either of the terminal amide bonds. The crystal structure of the retro-peptide containing a reversed Ala-Gly amide bond was also solved by X-ray diffraction and constitutes the first available data for this retro-peptide series. In contrast to the beta II-folded structure of the parent dipeptide, the retro-peptide molecule adopts an open conformation in the crystal.
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Affiliation(s)
- E J Gomez
- UA-CNRS-494, ENSIC-INPL, Nancy, France
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Shimohigashi Y, Kodama H, Waki M, Costa T. 2-Substitutedgem-Diamines Derived from Amino Acid Amides. Their Applications to Cross-linking in Peptide Dimerization and Conjugation of Dimer to Affinity Matrix. CHEM LETT 1989. [DOI: 10.1246/cl.1989.1821] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Aubry A, Marraud M. Pseudopeptides and beta folding: x-ray structures compared with structures in solution. Biopolymers 1989; 28:109-22. [PMID: 2720098 DOI: 10.1002/bip.360280113] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In order to restrain the flexibility of the peptide molecules and reduce their biodegradation, modifications of the main chain are now introduced in pseudopeptide analogues. Surprisingly, there is very little data on the conformational properties of these derivatives. We have examined pseudopeptide analogues of RCO-X-Y-NHR' model dipeptides in the depsi, N-methylated, reduced, retro, alpha, beta-dehydro, beta-amino acid, and hydrazino series, in the solid state by x-ray diffraction, and in solution by ir and 1H-nmr spectroscopy. This study provides us with accurate dimensions of the peptide surrogates, and gives some information on the conformational tendencies induced by these substitutions, with reference to those of the related dipeptide sequences.
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Rone R, Manesis N, Hassan M, Goodman M, Hagler AT, Kitson DH, Roberts VA. Conformational Analysis of Constrained Dilactam-bridged Tetrapeptides. Tetrahedron 1988. [DOI: 10.1016/s0040-4020(01)86125-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mierke DF, Lucietto P, Goodman M, Schiller PW. Conformational studies of diastereomeric cyclic enkephalins by 1H-NMR and computer simulations. Biopolymers 1987; 26:1573-86. [PMID: 2822165 DOI: 10.1002/bip.360260909] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Goodman M, Rone R, Manesis N, Hassan M, Mammi N. Peptidomimetics: synthesis, spectroscopy, and computer simulations. Biopolymers 1987; 26 Suppl:S25-32. [PMID: 3580499 DOI: 10.1002/bip.360260007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Edward JV, Spatola AF. Linear and Cyclic Enkephalin Pseudopeptides. Use of RP-HPLC to Separate and Identify Diastereomers Formed during Synthesis. ACTA ACUST UNITED AC 1986. [DOI: 10.1080/01483918608076679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Richman SJ, Goodman M, Nguyen TM, Schiller PW. Synthesis and biological activity of linear and cyclic enkephalins modified at the Gly3-Phe4 amide bond. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1985; 25:648-62. [PMID: 2993182 DOI: 10.1111/j.1399-3011.1985.tb02222.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
As part of our continuing effort to define structure-activity relationships for enkephalin and design enzymatically resistant analogs, we report the synthesis and biological activities of linear and cyclic enkephalin analogs modified at the Gly3-Phe4 amide bond. The partial retro-inverso enkephalin analog Tyr-D-Ala-gGly-(R,S)-mPhe-Leu-NH2 and its cyclic counterpart, Tyr-cyclo[D-A2 bu-gGly-(R,S)-mPhe-Leu-], were synthesized as diastereomeric mixtures using solution methodology. The racemic benzylmalonate allowed the linear analog to be synthesized by fragment coupling at the reversed bond. Cyclization of the second analog was carried out at high concentration, eliminating formation of polymer by the use of an insoluble base. All gem-diaminoalkyl residues were prepared by conversion of peptidyl amides with benzene iodonium bis(trifluoroacetate). Diastereomers of both compounds were separable by reverse phase HPLC but those of the linear compound racemized rapidly under conditions of testing and were therefore tested together. All analogs tested had activities ranging from 6 to 14% of the activity of Leu enkephalin, indicating that the Gly3-Phe4 amide bond is important, though not crucial, for receptor binding.
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Goodman M. Peptide homologs, isosteres, and isomers: a general approach to structure-activity relationships. Biopolymers 1985; 24:137-55. [PMID: 3986285 DOI: 10.1002/bip.360240112] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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