0000000001303493
AUTHOR
Satu Ikonen
showing 23 related works from this author
NMR crystallography of 2-Acylamino-6-[1H]pyridones: solid state NMR, GIPAW computational, and single crystal X-ray diffraction studies
2011
Abstract 2-Acylamino-6-[1H]-pyridones [acyl = RCO, where R = methyl (1), ethyl (2), iso-propyl (3), tert-butyl (4), and 1-adamantyl (5)] have been synthesized and characterized by NMR spectroscopy. From three congeners, 2, 3 and 5, also single crystal X-ray structures have been solved. For these derivatives GIPAW calculations acts as a “bridge” between solid-state NMR data and calculated chemical shifts based on X-ray determined geometry. In crystals all three compounds exist as pyridone tautomers possessing similar six-membered ring structure stabilized by intramolecular C O⋯HN hydrogen bond. Theoretical GIPAW calculated and experimental 13C and 15N CPMAS NMR shifts are in excellent agreem…
Facile synthesis of 5β-cholane-sym-triazine conjugates starting from metformin and bile acid methyl esters: Liquid and solid state NMR characterizati…
2009
Abstract Four bile acid-triazine conjugates: N2′,N2′-dimethyl-6′-(3α-hydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (lithocholyl triazine, 4a), N2′,N2′-dimethyl-6′-(3α,7α-dihydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (chenodeoxycholyl triazine, 4b), N2′,N2′-dimethyl-6′6′-(3α,12α-dihydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (deoxycholyl triazine) (4c), and N2′,N2′-dimethyl-6′-(3α,7α,12α-trihydroxy-5β-24-norcholyl)-1′,3′,5′-triazine-2′,4′-diamine (cholyl triazine) (4d) have been prepared and characterized by liquid and solid state NMR. An improved synthetic method produced better yields and an easier purification procedure for 4d than reported in the liter…
Synthesis of nucleoside and nucleotide conjugates of bile acids, and polymerase construction of bile acid-functionalized DNA.
2010
Aqueous Sonogashira cross-coupling reactions of 5-iodopyrimidine or 7-iodo-7-deazaadenine nucleosides with bile acid-derived terminal acetylenes linked via an ester or amide tether gave the corresponding bile acid–nucleoside conjugates. Analogous reactions of halogenated nucleoside triphosphates gave directly bile acid-modified dNTPs. Enzymatic incorporation of these modified nucleotides to DNA was successfully performed using Phusion polymerase for primer extension. One of the dNTPs (dCTP bearing cholic acid) was also efficient for PCR amplification.
The influence of CH bond polarization on the self-association of 2-acylaminopyrimidines by NH/CH···O/N interactions: XRD, NMR, DFT, and AIM study
2013
The single crystal structures of two 2-acylaminopyrimidines, where alkyl groups in acyl moiety are iso-propyl (1) and dichloromethyl (2), were solved by X-ray diffraction method. The strength of intermolecular hydrogen bonding interactions depends on the C–H bond polarization increased by exchanging two methyl groups by chlorine atoms in the adjacent substituent. The computational methods provide an additional insight into the intermolecular interactions and are utilized in explaining the differences in the observed crystal structures. The experimental and computational data together explain the differences in the formed aggregates and revealed that these simple substitutions cause crucial …
Novel lithocholaphanes: Syntheses, NMR, MS, and molecular modeling studies
2007
Abstract Novel head-to-head lithocholaphanes 6 and 11 have been synthesized via precursors 1 – 5 and 7 – 10 with overall good yields, and characterized by 1 H, 13 C, and 15 N NMR spectroscopy, ESI-TOF mass spectrometry, thermal analysis, and molecular modeling. In addition, the binding abilities of 6 and 11 towards alkali metal cations have been investigated via competitive complexation studies using equimolar mixtures of Li + , Na + , K + , and Rb + -cations, and cholaphanes 6 and 11 . The formation of cation–cholaphane adducts was detected by ESI-TOF mass spectrometry. The trends in these comparative binding studies are nicely reproduced theoretically with PM3 energetically optimized stru…
2-Acylamino- and 2,4-bis(acylamino)pyrimidines as supramolecular synthons analysed by multiple non-covalent interactions. DFT, X-ray diffraction, and…
2012
Intermolecular interactions of ten 2-acylamino and 2,4-bis(acylamino)pyrimidines (7 of which are previously unknown) have been investigated by X-ray structural, quantum chemical (DFT), and NMR spectral methods. Especially the concentration dependencies of the (1)H NMR chemical shifts and titrations with other molecules capable of multiple hydrogen bonding provided useful information regarding their association via triple or quadruple hydrogen bonding, which is controlled by the conformational preferences of 2-acylamino- and 2,4-bis(acylamino)pyrimidines. On comparison of the properties of 2-acylamino- and 2,4-bis(acylamino)pyrimidines with the corresponding pyridines, an additional nitrogen…
Solid-State NMR, X-ray Diffraction, and Thermoanalytical Studies Towards the Identification, Isolation, and Structural Characterization of Polymorphs…
2009
Combined solid-state NMR, powder, and single crystal X-ray diffraction, as well as thermoanalytical studies were performed towards the identification, isolation, and structural characterization of ...
Supramolecular architectures formed by co-crystallization of bile acids and melamine
2010
Supramolecular multicomponent crystals constructed from three different bile acids (viz. lithocholic, deoxycholic and cholic acid) and melamine have been prepared and the non-covalent interactions in the crystals studied. Both salts and co-crystals were found. While deoxycholic and cholic acid co-crystallized with melamine as a 1 : 1 isostructural molecular complexes in space group C2, lithocholic acid formed with melamine a 2 : 1 molecular complex in space group P21. This is the first report on a multicomponent crystal structure containing lithocholic acid.
Association of 2-acylaminopyridines and benzoic acids. Steric and electronic substituent effect studied by XRD, solution and solid-state NMR and calc…
2013
Abstract Eight single crystal X-ray structures, solid-state NMR spectroscopic, and theoretical studies utilizing QTAIM methodology were used to characterize the 2-acyl (alkyl in acyl = methyl, ethyl, t-butyl, and 1-adamantyl) amino-6-R-pyridine/4-R′-benzoic acid (R,R′ = H or Me) cocrystals. As expected among alkyl groups 1-adamantyl due to its bulkiness has the most significant effect on the relative positions of molecules in cocrystals. In addition, the subtle electronic and steric effects by the methyl substituents were observed. The theoretical calculations with full geometry optimizations are in agreement with the experimental findings (geometry, energy of hydrogen bonds). Based on the …
X-ray structures of five variably tert-butoxycarbonyl-substituted adenines and their liquid and solid state NMR investigations
2009
Abstract Adenine reacts selectively with di- tert -butyldicarbonate in THF in the presence of NaOH to give N 9-monoBoc-adenine 1 . The molecular structure and crystal packing of this and four other variably substituted Boc-derivatives of adenine were determined in solid state by means of X-ray diffraction and CP/MAS NMR experiments and characterized in liquid state by 1 H, 13 C, and 15 N NMR spectroscopy as well. Additionally, crystal structure of inclusion compound between N 6 -monoBoc-adenine 5 and CHCl 3 is reported. Tautomeric equilibria of mono- and disubstituted derivatives 4 and 5 in liquid state were studied by VT NMR experiments.
Bile acid-derived mono- and diketals—synthesis, structural characterization and self-assembling properties
2010
Three oxo-derivatives of bile acid methyl esters have been used as starting compounds in the preparation of novel bile acid monoketals with 1,2-benzenediol (catechol) and 2,3-naphthalenediol, as well as mono- and diketals with pentaerythritol. Monoketals of pentaerythritol showed a tendency to form thermoreversible gels in many aromatic solvents and the methyl lithocholate derivative proved to be a supergelator able to form a gel with t-butylbenzene at a concentration as low as 0.5% w/v. Whereas the naphthalenediol ketals formed film-type materials in the studied solvents, the catechol ketals underwent rapid crystallization into X-ray quality single crystals. Single crystal X-ray structures…
Antioxidative succinobucol–sterol conjugates: Crystal structures and pseudosymmetry in the crystals
2012
Abstract An extensive study to attach succinobucol to sterols has provided conjugates which comprise two pharmaceutically important compounds into one entity where the components are expected to have a synergistic effect. The motivation to design these novel conjugates was the need to broaden the armamentarium of current agents used in the treatment of atherosclerotic diseases and type 2 diabetes. In desire for detailed information of these compounds in solid state, which also have an influence to their physiological activity, systematic crystallization experiments were performed and as a result, X-ray quality single crystals were obtained from four succinobucol–sterol conjugates. All of th…
Succinobucol’s New Coat — Conjugation with Steroids to Alter Its Drug Effect and Bioavailability
2011
Synthesis, detailed structural characterization (X-ray, NMR, MS, IR, elemental analysis), and studies of toxicity, antioxidant activity and bioavailability of unique potent anti-atherosclerotic succinobucol-steroid conjugates are reported. The conjugates consist of, on one side, the therapeutically important drug succinobucol ([4-{2,6-di-tert-butyl-4-[(1-{[3-tert-butyl-4-hydroxy-5-(propan-2-yl)phenyl]sulfanyl}ethyl)sulfanyl]phenoxy}-4-oxo-butanoic acid]) possessing an antioxidant and anti-inflammatory activity, and on the other side, plant stanol/sterols (stigmastanol, β-sitosterol and stigmasterol) possessing an ability to lower the blood cholesterol level. A cholesterol-succinobucol prodr…
CCDC 957915: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 957918: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 957920: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 841777: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski , Erkki Kolehmainen , Satu Ikonen , Arto Valkonen , Adam Kwiatkowski , Izabela Grela , and Esa Haapaniemi|2012|J.Org.Chem.|77|9609|doi:10.1021/jo301643z
CCDC 841780: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski , Erkki Kolehmainen , Satu Ikonen , Arto Valkonen , Adam Kwiatkowski , Izabela Grela , and Esa Haapaniemi|2012|J.Org.Chem.|77|9609|doi:10.1021/jo301643z
CCDC 957919: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 957917: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 957914: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 957921: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047
CCDC 957916: Experimental Crystal Structure Determination
2013
Related Article: Borys Ośmiałowski, Erkki Kolehmainen, Krzysztof Ejsmont, Satu Ikonen, Arto Valkonen, Kari Rissanen, Nonappa|2013|J.Mol.Struct.|1054|157|doi:10.1016/j.molstruc.2013.09.047