0000000000147669
AUTHOR
Jari Tamminen
13C NMR spectral assignments of 3α,3′α-bis(arylcarboxy)-5β-cholan-24-oic acid ethane-1,2-diol diesters: new lithocholic acid-based molecular clefts
3α,3′α-Bis(arylcarboxy)-5β-cholan-24-oic acid ethane-1,2-diol diesters (1–3) were synthesized by the reaction of an aroyl chloride (aroyl=2,6-dichlorobenzoyl, 2-naphthoyl and 1-pyrenoyl) with lithocholic acid (3α-hydroxy-5β-cholan-24-oic acid) ethane-1,2-diol diester. The 13C NMR chemical shift assignments of the formed molecular clefts 1–3, pyrene-1-carboxylic acid methyl ester (4) (used as model compound) and 1-pyrenoyl chloride (5) are based on literature data and 13C DEPT-135, 1H,13C HMQC and 1H,13C HMBC experiments. The molecular weights of 1–3 were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Copyright © 1999 John Wiley & Sons, Ltd.
Multinuclear magnetic resonance, electrospray ionization time-of-flight mass spectral and molecular modelling characterization of lithocholic acid amide esters with various nitrogen heterocycles
1H, 13C and 15N NMR and electrospray ionization time-of-flight mass spectrometric characterizations of five lithocholate esters of piperazine diamides are described. Two of them are cholaphane-type cyclic structures esterified with 2,2′-bipyridine-4,4 ′ - and pyridine-2,6-dicarboxylic acid and the other three esters are open structures comprising two or four lithocholyl residues. The conformational preferences of the dimeric congeners were examined by using molecular modelling and variable-temperature 1H NMR techniques. Copyright © 2003 John Wiley & Sons, Ltd.
Comparison of calculated DFT/B3LYP and experimental 13C and 17O NMR chemical shifts, ab initio HF/6-31G* optimised structures, and single crystal X-ray structures of some substituted methyl 5β-cholan-24-oates
Abstract Single crystal X-ray structures (monoclinic space group P2 1 ) for methyl 3-oxo-5β-cholan-24-oate and methyl 3,12-dioxo-5β-cholan-24-oate have been solved and compared with HF/6-31G* optimised structures. In the crystalline packings the side chains are connected with weak OC(sp 3 ) H ⋯ O -type of interactions between C25– H and C24– O –C25 and the keto ends with weak C(sp 3 ) H ⋯ O C-type of interactions between C4– H and O C3. The orientations of the side chains, which steric configurations are of great importance to the biological activity of the molecules, are compared with the experimental structure of methyl 3α-hydroxy-5β-cholan-24-oate. Probable reasons for the observed dif…
Macrocycles prepared from lithocholic acid, piperazine and isomeric pyridine dicarboxylic acids and their selective affinities towards sodium and potassium
Abstract Two novel macrocycles prepared from lithocholic acid, piperazine and pyridine dicarboxylic acids (2,6- and 3,5-isomers), have been characterized by 13C NMR and ESI–MS techniques. In case of the pyridine-2,6-dicarboxylate derivative, the molecular formula of the cycle was C59H87O6N3 (I), while the pyridine-3,5-dicarboxylate derivative (II) was a trimeric structure by molecular mass when compared with I. Furthermore, cycle I showed a special affinity towards potassium cation, while II possessed significant proton and sodium cation recognition properties.
Comparison of epimeric methyl lithocholate and methyl iso-lithocholate molecules: single crystal X-ray structure of methyl lithocholate, ab initio HF/6-31G* optimized structures and experimental and calculated DFT/B3LYP 13C NMR chemical shifts
Abstract 13 C NMR chemical shifts have been measured and assigned for epimeric methyl 3α/β-hydroxy-5β-cholan-24-oates (methyl lithocholate [3α-OH epimer] and methyl iso-lithocholate [3β-OH epimer]). Their molecular dynamics simulations suggest that for both epimers there exists two predominant gas phase conformations, which have been further forwarded for ab initio/HF optimizations and DFT/GIAO based 13 C NMR chemical shift calculations. Excellent linear relationships have been observed between experimental and calculated 13 C NMR chemical shifts for both epimers. For methyl lithocholate (MeLC), the other minimum energy conformation equates very well with the single crystal X-ray structure …
Solid state structural studies of five bile acid derivatives
Five synthetically important bile acid derivatives have been characterized by 13 C CP-MAS, X-ray diffraction (both single crystal and powder), FTIR, and thermoanalytical (DSC and TG) methods. The crystallinity of all these derivatives is high, which can be deducted from the 13 C CP-MAS and powder X-ray diffraction data. Two of the compounds showed polymorphism, and one polymorph was structurally elucidated for both by comparing single crystal and powder X-ray diffraction data.
Synthesis, characterization, and thermal behavior of steroidal dendrons
A series of novel dendritic steroidal polyesters of first and second generation has been synthesized in convergent fashion by the use of 2,2-bis(hydroxymethyl)propionic acid as a repeating unit. The first- and second-generation hydroxy-functionalized dendrons with a variety of surface modifications were produced through the use of four bile acids: lithocholic acid (LCA), ursodeoxycholic acid (UDCA), deoxycholic acid (DCA), and cholic acid (CA). The thermal behavior of the steroidal dendrons was characterized by differential scanning calorimetry (DSC) and by thermogravimetric analysis (TGA). Finally, quantum chemical calculation methods were used to study the geometries of the dendrons and t…
1H-, 13C-, and 15N-NMR and ESI-TOF+ MS studies of a supramolecular complex of silver(I) and a cholaphane
A novel application of the mixed anhydride procedure for synthesising lithocholic acid piperazine diamide, an important intermediate in designing bile acid-based supramolecular host molecules, is reported. The synthesis of a thiophene-containing cholaphane with transition metal complexation ability and 1H-, 13C-, and 15N-NMR as well as ESI-TOF+ MS spectral characterisation of the ligand and its Ag(I) complex are included. The coordination of the Ag(I) ion as well as an ability of the cholaphane to recognise Ag(I) ion over alkali metal ions, especially potassium ion, is discussed. The possible medical applications are also presented.
3α,3′α-Bis(n-acetoxyphenylcarboxy)-5β-cholan-24-oic acid ethane-1,2-diol diesters (n = 2-4):13C NMR chemical shifts, variable-temperature and NOE1H NMR measurements and MO calculations of novel bile acid-based dimers
Three novel bile acid-based molecular dimers, 3α,3′α-bis(n-acetoxyphenylcarboxy)-5β-cholan-24-oic acid ethane-1,2-diol diesters (n = 2–4), 1–3, were synthesized from lithocholic acid (3α-hydroxy-5β-cholan-24-oic acid) ethane-1,2-diol diester and isomeric n-acetoxybenzoyl chlorides (n = 2–4). Their cleft type conformational preferences were suggested theoretically by PM3 molecular orbital calculations. Molecular weights determined by the matrix-assisted laser desorption/ionization time-of-flight technique and 13C NMR chemical shifts of the 1–3 are also presented. Copyright © 2000 John Wiley & Sons, Ltd.