@article{SzantoBenkoSzatmarietal.2004,
  author    = {Szanto, Attila and Benko, Szilvia and Szatmari, Istv{\´a}n and Balint, Balint L. and Furtos, Ibolya and Ruehl, Ralph and Molnar, Sandor and Csiba, Laszlo and Garuti, Rita and Calandra, Sebastiano and Larsson, Hanna and Diczfalusy, Ulf and Nagy, Laszlo},
  title     = {Transcriptional regulation of human CYP27 integrates retinoid, peroxisome proliferator-activated receptor, and liver X receptor signaling in macrophages},
  issn      = {0270-7306},
  year      = {2004},
  abstract  = {Cholesterol uptake and efflux are key metabolic processes associated with macrophage physiology and atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPARgamma) and liver X receptor alpha (LXRalpha) have been linked to the regulation of these processes. It remains to be identified how activation of these receptors is connected and regulated by endogenous lipid molecules. We identified CYP27, a p450 enzyme, as a link between retinoid, PPARgamma, and LXR signaling. We show that the human CYP27 gene is under coupled regulation by retinoids and ligands of PPARs via a PPAR-retinoic acid receptor response element in its promoter. Induction of the enzyme's expression results in an increased level of 27-hydroxycholesterol and upregulation of LXR-mediated processes. Upregulated CYP27 activity also leads to LXR-independent elimination of CYP27 metabolites as an alternative means of cholesterol efflux. Moreover, human macrophage-rich atherosclerotic lesions have an increased level of retinoid-, PPARgamma-, and LXR- regulated gene expression and also enhanced CYP27 levels. Our findings suggest that nuclear receptor-regulated CYP27 expression is likely to be a key integrator of retinoic acid receptor-PPARgamma-LXR signaling, relying on natural ligands and contributing to lipid metabolism in macrophages},
  language  = {en}
}
@article{BelasriTopalHeydenreichetal.2020,
  author    = {Belasri, Khadija and Topal, Leila and Heydenreich, Matthias and Koch, Andreas and Kleinpeter, Erich and Fulop, Ferenc and Szatmari, Istvan},
  title     = {Synthesis and conformational analysis of naphthoxazine-fused phenanthrene derivatives},
  series = {Molecules},
  volume    = {25},
  journal   = {Molecules},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules25112524},
  pages     = {15},
  year      = {2020},
  abstract  = {The synthesis of new phenanthr[9,10-e][1,3]oxazines was achieved by the direct coupling of 9-phenanthrol with cyclic imines in the modified aza-Friedel-Crafts reaction followed by the ring closure of the resulting bifunctional aminophenanthrols with formaldehyde. Aminophenanthrol-type Mannich bases were synthesised and transformed to phenanthr[9,10-e][1,3]oxazines via [4 + 2] cycloaddition. Detailed NMR structural analyses of the new polyheterocycles as well as conformational studies including Density Functional Theory (DFT) modelling were performed. The relative stability of ortho-quinone methides (o-QMs) was calculated, the geometries obtained were compared with the experimentally determined NMR structures, and thereby, the regioselectivity of the reactions has been assigned.},
  language  = {en}
}
@article{HeydenreichKochSzatmarietal.2008,
  author    = {Heydenreich, Matthias and Koch, Andreas and Szatm{\´a}ri, Istv{\´a}n and Fulop, Ferenc and Kleinpeter, Erich},
  title     = {Synthesis and conformational analysis of naphth[1,2-e][1,3]oxazino[4,3-a][1,3]isoquinoline and naphth[2,1- e][1,3]oxazino[4,3-a]isoquinoline derivatives},
  doi       = {10.1016/j.tet.2008.05.025},
  year      = {2008},
  abstract  = {Through the cyclization of 1-(;-hydroxynaphthyl)-1,2,3,4-tetrahydroisoquinoline and 1-(;- hydroxynaphthyl)-1,2,3,4-tetrahydroisoquinoline with formaldehyde, phosgene, p-nitrobenzaldehyde or p-chlorophenyl isothiocyanate, 8-substituted 10,11-dihydro-8H,15bH-naphth[1,2-e][1,3]oxazino[4,3-a]isoquinolines (3 and 4) and 10,11- dihydro-8H,15bH-naphth[2,1-e][1,3]oxazino[4,3-a]isoquinolines (15 and 16) were prepared. Conformational analysis of both the piperidine and the 1,3-oxazine moieties of these heterocycles by NMR spectroscopy and an accompanying theoretical study revealed that these two conformationally flexible six-membered ring moieties prefer twisted chair conformers.},
  language  = {en}
}
@article{CsuetoertoekiSzatmariKochetal.2012,
  author    = {Cs{\"u}t{\"o}rt{\"o}ki, Renata and Szatmari, Istvan and Koch, Andreas and Heydenreich, Matthias and Kleinpeter, Erich and Fulop, Ferenc},
  title     = {Syntheses and conformational analyses of new naphth[1,2-e][1,3]oxazino[3,2-c] quinazolin-13-ones},
  series = {Tetrahedron},
  volume    = {68},
  journal   = {Tetrahedron},
  number    = {24},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2012.04.026},
  pages     = {4600 -- 4608},
  year      = {2012},
  abstract  = {The syntheses of naphth[1,2-e][1,3]oxazino[3,2-c]quinazolin-13-one derivatives (3a-f) were achieved by the solvent-free heating of benzyloxycarbonyl-protected intermediates (2a-f) with MeONa. For intermediates 2a-f, prepared by the reactions of substituted aminonaphthols with benzyl N-(2-formylphenyl)carbamate, not only the expected trans ring form B and chain form A(1), but also the rearranged chain form A(2) as a new tautomer were detected in DMSO at room temperature. The quantity of A(2) in the tautomeric mixture was changed with time. Conformational analyses of the target heterocycles 3a-f by NMR spectroscopy and accompanying theoretical calculations at the DFT level of theory revealed that the oxazine ring preferred a twisted chair conformation and the quinazolone ring was planar. Besides the conformations, both the configurations at C-7a and C-15 and the preferred rotamers of the 1-naphthyl substituent at C-15 were assigned, which allowed evaluation of the aryl substituent-dependent steric hindrance in this part of the molecules. Configurational assignments were corroborated by quantifying the ring current effect of 15-aryl in terms of spatial NICS.},
  language  = {en}
}
@article{SzatmariMartinekLazaretal.2004,
  author    = {Szatmari, Istvan and Martinek, T. A. and Lazar, L. and Koch, Andreas and Kleinpeter, Erich and Neuvonen, Kari and Fulop, Ferenc},
  title     = {Stereoelectronic effects in ring-chain tautomerism of 1,3-diarylnaphth[1,2-e][1,3]oxazines and 3-alkyl-1- arylnaphth[1,2-e][1,3]oxazines},
  issn      = {0022-3263},
  year      = {2004},
  abstract  = {The disubstitution effects of X and Y in 1-(Y-phenyl)-3-(X-phenyl)-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines on the ring-chain tautomerism, the delocalization of the nitrogen lone pair (anomeric effect), and the C-13 NMR chemical shifts were analyzed by using multiple linear regression analysis. Study of the three-component equilibrium B reversible arrow A reversible arrow C revealed that the chain reversible arrow trans (A reversible arrow B) equilibrium constants are significantly influenced by the inductive effect (sigma(F)) of substituent Y on the 1-phenyl ring. In contrast, no significant substituent dependence on Y was observed for the chain reversible arrow cis (A reversible arrow C) equilibrium. There was an analogous dependence for the epimerization (C reversible arrow B) constants of 1-(Y-phenyl)-3- alkyl-2,3-dihydro-1H-naphth[1,2-e] [1,3]oxazines. With these model compounds, significant overlapping energies of the nitrogen lone pair was observed by NBO analysis in the trans forms B (to sigma*(C1-C1'), sigma*(C1-C10b), and sigma*(C3-O4)) and in the cis forms C (to sigma*(C1-H), sigma*(C1-C10b), and sigma*(C3-O4)). The effects of disubstitution revealed some characteristic differences between the cis and trans isomers. However, the results do not suggest that the anomeric effect predominates in the preponderance of the trans over the cis isomer. When the C-13 chemical shift changes induced Y by substituents X and Y (SCS) were subjected to multiple linear regression analysis, negative rho(F)(Y) and rho(F)(X) values were observed at C-1 and C-3 for both the cis and trans isomers. In contrast, the positive rho(R)(Y) values at C-1 and the negative rho(R)(X) values at C-3 observed indicated the contribution of resonance structures f (rho(R) > 0) and g (rho(R) < 0), respectively. The classical double bond-no-bond resonance structures proved useful in explaining the substituent sensitivities of the donation energies and the behavior of the SCS values},
  language  = {en}
}
@article{KleinpeterSzatmariLazaretal.2009,
  author    = {Kleinpeter, Erich and Szatm{\´a}ri, Istv{\´a}n and L{\´a}z{\´a}r, L{\´a}szl{\´o} and Koch, Andreas and Heydenreich, Matthias and Fulop, Ferenc},
  title     = {Visualization and quantification of anisotropic effects on the 1H NMR spectra of 1,3-oxazino[4,3- alpha]isoquinolines - indirect estimates of steric compression},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2009.07.038},
  year      = {2009},
  abstract  = {The anisotropic effects of the phenyl, alpha- and beta-naphthyl moieties in four series of 1,3-oxazino[4,3- a]isoquinolines on the H-1 chemical shifts of the isoquinoline protons were calculated by employing the Nucleus Independent Chemical Shift (NICS) concept and Visualized as anisotropic cones by a through-space NMR shielding grid. The signs and extents of these spatial effects on the H-1 chemical shifts of the isoquinoline protons were compared with the experimental H-1 NMR spectra. The differences between the experimental delta (H-1)/ppm values and the calculated anisotropic effects of the aromatic moieties are discussed in terms of the steric compression that occurs in the Compounds studied.},
  language  = {en}
}
@article{SzatmariTothKochetal.2006,
  author    = {Szatmari, Istvan and Toth, Diana and Koch, Andreas and Heydenreich, Matthias and Kleinpeter, Erich and Fulop, Ferenc},
  title     = {Study of the substituent-influenced anomeric effect in the ring-chain tautomerism of 1-alkyl-3-aryl-naphth[1,2- e][1,3]oxazines},
  doi       = {10.1002/ejoc.200600563},
  year      = {2006},
  abstract  = {The stabilities of the trans (B) and cis (C) tautomeric ring forms that are experimentally observed in the ring- chain tautomeric interconversion of 1-alkyl-3-aryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines has been investigated. Stability differences are explained by the analysis of the natural bond orbital results for the lone pairs of electrons that are on the heteroatoms in the oxazine ring system and by regression analysis of the calculated 13C NMR chemical shift values.},
  language  = {en}
}
@article{LaemmermannSzatmariFulopetal.2009,
  author    = {L{\"a}mmermann, Anica and Szatm{\´a}ri, Istv{\´a}n and Fulop, Ferenc and Kleinpeter, Erich},
  title     = {Inter- or intramolecular N···H-O or N-H···O Hydrogen bonding in 1,3-Amino-alpha/beta-naphthols : an experimental NMR and computational study},
  issn      = {1089-5639},
  doi       = {10.1021/Jp902731n},
  year      = {2009},
  abstract  = {The existence of intermolecular or intramolecular N···H;O or N;H···O hydrogen bonding in three series (series 1, substituted 1-aminoalkyl-2-naphthols: R = H, Me, Et, Pr, i-Pr; series 2, substituted 1-;- aminobenzyl-2-naphthols: H, p-OMe, p-F, p-Cl, p-Br, p-NO2, p-Me; series 3, substituted 2-;-aminobenzyl-1-naphthols: R = H, p-Me, p-F, p-Br, p-OMe, m-NO2, m-Br) are studied by NMR spectroscopy and computed at the DFT level of theory [B3LYP/6-311+G(d,p)]. The correct nature of the H-bond was assigned unequivocally both experimentally and computationally by potential energy scans rotating the involved dihedral angles. We investigated the effects of substituents on the strength of the H-bond by evaluating the corresponding hyperconjugative stabilization energy nlonepair ; ;*X;H and Hammett substituent constant plots. By this means, steric and electronic substituent effects could be easily quantified and separated.},
  language  = {en}
}
@article{ThothSzatmariHeydenreichetal.2009,
  author    = {Th{\´o}th, Di{\´a}na and Szatm{\´a}ri, Istv{\´a}n and Heydenreich, Matthias and Koch, Andreas and Kleinpeter, Erich and Fulop, Ferenc},
  title     = {Synthesis and conformational analysis of naphthylnaphthoxazine derivatives},
  issn      = {0166-1280},
  doi       = {10.1016/j.molstruc.2009.04.015},
  year      = {2009},
  abstract  = {Four new primary aminonaphthols (4, 5, 9 and 10) were synthesized from 1- or 2-naphthol and 1- or 2- naphthaldehyde via naphthoxazines in modified Mannich condensations. Simple ring-closure reactions of these aminonaphthols with paraformaldehyde, 4-nitrobenzaldehyde, phosgene or 4-chlorophenyl isothiocyanate led to new heterocyclic derivatives. In these transformations, either an sp2 or an sp3 carbon was inserted between the hydroxy and amino groups. The effects of substituents and the naphthyl ring on the conformation were investigated by means of NMR measurements, employing both dipolar and scalar couplings. The structures were confirmed by DFT quantum chemical calculations involving computed coupling constants, intramolecular distances between nuclei and the relative energies of the preferred conformers.},
  language  = {en}
}
@article{HeydenreichKochKlodetal.2006,
  author    = {Heydenreich, Matthias and Koch, Andreas and Klod, Sabrina and Szatmari, Istvan and Fulop, Ferenc and Kleinpeter, Erich},
  title     = {Synthesis and conformational analysis of naphth[1', 2':5,6][1,3]oxazino[3,2-c][1,3]benzoxazine and naphth[1', 2':5,6][1,3]oxazino[3,4-c][1,3]benzoxazine derivatives},
  series = {Tetrahedron},
  volume    = {62},
  journal   = {Tetrahedron},
  number    = {48},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2006.09.037},
  pages     = {11081 -- 11089},
  year      = {2006},
  abstract  = {A new functional group, the hydroxy group, was inserted into a Betti base by reaction with salicylaldehyde, and the naphthoxazine derivatives thus obtained were converted by ring-closure reactions with formaldehyde, acetaldehyde, propionaldehyde or phosgene to the corresponding naphth[1',2':5,6][1,3]oxazino[3,2-c][1,3]benzoxazine derivatives. Further, the conformational analysis of these polycyclic compounds by NMR spectroscopy and an accompanying molecular modelling are reported; especially, both quantitative anisotropic ring current effects of the aromatic moieties in these compounds and steric substituent effects were employed to determine the stereochemistry of the naphthoxazinobenzoxazine derivatives.},
  language  = {en}
}