4th EucheMs chemistry congress

tuesday, 28-Aug 2012
s684
chem. Listy 106, s587–s1425 (2012)
inorganic Chemistry plus Young inorganic chemistry day
inorganic/bioinorganic reaction mechanisms – i
o - 1 7 7
PhySiCoCheMiCAL StudieS And AntiCAnCer
PotenCy of rutheniuM(P-CyMene) CoMPLexeS
ContAininG AntiBACteriAL quinoLoneS
i. tureL 1 , 3 , J. KLJun 1 , A. K. BytzeK 2 ,
w. KAndioLLer 2 , C. BArteL 2 , M. A. JAKuPeC 2 ,
C. G. hArtinGer 2 , B. K. KePPLer 2
1 University of Ljubljana, Faculty of Chemistry, 1000
LJUBLJANA, Slovenia
2 University of Vienna, Institute of Inorganic Chemistry, Vienna,
Austria
3 EN-FIST Centre of Excellence, Dunajska 156, SI-1000
Ljubljana
Quinolone antibacterial agents are used in clinical practice
for nearly fifty years. It is known that metal ions coordinate to
quinolones and some complexes exert biological activity. [1] The
synthesis and study of metal complexes with drugs used in clinical
practice, which may exhibit synergistic activity, have attracted
much attention in last years.
Recently organometallic ruthenium complex of quinolone
ofloxacin (oflo), [(η6-p-cymene)RuCl(O,O-oflo)] (1), was isolated
and characterized. [2] In this “piano-stool” complex, quinolone is
bidentately coordinated to the metal through the ring carbonyl and
one of the carboxylic oxygen atoms. Interactions of this complex
with DNA were studied by different spectroscopic methods and
atomic force microscopy. Later, analogous compounds of the
quinolones nalidixic acid (2) and cinoxacin (3) were synthesized,
and their properties were compared to those of 1. [3] All compounds
undergo a rapid ligand exchange reaction from chlorido to aqua
species. In contrast, 2 and 3 are significantly more stable than 1
and undergo minor conversion to an unreactive species. In the
presence of human serum albumin 1–3 form adducts within
20 minutes of incubation. With guanosine 5'-monophosphate rapid
reactions yielding adducts via its N7 atom were observed,
illustrating that DNA is a possible target for this compound class.
A moderate capacity of inhibiting tumor cell proliferation in vitro
was observed for 1 in CH1 ovarian cancer cells, whereas 2 and 3
turned out to be inactive.
Acknowledgement: Financial support from the Slovenian
Research Agency through project J1-4131 is gratefully
acknowledged.
references:
1. I. Turel, Coord. Chem. Rev., 232, 27-47 (2002).
2. I. Turel, J. Kljun, F. Perdih, E. Morozova, V. Bakulev,
N. Kasyanenko, J. A. W. Byl, N. Osheroff, Inorg. Chem.,
49, 10750-10752 (2010).
3. J. Kljun, A. K. Bytzek, W. Kandioller, C. Bartel, M.
A. Jakupec, C. G. Hartinger, B. K. Keppler, I. Turel,
Organometallics, 30, 2506-2512 (2011).
Keywords: Bioinorganic chemistry; Ruthenium; Antibiotics;
Biological activity;
4 th EucheMs chemistry congress
inorganic/bioinorganic reaction mechanisms – i
o - 1 7 8
reACtivity of ni(0)-CoMPLexeS towArdS
ALKeneS And ALKyneS
L. vALentin 1 , A. henSS 1 , L. KohLer 1 ,
A. de MeiJere 2 , S. SChindLer 1
1 Justus-Liebig-Universität Gießen, Institut für Anorganische
und Analytische Chemie, Giessen, Germany
2 Georg-August-Universität Göttingen, Institut für Organische
und Biomolekulare Chemie, Göttingen, Germany
In regard to the application of Ni(0) compounds as catalysts
in organic synthesis [1] there is high interest in better understanding
of the reactivity of these complexes. Detailed kinetic
investigations have been performed previously on
substitution reactions of [Ni(bipy)COD] (bipy = 2,2'-bipyridine,
COD = 1,5-cyclooctadiene) by Schindler and co-workers. [2]
Furthermore, de Meijere and co-workers have synthesized
and characterized bicyclopropylidene bcp [3] and
dicyclopropylacetylene dcpa [4] and their reactivity. Based on
this background it seemed interesting to investigate the
according Ni(0) complexes of these compounds. Both
complexes, [Ni(bipy)bcp] and [Ni(bipy)dcpa] were structurally
characterized. The formation of these complexes could be
investigated by UV-VIS spectroscopy using “stopped-flow”
techniques.
Despite the negative entropy of activation a dissociative
mechanism was proposed for the reaction of [Ni(bipy)COD] with
bcp according to previous kinetic studies with other olefinic
ligands.
The reaction of [Ni(bipy)(COD)] with dcpa is slower
compared with bcp. Nevertheless, it was not possible to obtain
acceptable fittings to single-exponential functions for all
concentrations applied over the selected temperature range.
Therefore, the reaction with another alkine, dimethoxybutyne
dmbu was investigated. Detailed kinetic studies of this reaction
will be presented.
references:
1. Tamaru, Y., Modern Organonickel Chemistry, Wiley-VCH
Verlag GmbH & Co. KGaA, 2005
2. Geyer, C; Schindler, S., Organometallics 1998, 17 (20),
4400–4405
3. Zhao, L.; de Meijere, A. Adv. Synth. Catal. 2006, 348,
2484–2492
4. Emme, I.; Labahn, T.; Meijere, A. d. Eur. J. Org. Chem.
2006, 399
Keywords: Nickel; alkenes; alkynes; UV/Vis spectroscopy;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc