Organometallic complexes of (thio)allomaltol-based Mannich-products: Synthesis, stability and preliminary biological investigations

Synthesis, Modification, and Biological Evaluation of a Library of Novel Water‐Soluble Thiopyridone‐Based Organometallic Complexes and Their Unexpected (Biological) Behavior

“…The applied reaction time is strongly dependent on the coordination motif. While standard procedures for pyrone complexes with an O,O ‐coordination motif require at least several hours or even overnight syntheses, thiopyrone complexes featuring an S,O ‐coordination motif react much faster with reported reaction times of 3.5 h at most. Thus, the mixtures were stirred at room temperature for 1–3.5 h, depending on the utilized ligand.…”

Comparative solution equilibrium studies on pentamethylcyclopentadienyl rhodium complexes of 2,2ʹ-bipyridine and ethylenediamine and their interaction with human serum albumin

“…Recently, we reported RhCp* complexes of (O,O) donor containing 3-hydroxy-4-pyrone ligands [11] and 1,2-dimethyl-3-hydroxy-pyridin-4(1H)-one (deferiprone, dhp) [12], which showed cytotoxicity with IC 50 values of 50-300 μM, respectively in cancer cell lines. Whereas RhCp* complexes formed with 2-picolinic acid (pic) [12] and 3-hydroxy(thio)pyrones derivatized by morpholine, piperidine or N-methylpyrazine moieties [13] exhibited only poor or no bioactivity. Promising in vitro antiproliferative activities have been reported for the RhCp* complexes of (N,N) polypyridyl (pp) ligands by Sheldrick et al [14][15][16][17] possessing IC 50 values in the low micromolar range.…”

The First Anticancer Tris(pyrazolyl)borate Molybdenum(IV) Complexes: Tested in Vitro and in Vivo—A Comparison of O,O‐, S,O‐, and N,N‐Chelate Effects

“…Molybdic acid (85 %, Alfa Aesar), triphenylphosphine oxide (98 %, Sigma Aldrich), hydrochloric acid (30–33 %, Donauchem), sodium methoxide (≈95 %, Fluka), ethyl formate (97 %, Sigma Aldrich), isopropyl methyl ketone (≥98.5 %, Sigma Aldrich), hydrazine dichloride (≥98 %, Sigma Aldrich), Potassium borohydride (98 %, Sigma Aldrich), Lawesson's reagent (99 %, Acros Organics), sodium hydroxide (≥98 %, Sigma Aldrich), hydrogen peroxide (30 %, Sigma Aldrich), thionyl chloride (≥99 %, Fluka), zink powder (≥97 %, Fisher), triphenylphosphine (99 %, Alfa Aesar), triethylamine (99 %, Sigma Aldrich), PBS (sterile filtered, Sigma Life Science), maltol ( L1 ) (99 %, Sigma–Aldrich), 2‐(2'‐pyridyl)‐1 H‐ benzimidazole ( L6 ) (97 %, Sigma Aldrich) and polyvinylpyrrolidone—average mol wt 10.000 (PVP10, Sigma Aldrich) were purchased from the respective commercial source and used as obtained. Thiomaltol ( L2 ), thioallomaltol ( L3 ), 3‐hydroxy‐2‐(4′‐chlorophenyl)chromen‐4‐one ( L4 ) and chlorohydrotris(3‐isopropyl‐1 H‐ pyrazolyl)borodioxomolybdenum(VI), Tp i Pr MoO 2 Cl, were synthesized according to literature protocols. 3‐Hydroxy‐2‐(4′‐chlorophenyl)chromen‐4‐thione ( L5 ) was synthesized by using the same procedure as for thiomaltol, described in the literature .…”

“…[52] Molybdic Aldrich) and polyvinylpyrrolidone-average mol wt 10.000 (PVP10, Sigma Aldrich) were purchased from the respective commercial source and used as obtained. Thiomaltol [46,53,54] (L2), thioallomaltol [55] (L3), 3-hydroxy-2-(4'-chlorophenyl)chromen-4-one [56] (L4)a nd chlorohydrotris(3-isopropyl-1H-pyrazolyl)borodioxomolybdenum(-VI), Tp iPr MoO 2 Cl, [57,58] were synthesized according to literature protocols. 3-Hydroxy-2-(4'-chlorophenyl)chromen-4-thione (L5)w as synthesized by using the same procedure as for thiomaltol, described in the literature.…”