Synthesis, in vitro antitumor evaluation and structure activity relationship of heptacoordinated amino-bis(Phenolato) Ti(IV) complexes stabilized by 2,6-dipicolinic acid.

Eighteen novel Ti(IV) complexes stabilized by different chelating amino-bis(phenolato) (ONNO, ONON, ONOO) ligands and 2,6-dipicolinic acid as a second chelator were synthesized with isolated yields ranging from 79 to 93%. Complexes were characterized by H and C-NMR spectroscopy, as well as by HRMS and X-Ray diffraction analysis. The good to excellent aqueous stability of these Ti(IV) complexes can be modulated by the substitutions on the 2-position of the phenolato ligands.

Anti-tumoral Titanium Complexes Stabilized with Phenolato Ligands and Structure-Activity Relationship.

Titanocene dichloride and budotitane have opened a new chapter in medicinal chemistry of titanium complexes being novel non-platinum antitumor metallic agents. Numerous efforts have led to the discovery of the diamino -phenolato titanium complexes. Among which, the [ONNO] and [ONON] type ligands namely Salan, Salen and Salalen coordinated titanium alkoxyl complexes have demonstrated significantly enhanced aqueous stability, their and antitumor efficacy, mechanism of action, structure-activity relationships and combined tumor therapy have been intensively investigated.

Evaluating the antioxidant activity of secondary metabolites of endophytic fungi from Hypericum perforatum L. by an electrochemical biosensor based on AuNPs/AC@CS composite.

Due to the variety and activity of secondary metabolites of endophytic fungi (SMEF) from medicinal plants, and the operation cumbersome of existing methods for evaluating the activity, there is urgent to establish a simple, efficient and sensitive evaluation and screening technology. In this study, the prepared chitosan functionalized activated carbon (AC@CS) composite as the electrode substrate material was used to modify glassy carbon electrode (GCE), and the gold nanoparticles (AuNPs) was deposited on AC@CS/GCE by cyclic voltammetry (CV). A ds-DNA/AuNPs/AC@CS/GCE electrochemical biosensor for evaluating the antioxidant activity of SMEF from Hypericum perforatum L.

Three unprecedented thioether-linked dimeric pyrimidines isolated from the medicinal-edible herb Ligusticum striatum DC.

Three unprecedented thioether-linked dimeric pyrimidines, namely ligusticumines A-C, together with twelve known compounds were isolated and identified from the traditional Chinese medicinal-edible herb, Ligusticum striatum DC. The structures of all the isolated compounds were determined from NMR, HRESIMS and X-ray diffraction spectroscopies. Additionally, a novel 3-step synthetic route was developed to synthesize ligusticumine C by substitution, thiolation and coupling, with an overall yield of 5.

Synthesis and X-ray structure analysis of cytotoxic heptacoordinated Salan hafnium complexes stabilized with 2,6-dipicolinic acid.

Four novel Salan Hf complexes stabilized by 2,6-dipicolinic acid (Dipic) were synthesized and characterized by H, C NMR and X-ray diffraction spectroscopy. These Hfbis-chelates could be obtained in good to excellent yields (88%-91%) and demonstrated rather good stability in aqueous media and on silica gel. [LHfDipic] containing steric bulk L were stable in about 10% HO (HO/THF (v/v)), however, [LHfDipic] with non-steric L could slowly dissociate and release nontoxic L.

Investigating immunosensor for determination of SD-biomarker-Aβ based on AuNPs/AC@PANI@CS modified electrodes with amplifying the signal.

Sleep debt (SD) is one of the important triggers for causing not only physiological and mental illness but also dangerous work. Therefore, achieving an early and objective assessment of SD is of great significance in the precaution against SD-related diseases and unsafe work. Here, an ultrasensitive electrochemical immunosensor was constructed for analysis of SD biomarker amyloid-β (Aβ).

Facile synthesis of [ONON] type titaniumbis-chelated complexes in alcoholic solvents and evaluation of anti-tumor activity.

Novel anti-tumoral diamino-bis-(phenolato) [ONON] type titanium complexes stabilized by 2,6-dipicolinic acid were synthesis via an efficient protocol using n-propanol as solvent and HO for isolation. In total 20 [ONON] type and 2 Salan Tibis-chelated complexes were synthesized with yields ranging from 68% to 96%. All reactions could reach to completion in 1.

Cytotoxic heteroleptic heptacoordinate salan zirconium(iv)-bis-chelates - synthesis, aqueous stability and X-ray structure analysis.

Herein we report the synthesis and structural characterization of a series of novel Zr(iv)salan complexes. The initial metalation product [(L1)2Zr] is highly water sensitive while ligand exchanged [L1Zr(dipic)] hydrolyses slowly with a bis-hydroxo Zr(iv) species identified by MS as an intermediate. [L1Zr(dipic)] is cytotoxic in the range of cisplatin against two human carcinoma cell lines.

Synthesis and X-ray structure analysis of cytotoxic heptacoordinate sulfonamide salan titanium(IV)-bis-chelates.

A series of novel sulfonamide substituted heteroleptic salan titanium(IV)-bis-chelates complexed to 2,6-pyridinedicarboxylic acid were synthesized, structurally characterized and evaluated for their anticancer activity against two human carcinoma cell lines. All cytotoxic complexes showed complete inhibition of cell growth at active concentration, two complexes based on pyrrolidine and azepane substituted sulfonamides displayed IC50 values below 1.7 μM and are more cytotoxic than cisplatin in both tested cell lines.

Heptacoordinate Heteroleptic Salan (ONNO) and Thiosalan (OSSO) Titanium(IV) Complexes: Investigation of Stability and Cytotoxicity.

Seven heptacoordinate titanium(IV) complexes were synthesized based on the concept of hetero-bis-chelate stabilization of salan (ONNO) and thiosalan (OSSO) titanium(IV)alkoxides with 2,6-pyridinedicarboxylic acid (dipic) and derivatives thereof. The resulting compounds were investigated in a solid by X-ray diffraction and in solution by NMR spectroscopy. A thiosalan (OSSO) titanium(IV) complex could be isolated and its conformational stabilization by dipic was shown by (1)H NMR spectroscopy to lead to nonfluxional behavior even at room temperature.

Palladium-catalyzed tandem amination reaction for the synthesis of 4-quinolones.

An efficient palladium-catalyzed tandem amination approach was developed in one step to afford functionalized 4-quinolones in good to excellent yields from easily accessible o-haloaryl acetylenic ketones and primary amines.

Palladium-catalyzed amidation-hydrolysis reaction of gem-dihaloolefins: efficient synthesis of homologated carboxamides from ketones.

A simple and efficient palladium-catalyzed amidation-hydrolysis reaction has been developed to afford N-aryl monosubstituted carboxamides in good to excellent yields from easily accessible ketone-derived gem-dihaloolefins and aryl amines.