Synthesis, characterization and cytotoxicty of gold(III) complexes with R2edda-type esters

U ovom radu opisane su sinteze, karakterizacija i antiproliferativna aktivnost kompleksa zlata(III) sa dialkil estrima (S,S)-etilendiamin-N,N’-di-2-propanske kiseline, (S,S)-H2eddip, (S,S)-etilendiamin-N,N’-di-2-(4-metil)-pentanske kiseline, (S,S)-H2eddl, (S,S)-etilendiamin-N,N’-di-2-(3-cikloheksil)-propanske kiseline, (S,S)-H2eddch. Sintetisan je novi diizoamil estar sa (S,S)-H2eddip. Ovaj ligand prekursor je dobijen refluktovanjem suspenzije kiseline i apsolutnog izoamil alkohola, kome je prethodno ukapan tionil-hlorid. Estar je dobijen u obliku dihidrohlorida, [(S,S)-H2iAm2eddip]Cl2. Okarakterisan je elementalnom analizom, infracrvenom i NMR spektroskopijom, masenom spektrometrijom i polarimetrijskom analizom. Kompleksi zlata(III) dobijeni su u reakciji natrijum-tetrahloridoaurata(III) dihidrata, Na[AuCl4]∙2H2O, sa O,O’-dialkil-(S,S)-etilendiamin-N,N’-di-2-propanoatom, (R = nBu, nPe, iBu, iAm, cPe) ili O,O’-dialkil-(S,S)-etilendiamin-N,N’-di-2-(4-metil)-pentanoatom, (R = nPr, nBu, nPe, iBu) ili O,O’-dialkil-(S,S)-etilendiamin-N,N’-di-2-(3-cikloheksil)-propanoatom, (R = Me, Et, nPr, nBu, iBu, iAm) u metanolu i litijum-hidroksida u molskom odnosu 1:1:2, a kompleksi su dobijeni nakon dodavanja čvrstog amonijum-heksafluorofosfata. Kompleksi su opšte formule [AuCl2{(S,S)-R2eddip}]PF6 (R = nBu, nPe, iBu, iAm, cPe) i [AuCl2{(S,S)-R2eddl}]PF6 (R = nPr, nBu, nPe, iBu), [AuCl2{(S,S)-R2eddch}]PF6 (R = Me, Et, nPr, nBu, iBu, iAm). Okarakterisani su elementalnom analizom, UV/Vis, infracrvenom i NMR spektroskopijom i masenom spektrometrijom. Za sve sintetisane komplekse urađeni su DFT proračuni. Da bi se bolje razumeo mehanizam delovanja kompleksa zlata(III) kao antitumorskih agenasa, urađeno je elektrohemijsko ispitivanje svih kompleksa iz serije [AuCl2{(S,S)-R2eddip}]PF6 i [AuCl2{(S,S)-R2eddch}]PF6. Cikličnom i diferencijalnom pulsnom voltametrijom utvrđeno je da se redukcija zlato(III) kompleksa vrši do zlato(I) vrste, u vidu dva ireverzibilna elektronska koraka, praćena gubitkom hlorido liganda. Pojava redukcionog koraka AuIII/Au0 se isključuje zbog izostanka elementalnog zlata na platinskoj elektrodi što je potvrđeno nakon redukcije pri konstantnom potencijalu od −0,8 V (vs. Ag/AgCl) u trajanju od 15 minuta. Antiproliferativna aktivnost sintetisanih kompleksa određena je prema tumorskim ćelijama: humanog adenokarcinoma materice (HeLa), humanog malignog melanoma (Fem-x), humane mijeloidne leukemije (K562), kao i na zdravim humanim mononuklearnim ćelijama, izolovanim iz periferne krvi (PBMC), kao i na stimulisanim na proliferaciju PBMC ćelijama (PBMC + PHA) ili ćelijama fetalnog plućnog fibroblasta (MRC-5). Svi kompleksi iz serije [AuCl2{(S,S)-R2eddip}]PF6 pokazuju visoku citotoksičnu aktivnost prema svim ćelijskim linijama, a najveću prema Fem-x ćelijama. Najnižu IC50 vrednost prema Fem-x ćelijama pokazuje kompleks [AuCl2{(S,S)-iAm2eddip}]PF6, ali istovremeno i najvišu prema HeLa i K562 ćelijskim linijama. Indeks selektivnosti ovih kompleksa pokazuje da su manje toksični i znatno selektivniji od cisplatine. Posebno treba istaći da je kompleks [AuCl2{(S,S)-iAm2eddip}]PF6 4 puta aktivniji u 28 puta selektivniji od cisplatine. Kompleksi iz serije [AuCl2{(S,S)-R2eddl}]PF6 pokazuju najveću aktivnost prema K562 ćelijama koja je uporediva sa referentnom supstancom, cisplatinom. Iz serije [AuCl2{(S,S)-R2eddch}]PF6, najaktivniji je kompleks kada je R = iAm prema K562 ćelijama koji je aktivniji i od cisplatine, ali je umereno aktivan prema HeLa ćelijskoj liniji. Ovaj kompleks je ujedno i najselektivniji. Svi ispitivani kompleksi indukuju apoptozu. Ispitivanje stabilnosti kompleksa [AuCl2{(S,S)-iBu2eddip}]PF6 u DMSO-u i fiziološkom medijumu (PBS, pH 7,4) praćeno je pomoću UV/Vis i 13C NMR spektroskopije. Ispitivani kompleks je stabilan u DMSO-u tokom 24-časovnog praćenja UV/Vis spektroskopijom. Snimljeni 13C NMR spektri kompleksa u PBS-u tokom vremena (0, 2, 24 i 48 h) pokazuju koordinacione promene u kompleksu tako da verovatno dolazi do supstitucije hlorido liganada molekulima vode pri čemu nastaju [AuCl(H[AuCl(H[AuCl(H[AuCl(H[AuCl(H[AuCl(H[AuCl(H2O){(O){(O){(O){(S,S )-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]2+ ili [Au(H[Au(H[Au(H[Au(H[Au(H2O) 2{( S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]3+ . U cilju ispitivanja mogućnosti da se kompleksi zlata(III) redukuju u ćeliji sa biološki relevantnim reducentom, praćena je reakcija kompleksa [AuCl2{(S,S)-iBu2eddip}]PF6 sa askorbinskom kiselinom, snimanjem 13C NMR spektara. Ispitivanja su pokazala da askorbinska kiselina trenutno redukuje kompleks, što ukazuje na visoku mogućnost istog ishoda u živim ćelijama. Takođe, praćena je interakcija kompleksa [AuCl2{(S,S)-iBu2eddip}]PF6 sa goveđim serum albuminom (BSA) pomoću UV/Vis spektroskopije. Pretpostavlja se da se kompleks zlata(III), redukuje cisteinom iz albumina do zlato(I) vrste, što se može videti na spektrima nakon 2 sata reakcije. Nakon 24 i 48 h, UV/Vis spektri ukazuju da dolazi do disproporcionisanja zlata(I) do odgovarajućih zlato(III) jedinjenja i elementalnog zlata.This thesis describes synthesis, characterization and antiproliferative activity of gold(III) complexes with dialkyl esters of (S,S)-ethylenediamine-N,N’-di-2-propanoic acid, (S,S)-H2eddip, (S,S)-ethylenediamine-N,N’-di-2-(4-methyl)-pentanoic acid, (S,S)-H2eddl and (S,S)-ethylenediamine-N,N’-di-2-(3-cyclohexyl)-propanoic acid, (S,S)-H2eddch. A novel diisoamyl ester of (S,S)-H2eddip is synthesized. Thionyl chloride was introduced into a flask containing absolute isoamyl alcohol. (S,S)-H2eddip∙HCl was added forming a suspension which was reflucted. The ester was obtained as a dihydrochloride, [(S,S)-H2iAm2eddip]Cl2. This compound was characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry and polarimeter analysis. Gold(III) complexes are synthesized in a reaction of sodium-tetrachloroaurate(III) dihydrate, Na[AuCl4]∙2H2O, with O,O’-dialkyl-(S,S)-ethylenediamine-N,N’-di-2-propanoate, (R = nBu, nPe, iBu, iAm, cPe) or O,O’-dialkyl-(S,S)-ethylenediamine-N,N’-di-2-(4-methyl)-pentanoate, (R = nPr, nBu, nPe, iBu) or O,O’-dialkyl-(S,S)-ethylenediamine-N,N’-di-2-(3-cyclohexyl)-propanoate, (R = Me, Et, nPr, nBu, iBu, iAm) in methanol and lithium hydroxide in molar ratio 1:1:2. Desired complexes were obtained after addition of amonium hexafluorphosphate to the reaction mixture. Complexes general formulae are: [AuCl2{(S,S)-R2eddip}]PF6 (R = nBu, nPe, iBu, iAm, cPe), [AuCl2{(S,S)-R2eddl}]PF6 (R = nPr, nBu, nPe, iBu) and [AuCl2{(S,S)-R2eddch}]PF6 (R = Me, Et, nPr, nBu, iBu, iAm). These compounds are characterized by elemental analysis, UV/Vis, IR and NMR spectroscopy and mass spectrometry. DFT calculations were done for all synthesized complexes. In order to explain the mechanism of action of gold(III) complexes as antitumor agents, redox chemistry was studied by cyclic and differential pulse voltammetry of [AuCl2{(S,S)-R2eddip}]PF6 and [AuCl2{(S,S)-R2eddch}]PF6 complexes. The investigation confirmed two successive irreversible reduction steps followed by loss of chlorido ligands where AuI species were the final reduction product. The occurrence of the AuIII/Au0 reduction is rejected due to the lack of metalic gold at platinum electrode. This observation was also confirmed by potentiostatic reduction at –0.8 V (vs. Ag/AgCl) electrode for 15 min. In vitro antiproliferative activity of gold(III) complexes was determined against several tumor cell lines: human adenocarcinoma (HeLa), human myelogenous leukemia (K562), human malignant melanoma (Fem-x) as well as against normal and stimulated for proliferation human peripheral blood mononuclear cells (PBMC, PBMC + PHA) or human embryonic lung fibroblast (MRC-5). All complexes from series [AuCl2{(S,S)-R2eddip}]PF6 exhibit high activity against all three cancer lines, the highest against Fem-x cells. The lowest IC50 value is observed against Fem-x cells by complex [AuCl2{(S,S)-iAm2eddip}]PF6 and at the same time the highest against HeLa and K562. This complex is 4 times more active i 28 times more selective than cisplatin. Generally, selectivities of these complexes are significantly greater than cisplatin. Complexes from series [AuCl2{(S,S)-R2eddl}]PF6 show the highest activity against K562 cells comparable to the reference compound cisplatin. Complex [AuCl2{(S,S)-iAm2eddch}]PF6 was found to be the most effective against K562 cell line as well as to have higher activity in relation to cisplatin, but it was found moderately active against HeLa cell line. This complex also expressed the highest selectivity. All tested complexes induce apoptosis. The stability of [AuCl2{(S,S)-iBu2eddip}]PF6 was investigated in DMSO and physiological medium (PBS, pH 7,4) and experiments have been monitored by UV/Vis and 13C spectroscopy. Complex [AuCl2{(S,S)-iBu2eddip}]PF6 is stable in DMSO during 24 h monitoring by UV/Vis spectra. Stability study of [AuCl2{(S,S)-iBu2eddip}]PF6 in PBS, examined by 13C NMR spectroscopy at different time intervals (0, 2, 24 and 48 h), immediately showed coordination changes in the complex which presumably indicates instant coordination of water by displacement of the chlorido ligands to provide [AuCl(H[AuCl(H[AuCl(H[AuCl(H[AuCl(H[AuCl(H[AuCl(H2O){(O){(O){(O){(S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]2+ or [Au(H[Au(H[Au(H[Au(H[Au(H2O) 2{( S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]3+ species.species.species.species.species.species.species.species. In order to investigate the possibility of [AuCl[AuCl[AuCl[AuCl[AuCl2{( S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]PF6 being reduced in cells with a biologically relevant reductant, time-depending 13C NMR spectroscopy was performed for the reaction of [AuCl[AuCl[AuCl[AuCl[AuCl2{( S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]PF6 with ascorbic acid. It was found that ascorbic acid reduces the complex readily and instantly, indicating a high possibility of the same outcome in living cells. Also, interaction of [AuCl[AuCl[AuCl[AuCl[AuCl2{( S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]PF6 with bovine serum albumin (BSA) was examined by UV/Vis spectrometry. It is assumed that [AuCl[AuCl[AuCl[AuCl[AuCl2{( S,SS,SS,S)-iBu 2eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]eddip}]+ might be reduced with cysteine leading to gold(I) species which can be seen in spectra after 2 h of reaction. After 24 and 48 h, UV/Vis spectra indicate that gold(I) species disproportionate to corresponding gold(III) species and elemental gold

Chemical features and quality assessment of the natural mineral waters in the Vrnjačka Banja area, Serbia

Water is one of the most precious natural resources. The aim of the study was a preliminary examination on mineral waters quality (S1–S5) in the Vrnjačka Banja area, Serbia, through the standard physico-chemical parameters: temperature, pH value, conductivity, turbidity, content of chloride as well as the total organic matter. All samples of water were collected and analysed in the period April-May 2017. The obtained results were compared to the National and World Health Organization (WHO) water quality standards. The results for temperature, pH and conductivity were within the values defined by Regulation on the quality of mineral water, except for the conductivity in samples S2 and S5 that were slightly above prescribed (2980 and 3460 µS cm-1, respectively). Increased turbidity was observed in the sample S4 (5.24 NTU). The concentrations of total of organic matter in all analyzed samples were around 45 mg L-1 which indicates that the found values were 9 times greater than allowed and it can be result of a number of natural factors or the geographical location of the source itself

Design and In Vitro Biological Evaluation of a Novel Organotin(IV) Complex with 1-(4-Carboxyphenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione

A novel triphenyltin(IV) compound with 1-(4-carboxyphenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione was synthesized and characterized by IR, NMR spectroscopy, mass spectrometry, and elemental analysis. In vitro anticancer activity of ligand precursor and synthesized organotin(IV) compound was determined against tumor cell lines: human adenocarcinoma (HeLa), human myelogenous leukemia (K562), and human breast cancer (MDA-MB-453), using microculture tetrazolium test (MTT) assay. The results indicate that complex exhibited very high antiproliferative activity against all tested cell lines with IC50 values in the range of 0.22 to 0.53 mu M. The highest activity organotin(IV) compound expressed against the HeLa cells (IC50=0.22 +/- 0.04 mu M). The ligand precursor did not show anticancer activity (IC50>200 mu M). Furthermore, fluorescence microscopy analysis of HeLa cells reveal that organotin(IV) complex induced apoptosis as a mode of cell death, which is consistent with the increase of cells in the sub-G1 phase

Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment

Since natural-origin, sustainable ingredients are preferred by modern consumers, novel emulsifiers and emollients keep entering the market. This study hypothesizes that a combination of in silico, instrumental tools and simplified sensory studies could be used to efficiently characterize emulsions in a shorter timeframe. A total of 22 rather simple o/w emulsions were prepared by a time/energy-saving emulsification process. A natural mixed emulsifier (Lauryl Glucoside/Myristyl Glucoside/Polyglyceryl-6 Laurate) and two emollients (both with INCI name C15–19 Alkane) were used. The performed D-optimal experimental design within the response surface method (RSM) significantly narrowed down the number of samples about to enter the stage of texture, friction and sensory studies to the samples comprising 30% of a respective Emogreen emollient and 2% or 3% of the emulsifier. The sample comprising 2% emulsifier/30% Emogreen® L15 showed significantly higher firmness (42.12 mN) when compared to the one with 2% emulsifier/30% Emogreen® L19 (33.62 mN), which was somewhat unexpected considering the emollients’ inherent viscosity values (4.5 mPa·s for L15 and 9 mPa·s for L19). The sample with 2% emulsifier/30% Emogreen® L19 managed to maintain the lowest friction, while the one with 3% emulsifier/30% Emogreen® L19 released its full lubricating potential in the second part of the measurement (30–60 s). The obtained results revealed the strengths and weaknesses of each formulation, narrowing down their possible applications in the early development stage

In vitro anticancer evaluation of novel triphenyltin(IV) compounds with some N-acetyl-S-naphthoquinonylcysteine derivatives

Triphenyltin(IV) compounds with naphthoquinone derivatives containing N-acetylcysteine, N-acetyl-S-(3,4-dihydro-3,4-dioxo-1-naphthyl)cysteine (1,2-NQC), 1, and N-acetyl-S-(1,4-dihydro-1,4-dioxo-2-naphthyl)cysteine (1,4-NQC), 2, were synthesized and characterized by elemental microanalysis, IR, multinuclear (H-1, C-13, Sn-119) NMR spectroscopy as well as HR-ESI mass spectrometry. With the aim of in vitro anticancer activity determination of ligand precursors and novel synthesized organotin(IV) compounds against human cervix adenocarcinoma (HeLa), human colon carcinoma (HT-29) and melanoma carcinoma cell line (B16F10), MTT colorimetric assay method was applied. The results indicate that synthesized compounds exhibited remarkable antiproliferative activity toward all tested cell lines with IC50 in the range from 0.17 to 0.87 mu M. Complex 1 showed the greatest activity against HT-29 cells, with IC50 value of 0.21 +/- 0.01 mu M, 119 times better than cisplatin, while complex 2 demonstrated the highest activity toward HeLa cells, IC50 = 0.17 +/- 0.01 mu M, which is similar to 26 times better than cisplatin

Basic parameters of the static stability, loads and strength of the vital parts of a bucket wheel excavator's slewing superstructure

Determining a bucket wheel excavator (BWE)'s slewing superstructure weight and its center of gravity (COG) is of extreme importance not only in the design phase, but also after the completion of the erection process and during the operation of the machine. This paper presents a critical comparative analysis of the basic parameters of the static stability of a BWE 1600 superstructure, with the parameters being obtained by both analytical and experimental procedures. The analysis shows that a relatively small difference in superstructure mass, obtained by calculation, leads to a relatively large unfavorable shifting of its COG, necessitating a significant increase in counterweight mass for balancing. A procedure for superstructure 3D model mass correction is presented based on results obtained by weighing after the completion of the erection process. The developed model provides enough accuracy to determine the superstructure's COG in the entire domain of the bucket wheel boom inclination angle, and enables accurate load analysis of the superstructure's vital parts. The importance of this analysis is reinforced by the finding that the procedure prescribed by standard DIN 22261-2 gives results which are not on the side of safety, as shown by an example of strength analysis of a bucket wheel boom stays' end eyes

Basic parameters of the static stability, loads and strength of the vital parts of a bucket wheel excavator's slewing superstructure

Determining a bucket wheel excavator (BWE)'s slewing superstructure weight and its center of gravity (COG) is of extreme importance not only in the design phase, but also after the completion of the erection process and during the operation of the machine. This paper presents a critical comparative analysis of the basic parameters of the static stability of a BWE 1600 superstructure, with the parameters being obtained by both analytical and experimental procedures. The analysis shows that a relatively small difference in superstructure mass, obtained by calculation, leads to a relatively large unfavorable shifting of its COG, necessitating a significant increase in counterweight mass for balancing. A procedure for superstructure 3D model mass correction is presented based on results obtained by weighing after the completion of the erection process. The developed model provides enough accuracy to determine the superstructure's COG in the entire domain of the bucket wheel boom inclination angle, and enables accurate load analysis of the superstructure's vital parts. The importance of this analysis is reinforced by the finding that the procedure prescribed by standard DIN 22261-2 gives results which are not on the side of safety, as shown by an example of strength analysis of a bucket wheel boom stays' end eyes

Procena antikancerogene aktivnosti novih organokalaj(IV) jedinjenja koja sadrže derivate 2-propanske kiseline

Two novel organotin(IV) compounds containing 2-propanoic acid derivatives were synthesized and characterized by standard spectroscopic methods. In vitro antiproliferative activity of these complexes was investigated versus four tumor cell lines: PC3 (prostate), HT-29 (colon), MCF-7 (breast) and HepG2 (hepatic) using MTT and CV assays. The results have shown that that synthesized complexes exhibit remarkable anticancer activity toward all tested cell lines with 54 to 113 fold higher activity than the reference compound cisplatin. The obtained promising results indicate the necessity for further in vitro/in vivo research with the aim to investigate the mechanism of action of these potencial antitumor agents.Dva nova organokalaj(IV) jedinjenja, koja sadrže derivate 2-propanske kiseline, sintetisana su i okarakterisana pomoću standardnih spektroskopskih metoda. In vitro antiproliferativna aktivnost ovih jedinjenja ispitana je prema četiri tumorske ćelijske linije: PC3 (prostata), HT-29 (debelo crevo), MCF-7 (dojka) i HepG2 (jetra) pomoću MTT and CV testova. Rezultati ispitivanja ukazuju da sintetisana jedinjenja ispoljavaju izvanrednu antikancerogenu aktivnost prema svim ispitanim ćelijskim linijama i njihova aktivnost je od 54 do 113 puta veća od aktivnosti referentne supstance, cisplatine. Dobijeni rezultati ukazuju na neophodnost daljih in vitro/in vivo istraživanja sa ciljem ispitivanja mehanizma delovanja ovih potencijalnih antitumorskih agenasa

Procena antikancerogene aktivnosti novih organokalaj(IV) jedinjenja koja sadrže derivate 2-propanske kiseline

Two novel organotin(IV) compounds containing 2-propanoic acid derivatives were synthesized and characterized by standard spectroscopic methods. In vitro antiproliferative activity of these complexes was investigated versus four tumor cell lines: PC3 (prostate), HT-29 (colon), MCF-7 (breast) and HepG2 (hepatic) using MTT and CV assays. The results have shown that that synthesized complexes exhibit remarkable anticancer activity toward all tested cell lines with 54 to 113 fold higher activity than the reference compound cisplatin. The obtained promising results indicate the necessity for further in vitro/in vivo research with the aim to investigate the mechanism of action of these potencial antitumor agents.Dva nova organokalaj(IV) jedinjenja, koja sadrže derivate 2-propanske kiseline, sintetisana su i okarakterisana pomoću standardnih spektroskopskih metoda. In vitro antiproliferativna aktivnost ovih jedinjenja ispitana je prema četiri tumorske ćelijske linije: PC3 (prostata), HT-29 (debelo crevo), MCF-7 (dojka) i HepG2 (jetra) pomoću MTT and CV testova. Rezultati ispitivanja ukazuju da sintetisana jedinjenja ispoljavaju izvanrednu antikancerogenu aktivnost prema svim ispitanim ćelijskim linijama i njihova aktivnost je od 54 do 113 puta veća od aktivnosti referentne supstance, cisplatine. Dobijeni rezultati ukazuju na neophodnost daljih in vitro/in vivo istraživanja sa ciljem ispitivanja mehanizma delovanja ovih potencijalnih antitumorskih agenasa