Docking studies of 3-hydroxy-3-arylpropionic acids as potentially selective COX-2 inhibitors

Although non-steroidal anti-inflammatory agents (NSAID) are numerous, broad used and can be procured as OTC drugs, search for new non-steroidal NSAID is continuing. Main motive is to find compound which selectively inhibits inducible form of enzyme cyclooxygenase (COX-2), but would have at least 10 times less effect on constitutive form (COX-1). If this selectivity concept is achieved, adverse effect on gastric mucosa would be avoided [1]. According to current docking studies, a compound is considered selective if it can maintain interactions in hydrophilic side pocket, so called P3 region in the active site of COX-2 [2]. The aim of this study was to determine the impact of substitution of one or both phenyl rings in 3-hydroxy-3,3-diphenylpropanoic acid with some simple substituents on selectivity towards COX-2 inhibition. Molecular docking calculations were performed using Autodock v4.0.1 into the 3D structure of the catalytic site of COX-2 enzyme (pdb code: 1cx2). Structure of each compound was generated using the ChemOffice v7.0 Ultra software package and have been MM2 optimized. Each docking experiment consisted of 100 docking runs with 150 individuals and 500,000 energy evaluations. The structures were incorporated into 40x40x40 grid points receptor pocket, which was centered to the position of ibuprofen in crystallographic structure of the complex. Ibuprofen was used as a reference compound because of its structure similarity to tested compounds. All of the compounds have lower binding energies than ibuprofen (Fig. 1) and all of these compounds have the right structure which enables penetration into P3 region in the COX-2. Compound containing dimethylamino group penetrates deepest into this region indicating the best selectivity ratio of all tested compounds.Book of apstract- ICOSECS 8, 8th International Conference of the Chemical Societies of the South-East European Countrie

Determination of ionization constants (PKA) of β-hydroxy-β-arylalkanoic acids using high-pressure liquid chromatography

pKa values of five β-hydroxy-β-arylalkanoic acids and ibuprofen were determined using the RP-HPLC method. Stationary phase was octadecyl modified (C-18) silica gel, and mobile phase was a mixture of methanol and one of nine different buffers (60:40, v/v). wspH values were measured after mixing methanol with an appropriate buffer. The mean retention time of each compound was plotted against wspH of each mobile phase. The inflection point of each sigmoidal curve represented wspK a of the compound. Using wspK a in already known equations for the specific methanol/buffer mixture, wwpK a values were calculated. Obtained pKa values for synthesized compounds were in a narrow range from 3.34-3.81 and pKa for ibuprofen was 4.45. Predicted pKa values for these compounds in SPARC software showed good correlation with experimental pKa values (R2=0.8048)

Determination of ionization constants (PKA) of β-hydroxy-β-arylalkanoic acids using high-pressure liquid chromatography

pKa values of five β-hydroxy-β-arylalkanoic acids and ibuprofen were determined using the RP-HPLC method. Stationary phase was octadecyl modified (C-18) silica gel, and mobile phase was a mixture of methanol and one of nine different buffers (60:40, v/v). wspH values were measured after mixing methanol with an appropriate buffer. The mean retention time of each compound was plotted against wspH of each mobile phase. The inflection point of each sigmoidal curve represented wspK a of the compound. Using wspK a in already known equations for the specific methanol/buffer mixture, wwpK a values were calculated. Obtained pKa values for synthesized compounds were in a narrow range from 3.34-3.81 and pKa for ibuprofen was 4.45. Predicted pKa values for these compounds in SPARC software showed good correlation with experimental pKa values (R2=0.8048)

A modified RP-HPLC method for the determination of the pK(a) values of synthesized beta-hydroxy-beta-arylalkanoic acids

The pK(a) values of twelve beta-hydroxy-beta-arylalkanoic acids and ibuprofen were determined using a modified RP-HPLC method. The stationary phase was octadecyl modified (C-18) silica gel, and the mobile phases were mixtures of methanol and one of ten different buffers (60: 40 volume ratio). The mean retention time of each compound was plotted against the pH of each of the ten used mobile phases. The inflection point of the obtained sigmoidal curve represents the (s)(w)pK(a) of a compound. Using (s)(w)pKa in previously established equations for the specific methanol/buffer mixture, the (w)(w)pK(a) values (in pure water) were calculated. The obtained wwpKa values for the synthesized compounds were in a range from 3.40 to 3.74, and the (w)(w)pK(a) for ibuprofen was 4.27. The Predicted pK(a) values for this type of compounds in the MarvinSketch 5.11.5. Program were in poor correlation with the experimental results, while in ACD//I-Labs pK(a) values were calculated as a wide range

Određivanje lipofilnosti β-hidroksi-β-arilalkanskih kiselina primenom reverzno-fazne tečne hromatografije pod visokim pritiskom

Lipophilicity parameters (logP) were determined for thirteen synthesized β-hydroxy-β-arilalkanoic acids using reversed phase high performance liquid chromatography. Anti-inflammatory activity and potential selectivity towards cyclooxygenase-2 inhibition of synthetized compounds was assessed. Stationary phase was octadecyl modified (C-18) silicagel, and four used mobile phases contained different amount of methanol. Both synthetized and standard compounds with known logP values (aspirin, ibuprofen, ketoprofen, naproxen and phenanthrene) were tested in a chromatographic system. Using retention times for each standard and synthesized compound logk values (logarithm of capacity factor) were calculated. Intercept on a graph showing dependency of logk from methanol amount in the mobile phase for each compound represents logKw(capacity factor when organic solvent amount is zero). Graph showing linear dependency of logP of standard compounds from experimentally obtained logKw values was plotted. LogP values for synthetized compounds were obtained by interpolation from the plotted graph. Obtained values are in a range from 2.901 to 3.847. The best correlation between experimentally obtained and predicted logP values was using KOWWIN software (R2=0.8864), which makes this software appropriate for predicting logP values of this type of compounds.Parametri lipofilnosti (logP) su određeni za trinaest sintetisanih β-hidroksi-β-arilalkanskih kiselina primenom reverzno fazne tečne hromatografije. Ispitivanje je urađeno na derivatima kojima je tokom prethodnih istraživanja okarakterisana antiinflamatorna aktivnost i pretpostavljena je potencijalna selektivnost prema inhibiciji ciklooksigenaze-2. Oktadecil-modifikovani (C-18) silikagel je predstavljao stacionarnu fazu, a korišćene su četiri mobilne faze u kojima je variran udeo metanola. Hromatografski su testirana jedinjenja sa poznatim logP vrednostima (aspirin, ibuprofen, ketoprofen, naproksen i fenantren) i sintetisana jedinjenja. Na osnovu retencionog vremena za svako standardno i sintetisano jedinjenje izračunate su vrednosti logk (logaritam faktora kapaciteta). Odsečak na y osi grafika zavisnosti logk od udela metanola u mobilnoj fazi za svako jedinjenje predstavlja vrednost logKw (vrednost retencionog faktora za hromatografski sistem u kome je sadržaj organske komponente nula) za dato jedinjenje. Konstruisan je grafik zavisnosti logP za standardna jedinjenja od njihovih eksperimentalno dobijenih logKw vrednosti i uspostavljena je linearna zavisnost. Interpolacijom logKw sa grafika su očitane vrednosti logP za sintetisana jedinjenja. Dobijene vrednosti su u opsegu od 2,901 do 3,847. Za predviđanje logP vrednosti korišćeni su računarski programi: AlogPS, Molinspiration, MarvinSketch i KOWWIN. Najbolja korelacija između eksperimentalno određenih i predviđenih rezultata je u programu KOWWIN (R2=0,8864), što čini ovaj program pogodnim za predviđanje logP vrednosti ovog tipa jedinjenja

Optimizacija sinteze i in vitro proučavanje antimikrobnog dejstva α,β-nezasićenih i α-bromkarboksilnih kiselina

A series of α,β-unsaturated and α-bromo carboxylic acids were identified as potent antimicrobial agents. The antimicrobial activity was evaluated using the broth microdilution method. All acids 1-12 exhibited a significant activity against nine laboratory control strains of bacteria and two strains of yeast Candida albicans. The tested acids were efficiently prepared by optimized phase-transfer-catalyzed (PTC) reactions of ketones with bromoform and aqueous lithium hydroxide in alcoholic solvent with triethylbenzyl ammonium chloride (TEBA) as catalyst.U ovom radu je prikazano in vitro ispitivanje antimikrobnog dejstva serije α,β-nezasićenih i α-bromkarboksilnih kiselina i pokazano je da su one potencijalno dobri antimikrobni agensi. Sve kiseline 1-12 pokazale su značajnu aktivnost prema devet sojeva bakterija i dva soja gljivica Candida albicans. Ispitivane kiseline sintetisane su u optimizovanoj reakciji ketona sa bromoformom i litijum-hidroksidom u smesi rastvarača (terc-butanol/voda). Kao katalizator za prenos između faza upotrebljen je trietilbenzilamonijum-hlorid (TEBA)

In vitro ispitivanje selektivnosti antiproliferativnog dejstva dijetetskih izotiocijanata na tumorske u odnosu na normalne humane ćelije

Background/Aim. Numerous epidemiological studies have shown beneficial effects of cruciferous vegetables consumption in cancer chemoprevention. Biologically active compounds of different Brassicaceae species with antitumor potential are isothiocyanates, present in the form of their precursors - glucosinolates. The aim of this study was to determine the selectivity of antiproliferative action of dietary isothiocyanates for malignant versus normal cells. Methods. Antiproliferative activity of three isothiocyanates abundant in human diet: sulforaphane, benzyl isothiocyanate (BITC) and phenylethyl isothiocyanate, on human cervix carcinoma cell line - HeLa, melanoma cell line - Fem-x, and colon cancer cell line - LS 174, and on peripheral blood mononuclear cells (PBMC), with or without mitogen, were determined by MTT colorimetric assay 72 h after their continuous action. Results. All investigated isothiocyanates inhibited the proliferation of HeLa, Fem-x and LS 174 cells. On all cell lines treated, BITC was the most potent inhibitor of cell proliferation with half-maximum inhibitory concentration (IC50) values of 5.04 mmoL m-3 on HeLa cells, 2.76 mmol m-3 on Fem-x, and 14.30 mmol m-3 on LS 174 cells. Antiproliferative effects on human PBMC were with higher IC50 than on malignant cells. Indexes of selectivity, calculated as a ratio between IC50 values obtained on PBMC and malignant cells, were between 1.12 and 16.57, with the highest values obtained for the action of BITC on melanoma Fem-x cells. Conclusion. Based on its antiproliferative effects on malignant cells, as well as the selectivity of the action to malignant vs normal cells, benzyl isothiocyanate can be considered as a promising candidate in cancer chemoprevention. In general, the safety of investigated compounds, in addition to their antitumor potential, should be considered as an important criterion in cancer chemoprevention. Screening of selectivity is a plausible approach to the evaluation of safety of both natural isothiocyanates and synthesised analogues of these bioactive compounds.Uvod/Cilj. Brojne epidemiološke studije pokazale su povoljne efekte konzumiranja povrća iz familije kupusnjača (Brassicaceae) u hemioprevenciji karcinoma. Osnovni biološki aktivni sastojci ovog povrća su izotiocijanati, prisutni u obliku prekursora - glukozinolata. Cilj ovog rada bio je određivanje selektivnosti antiproliferativnog delovanja dijetetskih izotiocijanata na maligne ćelije u odnosu na normalne ćelije. Metode. Antiproliferativna aktivnost tri izotiocijanata zastupljena u ljudskoj ishrani: sulforafana (SFN), benzil-izotiocijanata (BITC) i feniletil-izotiocijanata (FEITC) na humane maligne ćelijske linije, HeLa, ćelijsku liniju karcinoma grlića materice, Fem-x, ćelijsku liniju melanoma, i LS 174, ćelijsku liniju karcinoma kolona, kao i na mononuklearne ćelije periferne krvi (MNĆPK), sa ili bez delovanja mitogena, određivana je MTT kalorimetrijskim testom, 72 h nakon kontinuiranog delovanja agenasa. Rezultati. Svi ispitivani izotiocijanati inhibirali su proliferaciju HeLa, Fem-x i LS 174 ćelija. Na svim ćelijskim linijama BITC je pokazao najizraženije delovanje sa vrednostima polumaksimalne inhibitorne koncentracije (IC50) od 5.04 mmol m-3 na HeLa ćelijama, 2,76 mmoL m-3 na Fem-x i 14,30 mmol m-3 na LS 174 ćelijama. Svi ispitivani izotiocijanati pokazali su citotoksično delovanje na MNĆPK, ali sa višim IC50 vrednostima u odnosu na maligne ćelije. Indeksi selektivnosti antitumorkog delovanja, izraženi kao odnos IC50 vrednosti dobijenih na MNĆPK i malignim ćelijama, bili su između 1,12 i 16,57, sa najvišom vrednosti pri delovanju BITC na Fem-x ćelije. Zaključak. Na osnovu antiproliferativne aktivnosti na maligne ćelije i selektivnosti antiproliferativnog delovanja na maligne u odnosu na normalne ćelije, benzil izotiocijanat se ističe kao perspektivni agens u hemioprevenciji karcinoma. Generalno, pored antitumorskog delovanja, bezbednost primene ovih jedinjenja treba da predstavlja važan kriterijum u izboru odgovarajućih izotiocijanata za primenu u primarnoj, sekundarnoj i tercijarnoj hemioprevenciji kancera. Ispitivanje selektivnosti predstavlja pogodan pristup oceni bezbednosti i prirodnih izotiocijanata i sintetskih analoga

Antiproliferative activity of β-hydroxy- β-arylalkanoic acids

Article describes the synthesis of fifteen β-hydroxy- β-arylalkanoic acids by Reformatsky reaction using the 1-ethoxyethyl-2- bromoalkanoates, aromatic or cycloalkyl ketones or aromatic aldehydes. The short survey of previously reported synthetic procedures for title compounds, is given. The majority of obtained compounds exert antiproliferative activity in vitro toward human: HeLa, Fem-X cells, K562, and LS174 cells, having IC 50 values from 62.20 to 205 μM. The most active compound is 3-OH-2,2-di-Me-3-(4-biphenylyl)-butanoic acid, having the IC 50 value 62.20 μM toward HeLa cells. Seven examined compounds did not affect proliferation of healthy human blood peripheral mononuclear cells (PBMC and PBMC+ PHA), IC 50 > 300 μM. The preliminary QSAR results show that estimated lipophilicity of compounds influences their antiproliferative activity in the first place. The ability of dehydration, and the spatial arrangement of hydrophobic portion, HBD and HBA in molecules are has almost equal importance as lipophilicity

Lipophilicity determination of β-hydroxy-β-arilalkanoic acids by reversed phase liquid chromatography under high pressure

Lipophilicity parameters (logP) were determined for thirteen synthesized β-hydroxy-β-arilalkanoic acids using reversed phase high performance liquid chromatography. Anti-inflammatory activity and potential selectivity towards cyclooxygenase-2 inhibition of synthetized compounds was assessed. Stationary phase was octadecyl modified (C-18) silicagel, and four used mobile phases contained different amount of methanol. Both synthetized and standard compounds with known logP values (aspirin, ibuprofen, ketoprofen, naproxen and phenanthrene) were tested in a chromatographic system. Using retention times for each standard and synthesized compound logk values (logarithm of capacity factor) were calculated. Intercept on a graph showing dependency of logk from methanol amount in the mobile phase for each compound represents logKw(capacity factor when organic solvent amount is zero). Graph showing linear dependency of logP of standard compounds from experimentally obtained logKw values was plotted. LogP values for synthetized compounds were obtained by interpolation from the plotted graph. Obtained values are in a range from 2.901 to 3.847. The best correlation between experimentally obtained and predicted logP values was using KOWWIN software (R2=0.8864), which makes this software appropriate for predicting logP values of this type of compounds