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ABSTRACT: Oxazolinodoxorubicin, a doxorubicin analog with a modified daunosamine moiety was synthesized. The properties of this compound and the parent doxorubicin were compared. The cytotoxicity in vitro studies against several human tumor cell lines (PC-3, MCF-7, SW707, HL-60, RPMI 8226, ACHN) showed higher antiproliferative potency for this new compound. Moreover, its ability to completely overcome the drug resistance of cancer cells in vitro was revealed (LoVo, LoVo/DX, MES-SA, MES-SA/DX5, HL-60, HL-60/Vinc, HL-60/MX2 cell lines). Cellular uptake analyzed on HL-60 and HL-60/MX2 cells, demonstrated higher penetration levels of oxazolinodoxorubicin compared to that of doxorubicin. In animal experiments, general toxicity of oxazolinodoxorubicin was lower than that observed for doxorubicin. Furthermore, similar antitumor effects was observed in NOD/SCID mice bearing resistant HL-60/Vinc leukemia tumor and in mice treated with the new or parent compounds. The presented results suggest that oxazolinodoxorubicin is a new anthracycline with an advantageous biological activity profile.
Anticancer research 07/2012; 32(7):2959-65. · 1.73 Impact Factor
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New Journal of Chemistry - NEW J CHEM. 01/2010; 34(4).
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ABSTRACT: We present a simple and general strategy for the synthesis of beta,delta-disubstituted-alpha-methylene-delta-lactones starting from easily available tert-butyl 2-(diethoxyphosphoryl)alk-2-enoates. The elaborated synthetic protocol includes pyrrolidine-catalyzed Michael addition of acetone, diastereoselective reduction of the carbonyl group, lactonization and finally the Horner-Wadsworth-Emmons reaction with formaldehyde. All alpha-methylene-delta-lactones were evaluated in vitro against mouse leukemia cell line L-1210 and two human leukemia cell lines HL-60 and NALM-6. Comparison of cytotoxic activity with corresponding alpha-methylene-gamma-lactones is also discussed.
European journal of medicinal chemistry 11/2009; 45(2):710-8. · 3.27 Impact Factor
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ABSTRACT: This work was undertaken to compare cytotoxicity, DNA damaging properties and effect on DNA cleavage by topoisomerase II of the anthracycline drug doxorubicin (DOX) and its two derivatives with a formamidino group containing a cyclic amine moiety such as morpholine (DOXM) or hexamethyleneimine (DOXH). The tetrazolium dye colorimetric assay was used to determine the cytotoxic activity of anthracyclines toward L1210 leukemia cells. DNA damage was measured by alkaline elution technique. The effect of anthracyclines on DNA cleavage was studied in a cell-free system containing supercoiled pBR322 DNA and purified human topoisomerase II. The cytotoxicity data and the results of studies on the mechanism of DNA break formation by anthracyclines at the cellular level and in the cell-free system showed that the presence of the formamidino group in the doxorubicin molecule reduced its ability to stimulate DNA cleavage by DNA topoisomerase II. Conclusion: DNA topoisomerase II is not a primary cellular target for DOXM or DOXH. An advantageous feature of formamidinoanthracyclines is their mechanism of cytotoxic action which is not related to the inhibition of DNA topoisomerase II. Therefore this class of anthracyclines seems to be a good source for selection of an anticancer drug directed toward cancer cells with the developed multidrug resistance attributed to the presence of altered DNA topoisomerase II.
Acta biochimica Polonica 03/2009; 56(1):135-42. · 1.49 Impact Factor
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ABSTRACT: A series of 5-aryl-3-alkylidenedihydrofuran-2(3H)-ones 6a-g'' and 11a,b as well as 5-aryl-3-methylidenepyrrolidin-2-ones 10a-c and 12 were synthesized starting from 4-aryl-2-diethoxyphosphoryl-4-oxobutanoates 3a-g. Reaction sequence includes reduction or reductive amination of the carbonyl group, lactonization or lactamization step and finally the Horner-Wadsworth-Emmons olefination of aldehydes using thus obtained 5-aryl-3-diethoxyphosphoryl-3,4-dihydrofuran-2(5H)-ones 5a-g'' or 5-aryl-3-diethoxyphosphorylpyrrolidin-2-ones 9a-c. Furanones 6 and 11, as well as pyrrolidinones 10 and 12, were evaluated in vitro against mouse leukemia cell line L-1210 and two human leukemia cell lines HL-60 and NALM-6. Several of the obtained furanones proved to be very potent against all three cell lines with IC(50) values lower than 6 microM. Structure-activity relationships of these compounds, as well as 5-alkyl or 5-arylmethyl-3-methylidenedihydrofuran-2(3H)-ones 13a-e, previously obtained in our laboratory, are discussed.
Bioorganic & medicinal chemistry 06/2008; 16(9):4872-82. · 2.82 Impact Factor
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ABSTRACT: A series of square-planar platinum(II) and palladium(II) complexes of the formula cis-[PtCl2L2] and trans-[PdCl2L2] [L stands for diethyl (pyridin-2-ylmethyl)phosphate (2-pmOpe) or diethyl (pyridin-3-ylmethyl)phosphate (3-pmOpe) or diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe)] have been synthesized and tested in vitro for their cytotoxicity against mouse leukemia L1210 cells. The results indicated that the cis-platinum complexes showed superior activity than trans-palladium complexes, but lower in comparison to cisplatin. The chemical reactivity of the tested complexes has been determined in an in vitro NBP test. The platinum complexes exhibited very high chemical reactivity in NBP test, higher than cisplatin. The results showed no correlation between cytotoxicity and chemical reactivity for platinum complexes. Two platinum(II) complexes {cis-[PtCl2(2-pmOpe)2], cis-[PtCl2(3-pmOpe)2]} have been synthesized and characterized by IR, 1H NMR, 31P NMR, and elemental analysis.
European journal of medicinal chemistry 06/2008; 44(2):660-4. · 3.27 Impact Factor
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ABSTRACT: Tachykinins are multifunctional neuropeptides that have been identified in vertebrates as well as invertebrates. The C-terminal FXGXRa-motif constitutes the consensus active core region of invertebrate tachykinins. In Drosophila, two putative G protein-coupled tachykinin receptors have been cloned: DTKR and NKD. This study focuses on the functional characterization of DTKR, the Drosophila ortholog of the stable fly's tachykinin receptor (STKR). Tachykinins containing an alanine residue instead of the highly conserved glycine (FXAXRa) display partial agonism on STKR-mediated Ca(2+)-responses, but not on cAMP-responses. STKR therefore seems to differentiate between a number of tachykinins. Gly- and Ala-containing tachykinins are both encoded in the Drosophila tachykinin precursor, thus raising the question of whether DTKR can also distinguish between these two tachykinin types. DTKR was activated by all Drosophila tachykinins and inhibited by tachykinin antagonists. Ala-containing analogs did not produce the remarkable activation behavior previously observed with STKR, suggesting different mechanisms of discerning ligands and/or activating effector pathways for STKR and DTKR.
Peptides 02/2007; 28(1):103-8. · 2.43 Impact Factor
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ABSTRACT: In search for new platinum-based anticancer drugs, four cisplatin analogues, which contain pyrazole rings as non-leaving ligands, have been synthesized: cis-PtCl(2)(3,5-DM HMPz)(2), cis-PtCl(2)(Pz)(2), cis-PtCl(2)(ClMPz)(2), and cis-PtCl(2)(HMPz)(2), where Pz=pyrazole, H=hydroxyl, M=methyl. We tested their cytotoxicity, apoptosis induction ability, DNA damaging and modification properties comparing them in respect to the parent compound. The cytotoxic activity of these platinum pyrazole complexes toward the murine leukemia cell line was 2.9-3.8 times lower than actvity of cisplatin. The tested compounds varied in their mechanism of action by producing different DNA lesions. The most interesting compound seems to be the complex with chloromethyl groups at N1 of pyrazole rings, which exhibited the highest ability to form bifunctional adducts with DNA in vitro.
Journal of Inorganic Biochemistry 11/2006; 100(10):1579-85. · 3.35 Impact Factor
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ABSTRACT: A novel, general method of synthesis of 4-methylideneisoxazolidin-5-ones 10 is described. The target compounds were synthesized starting from ethyl 2-diethoxyphosphoryl-2-alkenoates 6 or dicyclohexylammonium 4-diethoxyphosphoryl-2-alkenoates 7. Addition of N-methylhydroxylamine hydrochloride to these Michael acceptors, lactonization to 4-diethoxyphosphorylisoxazolidin-5-ones 9, and Horner-Wadsworth-Emmons olefination of formaldehyde using 9 gave the title isoxazolidinones 10. All obtained compounds were tested against L-1210, HL-60, and NALM-6 leukemia cell lines. Several isoxazolidinones 10 were found to be very potent with IC(50)<1 microM. The highest cytostatic activity against HL-60 was observed for 10a and against NALM-6 for 10b with IC(50) values of 0.74 and 0.34 microM, respectively.
Bioorganic & Medicinal Chemistry Letters 03/2006; 16(5):1430-3. · 2.55 Impact Factor
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ABSTRACT: Neurokinin receptors (NK1, NK2, NK3) are G-protein-coupled receptors, which upon activation by a peptide agonist induce a transient increase in the concentration of intracellular calcium. The functional assay based on aequorin-derived luminescence triggered by receptor-mediated changes in Ca2+ levels was used to compare the effect of spantides I-III on SP-, NKA- and NKB-stimulated NK1, NK2 and NK3 receptors, respectively. Recombinant cell lines expressing neurokinin receptors and apoaequorin were used in the study. The obtained results indicate that all three spantides acted as competitive antagonists at the NK1 and NK2 receptors and inhibited agonist-induced calcium responses. The rank order of antagonism at the NK1 receptor was spantide II>spantide III>spantide I and at the NK2 receptor was spantide III>spantide II>spantide I. All three spantides failed to antagonize NKB-induced calcium responses at the NK3 receptor.
Regulatory Peptides 12/2005; 131(1-3):23-8. · 2.11 Impact Factor
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ABSTRACT: A series of enantiomerically enriched 4,5-dihydro-5-[aryl(hydroxy)methyl]-3-methylidenefuran-2(3H)-ones (8) were synthesized by means of asymmetric Sharpless dihydroxylation of the 2-phosphorylated 5-aryl-pent-4-enoic acids 13, followed by Horner-Wadsworth-Emmons reaction of the resulting furanones 15 (Scheme 2). An enantiomeric excess (ee) of 20-95% was achieved for compounds 8, and their absolute configurations were determined by the Mosher ester method. Cytotoxic evaluation against L-1210 and HL-60 leukemia cell lines revealed that the target compounds 8 are active in the micromolar concentration range (Table 2). Thereby, significant differences in activity between the corresponding enantiomers were observed for the HL-60 cell line.
Chemistry & Biodiversity 10/2005; 2(9):1256-65. · 1.80 Impact Factor
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ABSTRACT: 5-Alkyl- and 5-arylalkyl-3-methylenedihydrofuran-2-ones 13a-e, 3-alkylidenedihydrofuran-2-ones 18a-c, and 3-methylenepyrrolidin-2-ones 16a-e were synthesized utilizing ethyl 2-diethoxyphosphoryl-4-nitroalkanoates 9a-e as common intermediates. All obtained compounds were tested against L-1210, HL-60, and NALM-6 leukemia cells. The highest cytotoxic activity was observed for 3-methylenefuranones 13d,e bearing benzyl or 3,4-dimethoxyphenylmethyl substituents at position 5, with IC(50) values of 5.4 and 6.0 microM, respectively. Contrary to the literature reports, no enhancement in activity due to the presence of a hydroxy group was found when the cytotoxicity of furanones 13a,b,d and 5-(1'-hydroxyalkyl)-3-methylenedihydrofuran-2-ones 6a,b,d was compared. The anticancer activity of pyrrolidinones 16a-e and 3-alkylidenefuranones 18a-c was much weaker than that of furanones 13a-e.
Journal of Medicinal Chemistry 06/2005; 48(10):3516-21. · 5.25 Impact Factor
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ABSTRACT: A series of 3-methylidenetetrahydro-2-furanones 7 bearing various hydroxyalkyl substituents in position 5 were synthesized using novel diastereo- and enantioselective methodology. In vitro cytotoxicity data demonstrated that all prepared compounds were active against L-1210 and HL-60 tissue culture cells with 7e being the most potent (IC(50) = 6.9 microM). Also an increase in activity with an increase in lipophilicity of the substituents in the order H < alkyl < phenyl was observed.
Journal of Medicinal Chemistry 02/2002; 45(5):1142-5. · 5.25 Impact Factor
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ABSTRACT: Doxorubicin (DOX), daunorubicin (DRB), epidoxorubicin (EDOX) and their analogues with a 3'-NH2 group in daunosamine form a covalent bond with a 2-NH2 group of guanine via a methylene group from formaldehyde (CH2O). It is assumed that a Schiff base type intermediate is formed between CH2O and the 3'-NH2 group in the reaction. This reaction is supposed to occur in the cell. New analogues of anthracyclines with formamidine functionality bound to C-3' of daunosamine and containing the bulky morpholine (DRBM, DOXM and EDOXM) or hexamethyleneimine rings attached are studied in our laboratory. These substituents decrease the association of the drugs to DNA and potentially hinder the formation of Schiff base-intermediates. Our experiments indicate that the formation of the covalent complexes by DRB, DOX and EDOX under these conditions is confirmed by a high enhancement (17-40x) of the inhibition of overall RNA synthesis by E. coli RNA polymerase on T7 DNA. DRBM and DOXM exhibit a lower enhancement of the inhibition by CH2O (7-13x). The other analogues show a 1.6-3x increase of inhibition. Hence, their covalent binding is lower than that of the parent compounds. These conclusions are confirmed by spectrophotometric estimations following removal of non-covalently associated drugs. Electrophoretic analysis of drug-DNA complexes formed in the presence of CH2O indicates that DRBM and DOXM as their parent compounds induce labile cross-links in DNA. Comparison of the results obtained at the subcellular level with cytotoxicity estimations indicates that there is a correlation between cytotoxicity of the anthracyclines on L1210 cells and transcriptional template activity of drug-DNA complexes formed in the presence of CH2O (r = 0.64; n = 9). These data confirm a notion that covalent attachment of anthracyclines to DNA is an essential event leading to cytotoxicity.
Zeitschrift fur Naturforschung C 59(9-10):739-48. · 0.77 Impact Factor
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ABSTRACT: We present a simple and general strategy for the synthesis of β,δ-disubstituted-α-methylene-δ-lactones starting from easily available tert-butyl 2-(diethoxyphosphoryl)alk-2-enoates. The elaborated synthetic protocol includes pyrrolidine-catalyzed Michael addition of acetone, diastereoselective reduction of the carbonyl group, lactonization and finally the Horner–Wadsworth–Emmons reaction with formaldehyde. All α-methylene-δ-lactones were evaluated in vitro against mouse leukemia cell line L-1210 and two human leukemia cell lines HL-60 and NALM-6. Comparison of cytotoxic activity with corresponding α-methylene-γ-lactones is also discussed.Graphical abstract
European Journal of Medicinal Chemistry. 45(2):710-718.
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ABSTRACT: The effect of the photobinding of 8-methoxypsoralen to phage T7 DNA on different steps of RNA synthesis in vitro was assayed. Total RNA synthesis is reduced to a few percent and the transcript size is decreased, as shown by means of gel filtration on a Sepharose 4B column when DNA of the adduct content of six drug molecules per 103 nucleotides is used. The initiation of RNA chains seems to be less affected, as inferred from an abortive initiation assay. Synthesis of pppApU on DNA of the same adduct content is inhibited to 34% of the corresponding controls, while the overall RNA synthesis is inhibited to 6%. The amount of the enzyme needed for maximal retention of DNA, the kinetics of its binding and the decay of the polymerase-DNA complex at high ionic strength (or on decrease of the temperature) are similar with DNA either irradiated in the absence of the drug or DNA bearing six 8-methoxypsoralen molecules per 103 nucleotides. It is concluded from this study that 8-methoxypsoralen partially inhibits initiation and blocks movement of RNA polymerase along the template, inducing premature termination. It does not appear to influence the binding of the enzyme to DNA.
Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression.
