Athanasios Papageorgiou

University of Patras, Rhion, West Greece, Greece

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Publications (21)45.96 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: On the basis of the results of in-silico predictions and in an effort to extend our structure-activity relationship studies, the aromatic nitrogen mustard 2-[4-N,N-bis(2-chloroethyl) amino-phenyl]butanoic acid (2-PHE-BU) was synthesized and conjugated with various steroidal alcohols. The resulting steroidal esters were evaluated for their in-vivo toxicity and antileukemic activity in P388-leukemia-bearing mice. The new derivatives showed significantly reduced toxicity and marginally improved antileukemic activity compared with free 2-PHE-BU. Nevertheless, they did not prove to be superior either to the template steroidal ester used for in-silico predictions or to previously synthesized steroidal esters of aromatic nitrogen mustards. The results obtained indicate that in-silico design predictions may guide the design and synthesis of new bioactive steroidal esters, but further parameters should be considered aiming at the discovery of compounds with optimum activity.
    Anti-cancer drugs 01/2013; 24(1):52-65. · 2.23 Impact Factor
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    ABSTRACT: Inhibitors of acetylcholine breakdown by acetylcholinesterase (AChE) constitute the main therapeutic modality for Alzheimer's disease. In the search for natural products with inhibitory action on AChE, this study investigated the activity of saffron extract and its constituents by in vitro enzymatic and molecular docking studies. Saffron has been used in traditional medicine against Alzheimer's disease. Saffron extract showed moderate AChE inhibitory activity (up to 30%), but IC(50) values of crocetin, dimethylcrocetin, and safranal were 96.33, 107.1, and 21.09 μM, respectively. Kinetic analysis showed mixed-type inhibition, which was verified by in silico docking studies. Safranal interacts only with the binding site of the AChE, but crocetin and dimethylcrocetin bind simultaneously to the catalytic and peripheral anionic sites. These results reinforce previous findings about the beneficial action of saffron against Alzheimer's disease and may be of value for the development of novel therapeutic agents based on carotenoid-based dual binding inhibitors.
    Journal of Agricultural and Food Chemistry 06/2012; 60(24):6131-8. · 2.91 Impact Factor
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    ABSTRACT: In order to reduce toxicity and to enhance anticancer activity of nitrogen mustards, three hybrid steroidal esters were synthesized and tested in vitro against human pancreatic cancer cells expressing uridine phosphorylase (UPase). The inhibition potency against a target protein implicated in the chemotherapy of solid tumors, such as UPase, is of fundamental importance in the design and synthesis of new anticancer drugs. MTT colorimetric assay and molecular docking were employed for the in vitro and in silico drug evaluation, respectively. A difference in cell sensitivity was found, which followed the known different UPase expression in the cell lines. Molecular docking studies on UPase protein, revealed the tested compounds to be bound to the binding cavity of the protein, with different affinity. Between the two D-modified compounds, the D-homo-aza (lactam)-hybrid compound (C2) was found to interact with the protein in a more efficient way. The molecular docking data were in accordance with the in vitro results, where the lactam steroid alkylator showed significantly higher cytostatic and cytotoxic activity than the non-D-modified compounds, which also correlated with the level of UPase expression in the pancreatic cancer cells.
    Anticancer research 03/2011; 31(3):831-42. · 1.71 Impact Factor
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    ABSTRACT: Modified steroidal derivatives (PK11-PK14) of p-bis(2-chloroethyl)aminophenyl propenate (PK15) were used to study their antitumour activity on Lewis lung carcinoma (LLC) and their effect on sister chromatid exchanges (SCEs) and human lymphocyte proliferation kinetics. LLC was tested in this study. C57BL mice were used for in vivo chemotherapy evaluation and the antitumour activity was assessed. Lymphocyte cultures were used to study the genotoxic effect in vitro. PK15 and PK11 were the most effective against LLC, causing significant inhibition of tumour growth. PK11 and PK15 induced significant increase in SCE rates. A correlation was observed between the cytogenetic effect and the antitumour effectiveness. The order of the antitumour effectiveness of PK11-PK15 resembled the order of the cytogenetic damage induced by the same compounds in vitro.
    Anticancer research 10/2010; 30(10):4201-4. · 1.71 Impact Factor
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    ABSTRACT: The aim of this study was to design new potentially antineoplastic agents by combining nitrogen mustard with steroidal skeleton, in an effort to improve specificity and simultaneously to reduce systemic toxicity. The steroidal part is aimed to act as a biological platform enabling the alkylating moiety to approach its site of action by altering its physicochemical properties. The compounds tested have, as alkylating agents, either p-N,N-bis(2-chloroethyl)aminophenyl-butyrate or p-N,N-bis(2-chloroethyl)aminophenyl-acetate esterified with a modified steroidal nucleus. The four newly synthesized compounds were compared on a molar basis, regarding their ability to induce sister chromatid exchanges and modify proliferation rate indices in cultured human lymphocytes. Life span of BDF1 mice inoculated with L1210 leukemia was also estimated (antileukemic activity). A compound having p-N,N-bis(2-chloroethyl)aminophenyl-acetate as the alkylator and two ketone groups in the steroidal part demonstrated the highest statistically significant enhancement of sister chromatid exchanges and suppression of proliferation rate indices, and also caused significant antineoplastic activity. The other compounds proved less active. These results suggest that cytogenetic and antileukemic activity of alkylating steroidal esters depends on the configuration of the whole molecule and the appropriate combination of the alkylator with the steroidal molecule.
    Genetic Testing and Molecular Biomarkers 12/2009; 14(1):93-7. · 1.44 Impact Factor
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    ABSTRACT: A series of aryl-acetic acids and hydroxamic acids possessing antioxidant/anti-inflammatory activities were tested for anticancer activity using different cancer cell lines. The compounds have low antitumor activity considering the 1/IC(50) values attained for the cell lines. Compound 5iv presents the best anticancer activity. Moreover, they depict the same activity pattern, suggesting similar mechanisms of action correlated to their antioxidant activities. The obtained results subjected in a QSAR analysis. It seems reasonable to conclude that the same molecular structural features are responsible for the compounds biological activity, these being the electron accepting/donating ability and the molar volume. For all cellular lines (HT-29, A-549 and OAW-42) log 1/IC(50) exhibits a reasonable correlation with a two parameters relationship in which the Esp-min and D term are present. Apart from Esp-min the other descriptor found important for anticancer activity is the molar volume (MgVol). The QSAR analyses did not indicate any role for lipophilicity Electrostatic potential, dipole moment and the bulk, primarily affect the biological response.
    Chemical Biology &amp Drug Design 10/2009; 74(3):266-75. · 2.47 Impact Factor
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    ABSTRACT: The synthesis and the in vivo evaluation against leukemias P388 and L1210 of six new alkylating steroidal esters are described. The esteric derivatives incorporating the 17beta-acetamido-B-lactamic steroidal skeleton exhibited increased antileukemic activity and lower toxicity, compared to the 17beta-acetamido-7-keto analogs. Among the 17beta-acetamido-B-lactamic steroidal esters, the most potent compound afforded four out of six cures in leukemia P388 and was measured to be almost non-toxic, producing significant low levels of toxicity.
    Bioorganic & medicinal chemistry 06/2008; 16(9):5207-15. · 2.82 Impact Factor
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    ABSTRACT: Recent Structure-αntileukemic αctiνiιy studies showed thαt the steroidαΙ pαrt of complex molecules contαining DNΑ αllqlαtors does not pΙαy only the role of the "biologicαl cαrrier''' New such compounds designed to poSSeSS αn αllylic 7-ketone showed enhαnced αntileukemic potency compαred ιηith deiναtiνes with α simpΙe steroidαl skeleιon. Ιn order to inνestigαte ιηhether the enhαncement of the αntileukemic potency is αttributed tο the introduction of the 7-ketone or to the Δ5'7-keto conjugαted steroidαl system we decided to reduce the Δ5 doubΙe bond. The 5α-7-keto-steroidαl skeletons synthesized were tethered to chlorαmbucil αnd phenyΙ αcetic αcid's nitrogen mustαrd αnd studied αgαinst leukemiα Pj38 in νiνo. The reduction of the double bond hαd α negαtiνe impαct on the αntileukemic potency since the compαrαtiνe study of the noνel deiνοtiνes sholη,ed thαt ο seies of νery potent Δ5 -7-keto- steroidal esters were conνerted by this modificαtion to compounds with mαrginαlly αccepted αctiνity.
    In vivo (Athens, Greece) 01/2008; 22(3):345-352. · 1.22 Impact Factor
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    ABSTRACT: This study was designed as a rational continuation of our research regarding the functional requirements essential for the antileukemic activity of compounds comprising an alkylating moiety and a modified steroid. The steroidal esteric derivatives of 4-methyl-3-N,N-bis(2-chloroethyl)amino benzoic acid were tested on leukemias P388 and L1210 in vivo and in normal human lymphocytes in vitro. Among them the B-lactamic steroidal esters proved more potent antileukemic agents than the 7-oxidized and those with a simple B-ring, but not more effective inducers of DNA damage and cell cycle arrest in vitro. We speculate that these results indicate a different mechanism of action induced by the lactamized B steroidal ring, in comparison to the 7-keto or the D-lactamic groups, which involves the interaction of the -NHCO- moiety with cellularcomponents essential for tumor growth. 4-Methyl-3-N,N-bis(2-chloroethyl)amino benzoic acid proved a more proper module for the B-lactams than chlorambucil and phenyl acetic acid's nitrogen mustard probably because the esteric bond is less cleaved by the esterases, resulting in an increased concentration of the drug in the vinicity of the target site essential for an antineoplasmatic response.
    Anti-Cancer Drugs 11/2007; 18(9):997-1004. · 2.23 Impact Factor
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    ABSTRACT: In order to study the role of the steroidal moiety on the expression of anti-leukemic activity, we synthesized six derivatives of chlorambucil (CHL), and tested them on leukemias P388 and L1210 in vivo and in normal human lymphocytes in vitro. Five of the six tested compounds produced submultiple toxicity, while the measured anti-leukemic potency was significantly increased. The lactamization of the B-steroidal ring rendered the molecules more potent, but the corresponding 7-oxidized derivatives proved better in both leukemias tested. The lactamization of the D-steroidal ring afforded potent compounds, regardless of the configuration of the B-ring. The best among all derivatives contains both chemical modifications and is intended as a promising key molecule that must be further studied. We speculate that in leukemic cells a tumor-specific protein is overexpressed, the steroid has the ability to bind and block this protein from carrying out its normal function, and the drug-protein complex prevents the repair of the adducts. The synthesis, physicochemical and spectroscopic data of these compounds and a modified route for the synthesis of CHL are also reported.
    Anti-Cancer Drugs 07/2006; 17(5):511-9. · 2.23 Impact Factor
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    ABSTRACT: The sensitivity of breast neoplasms to hormonal control provides the basis of novel investigational treatments with steroidal alkylators. An androsterone D-lactam steroidal ester, the 3beta-hydroxy-13alpha-amino-13,17-seco- 5alpha-androstan-17-oic-13,17-lactam, p-bis(2-chloroethyl)amino phenyl acetate (lactandrate) was synthesized and tested for antitumor activity against six human breast cancer cell lines in vitro and against two murine and one xenograft mammary tumors in vivo. A docking study on the binding interactions of lactandrate with the ligand-binding domain (LBD) of estrogen receptor-alpha (ERalpha) was inquired. In vitro testing of lactandrate cytostatic and cytotoxic activity was performed on T47D, MCF7, MDA-MB-231, BT-549, Hs578T, MDA-MB-435 breast adenocarcinoma human cell lines. In vivo testing was performed on two murine mammary tumors, the MXT tumor and CD8F1 adenocarcinoma, as well as on human mammary carcinoma MX-1 xenograft. Molecular modeling techniques were adopted to predict a possible location and interaction mode of the molecule into LBD. Lactandrate induced significantly high antitumor effect against all tested in vitro and in vivo models. The cell lines with positive ER expression found to be significantly more sensitive to lactandrate. Moreover, lactandrate found to be positioned inside the binding cavity with its steroidal moiety, whilst the alkylating moiety protrudes out of receptor's pocket. Lactandrate produced important anticancer activity on breast cancer in vitro and in vivo. Some correlation between ER and lactandrate effect was demonstrated. Docking studies provide the basis for the structure-based design of improved steroidal alkylating esters for the treatment of estrogen-related cancers.
    Breast Cancer Research and Treatment 06/2006; 97(1):17-31. · 4.47 Impact Factor
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    ABSTRACT: NSC 290205 (A) is a hybrid synthetic antitumor ester, which combines a D-lactam derivative of androsterone and nitrogen mustard. In this study, the antitumor activity of A in combination with ADR (AHOP) was investigated in comparison with the standard CHOP regimen. PAN02 adenocarcinoma was used in this study. C57Bl mice were used for chemotherapy evaluation. The activity was assessed from the inhibition of tumor growth and the oncostatic parameter T/C%. Treatment with A or cyclophosphamide produced almost equal borderline activity. Moreover, both the CHOP and AHOP regimens showed significant and comparable antitumor effects. AHOP caused the maximum effect, inhibiting tumor growth by 56.8%. CHOP was less effective, producing 47.7% tumor inhibition. It is very likely that the D-lactamic steroid (androstan) alkylator forA, containing the amide group -NH-CO-, combined with ADR which intercalates between DNA base-pairs, is the explanation for the higher activity of AHOP as compared to CHOP.
    Anticancer research 01/2006; 26(1A):243-7. · 1.71 Impact Factor
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    ABSTRACT: We have studied the effect of modification of the B-steroidal ring to lactamic on the anti-leukemic potency of D-modified and D-non-modified steroidal esters of chlorambucil's active metabolite. The compounds synthesized were studied against leukemias P388 and L1210 after the subsequent estimation of their toxicity in vivo, and for their ability to induce sister chromatid exchanges (SCEs) and to inhibit cell proliferation in normal human lymphocytes in vitro. The in vitro results correlated well, on a molar basis, with the results obtained from the study of the anti-leukemic potency. In a comparative study, the B-lactamic steroidal derivatives proved less active than the 7-oxidized ones against both leukemias. The presence of the -NHCO- group in the B-steroidal ring did not have the same positive effect on the biological action of chlorambucil's active metabolite esters as in the D-lactamic ring. However, this new modification of the B-ring rendered the final esteric derivatives much more toxic, compared with to the corresponding esters with a simple B-ring. This loss of the anti-leukemic specificity, which occurs from the modification of the B-ring, is additional evidence for the role of the steroidal part on the mechanism of action of these promising compounds. This provides support for the notion that the steroidal part of these molecules is not just a simple biological carrier, as has been speculated for many years.
    Anti-Cancer Drugs 12/2005; 16(10):1075-82. · 2.23 Impact Factor
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    ABSTRACT: The p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid esters of hecogenin and aza-homo-hecogenin have been prepared and their antineoplastic activity was evaluated against two basic drug screening systems in rodents, P388 lymphocytic and L1210 lymphoid murine leukemias. Among the compounds tested, the p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid ester of aza-homo-hecogenin was appeared to possess a significant higher antileukemic effect. These results support that the alkylating esters of hecogenin produce important antitumor activity as well as, indicate that the aza-homo-hecogenin ester exhibits significantly higher activity due to lactam group (-NHCO-) modification.
    Il Farmaco 11/2005; 60(10):826-9.
  • Dimitrios T P Trafalis, Charalambos Camoutsis, Athanasios Papageorgiou
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    ABSTRACT: Evidence indicating that hybrid steroid compounds of anti-cancer agents produce reduced toxicity, significantly lower than the cytotoxic components alone, and increased anti-cancer activity has prompted the design and development of such steroids, mostly alkylating esters. We investigated the in-vitro and in-vivo activity of a homo-aza-steroidal alkylating ester (HASE), in comparison with dacarbazine (DTIC), cisplatin (CPDD), carmustine (BCNU) and semustine (MeCCNU), in the treatment of malignant melanoma. Cytotoxicity was assessed in vitro by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using a panel of six human malignant melanoma cell lines, with or without the presence of rat liver microsome assay. B16 melanoma-bearing mice were used to evaluate in vivo the anti-tumour activity of the tested compounds. In all cases of in-vitro screening, HASE displayed a significantly higher (P<0.0001) cytostatic and cytotoxic effect than DTIC, BCNU and MeCCNU, but produced significantly lower (P<0.0001) activity than CPDD. HASE exhibited a significantly smaller range than CPDD between concentration levels that produced growth arrest and those that induced a cytotoxic effect against melanoma cells in vitro. The anti-tumour activity of HASE in B16 melanoma-bearing mice, as determined by tumour growth rate inhibition (<42%) and percentage survival prolongation (treated versus control, 167%), was significantly superior (P<0.001) to that achieved by DTIC, BCNU and MeCCNU and was equal to that of CPDD. HASE exhibited a toxicity similar to that of DTIC, BCNU and MeCCNU, but significantly lower than that of CPDD. It can be concluded that HASE displays significant in-vitro and in-vivo activity in the treatment of melanoma.
    Melanoma Research 08/2005; 15(4):273-81. · 2.52 Impact Factor
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    ABSTRACT: Summary NSC290205 (A) is an hybrid synthetic antineoplastic ester that is a combination of a d-lactam derivative of androsterone and an alkylating derivative of N,N-bis(2-chloroethyl)aniline. We tested NSC290205 for synergistic antileukaemic activity with adriamycin (ADR), (i) in vitro against the human lymphoid leukaemia cell lines: CCRF-CEM, MOLT-4, and RPMI-8226, (ii) in vivo against P388 lymphocytic and L1210 lymphoid murine leukaemias (at incipient and advanced phase). Our results indicated significant cytostatic and cytotoxic synergy of NSC290205 and ADR in vitro. We further examined these results in vivo by replacing cyclophosphamide in the standard CHOP (cyclophosphamide, hydroxydaunomycin, Oncovin, prednisone) regimen with NSC290205 (AHOP) and comparing the efficiency of these two regimens in vivo. Although treatment of P388 and L1210 with cyclophosphamide or NSC290205 alone yielded equivalent results, AHOP produced a clear benefit for survival compared with CHOP against advanced leukaemias, confirming the in vitro observations [higher percentage increase in median lifespan of treated animals over the untreated (control): 188% and 239% in L1210, 308% and 353% in P388, P < 0.01, for CHOP and AHOP respectively]. AHOP also proved to be more genotoxic and cytostatic than CHOP, inducing higher sister chromatid exchange levels and cell division delays on P388 cells in vivo. NSC290205 showed superior antineoplastic potential against lymphoid leukaemia and significant synergy with ADR, producing an excellent therapeutic outcome.
    British Journal of Haematology 03/2005; 128(3):343-50. · 4.94 Impact Factor
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    ABSTRACT: We have investigated the role of the allylic 7-ketone in oxidized Delta5-steroids on antileukemic activity. We synthesized and studied a series of oxidized and non-oxidized steroidal esters of p-N,N-bis(2-chloroethyl)aminophenylacetic acid (PHE), chlorambucil's active metabolite. In a comparative study of these 7-keto derivatives, on a molecular basis, regarding their ability to induce sister chromatid exchanges (SCEs) and to inhibit cell proliferation in normal human lymphocytes in vitro, the results with these 7-keto derivatives, on a molecular basis, correlated well with their antileukemic potency against leukemia P388- and L1210-bearing mice, which proved to be significantly increased compared to that of the non-oxidized derivatives. Our results indicate that the role of the steroidal skeleton it is not only for the transportation of the alkylating agent into the cell, but also contributes directly to the mechanism of antileukemic action, by an as-yet unknown way. The main conclusion from this study is that the existence of the allylic 7-keto group in the skeleton of the Delta5-steroidal esters impressively enhances their antileukemic activity, while the toxicity remains at clinically acceptable levels, suggesting that this structural modification should be further investigated.
    Anti-Cancer Drugs 12/2004; 15(10):983-90. · 2.23 Impact Factor
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    ABSTRACT: Four newly synthesized antitumor steroidal compounds were compared, on a molar basis, regarding their ability to induce sister chromatid exchanges (SCEs) and cell division delays. The concept of designing and developing these compounds (1-4) is to enhance the anticancer activity of esteric steroidal derivatives of nitrogen mustard by introduction of a keto group at the 7-position of the D5 steroidal skeleton, and a double bond between positions 6 and 7 of the B ring of the steroidal nucleus. In our study, the cytogenetic and antileukemic effects of these newly synthesized compounds are reported. The four substances induced statistically significant enhancement of SCEs and of cell division delays, and in both schedules used, therapeutic effects. However, compounds 1 and 3 showed increased genotoxicity towards human lymphocytes (p<0.001) and antileukemic activity towards P388 leukemias (p<0.001), compared to compounds 2 and 4. It seems that the introduction of a keto group at the 7-position of the steroidal skeleton enhances the antitumor effect of these substances in comparison with our previous studies with the corresponding compounds characterized by the absence of the 7-keto group. Therefore, the in vivo antitumor effect of the four compounds appears to correlate well with the in vitro cytogenetic effect caused by these chemicals.
    Anti-Cancer Drugs 07/2002; 13(6):637-43. · 2.23 Impact Factor
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    ABSTRACT: The increase of the damaging effects on specific DNA sequences and the reduction of the subsequent toxicity of nitrogen mustards has been achieved by their chemical conjugation with modified steroids through an esteric bond. In an attempt to study the structure-activity relationships of these compounds, we synthesized eight steroidal esters of 4-methyl-3-bis(2-chloroethyl)aminobenzoic acid (4-Me-CABA). The anti-leukemic and cytogenetic effects of the parent alkylating agent were compared with those produced by the steroidal compounds, in vivo against leukemias P388 and L1210 and in vitro for induction of Sister Chromatid Exchanges (SCE) and on proliferation rate indices (PRI). The results demonstrate that the existence of the NH-CO group, either as an endocyclic lactamic or as an out of the ring amidic one but at axial conformation, at the steroid-carrier moiety is necessary for the expression of the antileukemic activity. The synthetic route for the preparation of the steroidal esters and their physicochemical data are also reported.
    Anticancer research 01/2002; 22(4):2293-9. · 1.71 Impact Factor
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    ABSTRACT: Recent structure-antileukemic activity studies showed that the steroidal part of complex molecules containing DNA alkylators does not play only the role of the "biological carrier". New such compounds designed to possess an allylic 7-ketone showed enhanced antileukemic potency compared with derivatives with a simple steroidal skeleton. In order to investigate whether the enhancement of the antileukemic potency is attributed to the introduction of the 7-ketone or to the Delta5-7-keto conjugated steroidal system we decided to reduce the Delta5 double bond. The 5alpha-7-keto-steroidal skeletons synthesized were tethered to chlorambucil and phenyl acetic acid's nitrogen mustard and studied against leukemia P338 in vivo. The reduction of the double bond had a negative impact on the antileukemic potency since the comparative study of the novel derivatives showed that a series of very potent Delta 5-7-keto-steroidal esters were converted by this modification to compounds with marginally accepted activity.
    In vivo (Athens, Greece) 22(3):345-52. · 1.22 Impact Factor

Publication Stats

77 Citations
45.96 Total Impact Points

Institutions

  • 2002–2013
    • University of Patras
      • Department of Pharmacy
      Rhion, West Greece, Greece
  • 2008–2010
    • Θεαγένειο Αντικαρκινικό Νοσοκομείο
      Saloníki, Central Macedonia, Greece
  • 2006–2009
    • Aristotle University of Thessaloniki
      • Department of Pharmaceutical Chemistry
      Thessaloníki, Kentriki Makedonia, Greece
    • Theagenio Cancer Hospital
      Saloníki, Central Macedonia, Greece
  • 2005
    • International Institute of Anticancer Research
      Αθίκια, Peloponnese, Greece