Platinum-group metal half-sandwich complexes of sugar-isoxazol(in)e conjugates - synthesis and evaluation of their antineoplastic and antimicrobial activities.
Rahaf Akel, István Kacsir, Éva Kerekes, Csongor Freytag, Evelin Szoták, Dóra Boros-Pál, Eszter Anna Janka, Attila Bényei, Gábor Kardos, Éva Bokor, László Somsák, Péter Bai, Adrienn Sipos, Sándor Kun
{"title":"Platinum-group metal half-sandwich complexes of sugar-isoxazol(in)e conjugates - synthesis and evaluation of their antineoplastic and antimicrobial activities.","authors":"Rahaf Akel, István Kacsir, Éva Kerekes, Csongor Freytag, Evelin Szoták, Dóra Boros-Pál, Eszter Anna Janka, Attila Bényei, Gábor Kardos, Éva Bokor, László Somsák, Péter Bai, Adrienn Sipos, Sándor Kun","doi":"10.1016/j.ejps.2025.107260","DOIUrl":null,"url":null,"abstract":"<p><p>Platinum-group metal half-sandwich complexes are considered to be potential replacements of the clinically widely used platins which have several side effects and tend to cause resistance to develop. In our previous works, we used a range of 2-pyridyl-substituted N- and C-glycosyl heterocycles as N,N-chelating ligands to prepare ruthenium(II), osmium(II), iridium(III) and rhodium(III) polyhapto arene/arenyl half-sandwich complexes. Some of these complexes, particularly with the C-glucopyranosyl isoxazole derived ligand in its O-perbenzoylated form, exhibited greater anticancer efficiency than cisplatin and had minimal or negligible effects on non-transformed fibroblasts. Additionally, these cytostatic compounds exhibited micromolar antibacterial activity against multiresistant Gram-positive bacteria. In the present work, novel modes of conjugation between the sugar and the isoxazole moieties have been studied. Specifically, glycosylidene-spiro-isoxazoline and polyhydroxyalkylisoxazole scaffolds were synthesised and utilised in complex formation reactions. The spiro-isoxazolines were obtained in 1,3-dipolar cycloadditions of exo-glycals and nitrile oxides generated from pyridine-2-carbaldoximes. Ring opening of the spiro-isoxazolines under basic or transition-metal-mediated conditions produced polyhydroxyalkylisoxazoles. These compounds were then transformed into their O-peracetylated, O-perbenzoylated and O-unprotected variants, which were used for complex formation with the above-mentioned platinum-group metal ions. The complexes induced cytostasis in cellular models of ovarian cancer and pancreatic adenocarcinoma; the best compounds had submicromolar IC<sub>50</sub> values (0.4-0.5 µM). A subset of the cytostatic complexes retained their activity on cisplatin resistant ovarian cancer cells. Furthermore, a reasonable therapeutic index was detected when complexes were assessed on primary human fibroblasts pointing towards a potential applicability of the complexes. Unexpectedly, none of the complexes induced bacteriostasis in Gram-positive bacteria as Staphylococcus aureus or Enterococcus species.</p>","PeriodicalId":12018,"journal":{"name":"European Journal of Pharmaceutical Sciences","volume":" ","pages":"107260"},"PeriodicalIF":4.7000,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Pharmaceutical Sciences","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.ejps.2025.107260","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHARMACOLOGY & PHARMACY","Score":null,"Total":0}
引用次数: 0
Abstract
Platinum-group metal half-sandwich complexes are considered to be potential replacements of the clinically widely used platins which have several side effects and tend to cause resistance to develop. In our previous works, we used a range of 2-pyridyl-substituted N- and C-glycosyl heterocycles as N,N-chelating ligands to prepare ruthenium(II), osmium(II), iridium(III) and rhodium(III) polyhapto arene/arenyl half-sandwich complexes. Some of these complexes, particularly with the C-glucopyranosyl isoxazole derived ligand in its O-perbenzoylated form, exhibited greater anticancer efficiency than cisplatin and had minimal or negligible effects on non-transformed fibroblasts. Additionally, these cytostatic compounds exhibited micromolar antibacterial activity against multiresistant Gram-positive bacteria. In the present work, novel modes of conjugation between the sugar and the isoxazole moieties have been studied. Specifically, glycosylidene-spiro-isoxazoline and polyhydroxyalkylisoxazole scaffolds were synthesised and utilised in complex formation reactions. The spiro-isoxazolines were obtained in 1,3-dipolar cycloadditions of exo-glycals and nitrile oxides generated from pyridine-2-carbaldoximes. Ring opening of the spiro-isoxazolines under basic or transition-metal-mediated conditions produced polyhydroxyalkylisoxazoles. These compounds were then transformed into their O-peracetylated, O-perbenzoylated and O-unprotected variants, which were used for complex formation with the above-mentioned platinum-group metal ions. The complexes induced cytostasis in cellular models of ovarian cancer and pancreatic adenocarcinoma; the best compounds had submicromolar IC50 values (0.4-0.5 µM). A subset of the cytostatic complexes retained their activity on cisplatin resistant ovarian cancer cells. Furthermore, a reasonable therapeutic index was detected when complexes were assessed on primary human fibroblasts pointing towards a potential applicability of the complexes. Unexpectedly, none of the complexes induced bacteriostasis in Gram-positive bacteria as Staphylococcus aureus or Enterococcus species.
期刊介绍:
The journal publishes research articles, review articles and scientific commentaries on all aspects of the pharmaceutical sciences with emphasis on conceptual novelty and scientific quality. The Editors welcome articles in this multidisciplinary field, with a focus on topics relevant for drug discovery and development.
More specifically, the Journal publishes reports on medicinal chemistry, pharmacology, drug absorption and metabolism, pharmacokinetics and pharmacodynamics, pharmaceutical and biomedical analysis, drug delivery (including gene delivery), drug targeting, pharmaceutical technology, pharmaceutical biotechnology and clinical drug evaluation. The journal will typically not give priority to manuscripts focusing primarily on organic synthesis, natural products, adaptation of analytical approaches, or discussions pertaining to drug policy making.
Scientific commentaries and review articles are generally by invitation only or by consent of the Editors. Proceedings of scientific meetings may be published as special issues or supplements to the Journal.