A Recent Publication from the Laboratory of Organic Chemistry from the group of Associate Professor Christoforos Kokotos appeared in Green Chemistry (impact Factor 10.18) from the Royal Chemical Society

A recent publication from Nikoleta Spiliopoulou (PhD candidate) and Associate Professor Christoforos G. Kokotos entitled: «Photochemical metal-free aerobic oxidation of thiols to disulfides », which was carried out in the Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens appeared in the highly ranked international journal Green Chemistry (Impact factor 10.18).

The methodology (Green Chem., 2021, 23, 546) describes a novel and green organocatalytic photochemical transformation for the synthesis of both symmetrical and non-symmetrical disulfides from thiols. The developed protocol employs a small organic molecule (phenylglyoxylic acid) as the photoinitiator and is carried out under very mild conditions by irradiation employing either household lamps or sunlight. This novel methodology could find application in the synthesis of non-symmetrical disulfides, which very recently were introduced in literature as inhibitors of the SARS-Cov-2019 protein.

 

Publication Link: https://pubs.rsc.org/en/content/articlelanding/2021/GC/D0GC03818K

A research work in the field of Light Emitting Diodes (LEDs) was published in the international journal Nature Communications with the participation of Assoc. Prof. G. C. Vougioukalakis’ research team

Blue organic light emitting diodes (OLEDs) are highly important devices, in lighting, information storage, and display applications. Noble metal-based organometallic phosphors enable the fabrication of blue OLEDs with external quantum efficiencies (EQEs) exceeding 30%. However, the high cost and limited availability of noble metal phosphors have been the driving force for developing purely organic, thermally-activated delay fluorescent (TADF) emitters, relying on radiative deactivation from singlet states with 100% quantum efficiency. Through careful design and compositional engineering of such emitters, the EQEs of blue TADF OLEDs have steadily improved from 19.5% in 2014 to 38.4% in 2021.

In this work, a device combining a low triplet energy hole transporting interlayer with high mobility (two novel fluorinated-thiophene-quinoxaline copolymers were employed), with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface (combination of donor-acceptor bis(diphenylphosphine oxide)dibenzofuran –DBFPO– with diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide -TSPO1- as acceptor) was developed. Blue TADF OLEDs with an external quantum efficiency of 41.2% were thus successfully fabricated. This approach paves the way for further progress through exploring alternative device engineering approaches, instead of solely focusing on the demanding synthesis of organic compounds with complex architectures.

The work was the result of an international interdisciplinary collaboration of research groups based in Greece (NKUA, NCSR “Demokritos”, and NHRF), South Korea (POSTECH), UK (Imperial College London), and Brazil (CPGEI). The NKUA research group (Post-doctoral Fellow Dr. G. Rotas and Associate Professor G. C. Vougioukalakis) synthesized and characterized certain photoactive organic molecules used in the study.

Visit Associate Professor G. C. Vougioukalakis’ research group webpage for more info on this and other works: http://users.uoa.gr/~vougiouk

Contribution of Organic Chemistry in the understanding of the Role of Cholesterol in Hypertension (T. Mavromoustakos group)

Cholesterol is an essential component of our cellular membranes. Cholesterol is responsible for a plethora of functions in cellular membranes. It regulates their fluidity so that they respond in temperature changes without being subjected to damages while it also affects the way in which pharmaceutical molecules act on transmembrane receptors. Such a receptor is AT1, where the antihypertensive molecules, sartans, bind in order to block the detrimental action of the octapeptide hormone angiotensin II, in pathological conditions. The way in which sartans bind to the receptor is unknown in the molecular level. They could bind directly to the receptor via the extracellular area or indirectly through initial penetration in the bilayers and subsequent lateral diffusion to the receptor’s binding site. Cholesterol is shown to allosterically interact with the receptor, possibly facilitating the binding of AT1 antagonists. On the other hand, it is shown to retard the diffusion of the drugs in the lipid bilayers. This dual role of cholesterol which was highlighted by our research group, during the PhD thesis of Mrs Sofia Kiriakidi, in collaboration with the research groups of Assoc. Prof. A. Tzakos and Researcher B’  Z. Cournia, opens up new horizons for the understanding of the sartan action mechanism in the molecular level and the rational design of novel drugs.

This work was published in the Computational and Structural Biotechnology Journal with an impact factor of 6.018.

Kiriakidi S, Chatzigiannis C, Papaemmanouil C, Tzakos AG, Cournia Z, Mavromoustakos T. Interplay of cholesterol, membrane bilayers and the AT1R: A cholesterol consensus motif on AT1R is revealed. Comput Struct Biotechnol J. 2020 Dec 3;19:110-120. doi: 10.1016/j.csbj.2020.11.042. 

Contribution of the Laboratory of Organic Chemistry in the effort to fight diseases (T. Mavromoustakos Group)

1. Enhancing the treatment of glioblastoma polymorphism through rational design of the quercetin-losartan hybrid composition.

An article has been recently published in the journal Free Radical Biology and Medicine 160 (2), 391-402 (impact index in 2019 6.17 and last five years 6.46), entitled “Enhancing the treatment of polio glioblastoma through a quercetin hybrid –losartan”. In this article the team of the Laboratory of Organic Chemistry collaborated under the guidance of T. Mavromoustakos where rational drug design through Molecular Docking was performed, the team of Associate Professor A. Tzakos, under whose guidance the hybrid molecule was synthesized, conducting biological tests by the Departments of Medicine, Molecular Biology and Biotechnology and Biology of the University of Ioannina, the John Fulcher Neuro-Oncology Laboratory, Imperial College London, Hammersmith Hospital, London, UK and Monash Biomedicine Discovery Institute and Department of Biochemistry and M , Monash University, Clayton, VIC, 3800, Australia.

A brief summary of the research work is given below: Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumor. Maximal surgical resection followed by radiotherapy and concomitant chemotherapy with temozolomide remains the first-line therapy, prolonging the survival of patients by an average of only 2.5 months. There is therefore an urgent need for novel therapeutic strategies to improve clinical outcomes. Reactive oxygen species (ROS) are an important contributor to GBM development. Here, we describe the rational design and synthesis of a stable hybrid molecule tethering two ROS regulating moieties, with the aim of constructing a chemopreventive and anticancer chemical entity that retains the properties of the parent compounds. We utilized the selective AT1R antagonist losartan, leading to the inhibition of ROS levels, and the antioxidant flavonoid quercetin. In GBM cells, we show that this hybrid retains the binding potential of losartan to the AT1R through competition-binding experiments and simultaneously exhibits ROS inhibition and antioxidant capacity similar to native quercetin. In addition, we demonstrate that the hybrid is able to alter the cell cycle distribution of GBM cells, leading to cell cycle arrest and to the induction of cytotoxic effects. Last, the hybrid significantly and selectively reduces cancer cell proliferation and angiogenesis in primary GBM cultures with respect to the isolated parent components or their simple combination, further emphasizing the potential utility of the current hybridization approach in GBM.

2. Discovery of chemical compounds with dual inhibitory activity of TNF and RANKL, two proteins that are major targets for the treatment of chronic inflammatory diseases.

Distinction of published work: G. Melagraki, E. Ntougkos, V. Rinotas, C. Papaneophytou, G. Leonis, T. Mavromoustakos, G. Kantopidis, E. Douni, A. Afantitis, G. Kol. Cheminformatics-aided discovery of small-molecule protein-protein interaction (PPI) dual inhibitors of Tumor Necrosis Factor (TNF) and receptor activator of NF-κB B ligand (RANKL). PLOS Computational Biology 13 (4), e1005372 (2017). (I.F 2020 4.380). This article is among the top 10% published in the internationally renowned journal PLOS Computational Biology published in 2017.

Congratulations Thomas!
Your article is among the top 10% most cited PLOS Computational Biology papers published in 2017.

Cheminformatics-Aided Discovery of Small-Molecule Protein-Protein Interaction (PPI) Dual Inhibitors of Tumor Necrosis Factor (TNF) and Receptor Activator of NFKB Ligand (RANKL)
CITED 21 TIMES as of July 2020.

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Best Poster Award on Olive Oil study entitled “Potential of Ion Mobility combined with LC-HRMS in Food Authenticity Studies: Identification and Characterization of Secoiridoids Isomers found in Greek Extra Virgin Olive Oil”

Sofia Drakopoulou, a second-year PhD student, in the research group of Prof. Nikolaos Thomaidis, gained the award of Best Poster for her study on Olive Oil Authenticity, in the 9th Recent Advances in Food Analysis Symposium (RAFA 2019), conducted between 5th-8th of November in Prague, Czech Republic. The research study entitled “Potential of Ion Mobility combined with LC-HRMS in Food Authenticity Studies: Identification and Characterization of Secoiridoids Isomers found in Greek Extra Virgin Olive Oil” (Sofia K. Drakopoulou, Dimitrios E. Damalas, Carsten Baessmann, Nikolaos S. Thomaidis), has been included in the top 7 posters, awarded out of 500 posters participated in total.
Her research study focused on the identification and characterization of isomeric compounds found in olive oil, crucial in olive oil health claim. For the isomers separation, the cutting-edge technology of Trapped Ion Mobility combined to Q-TOF mass analyzer, introduced by Bruker, has been applied, while a novel structure elucidation workflow has also been proposed.
Her poster presented in the conference is part of her PhD research, which includes the development of advanced High-Resolution Mass Spectrometric methods for the thorough characterization of olive oil and discovery of new bioactive substances in food products of national importance and the substantiation of their authenticity.

Sofia Drakopoulou receives the best poster award during the closing ceremony of RAFA 2019

European Commission’s Innovation Radar Prize 2019 was awarded to a research project in which participates a research group from the Department of Chemistry of NKUA

The Innovation Radar is a European Commission initiative, which identifies high-potential innovations in EU-funded research and innovation projects. 36 of the best EU-funded innovators were identified to compete in four categories for the Innovation Radar Prize 2019.

The project LUMIBLAST: A paradigm shift in cancer therapy – using mitochondria-powered chemiluminescence to non-invasively treat inaccessible tumours, won the first prize in the category “Innovative Science 2019”.

LUMIBLAST aims at the development of a groundbreaking therapy, which will treat, in a non-invasive manner, difficult to reach tumors, such as glioblastoma multiforme (brain cancer). This therapeutic approach will use the energy produced from the mitochondria of the cancer cells to enable their self-fueled destruction. The goal of the NKUA research team is to design and synthesize the innovative molecules which will enable this therapy.

Besides the research team of the Department of Chemistry of NKUA, with Principal Investigator Assistant Professor Georgios C. Vougioukalakis, the other LUMIBLAST research groups come from Oslo University Hospital (PI: Prof. K. Berg), Universitat Politècnica de València (PI: Prof. M. Miranda), University of Oslo – School of Pharmacy (PI: Prof. H. H. Tønnesen) and Knight Scientific Limited from UK (PI: Dr. J. Knight). The LUMIBLAST concept has been submitted for intellectual property protection, in a patent application with co-inventors researchers from NKUA, Oslo University Hospital, and Universitat Politècnica de València.

For more information on LUMIBLAST, refer to the project’s webpage http://www.lumiblast.eu/ and the webpage of the research group of Assistant Professor Georgios C. Vougioukalakis http://users.uoa.gr/~vougiouk

Poster Award with title “Electronic Structure and Spectroscopy of Transition Metal Complexes”

Maria Drosou, a second-year PhD student in the group of Prof. Mitsopoulou, has been awarded a Physical Chemistry Chemical Physics Poster Prize at Summer School: ‘Electronic Structure and Spectroscopy of Transition Metal Complexes’, which held from 29 September – 4 October 2019 at Gelsenkirchen, Germany and was attended by 80 young researchers. The summer school was jointly organized by Prof. Frank Neese Dr. Serena DeBeer and Dr D. Pantazis working at the Mülheim Max-Planck Institutes (MPI für Chemische Energiekonversion and MPI für Kohlenforschung) (https://summerschool.cec.mpg.de/index.php?id=1202). It was also supported by the the Editorial Board of Physical Chemistry Chemical Physics (PCCP) of the Royal Society of Chemistry.

The summer school focused particularly on how the combination of spectroscopic techniques with quantum chemistry and high-level computation is used in transition metal chemistry. This combination is a fundamental component of modern molecular sciences since it drives cutting-edge research in fields ranging from inorganic chemistry to biochemistry and from catalysis to energy research.

Her Poster titled: ‘DFT Studies on the Mechanism of Hydrogen Evolution Catalyzed by Nickel Thiolates’ (M. Drosou, A. Zarkadoulas, F. Kamatsos, C. A. Mitsopoulou), and is part of her PhD research, which includes DFT and ab initio calculations for elucidating the mechanism of HER with catalysts of non- noble and abundant metal complexes in photocatalysis and elecrocatalysis.