Final Report Summary - NAINH (The Development of Mechanism-Based Inhibitors of Influenza Neuraminidase to target Drug Induced Resestance)
Project objectives
According to the original proposal and the Annex I of the Grant Agreement, the research and training objectives of the present project were divided into four main areas: carbohydrate synthesis, catalyst design, inhibition kinetics and virus inhibition (at CSIRO).
Project results
Following our planned work, during the initial part of the project the researcher focused on the synthesis of 2,3-difluoro sialic acids with axial amino functionalities introduced at carbon-4. In order to obtain those derivatives, she developed novel synthetic methods for Pd(0) catalysed allylic amination of sialic acid. Furthermore, novel fluorine containing sialic acids were generated through the modification of literature protocols. In relation to the fluorination reactions, an in-depth study of different derivatives of sialic acid was carried out with different substituents and configurations at carbon-4, and a variety of fluorination methods developed to control the stereo-selectivity of this reaction, permitting production of the different isomers with excellent enantio-selectivities.
Following the successful synthesis of target compounds, the researcher performed the kinetic evaluation of inhibitors towards influenza virus. A number of kinetic inhibition values were obtained which have provided essential information about the mechanism of binding these compounds with influenza neuraminidase. Doubtless, these encouraging initial results have opened new research lines within the group.
In collaboration with one of the world's eminent influenza virologists at CSIRO (Australia), virus inhibition studies were carried out against a panel of wild-type and drug-resistant mutant strains of influenza neuraminidase to check their activity across a range of influenza serotypes and the capacity of these compounds to be selective towards influenza neuraminidase over human neuraminidases. In addition, X-ray crystal structures of several inhibitors in complex with influenza neuraminidase were also obtained at CSIRO, providing insight into their structure-activity relationship.
Dissemination of results and project impact
As was planned in the initial proposal, the results obtained from the project have been presented at national and international conferences and will be published in high-impact international journals. As for participation in conferences, the researcher has participated in five major national and international conferences, including two poster presentations.
As for the research training, the researcher received initial training from the university's technical staff (MNR, Mass Spectrometry, HPLC, etc.) after which she developed most of her research work independently. Furthermore, she received training in enzyme kinetics and enzymology from Dr Andrew Watts.
Group and literature meetings took place during the two-year period helping to focus the research work and to identify new research areas of potential interest, as well as helping to enhance the researcher's knowledge of chemistry. She also presented numerous group meetings and written reports to extend and clarify the results obtained. During these group meetings the results obtained were presented as a lecture and concluded with an open discussion of ideas with group members. At the same time, the fellow was also involved in presenting workshops and tutorials to undergraduate students for the Department of Pharmacy, and supervised three undergraduate final-year students, three PhD students and a Masters student.
To summarise, the excellent research results obtained together with the very good quality of the training and new skills acquired by the researcher provided her with an exceptional opportunity to develop professional maturity, diversity, independence and leadership qualities.
According to the original proposal and the Annex I of the Grant Agreement, the research and training objectives of the present project were divided into four main areas: carbohydrate synthesis, catalyst design, inhibition kinetics and virus inhibition (at CSIRO).
Project results
Following our planned work, during the initial part of the project the researcher focused on the synthesis of 2,3-difluoro sialic acids with axial amino functionalities introduced at carbon-4. In order to obtain those derivatives, she developed novel synthetic methods for Pd(0) catalysed allylic amination of sialic acid. Furthermore, novel fluorine containing sialic acids were generated through the modification of literature protocols. In relation to the fluorination reactions, an in-depth study of different derivatives of sialic acid was carried out with different substituents and configurations at carbon-4, and a variety of fluorination methods developed to control the stereo-selectivity of this reaction, permitting production of the different isomers with excellent enantio-selectivities.
Following the successful synthesis of target compounds, the researcher performed the kinetic evaluation of inhibitors towards influenza virus. A number of kinetic inhibition values were obtained which have provided essential information about the mechanism of binding these compounds with influenza neuraminidase. Doubtless, these encouraging initial results have opened new research lines within the group.
In collaboration with one of the world's eminent influenza virologists at CSIRO (Australia), virus inhibition studies were carried out against a panel of wild-type and drug-resistant mutant strains of influenza neuraminidase to check their activity across a range of influenza serotypes and the capacity of these compounds to be selective towards influenza neuraminidase over human neuraminidases. In addition, X-ray crystal structures of several inhibitors in complex with influenza neuraminidase were also obtained at CSIRO, providing insight into their structure-activity relationship.
Dissemination of results and project impact
As was planned in the initial proposal, the results obtained from the project have been presented at national and international conferences and will be published in high-impact international journals. As for participation in conferences, the researcher has participated in five major national and international conferences, including two poster presentations.
As for the research training, the researcher received initial training from the university's technical staff (MNR, Mass Spectrometry, HPLC, etc.) after which she developed most of her research work independently. Furthermore, she received training in enzyme kinetics and enzymology from Dr Andrew Watts.
Group and literature meetings took place during the two-year period helping to focus the research work and to identify new research areas of potential interest, as well as helping to enhance the researcher's knowledge of chemistry. She also presented numerous group meetings and written reports to extend and clarify the results obtained. During these group meetings the results obtained were presented as a lecture and concluded with an open discussion of ideas with group members. At the same time, the fellow was also involved in presenting workshops and tutorials to undergraduate students for the Department of Pharmacy, and supervised three undergraduate final-year students, three PhD students and a Masters student.
To summarise, the excellent research results obtained together with the very good quality of the training and new skills acquired by the researcher provided her with an exceptional opportunity to develop professional maturity, diversity, independence and leadership qualities.