• Effect modification of the association between comorbidities and severe course of COVID-19 disease by age of study participants: a systematic review and meta-analysis.

      Fernández Villalobos, Nathalie Verónica; Ott, Jördis Jennifer; Klett-Tammen, Carolina Judith; Bockey, Annabelle; Vanella, Patrizio; Krause, Gérard; Lange, Berit; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (BMC, 2021-06-30)
      Adjusting the protecting group strategy, from an alkyl ether to a bidentate ketal at the carbohydrate backbone of uridine, facilitates a switchable diastereoselective α- or β-C4'/C5'-spirocyclopropanation. Using these spirocyclopropanated nucleosides as key intermediates, we synthesized a variety of C4'-methylated d-ribose and l-lyxose-configured uridine derivatives by a base-mediated ring-opening of the spirocyclopropanol moiety. Investigations of antiviral activity against the human respiratory syncytial virus were carried out for selected derivatives, showing moderate activity.