The first chapter of Advances in Chemistry Research. Volume 54 investigates the structure-function relationships of glycans. A recent structural analysis of oligomannose glycans, based on biophysical methods (including solution nuclear magnetic resonance and X-ray crystallographic analyses) are presented and discussed. A summary of the history, clinical uses, and pharmacokinetics of polyethylene glycol interferon are presented. Important features regarding its clinical efficacy in combination with new antiviral agents like ribavirin, telaprevir, entecavir, tenofovir, adefovir, sofosbuvir and ledipasvir are also discussed. The fluorescence properties of anthracene-based ligands are proposed to be suitable to design sensors for cations as well as anions. Some of the complexes of anthracene-based ligands are reported to have potential for light-emitting devices. Various quantum chemical properties, dipole moments, bond lengths, charges, total electronic energies, the highest occupied and lowest unoccupied molecular orbital energies and the interfrontier molecular orbital energy gap values are obtained and compared. An empirical equation is derived for calculating the free formaldehyde concentration in alcohol-formaldehyde systems at various temperatures and total formaldehyde concentrations, as well as an equation for evaluating solvent concentrations. In the final study, the authors exploit the intense fluorescence behavior of luminol for a quantitative understanding of hydrogen bonding behavior and its interaction with several biological media, with the help of steady state and time-resolved measurements as well as density functional theory calculations.