AbstractThis work reports the chemical evolution of adenine, alanine & glycine along with their precursor molecules during the collapsing phase of protostars. Since the abundances of these three molecules are not in the detectable range, we are proposing to observe some of its pre-cursor molecules to predict the abundances of these bio-molecules. We perform a higher order quantum chemical simulation to provide detailed spectroscopic knowledge of the precursor of these bio-molecules in the infrared and electronic range. These pre-biotic molecules could be produced in the gas phase as well as in the ice phase. Spectral properties significantly vary depending upon the environment around these molecules. To approximate recent observational/experimental features, we conduct our simulation for various astrophysical conditions. We found that our results are in line with the some recent experiments and observations.