  Inspired by recent work on anti-covid-19 drugs \cite{2} here we study the
Quantitative-structure property relationships(QSPR) of phytochemicals screened
against SARS-CoV-2 $3CL^{pro}$ with the help of topological indices like the
first Zagreb index $M_{1}$, second Zagreb index $M_{2}$, Randi$\acute{c}$ index
$R$, Balban index $J$ and sum-connectivity index $SCI(G)$. Our study has
raveled that the sum-connectivity index $(SCI)$ and the first Zagreb index
$(M_{1})$ are two important parameters to predict the molecular weight and the
topological polar surface area of phytochemicals respectively.
