## 3 Results and Discussion
### Biological Evaluations  
The majority of the compounds isolated were obtained in quantities insufficient for concurrent assessment of antiviral and cytotoxic activities. Consequently, the decision regarding which activity to evaluate for each compound was informed by literature and preliminary findings from fraction testing. EtOAc extract of _P. mauritianum_ showed moderate cytotoxic activity against the K562 leukemia cells and ovarian A2780 ovarian cancer cell line (Table 2). The triterpenes (**2-12**) were generally reported for cytotoxic activity in the literature [15; 16; 17; 18; 19; 20]. Since that field was already explored, it was preferred to test the isolated triterpenes in an antiviral assay. Compounds **1**, **14**, and **15** were tested and did not show significant cytotoxic activity. A fraction containing three methylated flavonoids previously mentioned was also tested and did not show significant activity. Thus, the cytotoxic potential of compounds was not further explored, and loss of activity was attributed to loss of synergy. Previous studies have highlighted the antiviral activity of the EtOAc extract of _P. mauritianum_ against emerging orthofluaviruses, such as Zika and dengue [4]. Aiming to confirm that the chemical composition of the extract could inhibit Zika virus infection in Vero cells--a virus-permissive cell line--a molecular clone of the Zika virus expressing GFP was used for infection. The cells were treated with varying concentrations of the extract fractions simultaneously with infection. Monitoring of the infection was conducted through the assessment of fluorescence intensity via flow cytometry. From the dose-dependent curves obtained, a nonlinear regression was performed to determine the IC\({}_{50}\), the concentration inhibiting 50% of the infection. Remarkably, the crude extract demonstrated an antiviral effect consistent with previous demonstrations [4], with fraction F5 showing the lowest IC\({}_{50}\) at 17.57 \(\upmu\)g/mL (Table 3). Fraction F5 exhibited consistent antiviral activity, with a slightly lower IC\({}_{50}\) value than the EtOAc crude extract. Although the difference in activity is not substantial, the distinct chemical profile of F5, including known antiviral triterpenes such as betulinic acid and corosolic acid, justified further investigation into its isolated compounds. Based on these findings, we focused on the secondary metabolites in fraction F5 to further evaluate their antiviral potential. \begin{table}
\begin{tabular}{c c c} \hline
**EtOAc Extract** & **Cell Lines** & \\ \hline Concentration (\(\upmu\)g/mL) & K562 & A2780 \\
10 & \(41\pm 2\) & \(35\pm 4\) \\
1 & \(89\pm 3\) & \(83\pm 2\) \\ \hline \end{tabular}
\end{table} 
Table 2: Cell viability (% of the control) of cancerous cells in the presence of a given concentration of _P. mauritianum_ crude extract. \begin{table}
\begin{tabular}{c c c} \hline
**Fraction Tested** & \
\begin{tabular}{c} **Antiviral Activity** \\ **IC\({}_{50}\) (\(\upmu\)g/mL)** \\ \end{tabular} &
\begin{tabular}{c} **Compounds Isolated from** \\ **the Fraction** \\ \end{tabular} \\ \hline EtOAc extract & \(25.81\pm 0.20\) & \\ F1 & \(52.38\pm 0.05\) & \\ F2 & \(62.91\pm 0.07\) & 13 \\ F3 & \(>\)100 & 2–8, 14 \\ F4 & \(>\)100 & F5 & 17.57 \(\pm\) 0.10 \\ F6 & \(>\)100 & \\ F7 & \(>\)100 & \\ F8 & \(>\)100 & \\ \hline \end{tabular}
\end{table} 
Table 3: Antiviral activity of _P. mauritianum_ (EtOAc) crude extract and fractions against Zika virus. Fraction F5 was identified as the most active in preliminary assays. Consequently, all terpen (**1**, **9-12**) from this fraction underwent initial antiviral testing against ZIKV (Table 4). Additionally, triterpenenes 2-8 from the inactive fraction F3 served as negative controls. For positive control, quercetin-3-\(\beta\)-O-D-glucose (Q3G), known for its anti-ZIKV efficacy [21; 22], was used.