## 4 Discussion
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline  & **S Score** &
\begin{tabular}{l} **Receptor** \\ **Reside** \\ \end{tabular} & **Interaction** & **Distance (Å)** & **E (kcal/mol)** \\ \hline (1) 5-Hydroxymethylfurfural & \(-\)4.3646 & (D) M112 & H-donor & 2.97 & \(-\)1.5 \\  & & (D) Q111 & pi–H & 4.56 & \(-\)0.5 \\  & & (D) Q111 & pi–H & 4.18 & \(-\)0.5 \\ (2) 2,3-Dihydro-3,5-dihydroxy-6-methyl-4h-pyran-4-one & \(-\)3.1840 & (B) R116 & H-acceptor & 2.94 & \(-\)4.0 \\ (3) 2,5-Diformylfuran & \(-\)3.5429 & (A) E39 & H-donor & 3.34 & \(-\)0.6 \\  & & (A) W41 & pi–pi & 3.59 & \(-\)0.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Molecular docking analysis. ssDNA-binding and oligomerization (SSBn) and a C-terminal domain for protein-protein interaction (SSBc). To date, the structure of SSBc has not been observed. Recently, the structure of the six additional residues in SSBc is revealed by our crystal structure of KpSSB. These residues, 114-GGRQGG-119 in SSBc, can interact with SSBn but are released when SSBn binds to ssDNA [60]. Thus, this motif in SSB may be a switch in regulating the ssDNA binding [60]. In our study, the docking results indicated that R116 in KpSSB plays a crucial role in forming hydrogen bonds and interacting with the potential inhibitor 2,3-dihydroxy-3,5-dihydroxy-6-methyl-4h-pyran-4-one (Figure 8E). Consequently, this compound may act as an inhibitor, potentially affecting the regulatory switch for SSBn or ssDNA binding. Given the relationship between the GGRQ motif and the ssDNA binding sites, further investigations are needed to understand whether this motif also impacts the SSB3/SSB65 distribution [24]. We are currently working on obtaining crystals of the KpSSB-inhibitor complex to conduct a more comprehensive analysis of these interactions. _P. cauliflora_ extracts have been previously recognized for their anti-proliferative activities and potential anti-carcinogenic effects on various cancer cell lines, including breast [14] and lung cancer cells [15]. The peel extracts exhibited inhibitory effects against _Bacillus subtilis_, _S. aureus_, _P. aeruginosa_, and _E. coli_ bacteria [61]. In alignment with these findings, our study revealed the antibacterial activities (Figure 3), as well as the cytotoxic (Figure 5) and antiproliferative effects (Figure 8) of the _P. cauliflora_ extract on the B16F10 cells. Additionally, we also found that the extract of _P. cauliflora_ could inhibit the cell migration and induce apoptosis. These preliminary results suggest that the extract of _P. cauliflora_ holds promise as a potential natural alternative for melanoma cancer, warranting further exploration for therapeutic applications. By using a DPPH assay, the IC\({}_{50}\) of an ethanol extract of _P. cauliflora_ seeds and peel had been reported to be 27 [62] and 37 \(\upmu\)g/mL [63], respectively. In this study, the fruit extract obtained using 50% ethanol had an IC\({}_{50}\) value of 46.5 \(\pm\) 0.5 \(\upmu\)g/mL (Figure 4). Regardless of the cost of alcohol, ethanol could be a better solvent for extractions. In conclusion, this study represents the first identification that the fruit extract from _P. cauliflora_ has the anti-KpSSB property. Rutin is a new inhibitor against KpSSB. Furthermore, the cytotoxic activities against melanoma cells were also investigated. Through GC-MS analysis, the top 15 compounds in this extract were detected, providing insights into the potential active components and their potential synergistic effects in these biological activities. [PERSON] performed the experiments; [PERSON] and [PERSON] analyzed the data; [PERSON] and [PERSON] contributed to the study design and manuscript writing. All authors reviewed the results, contributed to the data interpretation, and approved the final version of the manuscript. All authors have read and agreed to the published version of the manuscript. This research was supported by a grant from the National Science and Technology Council, Taiwan (NSTC 111-2622-E-025-002 to [PERSON]). Not applicable.