## 3 Results and Discussion
### Amino Acid Interaction of Lead Phytocompounds with Selected A. gambiae OBP  
The four lead phytocompounds demonstrated the highest binding energy to the OBP 7 (3R1O) than the other 3 OBPs; hence, it was selected for further interactive analysis with  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**RT** & **\%** & **Compounds** & **RIExp** & **RILH** \\ \hline
5.750 & 27.94 & \(\alpha\)-pinene & 934 & 931 \\
7.271 & 1.28 & sulcatone & 965 & 960 \\
7.800 & 8.38 & sabinene & 983 & 975 \\
8.289 & 16.78 & myrrene & 994 & 993 \\
8.384 & 1.44 & \(\alpha\) 3-care & 1012 & 1010 \\
8.805 & 0.65 & (E)-\(\beta\)-ocimene & 1032 & 1029 \\
9.192 & 6.72 & Cis-linalool & 1088 & 1086 \\  & & oxide & 1098 & 1092 \\
9.633 & 0.88 & trans-linalool & 1098 & 1092 \\  & & oxide & 1105 & 1102 \\
9.776 & 1.16 &linalool & 1105 & 1102 \\  & & cis-sabinene & 1178 & 1174 \\
9.871 & 1.03 & hydrate & 1178 & 1174 \\
10.76 & 1.81 & camphor & 1318 & 1316 \\
11.01 & 2.06 & citronellal & 1395 & 1389 \\
11.61 & 5.20 & borneol & 1414 & 1409 \\
11.96 & 1.05 & \(\alpha\)-terpineol & 1445 & 1437 \\
12.07 & 1.52 & verbenone & 1456 & 1452 \\
12.52 & 0.67 & n-decanal & 1459 & 1454 \\
12.61 & 2.87 & geraniol & 1491 & 1489 \\
13.01 & 3.95 & linalyl acetate & 1494 & 1492 \\
13.47 & 1.94 & bornyl acetate & 1499 & 1498 \\
13.86 & 3.71 & 4-terpinenyl & 1526 & 1522 \\  & & acetate & 1462 & 1561 \\
14.62 & 0.65 & \(\alpha\)-cubebene & 1561 & 1561 \\
14.93 & 0.97 & \(\alpha\)-ylangene & 1574 & 1574 \\
15.56 & 0.82 & \(\alpha\)-copaeae & 1578 & 1576 \\
15.99 & 0.94 & \(\beta\)-bourbonene & 1589 & 1582 \\
16.14 & 0.67 & \(\beta\)-elemene & 1599 & 1592 \\
16.56 & 0.77 & \(\alpha\)-gurjunene & 1610 & 1608 \\
16.68 & 0.64 & \(\beta\)-caryophyllene & 1637 & 1638 \\  & & trans \(\alpha\) & & \\  & & bergamotene & 1643 & 1649 \\
18.12 & 0.82 & \(\beta\)-selinene & 1889 & 1889 \\
18.59 & 0.67 & ledene & 1891 & 1890 \\  & 1.33 & Unknown & & \\ Monoterpenes & 80.16 & & & \\ Sesquiterpenenes & 7.63 & & & \\ Others & 10.88 & & & \\ \hline \hline \end{tabular} RT: retention time (min), RIExp: experimental retention index, and RILH: literature retention index [31; 43; 47].  
\end{table}
Table 1: Compositional variation in the essential oils of _V. negundo_.  
the lead phytocompounds. The interaction of the FLP with amino acid residues of the binding pocket of OBP 7 (3R1O) is presented in Table 2.  
It was observed that all FLP interacted with amino acid residues Phe54, Phe111, Phe120, and Pro41 majorly through hydrophobic interactions (Figure 2).  
Previous experimental binding studies have established that the binding grooves of the _A. gambiae_ OBPs are elongated hydrophobic groves that are capable of accommodating both linear and polycyclic compounds. The FLP interacted with binding site residues of known inhibitory compounds, including the AZO and palmitic acid binding sites. The properties of the interacting residues were responsible for the multiple hydrophobic interactions. It  
\begin{table}
\begin{tabular}{l l l l} \hline
**S/No** & **Compounds** & **Binding Energy (Kcal)** & **Interacting Amino Acid Residues** \\ \hline
1 & Beta-selinene & \(-12.2\) & Phe54, Phe111,Pro41, Tyr49, Phe120 \\
2 & Sulactone & \(-10.9\) & Phe54, Phe111, Phe120, Pro13, Tyr49 \\
3 & Beta-caryophyllene & \(-9.5\) & Phe54, Phe111, Phe120, Pro41 \\
4 & Alpha-ylangene & \(-9.3\) & Phe54, Phe111, Phe120, Pro41, Tyr49 \\ \hline \end{tabular}
\end{table}
Table 2: Amino acid interaction of lead phytocompounds with _A. gambiae_ OBP 7 (3R1O).  
Figure 2: Two-dimensional representation of post-docking interactions of the lead phytocompounds with _A. gambiae_ OBP 7.  
was also observed that the FLP exhibited a similar orientation in the hydrophobic pocket of the selected _A. gambiae_ OBP. Though the pocket is elongated, the FLP is accommodated in the same region of the binding pocket (Figure 3).