The diverse field of chemistry like structural and Analytical chemistry has offered the tools that are essential for purifying the plethora of phytochemical constituents. Such an untapped pool of phytochemicals from the plant world can be used as an alternative to synthetic insecticides in mosquito vector control programme. This investigation has used the Bioassay-guided Chromatography, Fourier-transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR) and GC-MS (Gas chromatography–mass spectrometry) to isolate and identify the most prominent toxic phytocompounds from the medicinal plants Xanthium strumarium and Acmella calva. The Map of the study site has been prepared using the Q-GIS. SPSS was used to perform the probit regression analysis and plot preparation. The isolated compounds such as Undecane (CH3(CH2)9CH3; 156.31 g/mol) (LC50: 2.599 mg/L (2.251 - 2.867); LC90 : 4.563 mg/L (3.960 - 6.006) and Phthalic acid, butyl undecyl ester (C23H36O4; 376.5 g/mol) (LC50: 4.072 mg/L (3.680 - 4.462); LC90: 6.894 mg/L (5.821-10.303) those are isolated from the Xanthium strumarium, and Acmella calva could be recognized as an innovative direction for the conception of natural insecticide against the Culex quinquefasciatus mosquito vectors since they produced a maximum range of toxicity. Moreover, the production of excessive free radicals in the phytocompounds exposed mosquito strain illustrated the probable role of oxidative stress in larval death. This investigation recommends that the isolated compounds can be used as an eco-friendly approach for mosquito control in the future.