Cu^II‐Tyrosinase Enzyme Catalyst‐Mediated Synthesis of 2‐Thioxopyrimidine Derivatives with Potential Mosquito Larvicidal Activity: Spectroscopic and Computational Investigation as well as Molecular Docking Interaction with OBPs of Culex quinquefasciatus

Abstract

A series of 2-thioxo pyrimidine derivatives 1, (1 a-1 e) and 2, (2 a-2 e) were synthesized via Biginelli reaction by using Cu IItyrosinase (Cu II -Tyr) as an enzyme catalyst in up to 80-92% yield. The compounds 1, (1 a-1 e) and 2, (2 a-2 e) were characterized by IR, 1 H NMR, 13 C NMR, mass spectra and elemental analyses. The synthesized compounds 1, (1 a-1 e) and 2, (2 a-2 e) were screened for mosquito larvicidal activity against Culex quinquefasciatus. The compound 2 a was 80% mortality at 100 μg/mL with the LD 50 value of 55.94 μg/mL than the control Permethrin 60.03 μg/mL respectively. Molecular docking studies of synthesized compounds were carried out and the results proposed that the compound 2 a as a potential candidate to mosquito odorant-binding protein 3OGN inhibitors. In addition, computational studies, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies showed that the charge transfer occurs in the inside of the molecule and also gives the chemical reactivity descriptors, and molecular electrostatic potential (MESP) is also calculated. Therefore, experimental and theoretical studies were well supported for the compound 2 a as a potential larvicide activity aganist mosquito larvae of Culex quinquefasciatus.

Mushroom tyrosinase enzyme catalysis: synthesis of larvicidal active geranylacetone derivatives against Culex quinquesfasciatus and molecular docking studies

“…We evaluated larval mortality by determining the ratios (as a percentage) of dead and living larvae resulting from exposure to the compounds. To calculate the LD 50 values, we used probit scale analysis ( Sathishkumar et al, 2020 ; Al-Zharani et al, 2022 ). After 24 h, the number of surviving larvae was recorded, and test was carried out three times, that ensure the statistical reliability of the results.…”

“…The test compounds were used for various concentrations 10, 25, 50 and 100 μg/mL. Mortality was analysis the ratios (%) of the numbers of dead and live fingerlings in screening, the method was followed by described previously ( Sathishkumar et al, 2020 ; Chidambaram et al, 2021 ). The toxicity values are summarized in ( Table 4 ).…”

Bio-Catalysis in Multicomponent Reactions

“…The enzyme quickly catalyzed the cyclization reaction to afford compounds whose biotests exhibited larvicidal and antifeedant activities. In a related study, a series of pyrimidine-thione derivatives with potential mosquito larvicidal activity were prepared via a Cu(II)-tyrosinase catalyzed Biginelli reaction in up to 90% yield [ 41 ].…”