ABSTRACT
A series of novel (3,5-dichloro-4-((5-aryl-1,3,4-thiadiazol-2-yl)methoxy)phenyl) aryl methanones (10a-f), were synthesized by condensing 2-chloromethyl-5-aryl-1,3,4-thiadiazole (9a-c) with aryl(3,5-dichloro-4-hydroxyphenyl) methanones (4a-b) using TBAB and K2CO3. The chemical structure of the newly synthesised compounds was characterized by analytical and spectral (IR, 1H NMR, and LC-MS) methods. The title compounds were screened for qualitative (zone of inhibition) and quantitative antimicrobial activity (MIC) by agar well and microbroth dilution technique, respectively. Among the synthesized compounds in the series, the compound 10f was found to exhibit significant antibacterial activity at lower concentration, against Gram positive bacteria such as Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus cereus and Gram negative bacteria such as E.coli, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae. The rest of the analogues in the series displayed moderate antimicrobial activity when compared to the standard positive controls gentamicin and nystatin.
ABSTRACT
This study aimed to identify 2,6-dichlorophenol (2,6-DCP) in Amblyomma cajennense and to evaluate its role in A. cajennense and Rhipicephalus sanguineus courtship. Hexanic extract from attractive females was purified by solid phase extraction and the phenol was identified by the single ion monitoring method using GC/MS. In an olfactometer, the responses of A. cajennense and R. sanguineus males to females, control rubber septa or rubber septa impregnated with 2,6-DCP at 50, 500, and 5000 ng, respectively, were studied. 2,6-DCP was identified in A. cajennense extract and the males oriented themselves toward the concentration of 500 ng. These septa and the females were recognized as copula partners. The septa treated with 2,6-DCP did not attract and were not even recognized by the R. sanguineus males, whereas the females were recognized. Due to the presence of 2,6-DCP in A. cajennense and the results of biological bioassays, it was concluded that this compound acts as an attractant and mounting sex pheromone in this tick, but it does not play any role in R. sanguineus courtship.