Comparison of Larvicidal, Adulticidal and Acaricidal Activity of Two Geometrical Butylidenephthalide Isomers

Mode of action of 3-butylidene phthalide as a competent natural pesticide

In this study, the biological activities and mode of action of 3-butylidene phthalide (3-BPH) were studied. 3-BPH had a superior efficiency against microsclerotia of Macrophomina phaseolina compared to the commercial fungicide tricyclazole. The microsclerotia formation and pigmentation were inhibited at 100 μg/mL. Moreover, the fungicide exhibited in silico affinity toward trihydroxy naphthalene reductase (3HNR). Both 3-BPH and tricyclazole showed congruence in the orientation and interaction within the 3HNR active site. 3-BPH displayed a strong interaction with SER-164, TYR-178, and TYR-223, with estimated binding energy and inhibition constant of -6.78 kcal mol^-1, and Ki = 12.6 μM, respectively. Furthermore, it showed in vitro and in silico inhibitory activity against Drosophila melanogaster acetylcholinesterase in a concentration-dependent manner with IC₅₀ = 730 μg/mL. It also impaired Galleria mellonella phenol oxidase enzyme, which corresponds with the insect's immune system. Phytotoxicity of 3-BPH was evident against Lemna minor at 1000 μg /mL; nevertheless, it was nontoxic at the concentrations inhibiting M. phaseolina microsclerotia and dark pigments suggest that it may be safe for use on other plants at low doses. Further assays are wanted to develop 3-BPH as a novel crop protection compound.

Antimicrobial activity of extracts and phthalides occurring in Apiaceae plants

Apiaceae plants exhibit a broad spectrum of activities, for instance, antithrombotic, hypotensive, antioxidant, and insecticidal. They also provide a source of phthalides, which display antimicrobial activity. Considering the fact of rising resistance of both bacteria and fungi against commonly used antibiotics, developing of new naturally derived compounds is undeniably attractive approach. To our best knowledge, there are no other reviews concerning this subject in the literature. In view of above, an attempt to summarize an antimicrobial potential of isolated compounds and extracts from Apiaceae plants has been made, by specifying techniques of activity determination and methods of extraction. Techniques of antimicrobial activity evaluation are mainly based on bioautography, diffusion, and dilution methods. Therefore, we focused on in vitro data described in literature so far.

Acaricidal and repellent effects of Cnidium officinale-derived material against Dermanyssus gallinae (Acari: Dermanyssidae)

The acaricidal activity of a methanolic extract and fractions from the rhizome of Cnidium officinale against Dermanyssus gallinae adults was investigated. The C. officinale methanolic extract exhibited 100% acaricidal activity after 48 h of treatment at a dose of 4000 ppm. The acaricidal constituents of the plant were sequentially partitioned with several solvents and then purified using silica gel column chromatography and high-performance liquid chromatography. Gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy revealed (Z)-ligustilide as a constituent of C. officinale. Acaricidal activity was examined in three experimental tests (spray, fumigation and contact), with the spraying method being the most effective. The methanolic extract of C. officinale showed both contact and fumigant activities, though only fumigant activity was observed with (Z)-ligustilide. The fumigant effects of the methanolic extract and (Z)-ligustilide caused 86.5 and 62.6% mortality, respectively, of D. gallinae adults at 48 h. Among (Z)-ligustilide, acaricides (bifenthrin, cypermethrin and spinosad) and butylidenephthalide, bifenthrin displayed the highest acaricidal activity, and the activity of butylidenephthalide was 2.3-fold higher than that of (Z)-ligustilide. These results suggest that C. officinale-derived material can be used for the development of a control agent for D. gallinae.