Insecticidal and Enzyme Inhibitory Activities of Sparassol and Its Analogues against Drosophila suzukii

Abstract

Drosophila suzukii is an economically important pest in America and Europe as well as in Asia. Sparassol and methyl orsellinate are naturally produced by the cultivating mushrooms Sparassis cripta and Sparassis latifolia. Fumigant and contact toxicities of synthetic sparassol and its analogues, methyl orsellinate and methyl 2,4-dimethoxy-6-methylbenzoate (DMB), were investigated. Negligible fumigant activity was observed from the tested compounds. However, DMB showed the strongest contact toxicity, followed by sparassol and methyl orsellinate. The possible modes of action of the compounds were assessed for their acetylcholinesterase (AChE)- and glutathione S-transferase (GST)-inhibiting activities. AChE activity was weakly inhibited by methyl orsellinate and DMB, but GST was inhibited by sparassol, methyl orsellinate, and DMB. Thus, DMB could be a promising alternative to common insecticides as it can be easily synthesized from sparassol, which is the natural product of Sparassis species. Sparassis species could be an industrial resource of DMB.

Myrtaceae Plant Essential Oils and their β-Triketone Components as Insecticides against Drosophila suzukii

“…Unfortunately, frequent application of the conventional insecticides is creating public concerns due to their adverse effects on the environment and human health. As a result, there is growing interest in finding less ecologically damaging SWD control methods, such as natural enemies [ 9 ] and biopesticides [ 10 , 11 , 12 , 13 ], and a strong push to develop new, organic and ecologically sustainable control methods for this destructive pest. Plant essential oils (EOs) could be an eco-friendly alternative to chemical insecticides as they have been reported to have an array of bioactivities, including insecticidal, repellent, and feeding and oviposition deterrent activities for control of a range of insect species [ 14 , 15 , 16 ].…”

“…Other advantages of volatile plant EOs as eco-friendly biopesticides include commercial availability, low cost, multiple modes of action, low toxicity to vertebrates, and brief persistence in the soil [ 17 , 18 , 19 , 20 , 21 ]. The insecticidal activity of EOs against SWD has been investigated [ 10 , 11 , 12 , 13 ]. In this study, we assessed the insecticidal activity of Myrtaceae plant EOs and their component β-triketones against adult SWD to find new types of alternatives to current insecticides.…”

Natural compounds for controlling Drosophila suzukii. A review

“…Among the tested substances, the most effective were Leptospermum ericoides and Leptospermum scoparium EO, the polar fraction of those EO and L. scoparium EO triketone fraction with LD 50 values between 0.13 and 0.71 μg/fly for males and 0.22 and 1.23 μg/fly for females (Fig. 2, Jang et al 2017;Kim et al 2016aKim et al , 2016bPark et al 2017Park et al , 2016. The contact toxicity of the non-polar fraction, made up of sesquiterpene hydrocarbons, was significantly lower than the toxicity of the polar fraction.…”

“…The fumigant toxicity of the fungal metabolites (sparassol, methyl orsellinate and DMB) was very low with mortality rates below 4% (Kim et al 2016a).…”

“…Error bars represent 95% confidence limits. Data were published by (a) Park et al (2017); (b) Park et al (2016); (c) Jang et al (2017); (d)Kim et al (2016b) and (e)Kim et al (2016a)…”