Synthesis and Antifeedant Activity of Racemic and Optically Active Hydroxy Lactones with the p-Menthane System

Abstract

Two racemic and two enantiomeric pairs of new δ-hydroxy-γ-lactones based on the p-menthane system were prepared from racemic and optically active cis- and trans-piperitols. The Johnson-Claisen rearrangement of the piperitols, epoxidation of the γδ-unsaturated esters, and acidic lactonization of the epoxy esters were described. The structures of the compounds were confirmed spectroscopically. The antifeedant activities of the hydroxy lactones and racemic piperitone were evaluated against three insect pests: lesser mealworm, Alphitobius diaperinus (Panzer); Colorado potato beetle, Leptinotarsa decemlineata (Say); and peach-potato aphid, Myzus persicae (Sulz.). The chemical transformation of piperitone by the introduction of a lactone moiety and a hydroxy group changed its antifeedant properties. Behavioral bioassays showed that the feeding deterrent activity depended on the insect species and the structure of the compounds. All hydroxy lactones deterred the settling of M. persicae. Among chewing insects, the highest sensitivity showed A. diaperinus adults.

Chemoenzymatic Synthesis of Enantiomeric, Bicyclic δ-Halo-γ-lactones with a Cyclohexane Ring, Their Biological Activity and Interaction with Biological Membranes

“…The halolactones (6)(7)(8) were obtained in five steps of chemical synthesis (Schemes 1-3) and together with all intermediates (2-5) their structures were established on the basis of spectroscopic data (IR, 1 H NMR, 13 C NMR, COSY, HMQC, HMBC). Starting from 1-acetylcyclohexene (1), the standard reduction with sodium borohydride in methanol was performed to obtain the racemic allylic alcohols (2).…”

“…The natural lactones isolated from fruits and essential oils can be used as fragrance components, like jasmine lactone or as a flavor in the food industry (δ-decalactone) [1][2][3]. Those compounds can also be pheromones [4,5] or antifeedants [6][7][8] but the largest interest is put in their antimicrobial and cytotoxic potential. There are numerous examples presenting the antibacterial and antifungal activity of lactones [8,9].…”

“…Recently, we have also reported that some bicyclic γ-lactones with a cyclohexane system exhibited cytotoxicity against selected cancer cell lines [20]. Assuming that the introduction of a halogen atom can potentially increase the cytotoxic effect exhibited by this group of compounds, we designed the synthesis in order to obtain a series of new halogen derivatives of γ-lactones with a cyclohexane ring (6)(7)(8), containing iodine, bromine and chlorine atoms in the lactone structure. The next important aspect was a comparison of biological activity of opposite enantiomers.…”

Behavioral sensitivity of Myzus persicae to volatile isoprenoids in plant tissues

“…Preparation and application of the compounds followed the procedure described by Polonsky et al (1989), later modified by Gabry s et al (2015) and Grudniewska et al (2015). Myzus persicae, kept as a multiclonal colony, and Chinese cabbage were reared in the laboratory at 20°C, 65% r.h., and L16:D8 photoperiod.…”

“…To mimic the natural environment under laboratory conditions, the VIPs were offered to aphids by application through their host plants. Preparation and application of the compounds followed the procedure described by Polonsky et al (1989), later modified by Gabry s et al (2015) and Grudniewska et al (2015). One-to 7-day-old adult apterous females of M. persicae and 3-week-old plants with 4-5 fully developed leaves were used for experiments.…”