Microbial Hydrolysis of Racemic β-Aryl-γ-ethylidene-γ-lactones and Antifeedant Activity of the Products against Alphitobius diaperinus Panzer.

Andrzej Skrobiszewski,Gabriela Maciejewska,Maryla Szczepanik,Czesław Wawrzeńczyk,Witold Gładkowski,Marcelina Mazur

doi:10.3390/molecules23071516

Abstract

Hydrolysis of (±)-β-aryl-γ-ethylidene-γ-lactones by fungal strain Aspergillus ochraceus AM370 afforded (−)-(S)-γ-ethylidene-γ-lactones 2a–d and (+)-(R)-γ-ketoacids 3a–d. Enantiomeric purity of the unreacted lactones was strictly related to a size of an aryl substituent at C-4 of γ-lactone ring, with the highest ee (77%) obtained for the (−)-(S)-γ-ethylidene-γ-lactone possessing unsubstituted benzene ring (2a) and the lowest one (15%) determined for the (−)-(S)-γ-ethylidene-γ-lactone with bulky 1,3-benzodioxole system (2d). Lactones 2a–d, both racemic and enantiomerically enriched, as well as products of their hydrolysis showed varying degrees of feeding deterrent activity against lesser mealworm, Alphitobius diaperinus Panzer, which depended on the structure of the compound and the developmental stage of the lesser mealworm. In the case of adults, more active were γ-lactones 2a–d, compared with ketoacids 3a–d. Only in the case of lactone 2a was the effect of configuration of stereogenic center on the activity found. Particularly strong deterrents against this stage (T > 180) were racemic and (−)-(S)-γ-ethylidene-γ-lactone with p-methoxysubstituted phenyl ring (2c).

Highlights

One of the most common methods for the production of enantiopure compounds is the enzymatic kinetic resolution of racemic mixtures [1,2,3,4]
Since we have proved their antifeedant, antifungal, antibacterial, and Recently, we have taken up research on synthesis of a series of β-aryl-γ-lactones and evaluation anticancer activityactivity
In our previous studies we presented i.a. synthesis of racemic γ-ethylidene-γ-lactones with aryl substituents at β-position (2a–d) and evaluation on their antifeedant activity towards Tribolium confusum, Trogoderma granarium and Sitophilus granaries [33,34]

Summary

Introduction

One of the most common methods for the production of enantiopure compounds is the enzymatic kinetic resolution of racemic mixtures [1,2,3,4]. In this process, the yield of products is limited to a maximum of 50% due to the fact that one of enantiomers remains unreacted [3,4]. In dynamic kinetic resolution, the non-reacting enantiomer is racemized in situ, which allows to overcome the limitation of 50% conversion [5,6]. Lipases found a widest application due to a high substrate specificity, selectivity, stability, ease of immobilization, and no need of cofactors [9,10,11]

Methods

Results

Conclusion