Lactones 32

Immobilization of Baeyer-Villiger monooxygenase from acetone grown Fusarium sp

OBJECTIVE

A novel biocatalyst for Baeyer-Villiger oxidations is necessary for pharmaceutical and chemical industries, so this study aims to find a Baeyer-Villiger monooxygenase (BVMO) and to improve its stability by immobilization.

RESULTS

Acetone, the simplest ketone, was selected as the only carbon source for the screening of microorganisms with a BVMO. A eukaryote, Fusarium sp. NBRC 109816, with a BVMO (FBVMO), was isolated from a soil sample. FBVMO was overexpressed in E. coli and successfully immobilized by the organic-inorganic nanocrystal formation method. The immobilization improved the thermostability of FBVMO. Substrate specificity investigation revealed that both free and immobilized FBVMO were found to show catalytic activities not only for Baeyer-Villiger oxidation of ketones to esters but also for oxidation of sulfides to sulfoxides. Furthermore, a preparative scale reaction using immobilized FBVMO was successfully conducted.

CONCLUSIONS

FBVMO was discovered from an environmental sample, overexpressed in E. coli, and immobilized by the organic-inorganic nanocrystal formation method. The immobilization successfully improved its thermostability.

Biocatalysis for terpene-based polymers

Accelerated generation of bio-based materials is vital to replace current synthetic polymers obtained from petroleum with more sustainable options. However, many building blocks available from renewable resources mainly contain unreactive carbon-carbon bonds, which obstructs their efficient polymerization. Herein, we highlight the potential of applying biocatalysis to afford tailored functionalization of the inert carbocyclic core of multicyclic terpenes toward advanced materials. As a showcase, we unlock the inherent monomer reactivity of norcamphor, a bicyclic ketone used as a monoterpene model system in this study, to afford polyesters with unprecedented backbones. The efficiencies of the chemical and enzymatic Baeyer-Villiger transformation in generating key lactone intermediates are compared. The concepts discussed herein are widely applicable for the valorization of terpenes and other cyclic building blocks using chemoenzymatic strategies.

Microbial synthesis of a useful optically active (+)-isomer of lactone with bicyclo[4.3.0]nonane structure

Lactone 2a of a bicyclo[4.3.0]nonane structure is a good starting material for synthesis of many attractive compounds. Enantiomerically enriched (−)-(3aR,7aS)-lactone 2a is produced by whole cells of bacteria. In order to examine the impact of the absolute configuration on biological activity we evaluated the process affording the opposite isomer. To this purpose Candida pelliculosa ZP22 characterized by high dehydrogenase activity was used. The goal of presented work was to perform bioreactor scale microbial one-pot oxidation of diol with selected yeast strain C. pelliculosa ZP22 to obtain chiral (+)-(3aS,7aR)-lactone 2a. The idea was to influence on alcohol dehydrogenase activity by increasing the activity of pro-(+)-ADH and simultanously diminishing the activity of pro-(−)-ADH. The optimization of biotransformation conditions involved the manipulation of the nutritional and physical parameters. Selection of the optimal medium in order to improve yield and process enantioselectivity was based on a two-level factorial design methodology. We have also studied the relationship between microbial growth and biosynthesis of lactone 2a. Preparative oxidation of diol 3a (400 mg/L, 2.9 mM) catalyzed by C. pelliculosa ZP22 in an optimized conditions afforded enantiomerically enriched (+)-(3aS,7aR)-isomer of lactone 2a with the isolated yield (30%).

Simple Preparation of Rhodococcus erythropolis DSM 44534 as Biocatalyst to Oxidize Diols into the Optically Active Lactones

In the current study, we present a green toolbox to produce ecological compounds like lactone moiety. Rhodococcus erythropolis DSM 44534 cells have been used to oxidize both decane-1,4-diol () and decane-1,5-diol () into the corresponding γ- () and δ-decalactones () with yield of 80% and enantiomeric excess (ee) = 75% and ee = 90%, respectively. Among oxidation of meso diols, (-)-(1S,5R)-cis-3-oxabicyclo[4.3.0]non-7-en-2-one (5a) with 56% yield and ee = 76% as well as (-)-(2R,3S)-cis-endo-3-oxabicyclo[2.2.1]dec-7-en-2-one (6a) with 100% yield and ee = 90% were formed. It is worth mentioning that R. erythropolis DSM 44534 grew in a mineral medium containing ethanol as the sole source of energy and carbon Chirality 28:623-627, 2016. © 2016 Wiley Periodicals, Inc.

Chemo-Enzymatic Synthesis of Optically Active γ- and δ-Decalactones and Their Effect on Aphid Probing, Feeding and Settling Behavior

The enantiomerically enriched γ- and δ-decalactones (4a and 4b) were prepared from corresponding racemic primary-secondary 1,4- and 1,5-diols (1a and 1b), as products of enzymatic oxidation catalyzed by different alcohol dehydrogenases. The results of biotransformations indicated that the oxidation processes catalyzed by alcohol dehydrogenase (HLADH), both isolated from horse liver and recombinant in Escherichia coli, were characterized by the highest degree of conversion with moderate enantioselectivity of the reaction. Useful, environmentally friendly extraction procedure of decalactones (4a and 4b) based on hydrodistillation using a Deryng apparatus was developed. Both racemic lactones (4a and 4b), as well as their enantiomerically enriched isomers, were tested for feeding deterrent activity against Myzus persicae. The effect of these compounds on probing, feeding and settling behavior of M. persicae was studied in vivo. The deterrent activity of decalactones (4a and 4b) against aphids depended on the size of the lactone ring and the enantiomeric purity of the compounds. δ-Decalactone (4b) appeared inactive against M. persicae while γ-decalactone (4a) restrained aphid probing at ingestional phase. Only (–)-(S)-γ-decalactone (4a) had strong and durable (i.e. lasting for at least 24 hours) limiting effect, expressed at phloem level.

Chiral phosphinate degradation by the fusarium species: scope and limitation of the process

Biodegradable capacities of fungal strains of Fusarium oxysporum (DSMZ 2018) and Fusarium culmorum (DSMZ 1094) were tested towards racemic mixture of chiral 2-hydroxy-2-(ethoxyphenylphosphinyl) acetic acid—a compound with two stereogenic centres. The effectiveness of decomposition was dependent on external factors such as temperature and time of the process. Optimal conditions of complete mineralization were established. Both Fusarium species were able to biodegrade every isomer of tested compound at 30°C, but F. culmorum required 10 days and F. oxysporum 11 days to accomplish the process, which was continuously monitored using the ³¹P NMR technique.