Biosynthesis of Stereoisomers of Dill Ether and Wine Lactone by Pleurotus sapidus

Abstract

The white-rot fungus Pleurotus sapidus (PSA) biosynthesizes the bicyclic monoterpenoids 3,6-dimethyl-2,3,3a,4,5,7a-hexahydrobenzofuran (dill ether) (1) and 3,6-dimethyl-3a,4,5,7a-tetrahydro-1-benzofuran-2(3H)-one (wine lactone) (2). Submerged cultures grown in different media were analyzed by gas chromatography−mass spectrometry. The stereochemistry of the formed isomers was elucidated by comparing their retention indices to those of reference compounds by enantioselective multidimensional gas chromatography. The basidiomycete produced the rare (3R,3aR,7aS) and (3S,3aR,7aS) stereoisomers of dill ether and wine lactone. Kinetic analyses of the volatilome and bioprocess parameters revealed that the biosynthesis of the bicyclic monoterpenoids correlated with the availability of the primary carbon source glucose. Spiking the media with 13 C-labeled glucose demonstrated that the compounds were produced de novo. Supplementation studies i.a. with isotopically labeled substrates further identified limonene and p-menth-1-en-9-ol as intermediate compounds in the fungal pathways. PSA was able to biotransform all enantiomeric forms of the latter compounds to the respective isomers of dill ether and wine lactone.

What's Hot, What's Not: The Trends of the Past 20 Years in the Chemistry of Odorants

“…[155] Other impressive insights relate to the mechanism of formation of 188 in vivo, [156] and to its biosynthesis using the fungus Pleurotus sapidus QuØl. [157] Gaudin discovered that the dihydrogenated analogues 189 possess pleasant coumarin odors,c loser to tonka beans than to coconut. [158] Surprisingly, 189 had been reported already in 1984 as an insect repellent, [159] but found applications in perfumery only in the early 2000s.…”

Production of an Anise- and Woodruff-like Aroma by Monokaryotic Strains of Pleurotus sapidus Grown on Citrus Side Streams

“…A compound with a comparatively high FD-factor was the bicyclic monoterpenoid dill ether 1 (17, FD 32,768), while dill ether 2 showed a much lower FD factor (20,FD 128). The biosynthesis of these monoterpene ethers as well as of wine lactone (39, FD 2048) by PSA has been reported by Trapp et al, who have shown that these benzofuranoid compounds were formed de novo by the fungus from D-glucose [14]. The biosynthesis of dill ether has also been reported for the fungus Cystostereum murrayi recently [31].…”

“…All of these compounds were also identified in the Citrus medium used for the cultivation of PSA Mk 37. Limonene and linalool have previously been identified in submerged cultures of PSA [14]. Therefore, the monoterpenes' origin might be attributed to both the culture substrate and the fungal metabolism.…”

“…The aroma profile of the fermentation products is completed via the de novo synthesis of the fungi. PSA is able to synthesize, among others, 3,6-dimethyl-2,3,3a,4,5,7ahexahydrobenzofuran (dill ether) and 3,6-dimethyl-3a,4,5,7a-tetrahydro-1-benzofuran-2(3H)-one (wine lactone), but also p-anisaldehyde [4,12,14,15]. According to studies with other basidiomycota, the formation of the latter substance and related structures starts from the aromatic amino acids L-phenylalanine and L-tyrosine, whereby different formation pathways have been postulated [16][17][18].…”

Heiße Luft oder cooler Duft? Die Trends der letzten 20 Jahre in der Riechstoffchemie

“…[155] Andere eindrucksvolle Einblicke betreffen den Mechanismus der Biosynthese von 188 [156] sowie dessen Biosynthese durch den Pilz Pleurotus sapidus QuØl. [157] Forschungsergebnisse von Gaudin haben zudem ergeben, dass hydrierte Analoga des Ty ps 189 einen angenehmen cumarinartigen Geruch besitzen, der mehr an Tonkabohnen als an Kokosnuss erinnert. [158] Überraschenderweise wurde 189 schon 1984 als Insektenschutzmittel beschrieben, [159] aber erst Anfang der 2000er Jahre als Riechstoff verwendet.…”