A dioxygenase of Pleurotus sapidus transforms (+)-valencene regio-specifically to (+)-nootkatone via a stereo-specific allylic hydroperoxidation

Crosses between monokaryons of Pleurotus sapidus or Pleurotus florida show an improved biotransformation of (+)-valencene to (+)-nootkatone

“…The two edible fungi, P. florida strain PFL-216 and P. sapidus strains PSA-69 and PSA-224, differ in several morphological and physiological features and have been extensively characterized for their ability to produce enzymes of industrial interest, such as laccase (del Vecchio et al, 2012;Linke et al, 2005), lipoxygenase (Krügener et al, 2010;Zelena et al, 2012), and esterases (Linke et al, 2009), and for their capability to transform terpene compounds . In order to produce new dikaryotic strains with increased capabilities in terpene transformation, basidiospore derived monokaryons obtained from these Pleurotus strains were isolated, screened and analyzed.…”

“…The transformation of (+)-valencene was carried out in glass vials (4 ml) in horizontal position in an orbital shaker (150 rpm, 25 mm shaking diameter; Multitron, Infors) at 24°C for 16 h in the absence of light (Fraatz et al, 2009b;Krügener et al, 2010).…”

“…High resolution gas chromatography mass spectrometry (HRGC-MS) analysis was carried out using a Fisons GC 8000 gas chromatograph and a Fisons MD 800 mass selective detector (interface: 230°C, ion source: 200°C, quadrupole: 100°C, electron impact ionization (ei, 70 eV), scan range m/z 33-300 amu) as described (Krügener et al, 2010). Analytical conditions were:…”

“…These processes outclass traditional chemistry, as they proceed under mild conditions, show better regio-and enantioselectivity, do not generate toxic wastes and result in products labeled 'natural' (Berger, 2009). In particular, the oxidation of (+)-valencene using Pleurotus sapidus is attractive to obtain the high added-value compound (+)-nootkatone, an impact flavour of grapefruit with an odor threshold of $1 lg L À1 water (Fraatz et al, 2009b;Krügener et al, 2010). Recently, the enzyme responsible this transformation was identified as the first http://dx.doi.org/10.1016/j.biortech.2014.08.061 0960-8524/Ó 2014 Elsevier Ltd. All rights reserved.…”

One-Pot Synthesis of (+)-Nootkatone via Dark Singlet Oxygenation of Valencene: The Triple Role of the Amphiphilic Molybdate Catalyst

“…They obtained (+)-nootkatone with a yield of 40%. On the other hand, various biocatalysts, such as G. pentaphyllum cultures, green algae Chlorella species, fungi Bothryosphaeria dothidea, the lyophilisate of edible mushroom Pleurotus sapidus, and several bacterial cytochrome P450 enzymes have also been studied for this transformation [27][28][29][30][31][32][33][34][35]. However, the costly culture conditions, the low conversion rate and yield, the inhibition of enzymes by products, and the presence of various by-products still hamper the industrial preparation of (+)-nootkatone via biocatalysts.…”