Pleurotus species convert monoterpenes to furanoterpenoids through 1,4-endoperoxides

authored by
Sven Krügener, Carmen Schaper, Ulrich Krings, Ralf G. Berger
Abstract

Enzymatic synthesis of furanoterpenoids from β-myrcene and related monoterpenes was observed using a solubilised enzyme fraction of mycelium lyophilisates of several Pleurotus species. The initial enzymatic step, the incorporation of molecular oxygen into the conjugated 1,3-diene moiety, was similar to a 2 + 4 cycloaddition of 1,3-dienes with dienophilic 1O2, and was followed by a non-catalysed degradation sequence leading to the furans. The cyclic peroxides 3,6-dihydro-4-(2-(3,3-dimethyloxiran-2-yl)ethyl)-1,2-dioxine and 5-(3,6-dihydro-1,2-dioxin-4-yl)-2-methylpentan-2-ol were identified as key intermediates. Biotransformation of β-myrcene in 18O-labelled HEPES-buffer did not yield a detectable label in perillene, so a water addition to 3,10-epoxy-β-myrcenes as an alternative was ruled out. The pathway suggested presents a substantiated biogenetic scheme for the formation of monoterpenoid furans and opens biotechnological access to valuable natural flavour compounds, such as perillene and rosefurane. Only one metabolite, identified as the new natural compound 6-methyl-2-methylene-hept-5-enal, carried the 18O-label. The enzymatic formation of this compound through a 1,2-endoperoxide (3-(5-methyl-1-methylene-hex-4-enyl)-[1,2]-dioxetane) is suggested. The label may simply result from a chemical oxygen exchange between the carbonyl group and the 18O-labelled water.

Organisation(s)
Institute of Food Chemistry
Type
Article
Journal
Bioresource technology
Volume
100
Pages
2855-2860
No. of pages
6
ISSN
0960-8524
Publication date
14.02.2009
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Bioengineering, Environmental Engineering, Renewable Energy, Sustainability and the Environment, Waste Management and Disposal
Sustainable Development Goals
SDG 7 - Affordable and Clean Energy
Electronic version(s)
https://doi.org/10.1016/j.biortech.2009.01.001 (Access: Unknown)