Identification and characterization of an anthrol reductase from Talaromyces islandicus (Penicillium islandicum) WF-38-12

Abstract

An NADPH-dependent oxidoreductase from Talaromyces islandicus WF-38-12, identified through genome analysis, catalyzes the regio- and enantioselective reduction of substituted anthrols.

A Biomimetic Synthesis of Racemic Dihydroanthracen‐1(2H)‐ones Using Sodium Borohydride in Water

“…For example, ( R )‐3,8,9,10‐tetrahydroxy‐6‐methyl‐3,4‐dihydroanthracen‐1(2 H )‐one ( 9 ) is synthesized by MdpC‐catalyzed reduction of emodin hydroquinones 13a/13b [formed in situ by the reduction of emodin ( 8 ) in the presence of Na 2 S 2 O 4 ] using NADPH as a cofactor in buffer (Figure b) . Other enzymes which also catalyze the same transformation include PHAR of Cochliobolus lunatus , AflM of Aspergillus parasiticus and ARti (anthrol reductase) of Talaromyces islandicus . Moreover, the utilization of ( R )‐ 9 (synthesized chemoenzymatically using PHAR) in the biomimetic synthesis of dimeric bisanthraquinone, (–)‐rugulosin ( 10 ) signifies its role as a putative biosynthetic precursor (Figure b) …”

“…Likewise, all the possible stereoisomers of 3,4‐dihydroxy‐3,4‐dihydronaphthalen‐1(2 H )‐one are obtained in single step by the reduction of lawsone using NaBH 4 in methanol . Recently, we have reported the synthesis of racemic dihydroanthracenones using NaBH 4 , however, the yields in such reactions were very low (< 5 %) . Therefore, to improve the yields and characterize the product formed, we planned to optimize the synthesis of racemic dihydroanthracenones.…”

“…Therefore, we tested the reduction of emodin ( 8 ) in water using ACN (acetonitrile) as a co‐solvent in the presence of 20 equivalent of Na 2 S 2 O 4. This resulted in the formation of the expected tautomers of hydroanthraquinones ( 13a/13b ) (Table , entry 2) (Scheme ) . Next, we extracted hydroquinone tautomers ( 13a/13b ) using acetonitrile (ACN) as per the reported procedure (see Supporting Information) .…”

“…This resulted in the formation of the expected tautomers of hydroanthraquinones ( 13a/13b ) (Table , entry 2) (Scheme ) . Next, we extracted hydroquinone tautomers ( 13a/13b ) using acetonitrile (ACN) as per the reported procedure (see Supporting Information) . When this mixture was added to the solution of 20 equivalent of NaBH 4 in methanol, it resulted in only small amount of the expected product, probably rac ‐ 9 , as analyzed from 1 H NMR spectra of the reaction mixture in acetone‐D 6 (Table , entry 3) (Scheme ).…”

A biocatalytic approach towards the preparation of natural deoxyanthraquinones and their impact on cellular viability

“…21 The transformation takes place via the formation of tautomers of emodin hydroquinone 20a/21a, which on reduction catalysed by an enzyme give 22a in 68% yield with 499% ee with MdpC (Scheme 1B). Other enzymes, which include AflM of Aspergillus parasiticus, 24 17b-HSD of Cochliobolus lunatus 30 and two anthrol reductases of Talaromyces islandicus, 31,32 have also been shown to catalyse the same transformation, indicating the existence of a similar biosynthetic pathway in other fungi. In addition to (R)-configured dihydroanthracenone 22a, chrysophanol (1) is also obtained as a side product in the same transformation and is formed non-enzymatically through oxidation of 22a followed by dehydration during the workup process.…”