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

Abstract

Herein, a two-step chemoenzymatic process for the synthesis of medicinally important 3-deoxygenated anthra-9,10-quinones is developed. It involves a regio- and stereoselective reduction of hydroanthraquinones to (R)-configured dihydroanthracenones using an anthrol...

Cystine-cored diphenylalanine appended peptide-based self-assembled fluorescent nanostructures direct redox-responsive drug delivery

“…Finally, a plate reader from Biotek Instruments was used to measure the optical density (OD) at a wavelength of 570 nm. 64 …”

“…The cell lysates were centrifuged, and with an excitation wavelength of 560 nm and an emission wavelength of 633 nm, the fluorescence level of the collected supernatant was evaluated. 64 …”

Anthrol reductases: discovery, role in biosynthesis and applications in natural product syntheses

“…This procedure resulted in the synthesis of various natural/ non-natural 3-deoxy anthraquinones in 65-80% yield (Scheme 22). 90 In addition, facile chemoenzymatic synthesis of diacerein (79) a marketed anti-osteoarthritis drug [91][92][93] was achieved using anthrol reductase (ARti-2) starting from emodin (6a) as well as chrysophanol (10a). 94…”

“…It includes chrysophanol ( 10a ), 76–78 3-methoxychrysazin ( 10b ), 79,80 aloe-emodin ( 10c ), 81,82 rhein ( 10d ), 83,84 1- O -methylchrysophanol ( 10e ), 85 1,3,8-trihydroxy anthraquinone ( 10g ) 80,86 and danthron ( 10h ) 87,88 which are widely isolated from natural sources and have been shown to display a wide array of biological activities. 89,90 The biosynthetic pathway for the formation of regioselective deoxygenation of anthraquinones as shown for the chrysophanol ( 10a ) and aloe-emodin ( 10c ) would involve anthrol reductases related enzymes. 40,57 In the previous sections, we have shown that the chemoenzymatic reduction of anthraquinones by anthrol reductases results in the formation of 3-deoxy anthraquinones as non-enzymatic side products (in less than 20% yield).…”