Enzymatic sulfation of quercetin by arylsulfotransferase from a human intestinal bacterium

Area of Science:

• Microbiology
• Biochemistry

Background:

• Polyphenols are plant compounds with various health benefits.
• Sulfation can modify polyphenol bioavailability and activity.
• Human intestinal bacteria are a source of novel enzymes.

Purpose of the Study:

• To characterize a novel arylsulfotransferase from human intestinal bacteria.
• To investigate the enzyme's substrate specificity and activity towards polyphenols.
• To establish an enzymatic method for polyphenol sulfate ester synthesis.

Main Methods:

• Partial purification of arylsulfotransferase from human intestinal bacteria.
• Enzymatic assays using various polyphenols (chalcone, xanthone, flavonoid, quercetin) and p-nitrophenyl sulfate (PNS) as a substrate.
• Analysis of sulfated products using chromatography and spectroscopy.

Main Results:

• The bacterial arylsulfotransferase effectively sulfated chalcones, xanthones, and flavonoids.
• Sulfation activity was dependent on the position of hydroxyl groups on the polyphenol.
• Quercetin was rapidly sulfated at the 3 and 3' positions, forming disulfate and trisulfate derivatives.
• The enzyme showed specificity, not sulfating the 4' and 5-hydroxyl groups of quercetin.
• The reaction conditions influenced the degree of sulfation, with excess PNS favoring trisulfate formation.

Conclusions:

• A novel bacterial arylsulfotransferase capable of regioselective polyphenol sulfation was identified and characterized.
• This enzymatic approach provides a specific and efficient method for synthesizing diverse polyphenol sulfate esters.
• The findings contribute to understanding microbial metabolism of dietary polyphenols and offer a tool for producing bioactive compounds.