New enzyme could lead to using sorghum to create healthier food

sorghum
Photo: Bishnu Sarangi/Pixabay

Stilbenes are natural compounds found in various plants that have shown potential health benefits for humans.

While resveratrol, found in grapes and red wine, is the most well-known stilbene, there has been increasing interest in other types of stilbenes that could offer additional health benefits.

Stilbenes provide a range of health benefits such as anti-ageing, anti-neurodegeneration, anti-diabetes, and chemo-preventive properties.

O-methylated stilbenes, which are produced by introduction of a methyl group (-CH3) to a hydroxyl (-OH) group on the stilbene backbone, are promising compounds for research. Some plant species, such as sorghum and wild sugarcane, have been found to produce different types of O-methylated stilbenes in response to abiotic or biotic stress and may have greater potency and bioavailability than non-methylated stilbenes.

Recently, a research team led by Clive Lo from the School of Biological Sciences at The University of Hong Kong (HKU) collaborated with laboratories at the University of Queensland (UQ), Australia, and the HKU School of Biomedical Sciences (SBMS), as well as scientists in China and Japan, to discover a novel stilbene O-methylase (SbSOMT) in sorghum, an enzyme responsible for catalyzing the production of O-methylated stilbenes.

The discovery offers a new way of producing O-methylated stilbenes in larger quantities and at lower costs, which could lead to the development of new functional foods, nutraceuticals, and pharmaceuticals that harness the potential health benefits of these compounds.

The research team conducted a study that showed how sorghum and wild sugarcane could produce different types of O-methylated stilbenes, such as pinostilbene, pterostilbene and isorhapontigenin. They used genetic techniques, including CRISPR-Cas9 mutagenesis and sorghum transformation, to identify the key enzyme, SbSOMT, which mediates the specific chemical modification of stilbene called 3,5-bis-O-methylation in sorghum. This modification affects the biological activity of the stilbene, including its antioxidant and anti-inflammatory properties.

Research significance

The researchers discovered that SbSOMT uses a chemical reaction similar to COMTs in the grass family, but it binds to the stilbene molecule differently. This different binding mode allows SbSOMT to modify the stilbene molecule in a specific way that produces different types of O-methylated stilbenes in sorghum.

The research has found that sorghum and wild sugarcane can potentially be used to produce O-methylated stilbenes. The findings suggest that it is possible to use molecular breeding and transgenic approaches to create specific types of O-methylated stilbenes with even more health benefits. This could open up new possibilities for creating healthier food and supplement options.

The research findings were published in Nature Communications.

Jim Cornall is editor of Future Food Today and publisher at Ayr Coastal Media. He is an award-winning writer, editor, photographer, broadcaster, designer and author. Contact Jim here.