By Rowenna Hoskin | Science Editor
Palo Alto, CA–Anthraquinones are a class of naturally occurring compounds celebrated for their medicinal purposes, not to mention their ecological friendly dyes. Until recently, this compound was shrouded in mystery.
New work from an international team of scientists, including Carnegie’s Sue Rhee, reveals the gene responsible for anthraquinone synthesis in plants. Their research could aid scientists in developing a plant-based mechanism for harvesting these useful compounds in bulk quantities.
“Senna tora is a legume with anthraquinone-based medicinal properties that have long been recognized in ancient Chinese and Ayurvedic traditions, including antimicrobial and antiparasitic benefits, as well as diabetes and neurodegenerative disease prevention,” Rhee explained.
Senna tora, also called Sticking Cassia, is a hairless shrub that grows wild on roadsides. The leaves are used in the treatment of skin diseases. The seeds contain compounds that are antibacterial, antifungal and hepatic (to do with the liver). The seed is used in Korea to treat constipation, oedema, glaucoma, nyctalopia and to protect the liver. A paste can be made from the seed too, and this is used in Nepal to treat leprosy and itchy skin. When the roots are made into a paste and mixed with lemon juice, it can be applied as a poultice to treat ringworm.
Genomic studies of Senna have been limited despite the advantageous applications. The research team, Sang-Ho Kang of the Korean National Institute of Agricultural sciences and Ramesh Prasad Pandey of Sun Moon University and MIT, used an array of sophisticated genetic and biochemical approaches to identify the first known anthranoid-forming enzyme in plants.
“Now that we’ve established the first step of the ladder, we can move quickly to elucidate the full suite of genes involved in the synthesis of anthraquinones,” said lead author Kang.
Once the process by which plants make these important compounds is fully known, this knowledge can be used to engineer a plant to produce high concentrations of anthraquinones that can be used medicinally.
“The same techniques that we use to help improve the yields of agricultural or biofuel crops can also be applied to developing sustainable production methods for plant-based medicines,” Rhee concluded.
This discovery of the gene responsible for these medicinal applications has the potential to help in the synthesis of plant-based medicines as opposed to chemically synthesized medicines.
Science and Technology Rowenna Hoskin