Using HPLC to Purify Polyphenols from Green Tea

Green tea is widely known as one of the healthiest beverages on the planet. Throughout history, green tea has been used as a folk remedy for a broad range of illnesses and it continues to be advocated as a complementary and alternative medicine today. These medicinal properties have been contended ever since the beverage’s discovery almost 3,000 years before the common era (BCE). Far from dispelling these long-held assumptions, modern research has lent credence to the health benefits associated with green tea consumption. The National Centre for Complementary and Integrative Health claims that: 

“Current uses of green tea as a beverage or dietary supplement include improving mental alertness, relieving digestive symptoms and headaches, promoting weight loss.”¹  

Deriving from the Camellia sinesis species, the medicinal properties of green tea are widely attributed to the plant’s high phenolic content. Studies using high-performance liquid chromatography (HPLC) have uncovered a rich spectrum of polyphenols in the dried leaves and buds of C. sinesis. These natural plant compounds constitute a range of metabolic groups (catechins, flavonoids, tannins, etc.), but extensive HPLC analysis has highlighted one metabolite in particular when it comes to questions of the human health benefits of green tea. 

Measuring Polyphenolic Content with HPLC 

Epigallocatechin gallate, or EGCG, is one of the primary metabolites of green tea. Although the polyphenol’s mechanism of action remains unclear, EGCG is increasingly linked to reduced cholesterol and is believed to possess both antibiotic and anticarcinogenic properties. However, its efficacy is still up for debate, as EGCG demonstrates poor stability and low absorptivity in physiological conditions – comprising less than 25% by mass of the fresh leaf.² 

Although rich in a spectrum of polyphenols, the comparatively low concentration of EGCG in particular has driven demand for high-purity extracts that consumers can use as supplements and complementary treatments with a range of purported health benefits. Preparative HPLC has proven instrumental in meeting the growing demands for premium dietary supplements based on high purity EGCG extracts.  

Knauer has successfully demonstrated the power of mass-triggered fractionation using the AZURA® Preparative HPLC system, providing a time and cost-effective method isolating EGCG and other key target molecules from green tea samples. If you would like to learn more about how the materials and HPLC method we used in this study, refer to our full application note below: 

Purification of epigallocatechin gallate and other related polyphenols from green tea by mass-triggered fractionation 

HPLC systems from KNAUER

Knauer manufactures premium HPLC systems for both preparative and analytical applications, providing the high-end scientific apparatuses that researchers and developers need to meet increasingly stringent parameters. The AZURA® Preparative HPLC system is incredibly versatile, easy to operate, and simple to maintain, helping you meet your needs with the utmost flexibility and reliability.  

If you would like any more information about our HPLC products, simply contact a member of the KNAUER team today.  

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References:

[1] https://nccih.nih.gov/health/greentea
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3124776/