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This project studies Chinese medicinal plants (CMP) which are used to treat patients suffering from rheumatoid arthritis (RA) at Guangdong Provincial Hospital of Chinese Medicine. Furthermore, some of the included CMPs are recommended in treatment of Covid-19. 

There is a growing interest in peptides as pharmaceutical agents. Plant derived peptides can be associated with different bioactivities such as anti-inflammatory, anticancer and antimicrobial activity. Since there is a research gap on peptides in these plant species, this study aimed to screen seven different CMPs for peptides. 

A small-scale extraction of all seven plants were performed using 60%, 30% and 10% AcN in water with FA, respectively. After SPE and SEC, samples were analyzed by LC-MS. Peptides were observed in all studied plant species. Descurainia sophia was selected for large-scale extraction of peptides. After extraction with 60% MeOH in water, LLE and further fractionation using HPLC was performed. Peptide containing fractions were reduced by DDT, alkylated by IAM and enzymatically cleaved by trypsin. In addition, fractions from Descurainia sophia were tested in toxicity assays on brine shrimp Artemia salina. This study is the first to discover peptides in Glycyrrhiza uralensis, Dioscorea nipponica and Descurainia sophia. Mostly, observed peptides had a mass between 2.5-4.5 kDa and were hydrophilic in nature. Additionally, fractions from Descurainia sophia showed toxic activity against Artemia salina. Further research is needed to find out more about these peptides and whether they can be useful in future treatments of different diseases.