Background: In recent years, the research and utilization of natural products and medicinal plants have significantly increased worldwide, alongside efforts to integrate traditional medicine with modern medical practices. Approximately 1,100 medicinal plant species are found in Mongolia, including 32 species belonging to the Papaveraceae family. Among them, Papaver nudicaule L. is widely distributed across various phytogeographical regions of Mongolia. Traditionally, this plant has been used to treat headaches, neuralgia, menstrual pain, dysentery, and gastrointestinal inflammation. However, studies on its chemical composition and biologically active constituents remain relatively limited. Therefore, investigating the phytochemical composition of this plant is essential for characterizing its medicinal raw materials and identifying its bioactive compounds. Aim: To investigate the phytochemical composition of the aerial parts of Papaver nudicaule L. Materials and Methods: The aerial parts of the plant were collected during the full flowering stage and subjected to fractionation using centrifugal partition chromatography (CPC). The structures of the isolated compounds were elucidated using spectroscopic techniques, including ¹H NMR, ¹³C NMR, HSQC, COSY, and HMBC. Result: A total of 27 compounds were identified and characterized from the aerial parts of Papaver nudicaule L. using CPC and liquid chromatography–mass spectrometry (LC-MS). Conclusion Twenty-seven compounds were identified from the aerial parts of Papaver nudicaule L., and their structures were elucidated. Among them, magnocurarine ((1R)-1-(4-hydroxyphenyl)methyl6-methoxy-2,2-dimethyl-3,4-dihydro-1H-isoquinolin-2-ium-7-ol), norcoclaurine (S-norcoclaurine), N-methylcanadine ((S)-N-methylcanadine), canadine (N-methylchelianthifoline), luteolin (3′,4′,5,7-tetrahydroxyflavone), and dihydrocryptopine (5,6,7,8-tetrahydrocryptopine) were reported for the first time from this species.

Background: Bioactive compounds derived from plants have been extensively studied and widely applied in cosmetic and dermatological fields. In particular, plant-derived polyphenols and anthraquinones are known for their antioxidant properties as well as their ability to inhibit elastase enzyme activity. Elastase is a key proteolytic enzyme responsible for degrading elastin, a structural protein essential for maintaining skin elasticity. Excessive elastase activity contributes to skin aging and wrinkle formation. Therefore, the identification of plant-derived compounds capable of interacting with elastase is of significant importance for improving the composition and efficacy of cosmetic products. Aim: To identify bioactive compounds in the extract of Rheum undulatum L. and to investigate their interaction with elastase enzyme activity. Materials and Methods: The root of Rheum undulatum L. was used as the study material. Sample preparation was performed by grinding the plant root followed by extraction using 50% ethanol assisted by an ultrasonic water bath. The obtained extract was evaporated to dryness using a vacuum centrifugation system to remove the solvent completely. A total of 10 mg of the dried extract was dissolved in 100 µL methanol and 900 µL water, then filtered through a 0.1 µm membrane filter. Subsequently, two sample sets were prepared: a control sample and an elastase-incubated sample at a 1:1 ratio. Both were analyzed using liquid chromatography–mass spectrometry (LC-MS). Data processing was performed using Agilent MassHunter Qualitative Analysis software (version 10.0). Results: LC-MS analysis revealed a total of 16 bioactive compounds in the root extract of Rheum undulatum L. Comparative analysis between the control and elastase-treated samples demonstrated a decrease in the peak areas of gluconic acid and citric acid, while an increase in the peak area of emodin was observed. These changes indicate compositional differences between the two sample conditions. Conclusion The LC-MS analysis of Rheum undulatum L. root extract identified multiple bioactive compounds belonging to anthraquinone, phenolic, and flavonoid classes. Variations in peak intensities between control and elastase-treated samples suggest potential interactions between certain compounds and the enzyme. These findings indicate that the root extract contains biologically active constituents capable of modulating elastase activity, supporting its potential application in anti-aging and cosmetic formulations.