Medicinal plants have long been recognised as valuable sources of bioactive compounds with therapeutic potential, particularly due to their antioxidant properties and their role in mitigating oxidative stress-related diseases. Among these, Platycladus orientalis, a species in the Cupressaceae family, has attracted growing scientific interest for its diverse pharmacological activities, including antioxidant, antimicrobial, and anti-inflammatory effects. Although previous studies have reported the presence of phenolic compounds and flavonoids in this species, detailed quantitative data on individual polyphenol profiles remain limited. This study aimed to evaluate the phytochemical composition and antioxidant activity of ethanolic leaf extracts of Platycladus orientalis. Total polyphenolic content was determined using the Folin–Ciocalteu method, while total flavonoid content was assessed using the AlCl₃ colourimetric method. Antioxidant activity was evaluated using the DPPH radical-scavenging assay. Furthermore, high-performance liquid chromatography (HPLC) was employed to identify and quantify individual polyphenolic compounds. The results revealed a significant presence of phenolic and flavonoid compounds, with rutin identified as the most abundant compound, followed by ferulic acid, epicatechin, resveratrol, and caffeic acid. Our findings revealed that the total phenolic content was 4919.42 mg GAE/Kg, the total flavonoid content was 3656.66 mg QE/Kg, and the DPPH radical scavenging activity was 9.09 µM TE/g, indicating a notable antioxidant potential of the extract. Pearson correlation analysis revealed significant relationships between individual polyphenols, total phenolic and flavonoid contents, and antioxidant activity, highlighting the contribution of specific compounds to the overall bioactivity. The findings have important implications for the potential application of this plant in pharmaceutical, nutraceutical, and cosmetic industries. Overall, this research contributes to the growing body of knowledge on Platycladus orientalis by offering a comprehensive evaluation of its antioxidant capacity and phytochemical composition, highlighting its potential as a natural source of bioactive compounds.

: Platycladus orientalis, total polyphenolic content, total flavonoid content, DPPH scavenging activity, individual polyphenolic content

agronomy

Presentation: poster