Objective China has abundant pine bark resources, yet their high-value utilization remains underdeveloped, primarily due to unclear characteristic bioactive components and the lack of quantitative quality control standards. This study selected the commercially produced New Zealand pine bark extract (Enzogenol®) to systematically analyze its polyphenol composition and correlate it with bioactivities, aiming to elucidate the relationship between chemical constituents and biological effects. The findings are expected to provide a scientific basis for developing standardized domestic pine bark products.

Methods The chemical fingerprint of Enzogenol® was established using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS), and its main components were quantified. In vitro antioxidant activity was evaluated through DPPH and ABTS radical scavenging assays, as well as Fe²⁺/Cu²⁺ chelation tests. Antibacterial activity against Staphylococcus aureus and Escherichia coli was determined using the microdilution method. Pearson correlation analysis was further employed to investigate the statistical relationships between chemical components and bioactivities.

Results Eight characteristic polyphenols were identified and quantified in Enzogenol®. Procyanidin B1 (2.55 mg/g) and catechin (1.17 mg/g) were identified as the core quality markers, demonstrating strong free radical scavenging ability and Fe²⁺ chelating activity in vitro. Moreover, their antibacterial effect against S. aureus was significantly stronger than that against E. coli. Correlation analysis revealed that the contents of procyanidin B1, procyanidin B2, catechin, and epicatechin were significantly positively correlated (p < 0.05) with the measured bioactivities. Structure-activity relationship analysis indicated that the bioactivity of the core components (procyanidin B1 and catechin) is closely related to their structural features: the dense distribution of phenolic hydroxyl groups contributes to their strong free radical scavenging and metal ion chelation abilities, while their moderate molecular weight and hydrophobicity mediate the selective antibacterial action.

Conclusion This study confirms that procyanidin B1 and catechin are the core active substances responsible for the antioxidant and antibacterial effects of Enzogenol®, with their contents showing a significant positive correlation with these bioactivities. The results provide important theoretical foundations and data support for the high-value development of China’s pine bark resources and the establishment of corresponding quality control standards.