Chongchong Chai

Background: Lonicerae japonicae flos (LJF), a traditional food and medicine with a history spanning thousands of years, undergoes drying as a critical processing step in modern applications after regular processing. While the by-products of this process are typically discarded as waste, the potential value of LJF condensate water (JYHC) remains largely unexplored. To address this gap and investigate its potential utilization, this study conducted widely targeted metabolome and volatile metabolomics profiling analyses of ‘JYHC’. Methods: This study analyzed the differential metabolites of ‘JYHC’ and dried Lonicerae japonicae flos (JYHG) based on widely targeted metabolomics using UPLC-MS/MS. Additionally, the metabolic differences between fresh Lonicerae japonicae flos (JYHX) and ‘JYHC’ based on GC-MS volatile metabolomics were comprehensively analyzed. Results: A total of 1651 secondary metabolites and 909 volatile metabolites were identified in this study. Among these, flavonoids and terpenoids were the predominant secondary metabolites, while esters and terpenoids dominated the volatile fraction. Further comparison of the ‘JYHC’ and ‘JYHG’ groups revealed that 58 differential metabolites with potential biological activities were significantly up-regulated, with the types being terpenoids, phenolic acids, and alkaloids, which included nootkatone, mandelic acid, sochlorogenic acid B, allantoin, etc. Notably, a total of 186 novel compounds were detected in ‘JYHC’ that had not been previously reported in LJF such as isoborneol, hinokitiol, agarospirol, 5-hydroxymethylfurfural, α-cadinol, etc. Conclusions: This study’s findings highlight the metabolic diversity of ‘JYHC’, offering new theoretical insights into the study of LJF and its by-products. Moreover, this research provides valuable evidence supporting the potential utilization of drying by-products from LJF processing, paving the way for further exploration of their pharmaceutical and industrial applications.