Iridoid glycosides as key discriminators of cranberry (Vaccinium macrocarpon) cultivars revealed by UHPLC–HRAM-MSn metabolomics

Authors: Geng, Ping; Sun, Jianghao; Chen, Pei

Submitted to: Journal of AOAC International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2026
Publication Date: 3/31/2026
Citation: Geng, P., Sun, J., Chen, P. 2026. Iridoid glycosides as key discriminators of cranberry (Vaccinium macrocarpon) cultivars revealed by UHPLC–HRAM-MSn metabolomics. Journal of AOAC International. Article qsag025. https://doi.org/10.1093/jaoacint/qsag025.
DOI: https://doi.org/10.1093/jaoacint/qsag025

Interpretive Summary: Cranberries are known to be rich in natural plant compounds that are good for health. In this study, six different cranberry varieties (Crimson Queen, Demoranville, Haines, Mullica Queen, Stevens, and Welker) were studied for their water-soluable components. 39 different water-soluble compounds were identified, including well-known plant chemicals such as anthocyanins and organic acids. Importantly, iridoid glycosides, which had not been well recognized in cranberries before, were discovered. Some of them were reported in cranberries for the first time. Chemometric analysis showed that iridoid glycosides were key compounds that helped distinguish the varieties, and these compounds were especially abundant in the Welker cultivar. Overall, the study shows that cranberries contain more beneficial compounds than previously thought. The discovery of iridoid glycosides is important because these compounds are known to have health-supporting effects, such as reducing inflammation and protecting the liver and brain. Their presence in edible cranberries opens up new possibilities for developing healthier foods and for breeding cranberry varieties with improved nutritional value.

Technical Abstract: Cranberry (Vaccinium macrocarpon) is a rich source of polyphenols, yet the diversity of its hydrophilic constituents and their cultivar-specific variation remain underexplored. In this study, water-soluble fractions of Sephadex® LH-20-separated cranberry extracts from six cultivars (Crimson Queen, Demoranville, Haines, Mullica Queen, Stevens, and Welker) were profiled using LC-MS-based metabolomics. A total of 39 putative hydrophilic metabolites were annotated based on high-resolution accurate mass (HRAM) and MS² fragmentation patterns, including hydroxycinnamic acid hexose derivative, anthocyanin, hydroxycinnamoylquinic acid, and notably, a group of iridoid glycosides. Among them, vaccinoside and other coumaroyl-substituted monotropein derivatives were structurally characterized for the first time in cranberry. Multivariate analysis revealed that sparse PLS-DA (sPLS-DA) demonstrated more satisfying classification performance than regular PLS-DA and was well able to select informative variables of each cranberry cultivar. sPLS-DA enabled the identification of iridoid glycosides as key discriminative metabolites, particularly enriched in the Welker cultivar. These findings highlight the previously underappreciated presence of iridoid glycosides in cranberries and their potential as chemotaxonomic markers. Given the known anti-inflammatory, hepatoprotective, and neuroprotective activities of iridoids, their occurrence in edible cranberry cultivars offers new perspectives for functional food development and phytochemical-based breeding strategies.