# Comparative metabolomics identifies enhanced ursane-type triterpenoids and antioxidant capacity in Actinidia arguta ‘Danyang’ kiwifruit

## TL;DR

This study compares kiwifruit varieties to find those with higher levels of beneficial triterpenoids and antioxidant properties.

## Contribution

The study reveals unique terpenoid profiles and antioxidant capacity in Actinidia arguta ‘Danyang’ and Actinidia chinensis ‘SunGold’ kiwifruit.

## Key findings

- Actinidia arguta ‘Danyang’ is enriched in ursane-type triterpenoids like pomolic acid and siegesbeckic acid.
- Actinidia chinensis ‘SunGold’ has high seco-iridoids like geniposide and strong antioxidant capacity.
- Cultivated Actinidia chinensis ‘Guichang’ shows reduced triterpenoids compared to its wild relative.

## Abstract

Chemical diversity is crucial for plant ecological adaptation and nutritional value. In kiwifruit, secondary metabolites such as terpenoids influence key traits such as flavor and nutraceutical properties, however, their diversity across different species and cultivars remains poorly characterized. This study employed UPLC-MS/MS-based metabolomics to profile terpenoids in five varieties representing both Actinidia chinensis (cultivars ‘Guichang’, GC; ‘SunGold’, SG; and a wild type, WL) and Actinidia arguta (cultivars ‘Maolvfeng’, LC; ‘Danyang’, DY). We identified 309 terpenoids, revealing profound diversity. Notably, the commercial A. chinensis ‘SunGold’ (SG) and A. arguta ‘Danyang’ (DY) exhibited the highest total terpenoid content, while SG uniquely possessed a soluble sugar content 2.4 to 6 times greater than other varieties. Both varieties also showed the strongest antioxidant capacity (455.20 and 438.91 µg TE/g FW, respectively), suggesting their superior nutraceutical potential. Multivariate analysis confirmed distinct terpenoid fingerprints, with DY enriched in ursane-type triterpenes e.g., pomolic acid, 1-oxo-siaresinolic acid, camellisin B, and siegesbeckic acid, while SG was uniquely abundant in seco-iridoids like geniposide (442-fold higher than WL). Within A. chinensis, the cultivated ‘Guichang’ (GC) showed a significant suppression of most triterpenoids compared to its wild relative (WL), demonstrating a possible breeding or selection effect. Our findings demonstrate that terpenoid profiles are likely influenced by genetic background, both at the species and cultivar level, providing a metabolic roadmap for the targeted breeding of kiwifruit with optimized health, nutraceutical, and sensory properties.