Detecting the coumarin profile in citrus fruit by a large-scale assessment of cultivated and wild accessions

Coumarins are bioactive compounds with health-promoting effects, and citrus fruit is an important natural source of coumarins. Here, we established a targeted system to analyze coumarins in citrus using ultra-high performance liquid chromatography mass spectrometry (UPLC-Q-TOF-MS). A large-scale investigation of 87 accessions revealed that 17 coumarins were widely distributed, and limettin, auraptene, oxypeucedanin, bergamottin and scopolin were identified as the dominant coumarins in citrus fruits. These five coumarins accumulated in abundance in lemon and citron, while C. reticulata and sweet orange contained rare coumarins. Of all the parts of the citrus fruit, the flavedo had the highest concentration of coumarins. The levels of major coumarins decreased during fruit ripening. This study highlights the coumarin profile of citrus fruits, including its composition and levels in different cultivars, wild germplasm, and its spatial pattern. This information is important for selectively breeding cultivars with a high coumarin content and developing bioactive products.