Non-fluorescent and yellow chlorophyll catabolites in Japanese plum fruits (Prunus salicina, Lindl.)

- Both non-coloured and yellow phyllobilins are present in fruits of the plum tree.
- A new yellow chlorophyll catabolite is described by means of spectroscopic data.
- The double bond at C15-16 in yellow phyllobilins promotes different ring fragmentation.
- Phyllobilins deserve attention in profiling of fruit phytochemicals.

Although several chlorophyll metabolites have been shown to exert prominent benefits to human health when consumed, the battery of linear chlorophyll derivatives (phyllobilins) presents in fruits is poorly understood. Yellow chlorophyll catabolites (YCCs) are a new kind of phyllobilins recently identified in senescent leaves, probably arising from an oxidative process of the terminal chlorophyll catabolites, NCCs (non-fluorescent chlorophyll catabolites). This work deals with the characterization by first time of this kind of phytochemicals in edible fruits. Two YCCs have been identified in yellow Japanese plums, one (Ps-YCC1) previously described in the senescent leaves of Cercidiphyllum japonicum Siebold & Zucc. and Ps-YCC2, a chlorophyll catabolite structure described by first time in the edible parts of Japanese plum fruits. These YCCs were characterized by high-resolution MS/MS, describing the specific fragmentation (ring A) and the absence of the typical cleavage of phyllobilins (ring D), as a consequence of the unsaturated bond at C15-16 typical of YCCs, allowing the differentiation from NCCs. To the already known array of phenolic acids, anthocyanins and carotenoids, NCCs and YCCs may contribute to the antioxidant potential of these fruits, a potential that deserves attention and future research, considering the photochemical and photophysical behaviour of this group of tetrapyrrolic breakdown products.

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