Non-fluorescent chlorophyll catabolites in quince fruits

- Chlorophyll breakdown products in quince fruits were characterized by using HPLC-ESI-MS.
- Four chlorophyll (chl) catabolites were analyzed by UV-spectrum and MS profile.
- Radical substituents in the chl catabolites described are consistent with previous ones.
- Chlorophyll catabolite profile is dominated by NDCCs for the first time in a fruit.

During senescence of leaf tissues and fruits, chlorophylls are degraded following a catabolic process that transforms the molecule of chlorophyll into final colorless, non-fluorescent chlorophyll catabolites (NCCs) and non-fluorescent dioxibilane chlorophyll catabolites (NDCCs). These compounds have been characterized in different vegetal species showing several structural constraints and defined functional groups at three peripheral positions. Information regarding the NCC profile of fruits is scarce, and at the moment NDCCs have not been described in fruits. Characterization of NCCs and NDCCs in ripened quince fruits (Cydonia oblonga, Miller) was analyzed by HPLC-ESI-MS, describing four chlorophyll breakdown products (two NCCs and two NDCCs) by considering their chromatographic properties, UV-spectrum and MS profile, and was compared, if possible, with NCC/NDCC standards. Co-NCC1 and Co-NDCC2 are equal to the catabolites identified in senescence leaves of maize and barley, respectively, while the catabolites Co-NCC2 and Co-NDCC1 are new structures but closely related to the previous ones. This is the first time that NDCCs are tentatively identified in a fruit tissue, which presents a NCC/NDCC profile dominated by the series of dioxibilin-type chlorophyll catabolites, an additional proof that the chlorophyll pathway is similar in leaves and fruits.