Organ-specific variation of phenolic compounds and antioxidant potential in Capparis spinosa L. from Iran

Capparis spinosa is a medicinal plant valued for its polyphenolic content and diverse nutritional and industrial applications, yet detailed information on organ- and developmental stage–specific bioactive compound distribution is limited. This study characterized biochemical and polyphenolic variations across leaves, flowers, flower buds, peduncles, and fruits at different ripening stages (unripe, semi-ripe, and fully ripe) to identify optimal plant parts for targeted uses. Total phenolics, total flavonoids, tannins, carbohydrates, antioxidant capacity, and individual phenolic compounds were quantified by HPLC. Organ-dependent differences were pronounced: flowers and leaves had the highest total phenolics and flavonoids, while fully ripe fruits showed lower levels of these compounds but the highest carbohydrate content (310.33 mg/g). Quercetin predominated in flower buds (2.85 mg/g) and flowers (0.86 mg/g), catechin and gallic acid increased during fruit ripening, peaking at in fully ripe fruits (0.83 and 2.02 mg/g, respectively), and ellagic acid accumulated mainly in flowers (2.85 mg/g) and flower buds. These patterns indicate a metabolic shift during fruit maturation from secondary metabolite biosynthesis toward carbohydrate accumulation and catechin enrichment. Overall, the polyphenolic profile of C. spinosa is strongly organ- and stage-specific, providing useful insights for the targeted selection of plant organs for future food, pharmaceutical, and industrial applications.