Profiling of phenolic compounds and antioxidant activity of Melia azedarach L. leaves and fruits at two stages of maturity

International audience; The present work aims to investigate the maturation-related changes in phenolic profile of Melia azedarach (L.) leaves (young and old) and fruits (pulp and kernel) at two developmental stages. A total of 26 phenolic compounds were identified by high-performance liquid chromatography-diode-array detector-hyphenated with tandem mass spectromdtry (HPLC-DAD-ESI MS/MS). They include phenolic acids, flavonols and flavanols which were found mostly in glycosylated forms. The main phenolic compounds were found to be rutin (5.86-21.33%, of total integrated peak area at 280 nm), quercetin-3-O-neohesperidoside (3.95-8.76%), kaempferol-3-O-rutinoside (2.73-11.23%), feruloylglucaric acid (0.85-11.84%) and feruloylquinic acid derivative (1.94-11.07%). The pattern distribution of phenolic compounds was organ-specific, and somewhat variable depending on the stage of maturation. Additionally, the total phenol content was determined as well as the antioxidant capacity using different in vitro assays. The extracts of young leaves demonstrated the highest total phenol content (85.4 mg GAE/g extract), and exhibited the strongest scavenging activity against 2,2-diphenyl-1-picrylhydrazyl DPPH and the highest oxygen radical absorbance capacity ORAC (235 and 328 mg Trolox equivalents/g extract, respectively) compared to old leaves and immature/mature fruit parts. In contrast, the highest metal chelating activity (MCA) was observed in immature pulp extracts (22.85 mg EDTA equivalents/g extract). Pearson's correlation and principal component analysis (PCA) showed that quercetin-3-O-neohesperidoside, rutin and kaempferol-3-O-rutinoside were the main contributors on the antioxidant capacity. On the basis of these results, M. azedarach could serve as an excellent source of natural antioxidants which could be used for pharmaceutical and cosmeceutical applications.