Characterization of of free, esterified and bound phenolics in custard apple (Annona squamosa L) fruit pulp by UPLC-ESI-MS/MS

Ultra high-performance liquid chromatography-electrospray ionization mass spectrometry (UPLC-ESI-MS) was used to identify the free, bound and esterified phenolic acids in the extracts of custard apple (Annona squamosa L). In total around 16, 15 and 13 free, bound and esterified phenolic compounds respectively were identified. Among these about 5 phenolic compounds like quinic acid, gallocatechin, gallocatechin gallate, caffeoylhexoside, dihydroxyquercetin have and been reported for the first time in A. squamosa. Also, compounds like 4-(beta-D-glucopyranosyloxy) benzoic acid, procyanidin B1, procyanidin C1 in free form, 7 hydroxycoumarin 7 glucoside (skimmin), dihydroquercetin, xanthotaxol acetate, decycloxybenzoic acid in bound extract and caffeoyl hexoside in esterified form have been tentatively identified. Apart from phenolic compounds few organic acids like malic, citric, citramalic, adipic and acotinic acid have been found in the custard apple extracts. This study provides a newer insight into the phenolic profile of custard apple and their characterization by UPLC-ESI-MS/MS. (C) 2016 Elsevier Ltd. All rights reserved.