HPLC-ESI-MS and GC-EI-MS Identification and Quantitation of Polyphenolics and Alkaloids in Moroccan Jujube Honeys

Abstract

The aim of this study was to determine the phytochemical content of Moroccan Jujube Honey and to establish the principal components of this staple Moroccan food, which contributes health benefit for the local population. Total phytochemical compounds as determined by analytical HPLC-ESI-MS in the honey extracts were 29.39±5.21 mg/kg (range 16.64–42.16) wet weight. The individual phytochemical compounds definitively identified by HPLC-DAD-ESI-MS in the Jujube honeys were the alkaloids: (I) 4-hydroxyquinoline glucoside, (II) 4-hydroxyquinoline and (V) kynurenic acid (17.66±0.87 mg/kg), and the phenolic compounds: (III) p-hydroxybenzoic acid, (IV) caffeic acid and (VI) methyl syringate (11.73±0.50 mg/kg). The structures were confirmed by GC-EI-MS apart from 4-hydroxyquinoline-glucoside. The major components were methyl syringate (8.34±2.49 mg/kg), 4-hydroxyquinoline (6.61±3.23 mg/kg) and kynurenic acid (6.56±0.97 mg/kg). The mean content of polyphenolic compounds (11.73±0.50 mg/kg) of Moroccan Jujube honeys compared favorably with those described for six Chinese Jujube honeys (2.49 mg/kg), five commercial Jujube honeys from different countries (0.92 mg/kg) and twelve Jujube honeys from Yemen (25.71 mg/kg). Reference studies did not identify alkaloids as components of Jujube honey, and therefore the phytochemical profile of Moroccan Jujube honey appears to be unique.

Impact of genus (Geotrigona, Melipona, Scaptotrigona) on the targeted 1H-NMR organic profile, and authenticity test by interphase emulsion of honey processed in cerumen pots by stingless bees in Ecuador

“…Kynurenic acid was found in small concentrations in Alpine honey from Italy ( Leoni et al, 2021 ). In Moroccan jujube Ziziphus lotus honey kynurenic acid contents were 17.7 mg/kg by HPLC-DAD-ESI-MS and 6.6 mg/kg by GC-EI-MS ( Khallouki et al, 2021 ). In the Ecuadorian pot-honeys, kynurenic acid was non-detected, like in the Chilean honeys ( Fuentes Molina et al, 2020 ).…”

Impact of genus (Geotrigona,Melipona,Scaptotrigona) in the1H-NMR organic profile and authenticity test of honey processed in cerumen pots by stingless bees in Ecuador

“…Kynurenic acid was found in small concentrations in Alpine honey from Italy (Leoni et al, 2021). In Moroccan jujube Ziziphus lotus honey kynurenic acid contents were 17.7 mg/kg by HPLC-DAD-ESI-MS and 6.6 mg/kg by GC-EI-MS (Khallouki et al, 2021). In the Ecuadorian pot-honeys, kynurenic acid was non-detected as in the Chilean honeys (Fuentes Molina et al, 2020).…”

Fingerprinting Chemical Markers in the Mediterranean Orange Blossom Honey: UHPLC-HRMS Metabolomics Study Integrating Melissopalynological Analysis, GC-MS and HPLC-PDA-ESI/MS

“…Quinolines are bioactive components (especially their fused alkaloid structures) rarely reported in honey [80]. However, it is imperative to mention that the specific compound was used as a chemical marker of jujube honey [81]. In addition, it is reported as a constituent of Rutaceae plants, abundant in Greek case study areas.…”

“…4-Hydroxyquinoline (tR = 4.78, with 145.0527 m/z Table 1) increased i samples expands the heterocyclic portfolio of citrus honey. Quinolines are ponents (especially their fused alkaloid structures) rarely reported in ho ever, it is imperative to mention that the specific compound was used as a ch of jujube honey [81]. In addition, it is reported as a constituent of Rutacea dant in Greek case study areas.…”