Identification of Flavonoid Glycosides of Methanol Extract from Cucumis dipsaceus Ehrenb. (Fruit) by using HPLC-UV-ESI-MS Methods

The present work is to identify the Chemical Composition of methanolic extract from Cucumis dipsaceus Ehrenb. (Fruit) by using HPLC-UV-ESI-MS Methods. It is very proficient method with amalgamation of liquid chromatography attached to electrospray ionization mass spectrometry in tendem means with positive and negative ion recognition. This is a simple and rapid method for characterization of flavonoid glycosides by using Reversed Phase High Performance Liquid Chromatography coupled to Electrospray Ionization Quadropole Time – of – Flight Mass Spectrometry (RP-HPLC-ESI-Q-TOF-MS). The correctness of mass information generated by Q-TOF-MS jointly with the fragmentation blueprint of the complete scan sprint of MS/MS investigation has been a valuable tool to cautiously characterization of 12 flavonoid glycosides (Molecular weight: 497.04 (RT:3.586), 475.06 (RT:6.801), 393.48 (RT:12.594), 336.50 (RT:16.473), 723.00 (RT:17.774), 452.52(RT:18.253), 978.95 (RT: 25.665), 836.20 (RT: 26.889), 893.00 (RT: 27.925), 838.32 (RT: 31.592), 507.44 (RT: 31.592), 415.18, (RT:33.849) in the methanol extract of this fruit. All these flavonoid glycosides are the first time reported from fruit of Cucumis dipsaceus Ehrenb., and also highlighting the importance of this fruit as a rich source of likely flavonoid glycosides as antioxidants and hepatoprotective agent. It was concluded that these flavonoid glycosides were Myceritin -3-O- β -D-glucopyranoside (497), Apigenin 7 – O – 6’’ – O acetyl – β – D - glucopyranoside (475), 5,6 Dihydroxy 7,8 – dimethoxyapigenin - 6 – O – sulfate (393), 5-p-coumaroylquinic acid (336 or 338), 6’’ -O-(3-hydroxy-3- methylglutaroyl)-2’’ - O - pentosyl-C - hexosyl-luteolin (723), Catechin-3-O-glucoside (452), 3’,4’,5’,5,7 – Methyl derivative of quercetin 3 – O – (2” - feruloylglucosyl)(1->6) – [apiosyl1->2)] glucoside (978.859), Quercetin 3 – O – β – D -(6 – O – sinnapoyl – 2 – O - – O – β – D glucopyranosyl) glucopyranoside (833), Apigenin 7-O-(6''-dihydrogalloyl)-glucosyl-8-C-rhamnosyl-6-C-glucoside (893), precursor or isomer ion of Quercetin 3 – O – β – D -(6 – O – sinnapoyl – 2 – O - – O – β – D glucopyranosyl) glucopyranoside 838.32 , 3’,4’,7 – Methyl derivative of quercetin 3 – O – β – D - glucopyranoside (507) and 415 (Daidzein 7 – O – glucoside).