SEPARATION AND PURIFICATION OF ANTIOXIDANT GLYCOGLYCEROLIPIDS FROM FRUIT OF CUCURBITA MOSCHATA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY COUPLED WITH PREPARATIVE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Abstract

Glyceroglycolipids, widely distributed in edible plants, possess potent antithrombotic, antiviral, antitumor, and anti-inflammatory activities. In this paper, a simple method based upon high-speed counter-current chromatography (HSCCC) coupled with preparative high-performance liquid chromatography (Pre-HPLC) was developed for the separation and purification of antioxidant glycoglycerolipids from the fruits of Cucurbita moschata (pumpkin). HSCCC separation was performed on a two-phase solvent system composed of dichloromethane–light petroleum (60–90°C)–ethanol–H₂O (6:2:4:4, v/v). Semi-purified peak fractions from HSCCC separation were further purified by Pre-HPLC to yield six glycoglycerolipid monomers with purities of over 98%. Their structures were elucidated by electrospray ionization mass spectrometry (ESI-MS), ¹H-NMR, and ¹³C-NMR. Their antioxidant activities in vitro were also evaluated through 1,1-diphenyl-2-picrylhydrazyl assays. Tetrasaccharide-containing glycoglycerolipids exhibited stronger antioxidant activity compared to that of butylated hydroxytoluene, and it can be assumed to be potentially useful as a safe antioxidant in food processing industries. The results indicate that the method is simple, fast, and efficient.

Keywords:

• antioxidant activity
• Cucurbita moschata
• glycoglycerolipid
• high-speed counter-current chromatography
• preparative high-performance liquid chromatography
• purification

ACKNOWLEDGMENT

The work was supported by Natural Science Foundation of Hainan Province of China (Grant No. 312075), Youth Foundation of Hainan University (Grant No. qnjj1180), Scientific Research Initiation Foundation of Hainan University (Grant No. kyqd1223), and National Natural Science Foundation of China (Grant no. 31260401).

Notes

^a 50% radical-scavenging activity concentration.