Antioxidant effect and active components of litchi (Litchi chinensis Sonn.) flower.
The effects of scavenging 2, 2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radicals and inhibiting low-density lipoprotein (LDL) oxidation, and phenolic quantities were used for the activity-guided separation to identify the effective components of litchi flower. The acetone extract of the flower with notable antioxidant capacities was suspended in water and sequentially partitioned with n-hexane, ethyl acetate (EA) and n-butanol. The EA partition with the highest phenolic levels and antioxidant capacities was subjected to silica gel column chromatography. Thirteen fractions (Fr. 1-13) were collected; Fr. 10-12 with higher phenolic levels and antioxidant effects were applied to Sephadex LH-20 column chromatography. Each fraction was further separated into three sub-fractions and the second ones (Fr. 10-II, 11-II, and 12-II) were the best, which two major compounds could be isolated by semi-preparative high performance liquid chromatography (HPLC). Through Mass (MS) and Nuclear Magnetic Resonance (NMR) measurements, they could be identified as (-)-epicatechin and proanthocyanidin A2. Their contents in the litchi flower were 5.52 and 11.12 mg/g of dry weight, respectively. The study was the first time to reveal the effective antioxidant components of litchi flower.
School of Health Diet and Industry Management and Department of Nutrition, Chung Shan Medical University and Chung Shan Medical University Hospital, 110, Section 1, Jianguo N. Road, Taichung 402, Taiwan.
Deng-Jye
DJ
Yang
Yan-Zin
YZ
Chang
Yi-Chen
YC
Chen
Shih-Chuan
SC
Liu
Chuan-Hsiang
CH
Hsu
Jau-Tien
JT
Lin
D000975:Antioxidants / Q000494:pharmacology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D035264:Flowers / Q000737:chemistry*; D032125:Litchi / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000494:pharmacology*
D000975:Antioxidants; D010936:Plant Extracts