Antioxidant Chemical Constituents from Lychee Seed (Litchi chinensis Sonn.)
Xuzhe Dong
School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China and Guangdong Engineering Research Center for Lead Compounds and Drug Discovery, Guangzhou 510006, China
Yihai Wang
School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China and Guangdong Engineering Research Center for Lead Compounds and Drug Discovery, Guangzhou 510006, China
Xiangjiu He *
School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China and Guangdong Engineering Research Center for Lead Compounds and Drug Discovery, Guangzhou 510006, China
*Author to whom correspondence should be addressed.
Abstract
Aims: To research non-flavonoids chemical constituents from the lychee seed.
Study Design: Chemical constituents were isolated and elucidated from the lychee seed and their antioxidant activities were also estimated.
Place and Duration of Study: School of Pharmacy, Guangdong Pharmaceutical University, between September 2015 and March 2018.
Methodology: All compounds were isolated by Silica gel, Sephadex LH-20, ODS as well as HPLC chromatography and confirmed by 1D and 2D NMR. The DPPH radical scavenging capacities of these isolated compounds were measured using the DPPH assay.
Results: Seventeen compounds were isolated and identified from the lychee seed (1–17). Among them, amentoflavone (1), (7R,8S)-dihydrodehydrodiconiferyl alcohol 9′-O-β-D-glucopyranoside (3), arjunglucoside I (5), 3β-hydroxy-7α-methoxy-24β-ethyl-cholest-5-ene (7), 4-hydroxy-5-(9′-oxo-8′-pyrrolidinyl)-benzoic acid (8), 1-pyrrolidineacetic methyl ester (9), phenylalanine methyl ester (10), 2-hydroxyquinoline-4-carboxyic acid (11), 3,4-dihydroxy-cyclohexanecarboxylic acid-methyl ester (13), 1,1-cyclopropanediacetic acid,1-methyl ester (15), cyclopropaneacetic acid, 2-(methoxycarbonyl) (16) were first isolated from lychee seed and 3 and 17 exhibited antioxidant capacities on DPPH radical scavenging.
Conclusion: This study suggests that compounds from the seed of Litchi chinensis Sonn. showed potential antioxidant properties, which mean that lychee seed could be utilized as a natural antioxidant for health care.
Keywords: Litchi chinensis Sonn, chemical constructions, antioxidant