Polyphenols and Alkaloids in Byproducts of Longan Fruits (Dimocarpus Longan Lour.) and Their Bioactivities

Abstract

The longan industry produces a large amount of byproducts such as pericarp and seed, resulting in environmental pollution and resource wastage. The present study was performed to systematically evaluate functional components, i.e., polyphenols (phenolics and flavonoids) and alkaloids, in longan byproducts and their bioactivities, including antioxidant activities, nitrite scavenging activities in simulated gastric fluid and anti-hyperglycemic activities in vitro. Total phenolic and total flavonoid contents in pericarp were slightly higher than those in seeds, but seeds possessed higher alkaloid content than pericarp. Four polyphenolic substances, i.e., gallic acid, ethyl gallate, corilagin and ellagic acid, were identified and quantified using high-performance liquid chromatography. Among these polyphenolic components, corilagin was the major one in both pericarp and seed. Alkaloid extract in seed showed the highest DPPH radical scavenging activity and oxygen radical absorbance capacity. Nitrite scavenging activities were improved with extract concentration and reaction time increasing. Flavonoids in seed and alkaloids in pericarp had potential to be developed as anti-hyperglycemic agents. The research result was a good reference for exploring longan byproducts into various valuable health-care products.

Corilagin in Cancer: A Critical Evaluation of Anticancer Activities and Molecular Mechanisms

“…Corilagin (β-1- O -galloyl-3,6-( R )-hexahydroxydiphenoyl- d -glucose) is a natural ellagitannin (ET) found in a wide range of plants. In recent years, corilagin has been documented to possess many biological and pharmacological attributes, such as antioxidant [21], anti-inflammatory [22], hepatoprotective [23], antimicrobial [24], antihypertensive [25], antidiabetic [21,26], and antitumor activities [27,28,29,30]. It inhibited reverse transcriptase activity of RNA tumor viruses and possessed significant antistaphylococcal activity (MIC 25 μg/mL) [31].…”

Two New Phenolic Constituents from the Stems of Euphorbia griffithii

“…1). Unit a was found matched perfectly corilagin [15] while the structure of unit b was quite similar to 1,2,6-tri- O -galloyl- β - d -glucopyranose [16], by comparisons of their spectral data.

Fig. 2Key 1 - 1 H COSY and HMBC correlations of 1 – 2

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Corilagin Represses Epithelial to Mesenchymal Transition Process Through Modulating Wnt/β-Catenin Signaling Cascade

“…Corilagin (CLG) can be isolated from wide range of medical plants [ 23 , 24 ] and can display many biological activities including those of anti-inflammatory, hepatoprotective, anti-microbial, antihypertensive, antidiabetic, and anti-tumor [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], but its impact on EMT has not been well characterized yet. We report here for the first time that CLG reduced levels of different mesenchymal markers and enhanced that of epithelial markers (occludin and E-cadherin) in both SNU-C2A and DU145 cells.…”

“…Corilagin (CLG) is one such unique component of the tannin family [ 23 ], which can be found in a wide range of medical plants such as Longan, Lumnitzera racemose , Terminalia catappa L, and Phyllanthus species [ 24 , 25 , 26 ]. CLG has been reported to possess many pharmacological and biological properties including anti-inflammatory, hepatoprotective, anti-microbial, antihypertensive, antidiabetic, and anti-tumor activities [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Recently, the anti-tumor effect of CLG has been focus of great interest in cancer biology [ 35 , 36 , 37 ].…”