Active Compound Identification in Extracts of N. lappaceum Peel and Evaluation of Antioxidant Capacity

Abstract

Nephelium lappaceum and its by-products have great potential in the agricultural, pharmaceutical, and food industries. Some studies have shown that N. lappaceum by-products exhibit antimicrobial, antioxidant, antidiabetic, and anticancer properties. However, studies focused on identifying these compounds are rare. The availability of polyphenolic compounds can vary according to environmental conditions, soil, plant variety, and agronomic management. Therefore, in this study, the active compounds in extracts of the N. lappaceum peel were identified, and their antioxidant properties were evaluated using various extraction solvents and both ultrasonic and boiling extraction techniques. The chemical characterization of the N. lappaceum peel exhibited carbohydrate and reducing sugar contents of 12 and 2%, respectively. Phytochemical analysis indicated the presence of flavonoids, tannins, terpenes, and steroids. The total phenolic and flavonoid contents and total antioxidant capacity were the highest in the hydroethanolic extract obtained by ultrasound, with values of 340 mg gallic acid equivalents g−1, 76 mg quercetin equivalents g−1, and 2.9 mmol of Trolox equivalents g−1, respectively. Contrarily, the total anthocyanin content was higher in the acid extract obtained by ultrasound, with a value of 0.7 mg cyanidin-3-O-glucoside equivalents g−1. A total of 18 compounds—including hydroxybenzene, phenolic acid, flavonoids, fatty acids (saturated, unsaturated, and ester), vitamin, arenecarbaldehyde, and phthalate—were identified for the first time in the N. lappaceum peel using gas chromatography-mass spectrometry. The identified compounds have been previously isolated from other plants and reportedly exhibit anticancer, anti-inflammatory, antimicrobial, and antioxidant activities. Thus, the N. lappaceum peel was shown to be a potential source of bioactive compounds of immense importance in the pharmacological and food industries.

Extraction of Tropical Fruit Peels and Development of HPMC Film Containing the Extracts as an Active Antibacterial Packaging Material

“…Clearly, 60% ethanol was a more proper solvent than pure water and ethanol. Other authors found that the hydroethanolic (60%) solvent provided higher yield of flavonoids than aqueous and ethanolic solvent in rambutan peel extraction using ultrasound and boiling [ 19 ]. The xanthones ( Figure 3 a) founded in mangosteen peel were mangostin, garcinone-E, gartanin and smeathxanthone-A, whereas mango peel contains mangiferin and quercetin ( Figure 3 b) derivatives as major flavonoids.…”

Review of Nephelium lappaceum and Nephelium ramboutan-ake: A High Potential Supplement

“…The oral toxicity of geraniin-and geraniin-enriched extracts revealed that the LD 50 cut off value of geraniin-and geraniin-enriched extracts (2000 mg/kg body weight) had no significant adverse effects to rat's body weight, water intake, histopathological, haematological and biochemical metabolites. However, a study found that rats experienced diarrhoea and the histopathology stain of the hepatocyte was observed to be 'foamy' [26]. Hence, caution should be taken while exploring the therapeutic effect of geraniin in N. lappaceum because of its potential to cause liver abnormalities.…”

“…However, another study indicated that the use of ethyl acetate contributes to high antioxidant activities [48]. This is due to the difference in solubility of active compounds in solvents with different polarities [26].…”

Biological Characterization and Quantification of Rambutan (Nephelium lappaceum L.) Peel Extract as a Potential Source of Valuable Minerals and Ellagitannins for Industrial Applications

“… 33 Studies have shown that extracts from rambutan peel possess ellagitannins that exhibit various biological activities in humans. 31 , 34 Among the ellagitannins, geraniin is the major compound in rambutan peel. 27 Geraniin is a substance that possesses a broad range of biological activities.…”

“…Currently, there has been an increasing global demand for bioactive compounds from plants by the pharmaceutical, cosmetic, and nutraceutical industries, as a result of their presumed roles in disease prevention, nutritional value, and ability to address human skin-related issues . Studies have shown that extracts from rambutan peel possess ellagitannins that exhibit various biological activities in humans. , Among the ellagitannins, geraniin is the major compound in rambutan peel . Geraniin is a substance that possesses a broad range of biological activities.…”