Extraction, identification, and antioxidant property evaluation of limonin from pummelo seeds

Abstract

Limonin, the main bioactive phytochemical constituent of limonoids with multi-functions, is enriched in citrus fruits and often found at a high concentration in citrus seeds. The present study was attempted to introduce a new and efficient extraction method to isolate limonoids from pummelo seeds, and to evaluate the antioxidant property of the main constituent limonin in HepG2 cells. Three key single factors were identified for the extraction of limonoids from pummelo seeds using the Box-Behnken experiment design of response surface methodology (RSM), and the optimized extraction parameters were treatment with 89.68 mL of anhydrous acetone for 4.62 h at 78.94 °C, while the yield of limonoids was 11.52 mg/g. The structure of isolated main constituent of the limonoids was further identified as limonin by Fourier transform infrared (FT-IR) spectrometer and nuclear magnetic resonance (NMR) spectrum. Moreover, the molecular data in HepG2 cells revealed that limonin exerted its anti-oxidant property mainly by the activation of nuclear factor (erythroid-2)-like 2 (Nrf2)/kelch-like ECH-associated protein 1 (Keap1)- antioxidant response element (ARE) pathway in the form of transcriptional regulation of Nrf2 mRNA and posttranscriptional regulation of Nrf2/Keap1 system. These results demonstrate that pummelo seeds are an ideal source of limonoids, and limonin is proved to exert its anti-oxidant property by the activation of Nrf2/Keap1 pathway.

Microwave-Assisted Improved Extraction and Purification of Anticancer Nimbolide from Azadirachta indica (Neem) Leaves

“…This was due to an affinity between the polarity of the solvent and the compound of interest [28]. The high extraction efficiency of ethanol was due to the high solubility of the limonoid group in alcohol [29]. It was consistent with previous reports that ethanol is a good solvent system for the extraction of polyphenolic compounds from Ocimum basilicum [30].…”

“…The microwave power and thermal effect for the extraction process were interrelated, as a high microwave power increased the temperature in the system [33]. However, high temperature might lead to its degradation due to the thermally labile property of nimbolide in limonoid group [29]. Therefore, 210-490 W was chosen for subsequent experimental design by the Box-Behnken design (BBD).…”

The MYB transcription factor CiMYB42 regulates limonoids biosynthesis in citrus

“…Citrus produces diverse secondary metabolites, including limonoids. Limonoids possess extensive biological and pharmacological activities [1], such as antioxidant [2] and insect antifeedant [3,4] as well as antibacterial [5,6], anticancer [7][8][9], antiviral [10,11], and anti-inflammatory [12] activities. The production of limonoids varies in different citrus species, organs and tissues, and developmental stages [13][14][15].…”

Nutritional Profile and Health Benefits of Kinnow: An Updated Review

“…The activity of extracts containing kaempferol involves the inhibition of VEGF expression and angiogenesis (Luo et al, 2012). Limonin present in fruits of citrus family is a multifunctional bioactive compound which posses antiobesity (Ono et al, 2011); anticancerous (Tian et al, 2001); and many more activities of pharmacological importance (Mandadi et al, 2007;Qin et al, 2018;Ribeiro et al, 2008).…”