Fast preparation of RG-I enriched ultra-low molecular weight pectin by an ultrasound accelerated Fenton process

Abstract

Pectin, a natural polysaccharide found in the cell wall of most higher plant such as citrus, has drawn much attention due to its potential beneficial role in facilitating the treatment of many diseases like cancer, hyper cholesterol and diabetes. However, the broad application of pectin faces great limitations as the large molecular size of pectin severely prevents its bioavailability in vivo. In this study, we report an effective and highly convenient approach to degrade natural pectin into lower molecular pectin. By combining ultrasound with Fenton system (US-Fenton), we show that ultrasound synergistically enhances the efficiency of Fenton reaction to degrade pectin into 5.5 kDa within only 35 minutes. Importantly, RG-I domain, the most effective portion of natural pectin, was well preserved and highly enriched. In addition, the antioxidant activities of US-Fenton-treated pectin was significantly elevated. The mechanism of this novel observation was further investigated through the multiple structural analyses including HPLC, IR and NMR. Taken together, we present a novel and convenient approach to generate ultra-low molecular weight pectin with high efficiency and higher bioactivity. We expect our approach will have broader applications in improving the bioavailability and bioactivity of other polysaccharide-based natural compounds.

Extraction and characterization of RG-I enriched pectic polysaccharides from mandarin citrus peel

“…Major signals observed in the spectrum of PA were assigned to the five protons of GalA (H-1, 4.97 ppm; H-2, 3.61 ppm; H-3, 3.88 ppm; H-4, 4.00 ppm and H-5, 4.34 ppm). In the anomeric region, the signals at 5.02 ppm and 4.84 ppm were attributed to the H-1 of Rha and H-1 of Gal, respectively (Zhi, et al, 2017b). There were additional peaks in the spectrum of PB that were difficult to assign.…”

“…Pectin is a complex polysaccharide that is extensively distributed in the primary cell wall and middle lamella of all plant tissues (Ridley, O'Neill, & Mohnen, 2001;Thakur, Singh, Handa, & Rao, 1997). It contains multiple "domains or building blocks" varying mainly in linear-forms of homogalacturonans (HG), highly branched-forms of rhamnogalacturonan-I (RG-I) and in rhamnogalacturonan-II (RG-II) (Zhi, et al, 2017a). The HG form, consisting of a linear backbone of 1,4-linked--D-galacturonic acid (GalA) units, which are partially methyl esterified at the carboxylic acid or acetylated (Xu, et al, 2014).…”

Oxidative DNA damage induced by ROS-modulating agents with the ability to target DNA: A comparison of the biological characteristics of citrus pectin and apple pectin

“…from apple pomace, and citrus peel) 19 , 20 . Recent studies indicate that plant pectins are effective against various cancers 21 . Pectins are capable of inducing apoptosis in cancer cells without having any adverse effect on normal cells, which make them good candidates in drug research.…”

Immunostimulatory Action of High-Content Active Arabinoxylan in Rice Bran

“…Lower molecular weight of polysaccharides increases bioavailability and bioactivity. 4 In addition, previous studies report that arabinoxylan isolated from rice bran has immunomodulatory properties by enhancing NK cells and macrophage activity in aged mice. 12 , 13 In addition, arabinoxylan increases NK cell activity that mediated antitumor activity on Ehrlich carcinoma-bearing mice.…”