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Black soybean seed (BSS) is a traditional edible and medical food. The cotyledons of BSS are either yellow or green, but that difference's effect on functional and bioactivities are not clear. In the present study, the concentrations of the main functional components, including anthocyanins, isoflavones, fatty acids, protein, and polysaccharides, and in vitro antioxidant activities of yellow-cotyledon and green-cotyledon BSS (YBS and GBS, respectively) were compared. The anti-fatigue activities of the ethanol extract of BSS (EEB) were evaluated using mouse swimming endurance tests. Additionally, a metabolomics comparison between YBS and GBS was done using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) on high doses of EEB-treated mouse plasma. The results indicated that YBS showed significantly higher contents of anthocyanin and protein, and stronger antioxidant activity and anti-fatigue activity than GBS; while GBS showed higher levels of isoflavone, stearic acid, and polysaccharide. By infusing the feed with EEB, the swimming time of mice increased in a dose-dependent manner. The metabolomics results suggested that the anti-fatigue effect of EEB correlated well with serotonin and melatonin biosynthesis in vivo. All of the above results showed that BSS has anti-fatigue potential and might be used as a potential source of functional food ingredients., This study was financially supported by the National Natural Science Foundation of China (Grant No. 31971853) and the China Postdoctoral Science Foundation (Grant No. 2014 M560724 & 2017T100707).

The berries of Sambucus nigra have traditionally been used and are still used to treat respiratory illnesses such as cold and flu in Europe, Asia and America. The aim of this paper was to elucidate the structures and the immunomodulating properties of the pectic polymers from elderberries. All the purified fractions obtained from 50% ethanol, 50°C water and 100°C water extracts showed potent dose-dependent complement fixating activity and macrophage stimulating activity. The isolated fractions consisted of long homogalacturonan regions, in addition to arabinogalactan-I and arabinogalactan-II probably linked to a rhamnogalacturonan backbone. Reduced bioactivity was observed after reduction of Araf residues and 1→3,6 Gal by weak acid hydrolysis. The rhamnogalacturonan region in SnBe50-I-S3-I and SnBe50-I-S3-II showed higher activity compared to the native polymer, SnBe50-S3, after enzymatic treatment with endo-α-d-(1→4)-polygalacturonase. These results indicated that elderberries contained immunomodulating polysaccharides, where the ramified regions express the activities observed.

The root bark, stem bark, and leaves of Terminalia macroptera were sequentially extracted with ethanol, 50% ethanol-water, and 50°C water using an accelerated solvent extractor (ASE). Six bioactive purified pectic polysaccharide fractions were obtained from the 50°C crude water extracts after anion exchange chromatography and gel filtration. The root bark, stem bark, and leaves of T. macroptera were all good sources for fractions containing bioactive polysaccharides. The high molecular weight fraction 50WTRBH-I-I, being the most active fraction in the complement fixation test, has a highly ramified rhamnogalacturonan type I (RG-I) region with arabinogalactan type II (AG-II) side chains. The most abundant fractions from each plant part, 50WTRBH-II-I, 50WTSBH-II-I, and 50WTLH-II-I, were chosen for pectinase degradation. The degradation with pectinase revealed that the main features of these fractions are that of pectic polysaccharides, with hairy regions (RG-I regions) and homogalacturonan regions. The activity of the fractions obtained after pectinase degradation and separation by gel filtration showed that the highest molecular weight fractions, 50WTRBH-II-Ia, 50WTSBH-II-Ia, and 50WTLH-II-Ia, had higher complement fixation activity than their respective native fractions. These results suggest that the complement fixation activities of these pectins are expressed mainly by their ramified regions.

Exo-polysaccharides were purified and characterized from the fermentation broth of Hypsizigus marmoreus, a popular edible mushroom consumed in Asia. Among them, B-I-I and B-II-I exhibited potent complement fixating activity, meanwhile, B-N-I, B-I-I, B-II-I and B-II-II exhibited significant macrophage stimulating activity. Molecular weights of the four exo-polysaccharides were determined to be 6.3, 120, 150 and 11 kDa respectively. Molecular characterisation showed that B-N-I is basically an α-1 → 4 glucan, with branches on C6; B-I-I is a heavily branched α-mannan with 1 → 2 linked main chain. B-II-I and B-II-II, have a backbone of rhamno-galacturonan with 1 → 2 linked l -rhamnose interspersed with 1 → 4 linked galacturonic acid. Structure–activity relationship analysis indicated that monosaccharide compositions, molecular weight, certain structural units (rhamno-galacturonan type I and arabinogalactan type II) are the principal factors responsible for potent complement fixating and macrophage-stimulating activities. Their immunomodulating activities may, at least partly, explain the health benefits of the mushroom.

Ethnopharmacological relevance Sutherlandia frutescens (syn. Lessertia frutescens) is an indigenous plant in Southern Africa and has been extensively studied from the ethnobotanical point of view. Amongst the various traditional uses, several illnesses involving the immune system have been reported. Due to some of the therapeutic effects observed, in relation to the traditional uses reported by the “khoi san” and “nama” people on cancer related illnesses, the plant has been given the local name kankerbos (cancerbush). Recently the plant has also been used amongst HIV/AIDS patients to stimulate the immune system. Materials and methods Leaves of Sutherlandia frutescens were extracted sequentially with ethanol, 50% ethanol/water, and water at 50 and 100 °C. The polysaccharides were extracted with water and fractionated by ion exchange chromatography and gel filtration to obtain enriched polysaccharide fractions. The bioactivities of the fractions were tested in the complement assay. Some of the fractions were treated with the enzyme pectinase, and the fragments thus produced were separated by gel filtration and their activities tested. Monosaccharide compositions and linkage analyses were determined for the relevant fractions. Results The leaves of Sutherlandia frutescens contain polysaccharides of the pectin type. Fractions from both the water extracts of 50 and 100 °C were bioactive. Fractions chosen for further studies showed that the fragment with the highest MW after the pectinase treatment had a substantially higher biological effect than the parent molecules. Based on a comparison of the different fractions it was concluded that galactose-rich regions were important for the bioactivity, these being of the AGII and AGI type, with the latter probably being more important than the former. Fragments rich in xylose also gave higher activity than those without it. Conclusions Our theory that the polysaccharides present in the leaves of Sutherlandia frutescens could be of importance as immunomodulating agents was confirmed. It was also shown that certain types of polysaccharides had a higher effect in the complement system than others. Thus both the water extracts obtained at 50 and 100 °C contain interesting biologically active polysaccharides.

Elderflowers have traditionally been used and are still used for its anti-inflammatory property. Traditionally elderflowers were used as remedies against cold, flu and diuretic. The aim of this study was to relate the structure of pectic-polysaccharides from elderflowers to immunomodulating properties. Purified fractions obtained by gelfiltration and ion exchange chromatography of 50% ethanol, 50°C water and 100°C water extracts exhibited strong complement fixating activity and macrophage stimulating activity. Reduced bioactivity was observed after removal of arabinose and 1,3,6-Gal linkages by weak acid hydrolysis. Enhanced bioactivity was observed after removal of estergroups by NaOH. Relating linkage analysis to the results of the bioactivity tests, led to the assumption that the branched moieties of the arabinogalactans linked to rhamnogalacturonan region, is important for the immunomodulating activity seen in elderflowers. No cytotoxity was observed.

Two pectic polysaccharides, 50WCP-II-I and 100WCP-II-I, were obtained from 50 and 100 °C water extracts of Codonopsis pilosula roots by ion exchange chromatography and gel filtration. The study of the sub-fractions obtained after pectinase degradation showed that the complement fixation activities of these pectins are expressed mainly by their ramified regions. The structure studies of native and sub-fractions showed the 50WCP-II-I is a pectic polysaccharide, with long homogalacturonan regions (some of the galacturonic acid units were methyl esterified), interrupted by one short rhamnogalacturonan I (RG-I) region. The side chains of the RG-I region are arabinogalactan type I (AG-I) and type II (AG-II) attached on position 4 of rhamnose. The 100WCP-II-I has two main ramified regions, one is galacturonan region with AG-I side chain on position 2 of GalA, and the other one is RG-I region with AG-II side chain on position 4 of Rha.

The root bark, stem bark and leaves of Terminalia macroptera were sequentially extracted with ethanol, 50% ethanol-water, and 50 °C and 100 °C water using an accelerated solvent extractor. Ten bioactive purified polysaccharide fractions were obtained from those crude extracts after anion exchange chromatography and gel filtration. The polysaccharides and their native extracts were characterized with respect to molecular weight, chemical compositions and effects in the complement assay. The chemical compositions showed that the polysaccharides are of pectic nature. The results indicated that there was no great difference of the complement fixation activities in the crude extracts from the different plant parts when extracting with the accelerated solvent extraction system. The purified polysaccharide fractions 100WTSBH-I-I and 100WTRBH-I-I isolated from the 100 °C water extracts of stem and root bark respectively, showed the highest complement fixation activities. These two fractions have rhamnogalacturonan type I backbone, but only 100WTSBH-I-I contains side chains of both arabinogalactan type I and II. Based on the yield and activities of the fractions studied those from the root bark gave highest results, followed by those from leaves and stem bark. But in total, all plant materials are good sources for fractions containing bioactive polysaccharides.

The bark of Parkia biglobosa is used in traditional medicine to cure a wide range of illnesses. Polysaccharides were extracted from the bark with 50% ethanol–water, 50 °C and 100 °C water, and seven active fractions obtained by anion exchange chromatography and gel filtration. The complement fixation and macrophage stimulating activities of the different fractions were determined. The acidic fractions PBEII-I and PBEII-IV were the most active in the complement fixation assay, but the other fractions were also potent compared to the positive control BPII from Biophytum petersianum . Fractions PBEII-I and PBEII-IV were also the most potent fractions in stimulating macrophages to release nitric oxide. Structural studies showed that PBEII-I and PBEII-IV were pectic type polysaccharides, containing arabinogalactan type II structures. The observed differences in biological activities among the seven purified polysaccharide sub-fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes.