Isolation and structural elucidation of a new saponin (‘Soyasaponin V’) from haricot bean (Phaseolus vulgaris L.)

A new triterpenoid saponin has been isolated from haricot beans and its structure shown to be 3-O-[β-D-glucopyranosyl(1→2)-β-D-galacto-pyranosyl (1→2)-β-D-glucuronopyranasyl] olean-12-en-3β, 22β, 24-triol. The dietary intakes of saponins are discussed and the possible physiological consequences are identified.     

Oligosaccharide structures formed during the hydrolysis of lactose by Aspergillus oryzae β-galactosidase

Di-, tri-, tetra-, penta- and hexasaccharides were formed during the hydrolysis of lactose by transgalactosylation reaction of Aspergillus oryzae β-galactosidase. In this study the isolation and characterization of the major constituents of tri-, tetra- and pentasaccharides are described. The structure elucidation of 3 tri-, 2 tetra- and 1 pentasaccharides was carried out by methylation analysis, mass spectrometry and ¹³C-nmr spectrometry. The trisaccharides are $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 3)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 4)-}\text{d}\text{-}\text{glucose}\text{(3′-}\text{galactosyl-lactose}\text{)}$, $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 4)-}\text{d}\text{-}\text{glucose}\text{(6′-}\text{galactosyl-lactose}\text{)}$ and $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 4)-O-[β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)]-}\text{d}\text{-}\text{glucose}\text{(4,6-}\text{digalactosyl-glucose}\text{)}$. Tetrasaccharides are $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 4)-}\text{d}\text{-}\text{glucose}$ and $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 3)}$ [or $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 3)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)]-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 4)-}\text{d}\text{-}\text{glucose}$. Pentasaccharide is $\text{O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 6)-O-β-}\text{d}\text{-}\text{galactopyranosyl}\text{-(1 → 4)-}\text{d}\text{-}\text{glucose}$.     

An Antifungal Saponin from White Asparagus ( Asparagus officinalis L) Bottoms

An antifungal saponin was isolated from the bottom cut of white asparagus (Asparagus officinalis L), which is unusable in food processing. The structure of the saponin was identified as 3-O-[{α-L -rhamnopyranosyl (1→2)} {α-L -rhamnopyranosyl (1→4)}-β-D -glucopyranosyl] (25S) spirost-5-ene-3β-ol from chemical and spectral data. This saponin was shown to be identical with collettinside III from Dioscorea collettii, and to inhibit the growth of some kinds of fungi at μg ml⁻¹ levels.     

Furostanol saponins in Allium caepa L. Var. tropeana seeds

An analysis of the polar extracts from seeds of Allium caepa L. var. tropeana led to the isolation of eight furostanol saponins, one of which was previously reported in the literature. On the basis of 1D, 2D NMR and mass spectrometry data, the structures of the compounds were elucidated as 1-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-1β,3β,22α,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 2″)-O-α-L-arabinopyranoside (1a), its epimer at position 22, 1-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-1β,3β,22β,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 2″)-O-α-L-arabinopyranoside (1b), 1-O-β-D-glucopyranosyl-22-O-methyl-(25R)-furost-5(6)-en-1β,3β,22ξ,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 2″)-O-α-L-arabinopyranoside (probably artefact) (2), 1-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-1β,3β,22β,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 6″)-O-β-D-galactopyranoside (3), 1-O-β-D-glucopyranosyl-22-O-methyl-(25R)-furost-5(6)-en-1β,3β,22ξ,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 6″)-O-β-D-galactopyranoside (probably artefact) (4), 26-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-3β,22α,26-triol-3-O-α-L-rhamnopyranosyl-(1″ → 2′)-O-[β-D-glucopyranosyl-(1‴ → 6′)-O]-β-D-glucopyranoside (5a) and its epimer at position 22,26-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-3β,22β,26-triol-3-O-α-L-rhamnopyranosyl-(1″ → 2′)-O-[β-D-glucopyranosyl-(1‴ → 6′)-O]-β-D-glucopyranoside (5b) and the known compound 26-O-β-D-glucopyranosyl-22-O-methyl-(25R)-furost-5(6)-en-3β,22ξ,26-triol-3-O-α-L-rhamnopyranosyl-(1″ → 2′)-O-[β-D-glucopyranosyl-(1‴ → 6′)-O]-β-D-glucopyranoside (6) [Mimaki, Y., Satou, T., Kuroda, M., Sashida, Y., & Hatakeyama, Y. (1999). Steroidal saponins from the bulbs of Lilium candidum. Phytochemistry, 51, 567–573]. This is the first report on furostanol saponins in the seeds of Allium caepa L. var. tropeana.     

A new steroidal saponin from the seeds of Allium tuberosum

A steroidal saponin, named tuberoside A, together with six known compounds, were isolated from the seeds of Allium tuberosum Rottl. ex Spreng. On the basis of acid hydrolysis, comprehensive spectroscopic analyses and comparison with spectral data of known compounds, its structure was established as (24S, 25S)-5β-spirostan-2β,3β,24-triol 3-O-α-l-rhamnopyranoyl-(1→2)-O-[α-l-rhamnopyranosyl-(1→4)]-β-d-glucopyranoside. The six known compounds were thymidine, adenosine, 2-hydroxy purine, adenine, uracil, and thymine. 2-hydroxy purine, adenine, uracil and thymine are isolated from the seeds of A. tuberosum for the first time. This paper deals with the isolation and structural elucidation of the new saponin.     

Saponins in Ipomoeabatatas tubers: Isolation,characterization, quantification and antioxidant properties

Triterpene saponins are a class of plant natural products with a wide range of bioactivities, which makes them an interesting research subject. This work reports, for the first time, the isolation and characterization of saponins in Ipomoeabatatas tuber flour, their quantification and antioxidant properties. Their structures were characterized on the basis of UV, FAB–MS, ESI–MS, GC–MS, polarimetry and NMR data, as: oleanolic acid-3-O-[β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyl]-28-O-β-d-glucopyranoside (sandrosaponin IX) (1) and oleanolic acid-3-O-[β-d-galactopyranosyl-(1→3)-β-d-glucuronopyranosyl]-28-O-β-d-glucopyranoside (2). A new quantitative HPLC–DAD method for saponin content determination in this tuber was developed and validated. Their total content was 200.01 mg/100 g dry weight (RSD = 7.2%; p < 0.001). The single saponin contents were: 161.20 mg/100 g dry weight (RSD = 0.58%; p < 0.001) for saponin 1 and 14.67 mg/100 g dry weight (RSD = 0.41%; p < 0.001) for saponin 2. The antioxidant activities, tested by DPPH and FRAP assay, of total phytochemical fraction and of single saponins were moderate in relation to commercial standards.     

Two new saponins from tetraploid jiaogulan (Gynostemma pentaphyllum), and their anti-inflammatory and α-glucosidase inhibitory activities

Jiaogulan tea has been commercialised globally. This study investigated the chemical components and health properties of a new jiaogulan genotype, tetraploid Gynostemma pentaphyllum. Two new saponins, (23S)-21β-O-methyl-3β,20ξ-dihydroxy-12-oxo-21,23-epoxydammar-24-ene-3-O-[α-l-rhamnopyranosyl(1→2)][β-d-glucopyranosyl(1→3)]-α-l-arabinopyranoside (4) and 23β-H-3β,20ξ-dihydroxy-19-oxo-21,23-epoxydammar-24-ene-3-O-[α-l-rhamnopyranosyl(1→2)][β-d-xylopyranosyl(1→3)]-α-l-arabinopyranoside (5), together with one lactone, 3,5-dihydroxyfuran-2(5H)-one (1), and two flavonoids, rutin (2) and kaempferol 3-O-rutinoside (3), were characterised in the aerial parts of tetraploid jiaogulan. The chemical structures of the five isolated compounds were elucidated by NMR, HR-MS spectra and chemical degradation. The five compounds were also examined and compared with the methanol extract and n-butanol soluble fraction of the jiaogulan for their inhibitory activities on lipopolysaccharide (LPS)-induced IL-1β, IL-6 and COX-2 mRNA expression in RAW 264.7 mouse macrophages, and their in vitro α-glucosidase suppressing capacities. The results from this study may be used to promote the potential application of jiaogulan in functional foods.     

Identification,quantification and antioxidant activity of acylated flavonol glycosides from sea buckthorn (Hippophae rhamnoides ssp. sinensis)

A novel acylated flavonol glycoside: isorhamnetin (3-O-[(6-O-E-sinapoyl)-β-d-glucopyranosyl-(1 → 2)]-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside) (1), together with two known acylated flavonol glycosides: quercetin (3-O-[(6-O-E-sinapoyl)-β-d-glucopyranosyl-(1 → 2)]-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside) (2) and kaempferol (3-O-[(6-O-E-sinapoyl)-β-d-glucopyranosyl-(1 → 2)]-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside) (3) were isolated from the n-butanol fraction of sea buckthorn (Hippophae rhamnoides ssp. sinensis) berries for the first time by chromatographic methods, and their structures were elucidated using UV, MS, ¹H and ¹³C NMR, and 2D NMR. Compounds 1–3 showed good scavenging activities, with respective IC₅₀ values of 8.91, 4.26 and 30.90 μM toward the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical; respective Trolox equivalent antioxidant capacities of 2.89, 4.04 and 2.44 μM μM⁻¹ toward 2,2′-azino-bis-3-ethyl-benzothiazoline-6-sulphonate (ABTS) radical. The quantitative analysis of the isolated acylated flavonol glycosides was performed by HPLC–DAD method. The contents of compounds 1–3 were in the range of 12.2–31.4, 4.0–25.3, 7.5–59.7 mg/100 g dried berries and 9.1–34.5, 75.1–182.1, 29.2–113.4 mg/100 g dried leaves, respectively.     

4-O-Methyl Modifications of Glucuronic Acids in Xylans Are Indispensable for Substrate Discrimination by GH67 α-Glucuronidase from Bacillus halodurans C-125

A GH67 α-glucuronidase gene derived from Bacillus halodurans C-125 was expressed in E. coli to obtain a recombinant enzyme (BhGlcA67). Using the purified enzyme, the enzymatic properties and substrate specificities of the enzyme were investigated. BhGlcA67 showed maximum activity at pH 5.4 and 45 °C. When BhGlcA67 was incubated with birchwood, oat spelts, and cotton seed xylan, the enzyme did not release any glucuronic acid or 4-O-methyl-glucuronic acid from these substrates. BhGlcA67 acted only on 4-O-methyl-α-D-glucuronopyranosyl-(1→2)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranose (MeGlcA³Xyl₃), which has a glucuronic acid side chain with a 4-O-methyl group located at its non-reducing end, but did not on β-D-xylopyranosyl-(1→4)-[4-O-methyl-α-D-glucuronopyranosyl-(l→2)]-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylop- yranose (MeGlcA³Xyl₄) and α-D-glucuronopyranosyl-(l→2)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranose (GlcA³Xyl₃). The environment for recognizing the 4-O-methyl group of glucuronic acid was observed in all the crystal structures of reported GH67 glucuronidases, and the amino acids for discriminating the 4-O-methyl group of glucuronic acid were widely conserved in the primary sequences of the GH67 family, suggesting that the 4-O-methyl group is critical for the activities of the GH67 family.     

Kaempferol acetylated glycosides from the seed cake of Camellia oleifera

The seed cake is a big by-product after crushing cooking oil from the seeds of Camellia oleifera Abel. Chemical investigation on the seed cake of C. oleifera led to the isolation of two new kaempferol acetylated glycosides (1 and 2). In addition, five kaempferol glycosides (3–7) and their aglycone, kaempferol (8), were also obtained, in addition to gallic acid (9). Their structures were determined by the detailed spectroscopic analysis and acidic hydrolysis. The new compounds were characterised as kaempferol-3-O-[4′′′′-O-acetyl-α-l-rhamnopyranosyl-(1→6)]-[β-d-glucopyranosyl-(1→2)]-β-d-glucopyranoside (1) and kaempferol-3-O-[4′′′′-O-acetyl-α-l-rhamnopyranosyl-(1→6)]-[β-d-xylopyranosyl-(1→2)]-β-d-gluco-pyranoside (2), respectively. The DPPH radical scavenging activity of all the isolated compounds was described.     

Flavonol glycosides from whole cottonseed by-product

Cottonseeds are fed to high-producing dairy cows as a source of fat and highly-digestible fibre. Seven flavonol glycosides have been identified from whole cottonseed by-product. Their structures were established as quercetin 3-O-{β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside} (1), kaempferol 3-O-{β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside} (2), quercetin 3-O-[β-d-apiofuranosyl-(1 → 2)-β-d-glucopyranoside] (3), quercetin 3-O-β-d-glucopyranoside (4), kaempferol 3-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside] (5), quercetin 3-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside] (6), and kaempferol 3-O-α-l-rhamnopyranoside (7). Gallic acid (8) and 3,4-dihydroxybenzoic acid (9) were also found. All structures were elucidated by ESI-MS and NMR spectroscopic methods. Total polyphenols were assayed by the Folin–Ciocalteu method.     

Spirostane and cholestane glycosides from the bulbs of Allium nigrum L

A phytochemical investigation of the fresh bulbs of Allium nigrum L. led to the isolation of new spirostane-type glycosides as two inseparable isomer mixtures, nigrosides A1/A2 (1a/1b) and nigrosides B1/B2 (2a/2b), two new cholestane-type glycosides, nigrosides C and D (3 and 4), together with the known compounds, 25(R,S)-5α-spirostan-2α,3β,6β-trio1-3-O-β-d-glucopyranosyl-(1 → 2)-O-[β-d-xylopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (5a/5b) and 25(R,S)-5α-spirostan-2α,3β,6β-trio1 3-O-β-d-glucopyranosyl-(1 → 2)-O-[4-O-(3S)-3-hydroxy-3-methylglutaryl-β-d-xylopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (6a/6b), isolated from this plant for the first time. All structures were elucidated mainly by spectroscopic analysis (1D and 2D NMR experiments, FABMS, HRESIMS) and by comparison with literature data. Cytotoxicity of the isolated compounds was assessed against human colon carcinoma (HT-29 and HCT 116) cell lines. Compounds 5a/5b and 6a/6b were found to be the most active with IC₅₀ values 1.09 and 2.82 μM against HT-29 and 1.59 and 3.45 μM against HCT 116, respectively.     

Novel acetylated flavonoid glycosides from the leaves of Allium ursinum

Seven flavonoid glycosides, kaempferol 3-O-α-L-rhamnopyranosyl (1→2)-[3-O-acetyl]-β-D-glucopyranoside (1), kaempferol 3-O-α-L-rhamnopyronosyl (1→2)-[6-O-acetyl]-β-D-glucopyranoside (2), kaempferol 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (3), kaempferol 3-O-β-D-glucopyranoside (4), kaempferol 3,7-di-O-β-D-glucopyranoside (5), 7-O-β-D-glucopyranosyl kaempferol 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (6), kaempferol 3-O-α-L-rhamnopyranosyl (1→2)-β-D-glucopyranoside-7-O-[2-O-(trans-p-coumaroyl)]-β-D-glucopyranoside (7) were isolated from the n-butanol fraction of Allium ursinum L. and the structures of these compounds were elucidated on the basis of mass spectrometry, ¹H NMR, ¹³C NMR, HMQC and HMBC data. Among them, 1 and 2 are novel compounds and compounds 4 and 5 were isolated from this plant species for the first time.     

Spirostane,furostane and cholestane saponins from Persian leek with antifungal activity

A phytochemical investigation of the seeds of Persian leek afforded the isolation of two new spirostane glycosides, persicosides A (1) and B (2), four new furostane glycosides, isolated as a couple of inseparable mixture, persicosides C1/C2 (3a/3b) and D1/D2 (4a/4b), one cholestane glycoside, persicoside E (5), together with the furostane glycosides ceposides A1/A2 and C1/C2 (6a/6b and 7a/7b), tropeosides A1/A2 and B1/B2 (8a/8b and 9a/9b), and ascalonicoside A1/A2 (10a/10b), already described in white onion, red Tropea onion, and shallot, respectively. Structure elucidation of the compounds was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and MS spectrometry, and by chemical evidences. The chemical structure of new compounds were identified as (25S)-spirostan-2α,3β,6β-triol 3-O-[β-d-glucopyranosyl-(1 → 3)] [β-d-xylopyranosyl-(1 → 2)]-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (1), (25S)-spirostan-2α,3β,6β-triol 3-O-[β-d-xylopyranosyl-(1 → 3)] [α-l-rhamnopyranosyl-(1 → 2)]-β-d-glucopyranosyl-(1 → 4)-O-β-d-galactopyranoside (2), furosta-1β,3β,22ξ,26-tetraol 5-en 1-O-β-d-glucopyranosyl (1 → 3)-β-d-glucopyranosyl (1 → 2)-β-d-galactopyranosyl 26-O-α-l-rhamnopyranosyl (1 → 2)-β-d-galactopyranoside (3a,3b), furosta-2α,3β,22ξ,26-tetraol 3-O-β-d-glucopyranosyl (1 → 3)-β-d-glucopyranosyl (1 → 2)-β-d-galactopyranosyl 26-O-β-d-glucopyranoside (4a,4b), (22S)-cholesta-1β,3β,16β,22β-tetraol 5-en 1-O-α-l-rhamnopyranosyl 16-O-α-l-rhamnopyranosyl (1 → 2)-β-d-galactopyranoside (5).     

Isolation and structural determination of a novel flavonol triglycoside and 7 compounds from the leaves of oriental raisin tree (Hovenia dulcis) and their antioxidative activity

The hot water and ethanol extracts of oriental raisin tree (Hovenia dulcis Thunb) leaves showed DPPH radical scavenging activities. Antioxidants were purified and isolated from hot water and ethanol extracts by various column chromatographic procedures with the guided assay of DPPH radical scavenging. The structure of a novel flavonol triglycoside was determined to kaempferol 3-O-α-l-rhamnopyranoside-7-O-[α-d-glucopyranosyl(1→3)-α-l-rhamnopyranoside] (4). In addition, 7 known compounds were identified as caffeine (1), kaempferol 3,7-O-α-l-dirhamnopyranoside (2), kaempferol 3-O-α-l-rhamnopyranosyl( 1→6)-O-β-d-glucopyranosyl(1→2)-O-β-d-glucopyranoside (3), E-3-carboxy-2-petenedioate 5-methyl ester (5), quercetin 3-O-α-l-rhamnopyranoside (6), kaempferol 3-O-α-l-rhamnopyranoside (7), and quercetin 3-O-β-d-glucopyranoside (8). Compound 1–3 and 5–8 were newly identified in this plant. Quercetin glycosides (5, 7) showed higher DPPH radical scavenging activity than other compounds.     

ENZYMIC QUANTIFICATION OF (1→3) (1→4)-β-D-GLUCAN IN BARLEY AND MALT

A simple and quantitative method for the determination of (1→3) (1→4)-β-D-glucan in barley flour and malt is described. The method allows direct analysis of β-glucan in flour and malt slurries. Mixed-linkage β-glucan is specifically depolymerized with a highly purified (1→3) (1→4)-β-D-glucanase (lichenase), from Bacillus subtilis, to tri-, tetra- and higher degree of polymerization (d.p.) oligosaccharides. These oligosaccharides are then specifically and quantitatively hydrolysed to glucose using purified β-D-glucosidase. The glucose is then specifically determined using glucose oxidase/peroxidase reagent. Since barley flours contain only low levels of glucose, and maltosaccharides do not interfere with the assay, removal of low d.p. sugars is not necessary. Blank values are determined for each sample allowing the direct measurement of β-glucan in maltsamples.α-Amylasedoes not interfere with the assay. The method issuitable for the routineanalysis of β-glucan in barley samples derived from breeding programs; 50 samples can be analysed by a single operator in a day. Evaluation of the technique on different days has indicated a mean standard error of 0–1 for barley flour samples containing 3–8 and 4–6% (w/w) β-glucan content.     

Antidiabetic and anti-inflammatory potential of sulphated polygalactans from red seaweeds Kappaphycus alvarezii and Gracilaria opuntia

Antidiabetic and anti-inflammatory potential of sulphated polygalactans isolated from the red seaweeds Kappaphycus alvarezii and Gracilaria opuntia were acquired by employing different in vitro systems. The sulphated galactopyran motif derived from G. opuntia possessed significant antidiabetic properties as identified by α-amylase (IC₅₀ 0.04 mg/mL), α-glucosidase (IC₅₀ 0.09 mg/mL) and dipeptidyl peptidase-4 (DPP-4, IC₅₀ 0.09 mg/mL) inhibitory activities. Based on the detailed nuclear magnetic resonance spectroscopy experiments the sulphated galactopyran motif of G. opuntia was designated as →3)-4-O-sulfonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulfonato)-α-D-galactopyranosyl-(1→3)-4-O-sulfonato-(6-O-acetyl)-β-D-xylosyl-(1→3)-4-O-sulfonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulfonato)-α-D-galactopyranan, while the one from K. alvarezii was demonstrated to be →4)-4-O-sulfonato-(2-O-methyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-methyl)-α-D-galactopyranan. The sulphated galactans from G. opuntia showed greater anti-inflammatory inhibitory activities as determined by cyclooxygenase-1 (COX-1, IC₅₀ 0.01 mg/mL), cyclooxygenase-2 (COX-2, IC₅₀ 0.03 mg/mL), and 5-lipoxygenase inhibitory activities (5-LOX, IC₅₀ 0.24 mg/mL). This study revealed that the sulfated polygalactan enriched concentrate from G. opuntia can be used as potential therapeutic candidate to suppress the hyperglycemic response in diabetic conditions and inflammatory activity. They can be used to develop functional food ingredient in nutraceutical products.     

Purification, chemical characterization, and antioxidant activity of a polysaccharide from the fruiting bodies of sanghuang mushroom (Phellinus baumii Pilát)

A purified water-soluble polysaccharide was isolated from the fruiting bodies of sanghuang mushroom (Phellinus baumii Pilát) using hot water extraction, DEAE Sepharose Fast Flow anion exchange and High-Resolution Sephacryl S-1000 gel-filtration chromatography. The purified polysaccharide was a complex β-d-glucan, with a molecular mass of 230 kDa. Fourier-transform infrared (FT-IR), methylation analysis, and NMR spectroscopy of sanghuang mushroom polysaccharide (PBF3) indicated that the polysaccharide contained (1→3)-β-d-, (1→4)-β-d-, and branched (1→3,6)-β-d-glucopyranosyl residues. On the basis of hydroxyl radical assay, superoxide radical assay, and DPPH radical assay, its antioxidant activities were investigated. PBF3 had significant effect on scavenging hydroxyl radicals, an equivalent inhibiting ability to vitamin C on superoxide radical, and a little lower scavenging activity on DPPH radical than vitamin C, and should be explored as a novel potential antioxidant.     

Terpenoids and hexenes from the leaves of Crataegus pinnatifida

Crataegus pinnatifida have long been used in traditional Chinese medicine and European herbal medicine, and are widely consumed as food, in the form of juice, drink, jam and canned fruit. Four new compounds, a sesquiterpene and its glycoside (1–2), two monoterpene glycosides (3–4), together with eight known compounds (5–12), were isolated from the leaves of C. pinnatifida. Their structures were elucidated as (5Z)-6-[5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl]-3-methylhexa-1,5-dien-3-ol (1), (5Z)-6-[5-(2-O-β-d-glucopyranosyl-propan-2-yl)-2-methyl tetrahydrofuran-2-yl]-3-methylhexa-1,5-dien-3-ol (2), 5-ethenyl-2-[2-O-β-d-glucopyranosyl-(1″ → 6′)-β-d-glucopyranosyl-propan-2-yl]-5-methyltetrahydrofuran-2-ol (3), 4-[4β-O-β-d-xylopyranosyl-(1″ → 6′)-β-d-glucopyranosyl-2,6,6-trimethyl-1-cyclohexen-1-yl]-butan-2-one (4), (Z)-3-hexenyl O-β-d-glucopyranosyl-(1″ → 6′)-β-d-glucopyranoside (5), (Z)-3-hexenyl O-β-d-xylopyranosyl-(1″ → 6′)-β-d-glucopyranoside (6), (Z)-3-hexenyl O-β-d-rhamnopyranosyl-(1″ → 6′)-β-d-glucopyranoside (7), (3R,5S,6S,7E,9S)-megastiman-7-ene-3,5,6,9-tetrol (8), (3R,5S,6S,7E,9S)-megastigman-7-ene-3,5,6,9-tetrol9-O-β-d-glucopyranoside (9), (6S,7E,9R)-6,9-dihydroxy-4,7-megastigmadien-3-one 9-O-[β-d-xylopyranosyl-(1″ → 6′)-β-d-glucopyranoside] (10), Linarionoside C (11), and (3S,9R)-3,9-dihydroxy-megastigman-5-ene 3-O-primeveroside (12), using a combination of mass spectroscopy, 1D and 2D NMR spectroscopy and chemical analysis. Cytotoxicity of the new compounds was assayed against selected human glioma (U87) cell lines.     

Arabinose-Containing Oligosaccharides from Tamarind Xyloglucan

Oligosaccharide mixtures were obtained by enzymatic degradation of tamarind xyloglucan from the seeds of Tamarindus indica by commercial Aspergillus niger endo-(1→4)-β-D -glucanase, and their composition analyzed by HPAE-PAD liquid chromatography revealing two major groups of oligosaccharides. The first group contained oligomers of DP 7, 8 and 9, while the second group consisted of a large variety of oligomers of DP 12 to 18. After purification by SEC and HPLC in semi-preparative scale, single oligomers were characterized by glycosyl-residue composition, glycosyl-linkage analysis and plasma desorption mass spectrometry. Beside β-D -Glucosyl, β-D -galactosyl and α-D -xylosyl units, some higher oligomers contained β-D -galactosyl-(1→5)-α-L -arabinosyl units, linked to O-6 in the glucosyl units of the (1→4)-β-D -glucan backbone. Other L -arabinosyl residues were located in terminal positions of α-D -xylosyl side chains. The variety of isolated oligomers reflected a complicated random distribution of side chains in tamarind xyloglucan. Based on the characteristics of the oligomers, four structure forming units for the polysaccharide are proposed.