Cornel iridoid glycoside alleviates microglia-mediated inflammatory response via NLRP3/calpain pathway / 中国药理学与毒理学杂志

OBJECTIVE Vascular dementia(VaD)is associated with cerebral hypoperfusion,which results in long-term cognitive impairment and memory loss.Neuroin-flammation is an important mechanism of vascular demen-tia.Cornel iridoid glycoside(CIG)is the major active con-stituent isolated from the ripe fruit of Cornus officinalis.Previous studies have shown that CIG enhances neuro-logical function in VaD rats.In the present research,we attempted to clarify the molecular processes underlying the role of CIG on neuroinflammation in VaD.METHODS In vivo,we created a chronic cerebral ischemia rat model by ligation of the bilateral common carotid arteries(2VO).The rats were divided into sham operation,2VO,2VO + CIG(60 and120 mg·kg-1·d-1),and 2VO+ butylphthalide(100 mg·kg-1·d-1)groups and then treated rats with differ-ent concentrations of CIG.In vitro,BV2 microglia cells were induced with bacterial lipopolysaccharide(LPS)and interferon-γ(IFN-γ)to construct the model of microglias with analog neuroinflammation.Histopathology and biel-schowsky silver staining were used to detect myelin integrity and neuronal loss.Immunofluorescence was used to observe changes in microglia.Magnetic Luminex Assay was used to detect changes in inflammatory fac-tors.Western blotting,ELISA or calpain activity assay was used to measure the expression and activity of cal-pain,as well as the expression of NLRP3 inflammasome protein.Furthermore,NLRP3 overexpressing cells were used to further elucidate the potential anti-inflammatory molecular mechanism of CIG.RESULTS ① CIG improved neuronal impairment in the brain of 2VO rats.②CIG increased white matter(WM)integrity in 2VO rats.③ CIG reduced microglia inflammatory response in the cortex and hippocampus of 2VO rats.④ CIG inhibited calpain activity in the cortex and hippocampus of 2VO rats.⑤ CIG exerted anti-inflammatory effects on BV2 cells stimulated by LPS and IFN-γ.⑥ CIG Inhibited the expression and activity of calpain in LPS/IFN-γ-activated BV2 cells.⑦ The main component of CIG had a weak binding force to calpain1.⑧ CIG inhibited the activation of the NLRP3 inflammasome.⑨CIG reduced the activity of calpain induced by NLRP3 overexpression.CONCLU-SION CIG inhibits microglial polarization into a proinflam-matory state by attenuating the assembly of the NLRP3 inflammasome and calpain activation,thus reducing brain inflammation,WM injury,and the loss of neurons.To sum up,the present study suggests that CIG inhibits neuroinflammation.The NLRP3/calpain pathway may be the main pathway by which CIG protects against neuroin-flammation.

Isolation and identification of two new compounds from Semen Persicae / 药学学报

Five compounds were isolated from the ethyl acetate fraction of Semen Persicae by using various chromatographic methods, including ODS, Sephadex LH-20, HPLC and semipreparative HPLC. Their structures were identified by 1D-NMR, 2D-NMR, HR-ESI-MS, UV, IR, circular dichroism (CD) and ECD calculation techniques: (2R,3R)-5,7,4′-trihydroxy-3′-methoxy-3-formylflavan-3-ol-5-O-β-D-glucopyranoside (1), (7R,8S)-dihydrodehydrodiconiferyl 6″-benzoyl alcohol-9-O-β-D-glucopyranoside (2), (7R,8S)-dihydrodehydrodiconiferyl alcohol-9-β-O-D-glucopyranosid (3), 2-methoxy-4-(2-propenyl)-phenyl-O-β-D-glucopyranoside (4), 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-propane-1,3-diol (5). Compound 1 and 2 are new compounds, and compounds 3-5 were obtained from Prunus davidiana (Carr.) Franch. for the first time.

Structural mechanism of a dual-functional enzyme DgpA/B/C as both a C-glycoside cleaving enzyme and an O- to C-glycoside isomerase

The C-glycosidic bond that connects the sugar moiety with aglycone is difficult to be broken or made due to its inert nature. The knowledge of C-glycoside breakdown and synthesis is very limited. Recently, the enzyme DgpA/B/C cascade from a human intestinal bacterium PUE was identified to specifically cleave the C-glycosidic bond of puerarin (daidzein-8-C-glucoside). Here we investigated how puerarin is recognized and oxidized by DgpA based on crystal structures of DgpA with or without substrate and biochemical characterization. More strikingly, we found that apart from being a C-glycoside cleaving enzyme, DgpA/B/C is capable of efficiently converting O- to C-glycoside showing the activity as a structure isomerase. A possible mechanistic model was proposed dependently of the simulated complex structure of DgpB/C with 3″-oxo-daidzin and structure-based mutagenesis. Our findings not only shed light on understanding the enzyme-mediated C-glycosidic bond breakage and formation, but also may help to facilitate stereospecific C-glycoside synthesis in pharmaceutical industry.

A new elemane-type sesquiterpenoid glycoside from Curcuma phaeocaulis / 药学学报

To study the chemical constituents and their biological activities in the rhizomes of Curcuma phaeocaulis, silica gel column chromatography, reverse medium pressure liquid chromatography, preparative thin layer chromatography, and semi-preparative high performance liquid chromatography were used for isolation and purification and modern spectroscopic methods were used to determine the structure of the isolated compound. Moreover, the effect of the compound on the proliferation of HUVECs was determined by the MTT assay. A new elemane-type sesquiterpenoid glycoside was isolated from the n-butanol soluble fraction of 95% ethanolic extract of the rhizomes of Curcuma phaeocaulis. Its structure was identified as (1Z)-2-hydroxy-curzerenone 2-O-β-D-glucoside. It showed no inhibitory effect on the proliferation of HUVECs.

A new ester glycoside compound from Cyclocarya paliurus / 中国药科大学学报

@#Chemical constituents of n-butanol part of ethanol extract from the leaves of Cyclocarya paliurus (Batalin) Iljinskaja were studied.Eight glycosides were separated and purified by silica gel, MCI, ODS, Sephadex LH-20 column chromatography and semi-preparative high-performance liquid chromatography.Based on the physicochemical properties and spectral data, these compounds were 3-ethyl-4-methyl-pentyl ester-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (1), juglanoside E (2), (4S)-α-terpineol-8-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside (3), (4S)-α-terpineol-8-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (4), eugenyl-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside (5), kaempferol-3-O-β-D-glucuronopyranosyl methylester (6), kaempferol-3-O-β-D-glucuronopyranoside (7), and quercetin-3-O-β-D-glucuronopyranoside (8).Among them, compound 1 was a new compound, and compounds 2-6 were isolated from the genus Cyclocarya for the first time.

Prospective insight into the role of benzyl propylene glycoside as a modulator of the cGAS-STING signaling pathway in the management of nonalcoholic fatty pancreas animal model

BACKGROUND: Nonalcoholic fatty pancreatitis (NAFP) is one of the metabolic syndrome manifestations that need further studies to determine its molecular determinants and find effective medications. We aimed to investigate the potential effect of benzyl propylene glycoside on NAFP management via targeting the pancreatic cGAS-STING pathway-related genes (DDX58, NFκB1 & CHUK) and their upstream regulator miRNA (miR-1976) that were retrieved from bioinformatics analysis. METHODS: The rats were fed either normal chow or a high-fat high-sucrose diet (HFHS), as a nutritional model for NAFP. After 8 weeks, the HFHS-fed rats were subdivided randomly into 4 groups; untreated HFHS group (NAFP model group) and three treated groups which received 3 doses of benzyl propylene glycoside (10, 20, and 30 mg/kg) daily for 4 weeks, parallel with HFHS feeding. RESULTS: The molecular analysis revealed that benzyl propylene glycoside could modulate the expression of the pancreatic cGAS-STING pathway-related through the downregulation of the expression of DDX58, NFκB1, and CHUK mRNAs and upregulation of miR-1976 expression. Moreover, the applied treatment reversed insulin resistance, inflammation, and fibrosis observed in the untreated NAFP group, as evidenced by improved lipid panel, decreased body weight and the serum level of lipase and amylase, reduced protein levels of NFκB1 and caspase-3 with a significant reduction in area % of collagen fibers in the pancreatic sections of treated animals. CONCLUSION: benzyl propylene glycoside showed a potential ability to attenuate NAFP development, inhibit pancreatic inflammation and fibrosis and reduce the pathological and metabolic disturbances monitored in the applied NAFP animal model. The detected effect was correlated with modulation of the expression of pancreatic (DDX58, NFκB1, and CHUK mRNAs and miR-1976) panel.

A new flavonoid glycoside from Epimedium sagittatum / 药学学报

Fourteen flavonoids were isolated and purified from Epimedium sagittatum by various chromatography techniques such as macroporous adsorbent resin, silica gel, ODS, Sephadex LH-20, HW-40C and semi-preparative HPLC. Their structures were identified by analysis of physicochemical properties and spectral data, and determined as 3′-hydroxy-baohuoside-Ⅱ (1), huazhongilexone-7-O-β-D-glucopyranoside (2), kaempferol-3-O-α-L-rhamnoside (3), baohuoside-Ⅱ (4), icariside-Ⅱ (5), kaempferol 3,7-di-O-α-L-rhamnopyranoside (6), (+)-aromadendrin (7), kaempferol 3-O-(2-O-β-D-apiofuranosyl)-α-L-rhamnopyranoside (8), sagittatoside A (9), 2″-O-rhamnosyl icariside-II (10), apigenin-7-O-β-D-glucoside (11), quercetin 3-O-β-D-apiofuranoyl-(1→2)-α-L-rhamnopyranoside (12), kaempferol (13), icariin (14). Among them, compound 1 is a new compound, while compounds 2, 6-8, 11, and 12 were isolated from E.sagittatum for the first time.

One new glycoside naphthopyranone from the Yiling cave-derived Metarhizium anisopliae NHC-M3-2 / 药学学报

Seven compounds were isolated from fermentation extract of cave-derived Metarhizium anisopliae NHC-M3-2 by silica gel, semi-preparative HPLC and other chromatographic methods. Their structures were elucidated by UV, IR, MS and NMR methods as 2,3-dehydroindigotide G (1), (-)-regiolone (2), naphtho-γ-pyrone (3), indigotide G (4), indigotide B (5) destruxin A (6) and destruxin B (7). Compound 1 is a new glycoside naphthopyranone compound. The anti-hepatitis B virus (HBV) activity of these compounds was evaluated. The EC50 and CC50 of compound 3 against HBV were 4.5 μmol·L-1 and 92.3 μmol·L-1, respectively. This is the first report of the antiviral activity of compound 3.

New anti-pulmonary fibrosis prenylflavonoid glycosides from Epimedium koreanum / 中国天然药物

Four new prenylflavonoid glycosides, namely koreanoside H-K (1-4), together with eleven known ones (5-15) were isolated from the leaves of Epimedium koreanum Nakai. Their structures were elucidated by 1D NMR, 2D NMR, HR-ESI-MS, IR and UV. The identification of the sugar moieties was carried out by means of acid hydrolysis and HPLC analysis of their derivatives. It is worth noting that compound 3 and compound 4 were elucidated to contain fucose and quinovose moieties, which were two extremely rare sugar units from the genus Epimedium. The anti-pulmonary fibrosis activity of the new compounds was evaluated using A549 cell line. Compounds 1, 2 and 4 showed significant anti-pulmonary fibrosis activities.

A new flavone glycoside from Eriocaulon buergerianum / 药学学报

Ten compounds were isolated from the water extract of Eriocaulon buergerianum by HP20, ODS, Sephadex LH-20 and MCI Gel CHP-20 column chromatographic methods. Their structures were identified by spectroscopic and chemical approaches as 6-methoxyquercetin-3-O-(2′′′-vanilloyl)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (1), syringaresinol-4′-O-β-D-glucopyranoside (2), rutin (3), 1-O-feruloylglycerol (4), 1,2-benzenediol (5), vomifoliol (6), β-D-(6-O-trans-feruloyl) fructofuranosyl-α-D-O-glucopyranosied (7), dihydroferulic acid (8), guanosine (9) and quercetin-3-O-β-gentiobioside (10). The compound 1 is a new compound, the compounds 2 and 4-10 were obtained from Eriocaulon genus for the first time, and the compound 3 was isolated from this plant for the first time. Molecular docking study showed that 1 is a potential inhibitor of TNF-α. The compound 1 was evaluated for their anti-inflammatory activities in vitro, and 1 showed significant inhibitory activity against TNF-α production in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells at the concentrations of 1, 10 and 100 μmol·L-1.

Study on the separation and identification of flavone C-glycosides from the leaves of Dendrobium officinale and their inhibitory activities to α-gulcosidase / 中国药房

OBJECTIVE To separ ate and identify the flavone C-glycosides from the leaves of Dendrobium officinale ，and to evaluate their in vitro inhibitory activities to α-glucosidase. METHODS The flavone C-glycosides from the leaves of D. officinale were separated and purified by macroporous adsorption resin and preparative high -performance liquid chromatography . The structure of obtained compound was elucidated and identified by spectroscopic methods ，such as ultraviolet spectrum ，nuclear magnetic resonance，high-resolution electrospray ionization mass spectrometry ，etc. The in vitro inhibitory activities of flavone C-glycosides and positive control （acarbose）to α-glucosidase were investigated . RESULTS Five apigenin -6，8-di-C-glycosides were isolated and purified from the leaves of D. officinale，and identified as apigenin -6-C-α-L-rhamnosyl-8-C-β-D-quinovoside（1）， schaftoside（2），isoschaftoside（3），isoviolanthin（4）and violanthin （5）. Half inhibitory concentration of compound 1-5 and acarbose inhibiting α-glucosidase were （1.79±1.27），（2.05±0.72），（1.93±0.67），（1.09±0.46），（1.36±0.58），（18.69±1.24）μmol/L， respectively. CONCLUSIONS Five apigenin -6，8-di-C-glycosides with α-glucosidase inhibitory activity are isolated from the leaves of D. officinale，of which compound 1 is a new compound and compound 2 is isolated from this plant for the first time .

Analysis of flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim based on UHPLC-LTQ-orbitrap-MS / 药学学报

Ultra high performance liquid chromatography tandem linear ion trap orbitrap mass spectrometry (UHPLC-LTQ-orbitrap-MS) was applied to analyze and identify flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim. A method of data-dependent scan coupling with dynamic exclusion was developed for analyzing flavonoids and phenylethanoid glycosides under positive and negative ion mode of electrospray ionization (ESI). The compounds of Lagotis brevituba Maxim. were systematically identified through exact molecular mass, fragmentation patterns, retention time and reported references. A total of 167 compounds were detected, of which 84 were flavonoids and 83 were phenylethanoid glycosides, which greatly enriched the number and types of flavonoids and phenylethanol glycosides in Lagotis genus medicinal plants. Baohuoside Ⅰ, 4 disaccharide O-glycoside flavonoids (composed of deoxyhexose and glucuronic acid), 9 C-glycoside flavonoids, 15 tetrasaccharide phenylethanoid glycosides and 5 phenylethanoid glycosides with substituents on the β-position of the phenylethyl group were identified in Lagotis genus medicinal plants for the first time. This study provides scientific support for elucidating the material basis and improving the quality control of Lagotis brevituba Maxim.

Research progress on the biotransformation of flavonoid glycosides in Epimedii Folium / 中国药房

Flavonoid glycosides are the main active constituents of Epimedii Folium and its related plants. They can be divided into polyglycosides and low glycosides according to the number of glycosyl group. The polyglycosides of Epimedii Folium can be transformed into low glycosides after biotransformation ；pharmacological activities of low glycosides in anti-tumor ，tonifying kidney yang and anti-osteoporosis are stronger than those of polyglycosides. In this paper ， the research progress about biotransformation technology of flavonoid glycosides of Epimedii Folium was reviewed. It was found that the main biotransformation pathway of flavonoid glycosides of Epimedii Folium was to obtain low glycosides by removing glycosyl group ； related methods were mainly enzymatic hydrolysis and microbial transformation ，and also included plant cell transformation ，acid hydrolysis method and synthesis method.

Full-length transcriptome sequence and identification of genes involved in phenylethanol glycoside biosynthesis in Rehmannia glutinosa / 药学学报

italic>Rehmannia glutinosa belongs to the Scrophulariaceae family with important medicinal value. In order to effectively explore the transcriptome information of R. glutinosa and identify the genes encoding enzymes involved in phenylethanol glycoside (PhGs) biosynthesis, the leaves, stems and tuberous roots of R. glutinosa were used for transcriptome sequencing using Pacific Biosiences RS II platform. A total of 27 773 transcripts were generated with an average length of 2 380 bp, and 27 236 coding sequences (CDS) were predicted. Using BLAST software, non-redundant transcript sequences were annotated with NR, NT, GO, COG, KEGG, SwissProt and Interpro databases and a total of 27 399 annotated genes were obtained. Among them, the number of genes related to Sesamum indicum in the NR database was the highest (81.44%), which is consistent with their evolutionary relationship. Enzymes likely involved in the biosynthesis of isoacteoside, echinacoside, cistanosides A, cistanosides F, 2′-acetylacteoside and leonoside F were identified, and 143 genes were identified in R. glutinosa full-length transcriptome. The expression levels of 19 genes correlated with acteoside content in twelve tissues of R. glutinosa, and most showed higher expression levels in leaf tissues and floral organs. This study provides more reliable transcriptome data for screening R. glutinosa for functional genes and provides a foundation for the study of the molecular mechanisms of PhGs biosynthesis.

Identification of α-L-fucosidase (ALFuc) of Blastocystis sp. subtypes ST1, ST2 and ST3

ABSTRACT Blastocystis sp. is a common intestinal microorganism. The α-L-fucosidase (ALFuc) is an enzyme long associated with the colonization of the gut microbiota. However, this enzyme has not been experimentally identified in Blastocystis cultures. The objective of the present study was to identify ALFuc in supernatants of axenic cultures of Blastocystis subtype (ST)1 ATCC-50177 and ATCC-50610 and to compare predicted ALFuc proteins of alfuc genes in sequenced STs1-3 isolates in human Blastocystis carriers. Excretion/secretion (Es/p) and cell lysate proteins were obtained by processing Blastocystis ATCC cultures and submitting them to SDS-PAGE and immunoblotting. In addition, 18 fecal samples from symptomatic Blastocystis human carriers were analyzed by sequencing of amplification products for subtyping. A complete identification of the alfuc gene and phylogenetic analysis were performed. Immunoblotting showed that the amplified band corresponding to ALFuc (~51 kDa) was recognized only in the ES/p. Furthermore, prediction analysis of ALFuc 3D structures revealed that the domain α-L-fucosidase and the GH29 family's catalytic sites were conserved; interestingly, the galactose-binding domain was recognized only in ST1 and ST2. The phylogenetic inferences of ALFuc showed that STs1-3 were clearly identifiable and grouped into specific clusters. Our results show, for the first time through experimental data that ALFuc is a secretion product of Blastocystis sp., which could have a relevant role during intestinal colonization; however, further studies are required to clarify this condition. Furthermore, the alfuc gene is a promising candidate for a phylogenetic marker, as it shows a conserved classification with the SSU-rDNA gene.

Chemical constituents from fruits of Cornus officinalis and their anti-Alzheimer's disease activity / 药学学报

Fifteen compounds were isolated from fruits of Cornus officinalis by various chromatographic techniques such as Toyopearl HW-40C, Sephadex LH-20, silica gel, and the semi-preparative HPLC. Their chemical structures were identified by analysis of physicochemical properties and spectral data, and determined as neolignan A (1), caffeic acid (2), trans-p-hydroxy cinnamic acid (3), esculetin (4), scopoletin (5), benzyl-7-O-β-D-glucopyranoside (6), tachioside (7), 6-O-(4-hydroxybenzoyl) arbutin (8), 2-(3′,4′-dihydroxyphenyl)-1,3-benzodioxole-5-carboxaldehyde (9), (-)-pinoresinol-4-O-β-D-glucopyranoside (10), (7S,8R)-dihydrodehydrodiconiferyl alcohol-9-O-β-D-glucopyranoside (11), (7S,8R)-dihydrodehydrodiconiferyl alcohol-9′-O-β-D-glucopyranoside (12), (+)-lyoniresinol (13), (+)-isolariciresinol-9-O-β-D-glucopyranoside (14), and isolariciresinol-9′-O-β-D-glucopyranoside (15). Compound 1 was a new compound and named as neolignan A, and compounds 6-9 and 14 were isolated from Cornus officinalis for the first time. Compounds 2, 3 and 15 efficiently alleviated the PC12 cells injury induced by Aβ25-35, suggesting their potential anti-Alzheimer's disease activity.

Integrating systematic pharmacology-based strategy and experimental validation to explore mechanism of Tripterygium glycoside on cholangiocyte-related liver injury / 中草药·英文版

Objective: Tripterygium glycoside (TG) is widely used in clinical practice for its multiple bioactivities including anti-inflammatory and immunosuppressive effects. However, emerging studies have frequently reported TG-induced adverse reactions to multiple organs, especially liver. Here, this study aimed to investigate the mechanism of liver damage induced by TG and explore representative components to reflect TG hepatotoxicity. Methods: Network pharmacology was used to determine the potential targets of bile duct injury caused by TG. Next, the hepatotoxic effects of TG, triptolide (TP) and celastrol (CEL) were investigated and compared in vivo and in vitro. Liver function was determined by measuring serum transaminase and histopathology staining. The cell proliferation and apoptosis were determined by cell viability assay, scratch assay and flow cytometry. The expression of gene of interest was determined by qPCR and Western blot. Results: Based on the network pharmacological analysis of 12 bioactive ingredients found in TG, a total of 35 targets and 15 pathways related to bile duct injury were obtained. Both TG and TP resulted in cholangiocyte damage and liver injury, as illustrated by increased levels of serum transaminase and oxidative stress, stimulated portal edema and lymphocytic infiltration and decreased expression of cholangiocyte marker, cytoskeletal 19. In addition, TG and TP inhibited cell proliferation and migration, arrested cell cycle and promoted Caspase-dependent apoptosis of cholangiocytes via suppressing the phosphorylation of extracellular regulated protein kinases 1/2 (ERK1/2) and protein kinase B (AKT). While, CEL at equivalent dosage had no obvious hepatotoxicity. Conclusion: We revealed that TG-stimulated liver injury was specifically characterized by cholangiocyte damage and TP might be the decisive ingredient to reflect TG hepatotoxicity. Our results not only provide novel insights into the mechanism underlying the hepatotoxicity effects of TG but also offer reference for clinical rational use of TG.

LXYL-P1-2 immobilized on magnetic nanoparticles and its potential application in paclitaxel production

BACKGROUND: LXYL-P1-2 is the first reported glycoside hydrolase that can catalyze the transformation of 7-b-xylosyl-10-deacetyltaxol (XDT) to 10-deacetyltaxol (DT) by removing the D-xylosyl group at the C7 position. Successful synthesis of paclitaxel by one-pot method combining the LXYL-P1-2 and 10- deacetylbaccatin III-10-b-O-acetyltransferase (DBAT) using XDT as a precursor, making LXYL-P1-2 a highly promising enzyme for the industrial production of paclitaxel. The aim of this study was to investigate the catalytic potential of LXYL-P1-2 stabilized on magnetic nanoparticles, the surface of which was modified by Ni2+-immobilized cross-linked Fe3O4@Histidine. RESULTS: The diameter of matrix was 20­40 nm. The Km value of the immobilized LXYL-P1-2 catalyzing XDT (0.145 mM) was lower than that of the free enzyme (0.452 mM), and the kcat/Km value of immobilized enzyme (12.952 mM s 1 ) was higher than the free form (8.622 mM s 1 ). The immobilized form maintained 50% of its original activity after 15 cycles of reuse. In addition, the stability of immobilized LXYL-P1-2, maintained 84.67% of its initial activity, improved in comparison with free form after 30 d storage at 4 C. CONCLUSIONS: This investigation not only provides an effective procedure for biocatalytic production of DT, but also gives an insight into the application of magnetic material immobilization technology.

Enzymatic preparation of manno-oligosaccharides from locust bean gum and palm kernel cake, and investigations into its prebiotic activity

BACKGROUND: Manno-oligosaccharides (MOS) is known as a kind of prebiotics. Mannanase plays a key role for the degradation of mannan to produce MOS. In this study, the mannanases of glycoside hydrolase (GH) families 5 Man5HJ14 and GH26 ManAJB13 were employed to prepare MOS from locust bean gum (LBG) and palm kernel cake (PKC). The prebiotic activity and utilization of MOS were assessed in vitro using the probiotic Lactobacillus plantarum strain. RESULTS: Galactomannan from LBG was converted to MOS ranging in size from mannose up to mannoheptose by Man5HJ14 and ManAJB13. Mannoheptose was got from the hydrolysates produced by Man5HJ14, which mannohexaose was obtained from LBG hydrolyzed by ManAJB13. However, the same components of MOS ranging in size from mannose up to mannotetrose were observed between PKC hydrolyzed by the mannanases mentioned above. MOS stability was not affected by high-temperature and high-pressure condition at their natural pH. Based on in vitro growth study, all MOS from LBG and PKC was effective in promoting the growth of L. plantarum CICC 24202, with the strain preferring to use mannose to mannotriose, rather than above mannotetrose. CONCLUSIONS: The effect of mannanases and mannan difference on MOS composition was studied. All of MOS hydrolysates showed the stability in adversity condition and prebiotic activity of L. plantarum, which would have potential application in the biotechnological applications.

Application of immobilized glycosidase in the synthesis of glycoside compounds / 生物工程学报

Glycoside compounds are widely used in medicine, food, surfactant, and cosmetics. The glycosidase-catalyzed synthesis of glycoside can be operated at mild reaction conditions with low material cost. The glycosidase-catalyzed processes include reverse hydrolysis and transglycosylation, appropriately reducing the water activity in both processes may effectively improve the catalytic efficiency of glucosidase. However, glucosidase is prone to be deactivated at low water activity. Thus, glucosidase was immobilized to maintain its activity in the low water activity environment, and even in neat organic solvent system. This article summarizes the advances in glycosidase immobilization in the past 30 years, including single or comprehensive immobilization techniques, and immobilization techniques combined with genetic engineering, with the aim to provide a reference for the synthesis of glycosides using immobilized glycosidases.