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Hiroshi Saito - One of the best experts on this subject based on the ideXlab platform.
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effects of saffron extract and its constituent crocin on learning behaviour and long term potentiation
Phytotherapy Research, 2000Co-Authors: Hiroshi SaitoAbstract:Crocus sativus L., commonly known as saffron, is used in folk medicine for various purposes. Modern pharmacological studies have demonstrated that saffron extracts have antitumour effects, radical scavenger properties or hypolipaemic effects. Among the constituents of saffron extract, crocetin is mainly responsible for these pharmacological activities. In addition, recent behavioural and electrophysiological studies have demonstrated that saffron extract affects learning and memory in experimental animals. Saffron extract improved ethanol-induced impairments of learning behaviours in mice, and prevented ethanol-induced inhibition of hippocampal long-term potentiation, a form of activity-dependent synaptic plasticity that may underly learning and memory. This effect of saffron extract is attributed to crocin (crocetin di-Gentiobiose ester), but not crocetin. Saffron extract or its active constituents, crocetin and crocin, could be useful as a treatment for neurodegenerative disorders accompanying memory impairment. Copyright © 2000 John Wiley & Sons, Ltd.
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effects of saffron extract and its constituent crocin on learning behaviour and long term potentiation
Phytotherapy Research, 2000Co-Authors: Kazuho Abe, Hiroshi SaitoAbstract:Crocus sativus L., commonly known as saffron, is used in folk medicine for various purposes. Modern pharmacological studies have demonstrated that saffron extracts have antitumour effects, radical scavenger properties or hypolipaemic effects. Among the constituents of saffron extract, crocetin is mainly responsible for these pharmacological activities. In addition, recent behavioural and electrophysiological studies have demonstrated that saffron extract affects learning and memory in experimental animals. Saffron extract improved ethanol-induced impairments of learning behaviours in mice, and prevented ethanol-induced inhibition of hippocampal long-term potentiation, a form of activity-dependent synaptic plasticity that may underly learning and memory. This effect of saffron extract is attributed to crocin (crocetin di-Gentiobiose ester), but not crocetin. Saffron extract or its active constituents, crocetin and crocin, could be useful as a treatment for neurodegenerative disorders accompanying memory impairment.
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crocin and crocetin derivatives inhibit skin tumour promotion in mice
Phytotherapy Research, 1998Co-Authors: Takao Konoshima, Hiroshi Saito, Midori Takasaki, Harukuni Tokuda, Satoshi Morimoto, Hiroyuki Tanaka, E Kawata, Li Jiang Xuan, Minoru Sugiura, Jozsef MolnarAbstract:The addition of 100 μg/mL of a 50% EtOH extract of Crocus sativus (ECS) exhibited significant inhibitory effects on EBV-EA activation and preserved the high viability of Raji cells. The attenuating effect of ECS was dose-dependent. The oral administration of ECS demonstrated an inhibitory effect on two-stage carcinogenesis of mouse skin papillomas, using DMBA as an initiator and TPA as a promoter. Crocetin Gentiobiose glucose ester and crocetin di-glucose ester were less potent than crocin in inhibiting the EBV-EA induction effect. When crocin was applied before each TPA treatment, it delayed the formation of papillomas; only about 10% of mice bore papillomas at 9 weeks of promotion and after 13 weeks of promotion 20% of mice still bore no papilloma. The effect of crocin was not mimicked by Gentiobiose or glucose alone. © 1998 John Wiley & Sons, Ltd.
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crocin crocetin di Gentiobiose ester prevents the inhibitory effect of ethanol on long term potentiation in the dentate gyrus in vivo
Journal of Pharmacology and Experimental Therapeutics, 1994Co-Authors: M Sugiura, Hiroshi Saito, Y Shoyama, Kazuho AbeAbstract:The effects of crocin (crocetin di-Gentiobiose ester) and its analogs on long-term potentiation (LTP) of evoked potential in the dentate gyrus were investigated by using anesthetized rats. Intracerebroventricular injection of crocin (51.2 nmol) alone did not affect the synaptic potential evoked by single stimulation of the medial perforant path, and neither inhibited nor facilitated the LTP induced by strong (30 pulses at 60 Hz) or weak (20 pulses at 60 Hz) tetanus. Administration of ethanol (30 v/v%, 2 ml/kg i.v.) blocked the LTP induced by application of tetanus (30 pulses at 60 Hz), but the LTP-blocking effect of ethanol was prevented by preadministration of crocin (51.2 nmol i.c.v.). Crocetin Gentiobiose glucose ester also antagonized the LTP-blocking effect of ethanol, but it required a higher dose (102.5 nmol i.c.v.) to exhibit a more significant effect than crocin. Crocetin di-glucose ester at a dose up to 102.5 nmol (i.c.v.) did not significantly affect the LTP-blocking effect of ethanol. Neither Gentiobiose alone (102.5 nmol i.c.v.) nor glucose alone (204.9 nmol i.c.v.) mimicked the activity of crocin. These results suggest that crocin can prevent the ethanol-induced impairment of hippocampal synaptic plasticity in vivo and that Gentiobioses attached to the fatty acid chain are important for crocin to exert the biological activity.
Javad Aghamohammadian - One of the best experts on this subject based on the ideXlab platform.
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extraction of crocin from saffron crocus sativus using molecularly imprinted polymer solid phase extraction
Journal of Separation Science, 2010Co-Authors: Seyed Ahmad Mohajeri, Fariborz Keyhanfar, Hossein Hosseinzadeh, Javad AghamohammadianAbstract:A new molecularly imprinted polymer for extraction of crocin from saffron stigmas was prepared using Gentiobiose (a glycoside moiety in crocin structure) as a template. Crocin binding to Gentiobiose imprinted polymer (Gent-MIP) was studied in comparison with a blank nonimprinted polymer in aqueous media. Affinity of the Gent-MIP for the crocin was more than the nonimprinted polymer at all concentrations. In Scatchard analysis, the number of binding sites in each gram of polymer (maximum binding sites) and dissociation constant of crocin to binding sites were 18.4 μmol/g polymer and 11.2 μM, respectively. The Gent-MIP was then used as the sorbent in an SPE method for isolation and purification of crocin from methanolic extract of saffron stigmas. The recovery of crocin, safranal and picrocrocin was determined in washing and elution steps. The Gent-MIP had significantly higher affinity for crocin than other compounds and enabled selective extraction of crocin with a high recovery (84%) from a complex mixture. The results demonstrated the possibility of using a part of a big molecule in preparing a molecularly imprinted polymer with a good selectivity for the main structure.
Seyed Ahmad Mohajeri - One of the best experts on this subject based on the ideXlab platform.
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extraction of crocin from saffron crocus sativus using molecularly imprinted polymer solid phase extraction
Journal of Separation Science, 2010Co-Authors: Seyed Ahmad Mohajeri, Fariborz Keyhanfar, Hossein Hosseinzadeh, Javad AghamohammadianAbstract:A new molecularly imprinted polymer for extraction of crocin from saffron stigmas was prepared using Gentiobiose (a glycoside moiety in crocin structure) as a template. Crocin binding to Gentiobiose imprinted polymer (Gent-MIP) was studied in comparison with a blank nonimprinted polymer in aqueous media. Affinity of the Gent-MIP for the crocin was more than the nonimprinted polymer at all concentrations. In Scatchard analysis, the number of binding sites in each gram of polymer (maximum binding sites) and dissociation constant of crocin to binding sites were 18.4 μmol/g polymer and 11.2 μM, respectively. The Gent-MIP was then used as the sorbent in an SPE method for isolation and purification of crocin from methanolic extract of saffron stigmas. The recovery of crocin, safranal and picrocrocin was determined in washing and elution steps. The Gent-MIP had significantly higher affinity for crocin than other compounds and enabled selective extraction of crocin with a high recovery (84%) from a complex mixture. The results demonstrated the possibility of using a part of a big molecule in preparing a molecularly imprinted polymer with a good selectivity for the main structure.
Arun Goyal - One of the best experts on this subject based on the ideXlab platform.
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gentio oligosaccharides from leuconostoc mesenteroides nrrl b 1426 dextransucrase as prebiotics and as a supplement for functional foods with anti cancer properties
Food & Function, 2015Co-Authors: Damini Kothari, Arun GoyalAbstract:Gentio-oligosaccharides (GnOS) were synthesized by the acceptor reaction of dextransucrase from Leuconostoc mesenteroides NRRL B-1426 with Gentiobiose and sucrose. GnOS were purified by gel permeation chromatography using a Bio-Gel P-2 column and identified by mass spectrometry. The purified GnOS (degree of polymerization ≥3) were investigated for their in vitro prebiotic and cytotoxic activity. GnOS exhibited a significantly lower degree of digestibility of 18.1% by simulated human gastric juice (pH 1.0) and 7.1% by human α-amylase (pH 7.0) after 6 h, whereas inulin, a standard prebiotic, showed 39.7% and 12.8% of digestibility, respectively. The prebiotic score showed that GnOS significantly supported the growth of probiotics such as Bifidobacterium infantis and Lactobacillus acidophilus and was comparable to that of inulin. The selective inhibitory effect of GnOS on human colon carcinoma (HT-29) cells revealed its potential as an anti-cancer agent that can serve as a functional food additive for the benefit of human health.
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structural characterization of enzymatically synthesized dextran and oligosaccharides from leuconostoc mesenteroides nrrl b 1426 dextransucrase
Biochemistry, 2013Co-Authors: Damini Kothari, Arun GoyalAbstract:Leuconostoc mesenteroides NRRL B-1426 dextransucrase synthesized a high molecular mass dextran (>2 × 10(6) Da) with ~85.5% α-(1→6) linear and ~14.5% α-(1→3) branched linkages. This high molecular mass dextran containing branched α-(1→3) linkages can be readily hydrolyzed for the production of enzyme-resistant isomalto-oligosaccharides. The acceptor specificity of dextransucrase for the transglycosylation reaction was studied using sixteen different acceptors. Among the sixteen acceptors used, isomaltose was found to be the best, having 89% efficiency followed by Gentiobiose (64%), glucose (30%), cellobiose (25%), lactose (22.5%), melibiose (17%), and trehalose (2.3%) with reference to maltose, a known best acceptor. The β-linked disaccharide, Gentiobiose, showed significant efficiency for oligosaccharide production that can be used as a potential prebiotic.
Sheng Yuan - One of the best experts on this subject based on the ideXlab platform.
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a novel endo β 1 6 glucanase from the mushroom coprinopsis cinerea and its application in studying of cross linking of β 1 6 glucan and the wall extensibility in stipe cell walls
International Journal of Biological Macromolecules, 2020Co-Authors: Xiao Liu, Rui Wang, Liqin Kang, Jiangsheng Zhou, Baiyun Duan, Zhonghua Liu, Sheng YuanAbstract:Abstract We previously reported that chitinases reconstituted heat-inactivated stipe cell wall extension in a steady and continuous extension profile by cleaving chitins cross-linked to various polysaccahrides, whereas, endo-β-1,3-glucanases reconstituted heat-inactivated stipe wall extension in a profile of an initially fast extension and subsequent termination of extension due to its degradation of β-1,3-glucan but not other polysaccharides such as β-1,6-glucans cross-linked to chitins. Thus, a novel endo-β-1,6-glucanase, GH30A, from Coprinopsis cinerea was cloned and characterized to study cross-linking of β-1,6-glucan and wall extensibility in stipe walls. GH30A had higher activity and better thermophilicity than reported β-1,6-glucanases. GH30A hydrolyzed pustulan having β-1,6-linkages but not other polysaccharides without β-1,6-linkages; GH30A did not cleave Gentiobiose and single β-1,6-linkage branches in laminarin from Laminaria digitata but cut consecutive β-1,6-linkage branches in laminarin from Eisenia bicyclis. GH30A reconstituted heated-inactivated stipe cell wall extension with release of glucose and Gentiobiose, indicating that β-1,6-glucans were present and cross-linked to chitins in stipe walls, and cleaving β-1,6-glucans cross-linked to chitins by GH30A led to wall loosening for extension. However, GH30A individually or in combination with endo-β-1,3-glucanase reconstituted-stipe wall extension profile was similar to individual endo-β-1,3-glucanase's, exploring that chitins were also cross-linked to other polysaccharides besides β-1,3-glucans and β-1,6-glucans.
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β glucosidase bgl1 from coprinopsis cinerea exhibits a distinctive hydrolysis and transglycosylation activity for application in the production of 3 o β d gentiobiosyl d laminarioligosaccharides
Journal of Agricultural and Food Chemistry, 2019Co-Authors: Liqin Kang, Rui Wang, Zhonghua Liu, Xingwei Zhang, Cuicui Liu, Zhenqing Zhang, Sheng YuanAbstract:We previously reported that β-glucosidase BGL1 at low concentration (15 μg mL-1) from Coprinopsis cinerea exhibited hydrolytic activity only toward laminarioligosaccharides but not toward cellooligosaccharides and Gentiobiose. This study shows that BGL1 at high concentration (200 μg mL-1) also hydrolyzed cellobiose and Gentiobiose, which accounted for only 0.83 and 2.05% of its activity toward laminaribiose, respectively. Interestingly, BGL1 at low concentration (1.5 μg mL-1) showed transglycosylation but BGL1 at high concentration (200 μg mL-1) did not. BGL1 utilizes only laminarioligosaccharides but not glucose, Gentiobiose, and cellobiose to synthesize the higher oligosaccharides. BGL1 transferred one glucosyl residue from substrate laminarioligosaccharide to another laminarioligosaccharide as an acceptor in a β(1 → 3) or β(1 → 6) fashion to produce higher laminarioligosaccharides or 3-O-β-d-gentiobiosyl-d-laminarioligosaccharides. The BGL1-digested laminaritriose exhibited approximately 90% enhancement in the anti-oxidant activity compared to that of untreated laminaritriose, implying a potential application of BGL1-based transglycosylation for the production of high value-added rare oligosaccharides.
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purification characterization and synergism in autolysis of a group of 1 3 β glucan hydrolases from the pilei of coprinopsis cinerea fruiting bodies
Microbiology, 2015Co-Authors: Yajun Zhou, Zhonghua Liu, Wenming Zhang, Jun Wang, Sheng YuanAbstract:Using a combined chromatography method, we simultaneously purified three protein fractions (II-2, II-3 and II-4) with 1,3-β-glucanase activity from extraction of pilei of Coprinopsis cinerea fruiting bodies. MALDI-TOF/TOF amino acid sequencing showed that these three fractions matched a putative exo-1,3-β-glucanase, a putative glucan 1,3-β-glucosidase and a putative glycosyl hydrolase family 16 protein annotated in the C. cinerea genome, respectively; however, they were characterized as a 1,3-β-glucosidase, an exo-1,3-β-glucanase and an endo-1,3-β-glucanase, respectively, by analysis of their substrate specificities and modes of action. This study explored how these three 1,3-β-glucoside hydrolases synergistically acted on laminarin: the endo-1,3-β-glucanase hydrolysed internal glycosidic bonds of laminarin to generate 1,3-β-oligosaccharides of various lengths, the exo-1,3-β-glucanase cleaved the longer-chain laminarioligosaccharides into short-chain disaccharides, laminaribiose and Gentiobiose, and the 1,3-β-glucosidase further hydrolysed laminaribiose to glucose. The remaining Gentiobiose must be hydrolysed by other 1,6-β-glucosidases. Therefore, the endo-1,3-β-glucanase, exo-1,3-β-glucanase and 1,3-β-glucosidase may act synergistically to completely degrade the 1,3-β-glucan backbone of the C. cinerea cell wall during fruiting body autolysis. These three 1,3-β-glucoside hydrolases share a similar optimum pH and optimum temperature, supporting the speculation that these enzymes work together under the same conditions to degrade 1,3-β-glucan in the C. cinerea cell wall during fruiting body autolysis.