5346-76-9

Upstream product

• 87-79-6 L-sorbose 
• 488-45-9 L-iditol 
• 108-24-7 acetic anhydride 
• 463-51-4 Ketene 
• 50-70-4 D-sorbitol 
• 536-11-8 β-D-galactopyranosyl-(1->6)-D-glucopyranose 
• 2280-44-6 D-Glucose 
• 50-99-7 D-glucose 
• 112516-05-9 2-(3,4-dihydroxyphenyl)-ethyl O-α-L-rhamnopyranosyl-(1->3)-O-[β-D-clucopyranosyl-(1->6)]-2-O-acetyl-4-O-[(E)-caffeoyl]-β-D-glucopyranoside 
• 112503-94-3 tubuloside D 
• 112503-95-4 tubuloside C 
• 100427-98-3 4-O-(α-D-glucopyranosyl)-D-galactopyranose 
• 10300-83-1 O²,O³,O⁴,O⁶-Tetraacetyl-O¹-nitro-α-D-glucopyranose 
• 479-98-1 aucubin 

Downstream Products

• 488-45-9 L-iditol 
• 5334-20-3 2,4:3,5-di-O-methylene-L-iditol 
• 15410-52-3 tetra-O-acetyl-1,6-dibromo-1,6-dideoxy-galactitol 
• 643-03-8 D-talitol 

Relevant academic research and scientific papers

Polyketide glycosides from bionectria ochroleuca inhibit candida albicans biofilm formation

One of the challenges presented by Candida infections is that many of the isolates encountered in the clinic produce biofilms, which can decrease these pathogens' susceptibilities to standard-of-care antibiotic therapies. Inhibitors of fungal biofilm formation offer a potential solution to counteracting some of the problems associated with Candida infections. A screening campaign utilizing samples from our fungal extract library revealed that a Bionectria ochroleuca isolate cultured on Cheerios breakfast cereal produced metabolites that blocked the in vitro formation of Candida albicans biofilms. A scale-up culture of the fungus was undertaken using mycobags (also known as mushroom bags or spawn bags), which afforded four known [TMC-151s C-F (1-4)] and three new [bionectriols B-D (5-7)] polyketide glycosides. All seven metabolites exhibited potent biofilm inhibition against C. albicans SC5314, as well as exerted synergistic antifungal activities in combination with amphotericin B. In this report, we describe the structure determination of the new metabolites, as well as compare the secondary metabolome profiles of fungi grown in flasks and mycobags. These studies demonstrate that mycobags offer a useful alternative to flask-based cultures for the preparative production of fungal secondary metabolites.

Structure and biological activity of maculansin A, a phytotoxin from the phytopathogenic fungus Leptosphaeria maculans

During a search for elicitors and phytotoxins produced by virulent isolates of the phytopathogenic fungus Leptosphaeria maculans (Desm.) Ces. et de Not. [asexual stage Phoma lingam (Tode ex Fr.) Desm.], the selective phytotoxin maculansin A was isolated and its structure determined by analysis of spectroscopic data and chemical degradation. Maculansin A, a unique derivative of mannitol containing the unusual chromophore 2-isocyano-3-methyl-2-butenoyl, was isolated from potato dextrose cultures of L. maculans virulent on canola (Brassica napus L. cv. Westar). Surprisingly, maculansin A was more toxic to resistant plants (B. juncea L. cv. Cutlass, brown mustard) than to susceptible plants (canola). Maculansin A, however, did not elicit the production of phytoalexins either in resistant or susceptible plants. In addition, other maculansin type structures and the metabolite 2,4-dihydroxy-3,6-dimethylbenzaldehyde were isolated and the latter was found to be a strong inhibitor of root growth of both brown mustard and canola. Considering that L. maculans seems to be expanding its host range to infect brown mustard as well, maculansins could assist in chemotaxonomic studies to group the diverse isolates.

Structure of Brassicicolin A: A Novel Isocyanide Antibiotic from the Phylloplane Fungus Alternaria brassicicola

Studies of the secondary metabolites produced in culture by the plant pathogenic phylloplane fungus Alternaria brassicicola (Schweinitz) Wiltshire (NRRL 1299 = ATCC 6650) have led to the isolation of brassicicolin A (6), a novel isocyanide antibiotic with potent in vitro activity against the gram-positive bacteria Bacillus subtilis and Staphylococcus aureus.Brassicicolin A is a fully acylated derivative of D-mannitol containing two D-α-hydroxyisovaleryl units, two acetyl groups, and two epimerized α-isocyanoisovaleryl units.The structure of brassicicolin A was assigned as 6 primarily trough chemical degradation studies and by NMR and mass spectral analysis of its deisocyanation product.This account represents the first report of the α-isocyanoisovaleryl group as a naturally occurring structural unit.

A novel low-molecular-mass pumpkin polysaccharide: Structural characterization, antioxidant activity, and hypoglycemic potential

The novel natural low-molecular-mass polysaccharide (SLWPP-3) from pumpkin (Cucurbia moschata) was separated from the waste supernatant after macromolecular polysaccharide production and purified using a DEAE cellulose-52 column and gel-filtration chromatography. Chemical and instrumental studies revealed that SLWPP-3 with a molecular mass of 3.5 kDa was composed of rhamnose, glucose, arabinose, galactose and uronic acid with a weight ratio of 1: 1: 4: 6: 15, and primarily contained →3,6)-β-D-Galp-(1→, →4)-α-GalpA-(1→(OMe), →4)-α-GalpA-(1→, →2,4)-α-D-Rhap-(1→, →3)-β-D-Galp-(1→, →4)-α-D-Glcp, and →4)-β-D-Galp residues in the backbone. The branch chain passes were connected to the main chain through the O-4 atom of glucose and O-3 atom of arabinose. Physiologically, the ability of SLWPP-3 to inhibit carbohydrate-digesting enzymes and DPPH and ABTS radicals, as well as protect pancreatic β cells from oxidative damage by decreasing MDA levels and increasing SOD activities, was confirmed. The findings elucidated the structural types of pumpkin polysaccharides and revealed a potential adjuvant natural product with hypoglycemic effects.

Structural features and antioxidant activity of a new galactoglucan from edible mushroom Pleurotus djamor

A new water soluble galactoglucan with apparent molecular weight ~1.61 × 105 Da, was isolated from the edible mushroom Pleurotus djamor by hot water extraction followed by purification through dialysis tubing cellulose membrane and sepharose 6B column chromatography. The sugar analysis showed the presence of glucose and galactose in a molar ratio of nearly 3:1 respectively. The structure of the repeating unit in the polysaccharide was determined through chemical and NMR experiments as:[Formula presented] In vitro antioxidant studies showed that the PDPS exhibited hydroxyl radical scavenging activity (EC50 = 1.681 ± 0.034 mg/mL), DPPH radical scavenging activity (EC50 = 3.83 ± 0.427 mg/mL), reducing power (EC50 = 4.258 ± 0.095 mg/mL), and ABTS radical quenching activity (EC50 = 0.816 ± 0.077 mg/mL). So, PDPS should be explored as a natural antioxidant.

Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses

Sugar alcohols are of great importance for the food industry and are promising building blocks for bio-based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on commercially available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi-gram scale allowing sugar alcohols to be isolated in large quantities at high atom economy.

Method for preparing amino alcohol derivative

The invention provides a method for preparing an amino alcohol derivative. The method is characterized in that substitution reaction is carried out on ester groups of dihydric alcohol carboxylic esteror polyhydric alcohol carboxylic ester to obtain the amino alcohol derivative, wherein the amidogen is derived into sulfonamido, and at least one carboxylic ester group remains. The method for preparing the amino alcohol derivative has the advantages that the raw materials are cheap and obtained easily, the use quantity of catalysts is low, the reaction condition is simple, and the selectivity ofproducts is high.

Discovery and characterization of family 39 glycoside hydrolases from rumen anaerobic fungi with polyspecific activity on rare arabinosyl substrates

Enzyme activities that improve digestion of recalcitrant plant cell wall polysaccharides may offer solutions for sustainable industries. To this end, anaerobic fungi in the rumen have been identified as a promising source of novel carbohydrate active enzymes (CAZymes) that modify plant cell wall polysaccharides and other complex glycans. Many CAZymes share insufficient sequence identity to characterized proteins from other microbial ecosystems to infer their function; thus presenting challenges to their identification. In this study, four rumen fungal genes (nf2152, nf2215, nf2523, and pr2455) were identified that encode family 39 glycoside hydrolases (GH39s), and have conserved structural features with GH51s. Two recombinant proteins, NF2152 and NF2523, were characterized using a variety of biochemical and structural techniques, and were determined to have distinct catalytic activities. NF2152 releases a single product, β1,2-arabinobiose (Ara2) from sugar beet arabinan (SBA), and β1,2-Ara2 and α-1,2-galactoarabinose (Gal-Ara) from rye arabinoxylan (RAX). NF2523 exclusively releases α-1,2-Gal-Ara from RAX, which represents the first description of a galacto-(-1,2)-arabinosidase. Both β-1,2-Ara2 and α-1,2-Gal-Ara are disaccharides not previously described within SBA and RAX. In this regard, the enzymes studied here may represent valuable new biocatalytic tools for investigating the structures of rare arabinosyl-containing glycans, and potentially for facilitating their modification in industrial applications.

Isolation, purification and structural characterization of a water-soluble polysaccharide HM41 from Halenia elliptica D. Don

A water-soluble polysaccharide, HM41, was obtained from Halenia elliptica D. Don by acidic ethanol fractionation and gel filtration. Its homogeneity was confirmed by chromatography using multiple systems. HM41 was composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), galactose (Gal), glucose (Glc) with a molar ratio of 1.0:5.5:1.8:3.0:9.4:21. The average molecular weight of HM41 was approximately 1.17 × 104. Periodate oxidation, Smith degradation, methylation and GC, IR, NMR, XRD, GC-MS analysis were used for the structural analysis of HM41. Its main chain was composed mainly of β-(1 → 4)Gal, β-(1 → 4)Glc and β-(1 → 6)Glc. β-(1 → 4)Gal were substituted at 6-O and on average there were 14 branches among 23 main chain residues; (1 → 4)Glc had no branch; (1 → 6)Glc were substituted at 3-O and on average there were 9 branches among 14 main chain residues. The side chain was composed of (1 → 3,6)-Rha, (1 → 4)/(1 → 5)-Ara, (1 → 4)/(1 → 5)-Xyl, (1 → 4,6)-Man and (1 → 2)-Glc. The terminal residue was composed of Ara, Xyl, Man, Gal, and Glc. Then, we demonstrated that HM and HM41 had strong scavenging activities in vitro hydroxyl. Overall, HM and HM41 may have potential applications in the antioxidants for medical and food industry.

Efficient and selective N-, S- and O-acetylation in TEAA ionic liquid as green solvent. Applications in synthetic carbohydrate chemistry

Background: The ionic liquid triethylammonium acetate (TEAA) was found to be an efficient solvent in the acetylation of alcohols, amines, oximes and thiols to their corresponding acetyl compounds using only a 10% excess of acetic anhydride under mild conditions. Moreover TEAA is not only an inexpensive and recyclable solvent but also an anomeric selective catalyst in the per-O-acetylation of sugar moieties. Methods: Simple and effective organic synthesis protocols were provided for the selective acetylation of several substrates. The products were fully characterized by 1H and 13C NMR spectroscopy and the anomeric ratios were obtained from the 1H spectra. Results: Structurally diverse alcohols, phenols, thiols, amines, carbohydrates and oximes underwent acylation under mild conditions by this procedure to provide the corresponding acetates in excellent yields. TEAA ionic liquid is unique in its capability to act as both, solvent and high selective catalyst. As expected, the reaction proceeds with high b anomeric selectivity for sugars derivatives. Moreover, the ionic liquid was regenerated, recycled and reused for three times without apparent loss of reactivity and selectivity in all cases. Conclusions: The present procedure provides a powerful and versatile acylation method for alcohols, phenols, thiols, amines, oximes and carbohydrates. This protocol is endowed with several unique merits: selectivity, cost-efficiency, atom-economy and mild reaction conditions tolerable to acid sensitive functionalities. With these features, this method may be considered as a better alternative for the acetylation of a wide range of substrates.