Sugar Aldehydes Research Articles

Synthesis, Antioxidant, and Anticancer Studies of New 1,3,4‐Oxadiazole Derivatives Linked to Benzoquinoline

AbstractA series of some new 1,3,4‐oxadiazole derivatives was synthesized. Hydrazide derivative 4 was reacted with some sugar aldehydes to give the corresponding sugar hydrazones 5 a–c. Acetylation of 5 a–c with acetic anhydride in pyridine, managed the per‐O‐acetyl derivatives 6 a–c while refluxing in acetic anhydride gave the corresponding 1,3,4‐oxadiazolines 7 a–c. On the other hand, 1,3,4‐oxadiazoles 8 a,b, 9, 10, 12, 14, and 15 were synthesized via the reaction of 4 with different reagents including p‐chlorobenzoic acid, nicotinic acid, methyl iodide, morpholine, phenyl isothiocyanate, potassium iodide, chloroacetyl chloride, and phosphorus oxychloride, respectively. The new compounds were assessed for their anticancer and antioxidant activities. Compounds 8 a,b, 10, and 12–15 displayed the most antioxidant activity. In addition, compounds 8 a, 8 b, and 13 showed strong cytotoxic activity.

Research on the Impact of Deep Eutectic Solvent and Hot-Water Extraction Methods on the Structure of Polygonatum sibiricum Polysaccharides.

Deep eutectic solvent (DES) and hot-water extraction (HWE) methods were utilized to extract polysaccharides from Polygonatum sibiricum, referred to as DPsP and WPsP, respectively. The extracted polysaccharides were purified using the Superdex-200 dextran gel purification system, resulting in three components for each type of polysaccharide. The structures of these components were characterized. The molecular weight analysis revealed that DPsP components had slightly larger molecular weights compared with WPsP, with DPsP-A showing a slightly higher dispersity index and broader molecular weight distribution. The main monosaccharide components of both DPsP and WPsP were mannose and glucose, while DPsP exhibited a slightly greater variety of sugar components compared with WPsP. FTIR analysis demonstrated characteristic polysaccharide absorption peaks in all six PSP components, with a predominance of acidic pyranose sugars. NMR analysis revealed the presence of pyranose sugars, including rhamnose and sugar aldehyde acids, in both DPsP-B and WPsP-A. DPsP-B primarily exhibited β-type glycosidic linkages, while WPsP-A predominantly displayed α-type glycosidic linkages, with a smaller fraction being β-type. These findings indicated differences in monosaccharide composition and structure between PSPs extracted using different methods. Overall, this study provided experimental evidence for future research on the structure-function relationship of PSPs.

Characteristics of the bacteria Escherichia coli isolated from biomaterial of Mais snake

The aim of the work is to carry out bacteriological methods of isolation of enterobacteria from the feces of the maize fly and their identification.Fecal masses were selected after molting from a male maize runner named Rabbit morphs Bloodred het Pied-Sided (Fig.1). Date of release from the egg: 06/19/2020.The primary sowing of "tampon-loop" was carried out on chocolate agar and Endo medium. The final identification was carried out by the RapID ONE System test system (Thermo Fisher Scientific, USA).As a result of the work, morphological properties were studied: gram-negative rods collected in groups or arranged singly, the presence of a capsule was established.Isolated E.coli cleaved lactose, sugar aldehyde, glucose, mannitol, sorbitol, rhamnose, melibiose and arabinose, possessed enzymes lysine decarboxylase, ornithine decarboxylase, γ-glutamyltranspeptidase, reacted with aliphatic thiol.

Flexible and wet stable starch films crosslinked with sugar-based aldehydes

Starch films always suffer from brittleness and poor wet stability. Besides, numerous reinforcements have enormous limitations. Because of the high reactivity, sugar aldehydes should have substantially improved properties of starch products. However, sugar-aldehydes not only had limited property improvement of starch products but also contained a significant amount of formaldehyde. Various saccharides were oxidized under different conditions to evaluate the generation of formaldehyde and crosslinking performance. Mechanical properties of starch films were controlled by length and concentrations of crosslinkages from formyl-saccharides. Via engineering crosslinkages of formyl-saccharides, tensile strength and breaking elongation of starch films were improved from 7 MPa and 5%–25 MPa and 28 %, respectively. Formyl-saccharide crosslinkages also ensured 93 % weight retention of starch film in water and unchanged cytocompatibility. Less than 2% of crosslinkages formed by formyl-saccharides were damaged at 50 °C for 7 days at various pHs. This work demonstrates that starch films with desirable tensile strength, flexibility, wet stability and cytocompatibility can be developed via structure-controlled formaldehyde-free formyl-saccharide crosslinkages.

Synthesis and Structural Characterization of 1-(E-1-Arylpropenon-3-yl)-3,4,6-tri-O-benzyl-d-glucals and Their Transformation into Pentasubstituted (2R,3S,4R)-Chromanes via Pd-Catalyzed Cross Dehydrogenative Coupling Reaction.

We have developed an efficient methodology for the synthesis of (2R,3S,4R)-2-hydroxymethyl-3,4-dihydroxy-6-aryl-7-aroylchromanes in which the chirality at the C-2, C-3, and C-4 positions is being drawn from C-glucopyranosyl aldehyde, which in turn can be efficiently synthesized from d-glucose. Thus, the synthesis starts with the transformation of sugar aldehyde into 1-(E-1-arylpropenon-3-yl)-3,4,6-tri-O-benzyl-d-glucals using Claisen–Schmidt type condensation reaction with different acetophenones and then to 1,2-disubstituted glucals via Pd(II)-catalyzed cross dehydrogenative coupling reaction, which in turn has been efficiently converted into (2R,3S,4R)-chromanes via 6π-electrocyclization and in situ dehydrogenative aromatization.

A Concise Organocatalytic Synthesis of 3‐Deoxy‐2‐ulosonic Acids through Cinchona‐Alkaloid‐Promoted Aldol Reactions of Pyruvate

Direct cross‐aldol reactions of a pyruvate ester with chiral aldehydes, mediated by purely organic catalysts, is described as a crucial step in the synthesis of ulosonic acids. Cinchona alkaloids containing a tertiary amine group efficiently promote direct aldol reactions of a sterically hindered pyruvate ester with various sugar aldehydes. The pyruvic acid ester can be directly used as chemical equivalent of PEP (phosphoenolpyruvate) in imitation of the synthetic principle used in nature. The appropriate combination of a chiral aldehyde with a chiral catalyst allows the flexible preparation of anti‐ or syn‐configured aldols, as desired. As a result, concise syntheses of diverse six‐, seven‐, eight‐, and nine‐carbon ulosonic acid esters are described, by using a biomimetic three‐carbon chain elongation of various sugar aldehydes. Consequently, short and practical syntheses of several ulosonic acids, including three important naturally occurring sugars – 3‐deoxy‐d‐erythro‐hex‐2‐ulosonic acid (KDG), 3‐deoxy‐d‐manno‐oct‐2‐ulosonic acid (KDO), and the rare 3‐deoxyglucosone (3DG), in good overall yields are presented.

Design, synthesis and immunomodulating activity of C - pseudo nucleosides containing thiazolidin-4-one and phenyl connected by acetamide bond

Abstract Several novel C - pseudo nucleosides containing thiazolidin-4-one and phenyl connected by acetamide bond were rationally designed and easily synthesized at room temperature by using the unprotected sugar aldehyde as the starting material. The effects of the compounds on Con A-induced T cell proliferation were evaluated at five concentrations of 5, 10, 25, 50, and 100 μmol/L Interestingly, compounds 7a and 8a ( n = 2, R = H) exhibited immunostimulating activities, while compounds 5a , 6a ( n = 1, R = H) and 7b , 8b ( n = 2, R = CH 3 ) showed immunosuppressive activities. Another two compounds 5b and 6b ( n = 1, R = CH 3 ) had no immunomodulating activities. These initial biological results suggested that subtle structural changes to the phenyl and acetamide bond of C - pseudo nucleosides could have a significant effect on T cell proliferation bias, although it was difficult to formulate a rigorous structure-activity relationship based on the observed activities.

ChemInform Abstract: Chemistry of Pyruvate Enolates: anti‐Selective Direct Aldol Reactions of Pyruvate Ester with Sugar Aldehydes Promoted by a Dinuclear Zinc Catalyst.

ChemInform Abstract: Chemistry of Pyruvate Enolates: anti‐Selective Direct Aldol Reactions of Pyruvate Ester with Sugar Aldehydes Promoted by a Dinuclear Zinc Catalyst.

Organocatalytic Synthesis of Higher-Carbon Sugars: Efficient Protocol for the Synthesis of Natural Sedoheptulose and d-Glycero-l-galacto-oct-2-ulose.

Herein we report a short and efficient protocol for the synthesis of naturally occurring higher‐carbon sugars—sedoheptulose (d‐altro‐hept‐2‐ulose) and d‐glycero‐l‐galacto‐oct‐2‐ulose—from readily available sugar aldehydes and dihydroxyacetone (DHA). The key step includes a diastereoselective organocatalytic syn‐selective aldol reaction of DHA with d‐erythrose and d‐xylose, respectively. The methodology presented can be expanded to the synthesis of various higher sugars by means of syn‐selective carbon–carbon‐bond‐forming aldol reactions promoted by primary‐based organocatalysts. For example, this methodology provided useful access to d‐glycero‐d‐galacto‐oct‐2‐ulose and 1‐deoxy‐d‐glycero‐d‐galacto‐oct‐2‐ulose from d‐arabinose in high yield (85 and 74 %, respectively) and high stereoselectivity (99:1).

Chemistry of Pyruvate Enolates: anti‐Selective Direct Aldol Reactions of Pyruvate Ester with Sugar Aldehydes Promoted by a Dinuclear Zinc Catalyst

AbstractA chiral dinuclear zinc complex can effectively catalyse the direct aldol reactions of pyruvic acid ester with various chiral sugar aldehydes, thus functionally mimicking the pyruvate‐dependent type II aldolases. Application of sterically hindered aryl esters allows for the elusive aldol reaction of the pyruvate donor with controlled anti‐selectivity en route to the short and efficient synthesis of 3‐deoxy‐2‐ulosonic acids. Pyruvic acid ester is here used as a chemical equivalent of phosphoenol pyruvate (PEP) in imitation of the synthetic principle used in nature. The presented biomimetic methodologies use enol formation for the highly efficient and flexible formation of various C6–C9 ulosonic acids. Particularly, efficient and concise syntheses of 3‐deoxy‐D‐erythro‐hex‐2‐ulosonic acid (KDG, overall 50% yield), 3‐deoxy‐D‐ribo‐hept‐2‐ulosonic acid (DRH, overall 53% yield) and 3‐deoxy‐D‐glycero‐D‐talo‐non‐2‐ulosonic acid (4‐epi‐KDN, overall 78% yield) are described. This direct efficient application of pyruvic esters does not require additional demasking steps and thus surpassess previously methodologies utilising masked pyruvic synthons such 2‐acetylthiazole and pyruvic aldehyde dimethyl acetal.magnified image

The aldo-keto reductases (AKRs): Overview

The aldo-keto reductase (AKR) protein superfamily contains >190 members that fall into 16 families and are found in all phyla. These enzymes reduce carbonyl substrates such as: sugar aldehydes; keto-steroids, keto-prostaglandins, retinals, quinones, and lipid peroxidation by-products. Exceptions include the reduction of steroid double bonds catalyzed by AKR1D enzymes (5β-reductases); and the oxidation of proximate carcinogen trans-dihydrodiol polycyclic aromatic hydrocarbons; while the β-subunits of potassium gated ion channels (AKR6 family) control Kv channel opening. AKRs are usually 37kDa monomers, have an (α/β)8-barrel motif, display large loops at the back of the barrel which govern substrate specificity, and have a conserved cofactor binding domain. AKRs catalyze an ordered bi bi kinetic mechanism in which NAD(P)H cofactor binds first and leaves last. In enzymes that favor NADPH, the rate of release of NADP+ is governed by a slow isomerization step which places an upper limit on kcat. AKRs retain a conserved catalytic tetrad consisting of Tyr55, Asp50, Lys84, and His117 (AKR1C9 numbering). There is conservation of the catalytic mechanism with short-chain dehydrogenases/reductases (SDRs) even though they show different protein folds. There are 15 human AKRs of these AKR1B1, AKR1C1–1C3, AKR1D1, and AKR1B10 have been implicated in diabetic complications, steroid hormone dependent malignancies, bile acid deficiency and defects in retinoic acid signaling, respectively. Inhibitor programs exist world-wide to target each of these enzymes to treat the aforementioned disorders. Inherited mutations in AKR1C and AKR1D1 enzymes are implicated in defects in the development of male genitalia and bile acid deficiency, respectively, and occur in evolutionarily conserved amino acids. The human AKRs have a large number of nsSNPs and splice variants, but in many instances functional genomics is lacking. AKRs and their variants are now poised to be interrogated using modern genomic and informatics approaches to determine their association with human health and disease.

Au(I)/Ag(I)-catalyzed annulation of sugar aldehyde tethered with 3-phenylprop-2-yn-1-yl ether with aryl amines for the pyrano[4,3-b]quinoline derivatives

Aryl amines undergo smooth annulation with O-phenylpropynyl sugar aldehyde in the presence of the Ph3PAuCl (10mol%)/AgSbF6 (10mol%) catalytic system to afford the corresponding tetrahydro-3aH-spiro[[1,3]dioxolo[4″,5″:4′,5′]furo[3′,2′:5,6]pyrano[4,3-b]quinoline-2,1′-cyclohexane] derivatives in good yields and selectivity.

Stereoselective Synthesis of Orthogonally Protected 1,2-Diaminoinositols from d-Mannose

We present herein a promising novel strategy for the transformation of sugar aldehydes into 1,2-diaminoinositols. This process, based on the sequential intermolecular aza-Henry reaction and intermolecular Henry reaction allowed the total synthesis of a 1,2-diaminoinositols with total stereochemical control. The new route constitutes a simpler and more efficient approach than those previously described routes to 1,2-diaminoinositols and it has the additional advantage of offering the possibility of orthogonal protection of the amino groups.

Design, synthesis and bioactivity of novel glycosylthiadiazole derivatives.

A series of novel glycosylthiadiazole derivatives, namely 2-phenylamino-5-glycosyl-1,3,4-thiadiazoles, were designed and synthesized by condensation between sugar aldehydes A/B and substituted thiosemicarbazide C followed by oxidative cyclization by treating with manganese dioxide. The original fungicidal activities results showed that some title compounds exhibited excellent fungicidal activities against Sclerotinia sclerotiorum (Lib.) de Bary and Pyricularia oryzae Cav, especially compounds F-5 and G-8 which displayed better fungicidal activities than the commercial fungicide chlorothalonil. At the same time, the preliminary studies based on the Elson-Morgan method indicated that many compounds exhibited some inhibitory activity toward glucosamine-6-phosphate synthase (GlmS). The structure-activity relationships (SAR) are discussed in terms of the effects of the substituents on both the benzene and the sugar ring.

ChemInform Abstract: Facile Synthesis of Novel Glycosyl Oxindoles Through 1,3‐Dipolar Cycloaddition.

AbstractAn efficient synthesis of sugar‐fused spirooxindole heterocycles is achieved using the 1,3‐dipolar cycloaddition of azomethine ylides, generated in situ from the sugar aldehyde (I), and α‐amino acids.

Synthesis of Enantiopure 2-C-Glycosyl-3-nitrochromenes

A novel methodology has been developed to obtain enantiopure 2-C-glycosyl-3-nitrochromenes. First, (Z)-1-bromo-1-nitroalkenes were prepared from the corresponding sugar aldehydes through a sodium iodide-catalyzed Henry reaction with bromonitromethane followed by elimination of the resulting 1-bromo-1-nitroalkan-2-ols. In the next step, reaction of the sugar-derived (Z)-1-bromo-1-nitroalkenes with o-hydroxybenzaldehydes afforded enantiopure (2S,3S,4S)-3-bromo-3,4-dihydro-4-hydroxy-3-nitro-2H-1-benzopyrans, which, upon SmI2-promoted β-elimination, yielded chiral enantiopure 2-C-glycosyl-3-nitrochromenes.

ChemInform Abstract: One‐Pot Synthesis of Vicinal Aminoalkanols from Sugar Aldehydes.

AbstractA novel indium catalyzed Henry reaction followed by nitro group reduction gives the title compounds in good to excellent stereoselectivities.

New Approach to Sugar Dienes; Useful Building Blocks for the Synthesis of Bicyclic Derivatives

A sugar aldehyde with silyl protection at C1, readily prepared from methyl α- d -glucopyranoside, reacted with allylborate or allylchromium reagents to afford the corresponding (anti) adducts, which were selectively converted into either E- or Z-diene. Deprotection of the anomeric position with TBAF proceeded in excellent yield, and further functionalization of the resulting hemiacetal led to the formation of complex bicyclic products such as highly functionalized oxazolidines.

Synthesis and immunostimulating activity of C-pseudonucleosides containing N-phenyl thiazolidin-4-one

Several novel C-pseudonucleosides containing N-phenyl thiazolidin-4-one were synthesized at room temperature using the unprotected sugar aldehyde as the starting material. The effects of the compounds on Con A-induced T cell proliferation were evaluated at five concentrations of 5, 10, 25, 50, and 100 μM. Some compounds, such as 5d, 5e, 5f, and 4g could significantly increase the proliferation by 62, 63, 70, and 53 % at low concentration of 5 μM, respectively. The structure–activity relationship indicated that the lipophilicity substituents like chloro atom, methyl, and methoxyl on the para position of N-3 phenyl at the thiazolidin-4-one ring had a detrimental impact on the T cell proliferation. The C-2 configuration and the electronic property of the lipophilicity substituents likely had slight effects on the immunostimulatory activities of such C-pseudonucleosides.

One-pot synthesis of vicinal aminoalkanols from sugar aldehydes

A novel synthetic method of carbohydrate derived vicinal aminoalcohols, from sugar aldehydes and bromonitroalkanes, has been developed. It involves an indium-catalyzed one-pot Henry reaction and nitro group reduction, and proceeds with a remarkably high anti-selectivity. The reaction of the intermediate aminoalcohols with alkylating agents furnished the corresponding carbohydrate-based tertiary aminoalcohols with excellent stereoselectivity. This very simple methodology allows easy access to families of N,N-dialkylated vicinal aminoalkanols, useful intermediates in the synthesis of derivatives of biological interest and sugar-based stereodifferentiating agents for asymmetric catalysis.