Showing papers on "Pyranose published in 2013"

The 1.6 Å crystal structure of pyranose dehydrogenase from Agaricus meleagris rationalizes substrate specificity and reveals a flavin intermediate.

Abstract: Pyranose dehydrogenases (PDHs) are extracellular flavin-dependent oxidoreductases secreted by litter-decomposing fungi with a role in natural recycling of plant matter. All major monosaccharides in lignocellulose are oxidized by PDH at comparable yields and efficiencies. Oxidation takes place as single-oxidation or sequential double-oxidation reactions of the carbohydrates, resulting in sugar derivatives oxidized primarily at C2, C3 or C2/3 with the concomitant reduction of the flavin. A suitable electron acceptor then reoxidizes the reduced flavin. Whereas oxygen is a poor electron acceptor for PDH, several alternative acceptors, e.g., quinone compounds, naturally present during lignocellulose degradation, can be used. We have determined the 1.6-A crystal structure of PDH from Agaricus meleagris. Interestingly, the flavin ring in PDH is modified by a covalent mono- or di-atomic species at the C(4a) position. Under normal conditions, PDH is not oxidized by oxygen; however, the related enzyme pyranose 2-oxidase (P2O) activates oxygen by a mechanism that proceeds via a covalent flavin C(4a)-hydroperoxide intermediate. Although the flavin C(4a) adduct is common in monooxygenases, it is unusual for flavoprotein oxidases, and it has been proposed that formation of the intermediate would be unfavorable in these oxidases. Thus, the flavin adduct in PDH not only shows that the adduct can be favorably accommodated in the active site, but also provides important details regarding the structural, spatial and physicochemical requirements for formation of this flavin intermediate in related oxidases. Extensive in silico modeling of carbohydrates in the PDH active site allowed us to rationalize the previously reported patterns of substrate specificity and regioselectivity. To evaluate the regioselectivity of D-glucose oxidation, reduction experiments were performed using fluorinated glucose. PDH was rapidly reduced by 3-fluorinated glucose, which has the C2 position accessible for oxidation, whereas 2-fluorinated glucose performed poorly (C3 accessible), indicating that the glucose C2 position is the primary site of attack.

Low-energy electron scattering by cellulose and hemicellulose components

Abstract: We report elastic integral, differential and momentum transfer cross sections for low-energy electron scattering by the cellulose components β-D-glucose and cellobiose (β(1 → 4) linked glucose dimer), and the hemicellulose component β-D-xylose. For comparison with the β forms, we also obtain results for the amylose subunits α-D-glucose and maltose (α(1 → 4) linked glucose dimer). The integral cross sections show double peaked broad structures between 8 eV and 20 eV similar to previously reported results for tetrahydrofuran and 2-deoxyribose, suggesting a general feature of molecules containing furanose and pyranose rings. These broad structures would reflect OH, CO and/or CC σ* resonances, where inspection of low-lying virtual orbitals suggests significant contribution from anion states. Though we do not examine dissociation pathways, these anion states could play a role in dissociative electron attachment mechanisms, in case they were coupled to the long-lived π* anions found in lignin subunits [de Oliveira et al., Phys. Rev. A, 2012, 86, 020701(R)]. Altogether, the resonance spectra of lignin, cellulose and hemicellulose components establish a physical-chemical basis for electron-induced biomass pretreatment that could be applied to biofuel production.

Six pyranoside forms of free 2-deoxy-D-ribose.

Abstract: Carbohydrates are one of the most versatile biochemical building blocks, widely acting in energetic, structural, or recognition processes. The interpretation of the biological activity of saccharides is based on the structure and relative stability of their conformers. One of the obstacles to resolving the basic structure issues arises from their ability to form strong intermolecular hydrogen bonds with polar solvents, which in turn can result in conformational changes. A clear picture of the conformational panorama of isolated 2-deoxyd-ribose has been revealed using Fourier-transform microwave spectroscopy in conjunction with a UV ultrafast laser ablation source. Additionally, the availability of rotational data has been the main bottle-neck for examining the presence of these building blocks in interstellar space, so these studies could also be useful to the astrochemistry community. 2-Deoxy-d-ribose (2DR, C5H10O4; Figure 1a) is an important naturally occurring monosaccharide, present in nucleotides, which are the building blocks for DNA. In DNA, 2DR is present in the furanose (five-membered) ring form, whereas free in aqueous solution it cyclizes into fiveor six-membered rings, with the latter—the pyranoid form—being dominant. By closing the chain into a six-membered ring, the C1 carbon atom is converted into an asymmetric center, yielding two possible stereochemical a and b anomeric species (Figure 1b). In aqueous solution, 2DR primarily exists as a mixture of nearly equal amounts of a and b pyranose forms, present in their low-energy chair conformations, C1 and C4 (Figure 1c). [4] Such configurations are connected through ring inversion, thus establishing the axial or equatorial position of the OH group for each conformer. In addition, the monossacharides exhibit an unusual preferential stabilization of pyranose rings containing an axial OH group at the C1 carbon over the equatorial orientation, widely known as the anomeric effect, although its physical origin remains controversial. Nevertheless, structural analysis of 2DRmust take into consideration the intramolecular hydrogen bonding between adjacent OH groups. The formation of hydrogenbond networks reinforces their stability owing to hydrogenbond cooperativity effects. Such networks are fundamental to the molecular recognition of carbohydrates. By dissecting all these factors we can determine the most stable conformers of 2DR and the relative arrangement of the different hydroxy groups under isolated conditions, such as in the gas phase. In vacuo theoretical calculations, carried out on a-/bpyranoses, a-/b-furanoses, and open-chain conformations, predict 15 furanose and pyranose forms (Figure 1d, Table 1) in an energy window of 12 kJmol 1 above the predicted cc-apyr C1 global minimum. The notation used to label the different conformers include the symbols a and b to denote the anomer type, C1 and C4 to denote the pyranose chair form, C2-endo or C3-endo to denote the furanose envelope forms, and “c” or “cc” to indicate a clockwise or counterclockwise configuration of the adjacent OH bonds, respectively. A number is added to provide theMP2 energy ordering within the same family. To validate the predicted conformational behavior, comparison with precise experimental data of 2DR is needed. Previous experiments to determine the conformation of monosaccharides were based on X-ray and NMR measurements. However, these data are influenced by environmental effects associated with the solvent or crystal lattice. Recently, an IR spectrum of 2DR in an inert matrix in

Molecular dynamics simulations give insight into D-glucose dioxidation at C2 and C3 by Agaricus meleagris pyranose dehydrogenase.

Abstract: The flavin-dependent sugar oxidoreductase pyranose dehydrogenase (PDH) from the plant litter- degrading fungus Agaricus meleagris oxidizes D-glucose (GLC) efficiently at positions C2 and C3. The closely related pyranose 2-oxidase (P2O) from Trametes multi- color oxidizes GLC only at position C2. Consequently, the electron output per molecule GLC is twofold for PDH compared to P2O making it a promising catalyst for bio- electrochemistry or for introducing novel carbonyl func- tionalities into sugars. The aim of this study was to rationalize the mechanism of GLC dioxidation employing molecular dynamics simulations of GLC-PDH interac- tions. Shape complementarity through nonpolar van der Waals interactions was identified as the main driving force for GLC binding. Together with a very diverse hydrogen- bonding pattern, this has the potential to explain the experimentally observed promiscuity of PDH towards different sugars. Based on geometrical analysis, we pro- pose a similar reaction mechanism as in P2O involving a general base proton abstraction, stabilization of the tran- sition state, an alkoxide intermediate, through interaction with a protonated catalytic histidine followed by a hydride transfer to the flavin N5 atom. Our data suggest that the presence of the two potential catalytic bases His-512 and His-556 increases the versatility of the enzyme, by employing the most suitably oriented base depending on the substrate and its orientation in the active site. Our findings corroborate and rationalize the experimentally observed dioxidation of GLC by PDH and its promiscuity towards different sugars.

o-Xylylene protecting group in carbohydrate chemistry: application to the regioselective protection of a single vic-diol segment in cyclodextrins.

Abstract: A systematic study of the suitability of α,α′-dibromo-o-xylene as a reagent for cyclic o-xylylene protection of vic-diols in different monosaccharide substrates is reported. The installation of this protecting group, formally equivalent to a di-O-benzylation reaction, proceeds with good regioselectivity toward 1,2-trans-diequatorial diol systems in pyranose and furanose rings. Initially, the benzyl ether-type derivative of the more acidic hydroxyl is preferentially formed. Subsequent intramolecular etherification toward the equatorial-oriented vicinal OH is kinetically favored. The methodology has been implemented for the simultaneous protection of the secondary O-2 and O-3 positions of a single d-glucopyranosyl unit in cyclic oligosaccharides of the cyclodextrin (CD) family (cyclomaltohexa-, -hepta-, and -octaose; α, β, and γCD).

Characterizing the catalyzed hydrolysis of β-1,4 glycosidic bonds using density functional theory.

Abstract: Unraveling the mechanistic details of biomass deconstruction at ambient conditions has remained a challenge for many years. In this study we examine a crucial step in the pretreatment of biomass: the hydrolytic cleavage of the glycosidic bond present in many forms of biomass and other oligomeric saccharides. We present the detailed mechanistic steps found using density functional theory and transition state calculations on the acid catalyzed hydrolysis of a pyranose dimer linked by a β-1,4 glycosidic bond in a vacuum and various continuum solvation models. The order that the bonds in the double displacement reaction form and break was revealed along with the transition state energies and an overall intrinsic reaction pathway for the two-step mechanism. The uncatalyzed hydrolysis reaction, mediated by a single water splitting event, was also determined with DFT calculations and a detailed comparison to the two-step catalyzed reaction was performed. The effects of the surrounding solvent on the reaction ene...

Regiospecific anomerisation of acylated glycosyl azides and benzoylated disaccharides by using TiCl4.

Abstract: Chelation induced anomeri- sation is promoted when Lewis acids, such as TiCl4 or SnCl4, coordinate to the pyranose ring oxygen atom and an- other site, giving rise to endocyclic cleavage and isomerisation to the more stable anomer. In this research regio- specific site-directed anomerisation is demonstrated. TiCl4 (2.5 equiv) was employed to induce anomerisation of 15 glycosyl azide and disaccharide sub- strates of low reactivity, and high yields (> 75 %) and stereoselectivies (a/b > 9:1) were achieved. The examples in- cluded glucopyranuronate, galactopyra- nuronate and mannopyranuronate as well as N-acetylated glucopyranuro- nate and galactopyranuronate deriva- tives. A disaccharide with the a1!4 linkage found in polygalacturonan was included. The use of benzoylated sac- charides was found to be important in disaccharide anomerisation as attempts to isomerise related acetyl protected and 2,3-carbonate protected derivatives were not successful.

Oxidation Mode of Pyranose 2-Oxidase Is Controlled by pH

Abstract: Pyranose 2-oxidase (P2O) from Trametes multicolor is a flavoenzyme that catalyzes the oxidation of D-glucose and other aldopyranose sugars at the C2 position by using O2 as an electron acceptor to form the corresponding 2-keto-sugars and H2O2. In this study, the effects of pH on the oxidative half-reaction of P2O were investigated using stopped-flow spectrophotometry. The results showed that flavin oxidation occurred via different pathways depending on the pH of the environment. At pH values lower than 8.0, reduced P2O reacts with O2 to form a C4a-hydroperoxy-flavin intermediate, leading to elimination of H2O2. At pH 8.0 and higher, the majority of the reduced P2O reacts with O2 via a pathway which does not allow detection of the C4a-hydroperoxy-flavin, and flavin oxidation occurs with decreased rate constants upon the rise in pH. The switching between the two modes of P2O oxidation is controlled by protonation of a group which has a pKa of 7.6 ± 0.1. Oxidation reactions of reduced P2O under rapid pH change as performed by stopped-flow mixing were different from the same reactions performed with enzyme pre-equilibrated at the same specified pH values, implying that the protonation of the group which controls the mode of flavin oxidation cannot be rapidly equilibrated with outside solvent. Using a double-mixing stopped-flow experiment, a rate constant for proton dissociation from the reaction site was determined to be 21.0 ± 0.4 s-1.

Permeation of Aldopentoses and Nucleosides Through Fatty Acid and Phospholipid Membranes: Implications to the Origins of Life

Abstract: Permeation of aldopentoses and nucleosides through fatty acid and phospholipid membranes was investigated by way of molecular dynamics simulations. Calculated permeability coefficients of membranes to aldopentoses, which exist predominantly in the pyranose form, are in a very good agreement with experimental results. The unexpected preferential permeation of ribose, compared to its diastereomers, found by Sacerdote and Szostak, is explained in terms of inter- and intramolecular interactions involving hydroxyl groups. In aqueous solution, these groups favor the formation of intermolecular hydrogen bonds with neighboring water molecules. Inside the membrane, however, they form intramolecular hydrogen bonds, which in ribose are arranged in a chain. In its diastereomers this chain is broken, which yields higher free energy barrier to transfer through membranes. Faster permeation of ribose would lead to its preferential accumulation inside cells if sugars were converted sufficiently quickly to nonpermeable derivatives. An estimate for the rate of such reaction was derived. Preferential accumulation of ribose would increase the probability of correct monomers' incorporation during synthesis of nucleic acids inside protocells. The same mechanism does not apply to nucleosides or their activated derivatives because sugars are locked in the furanose form, which contains fewer exocyclic hydroxyl groups than does pyranose. The results of this study underscore concerted early evolution of membranes and the biochemical processes that they encapsulated.

Pyranose Dehydrogenase from Agaricus campestris and Agaricus xanthoderma: Characterization and Applications in Carbohydrate Conversions

Abstract: Pyranose dehydrogenase (PDH) is a flavin-dependent sugar oxidoreductase that is limited to a rather small group of litter-degrading basidiomycetes. The enzyme is unable to utilize oxygen as an electron acceptor, using substituted benzoquinones and (organo) metal ions instead. PDH displays a broad substrate specificity and intriguing variations in regioselectivity, depending on substrate, enzyme source and reaction conditions. In contrast to the related enzyme pyranose 2-oxidase (POx), PDHs from several sources are capable of oxidizing α- or β-1→4-linked di- and oligosaccharides, including lactose. PDH from A. xanthoderma is able to perform C-1 and C-2 oxidation, producing, in addition to lactobionic acid, 2-dehydrolactose, an intermediate for the production of lactulose, whereas PDH from A. campestris oxidizes lactose nearly exclusively at the C-1 position. In this work, we present the isolation of PDH-encoding genes from A. campestris (Ac) and A. xanthoderma (Ax) and a comparison of other so far isolated PDH-sequences. Secretory overexpression of both enzymes in Pichia pastoris was successful when using their native signal sequences with yields of 371 U·L−1 for AxPDH and 35 U·L−1 for AcPDH. The pure enzymes were characterized biochemically and tested for applications in carbohydrate conversion reactions of industrial relevance.

Sequential Norrish type II photoelimination and intramolecular aldol cyclization of α-diketones: synthesis of polyhydroxylated cyclopentitols by ring contraction of hexopyranose carbohydrate derivatives.

Abstract: The excitation of the innermost carbonyl of nono-2,3-diulose derivatives by irradiation with visible-light initiates a sequential Norrish typeII photoelimination and aldol cyclization process that finally gives polyfunctionalized cyclopentitols. The rearrangement has been confirmed by the isolation of stable acyclic photoenol intermediates that can be independently cyclized by a thermal 5-(enolexo)-exo-trig uncatalyzed aldol reaction with high diastereoselectivity. In this last step, the large deuterium kinetic isotope effect found for the 1,5-hydrogen atom transfer seems to indicate that the aldol reaction runs through a concerted pericyclic mechanism. Owing to the ready availability of pyranose sugars of various configurations, this protocol has been used to study the influence of pyranose ring-substituents on the diastereoselectivity of the aldol cyclization reaction. In contrast with other pyranose ring contraction methodologies no transition-metal reagents are needed and the sequential rearrangement occurs simply by using visible light and moderate heating (0 to 60 degrees C).

Synthesis of carbohydrate fused chiral macrocyclic benzolactones through Sonogashira reaction

Abstract: Synthesis of 10-, 11- and 12-membered chiral benzolactones fused to furanose/pyranose sugars has been achieved in good to excellent yields using an intramolecular Sonogashira reaction. Positions 1–2, 3–5, 3–6 and 5–6 of sugar were utilized for the construction of the macrocycles. The requisite furanose/pyranose scaffolds were synthesized utilising conventional protection–deprotection strategies like benzylation, tritylation, detritylation, EDC coupling, propargylation, etc.

Solution phase conformation and proteolytic stability of amide-linked neuraminic acid analogues.

Abstract: Amide-linked homopolymers of sialic acid offer the advantages of stable secondary structure and increased bioavailability making them useful constructs for pharmaceutical design and drug delivery. Defining the structural characteristics that give rise to secondary structure in aqueous solution is challenging in homopolymeric material due to spectral overlap in NMR spectra. Having previously developed computational tools for heteroologomers with resolved spectra, we now report that application of these methods in combination with circular dichroism, NH/ND NMR exchange rates and nOe data has enabled the structural determination of a neutral, δ-amide-linked homopolymer of a sialic acid analogue called Neu2en. The results show that the inherent planarity of the pyranose ring in Neu2en brought about by the α,β-conjugated amide bond serves as the primary driving force of the overall conformation of the homooligomer. This peptide surrogate has an excellent bioavailability profile, with half-life of ~12 hours in human blood serum, which offers a viable peptide scaffold that is resistant to proteolytic degradation. Furthermore, a proof-of-principle study illustrates that Neu2en oligomers are functionalizable with small molecule ligands using 1,3-dipolar cycloaddition chemistry.

Optical compensation film, and polarizing plate and liquid crystal display employing the same

Abstract: The present invention provides an optical compensation film, which has excellent visibility such as light leakage, uneven color tone and front contrast, and can simultaneously realize retardation and wavelength dispersion. The optical compensation film is characterized by containing a cellulose ester, the following polymer (a), and the following compound (b). (a) A polymer produced by copolymerizing an ethylenically unsaturated monomer having in its molecule a partial structure represented by Formula (1) with at least one ethylenically unsaturated monomer. (b) An esterified compound produced by esterifying all or a part of OH groups in a compound (A) having one furanose structure or one pyranose structure, or an esterified compound produced by esterifying all of or a part of OH groups in a compound (B) containing nor less than 2 and not more than 12 structures of at least one of a furanose structure or a pyranose structure.

Substrate binding to Candida tenuis xylose reductase during catalysis

Abstract: Candida tenuis xylose reductase (CtXR) is studied by in situ NMR, saturation transfer difference (STD) NMR, and molecular docking with respect to its substrate and coenzyme binding in ternary complexes. The natural substrate Xyl as well as Glc and methyl-glucosides preferentially bind as α-anomers of the pyranose forms. These α-anomers are transformed faster, predominately leading to STD effects in the formed products, and can be better docked into the CtXR active site than the β-anomer. The reduction is initiated by α-Xylp ring opening prior to hydride transfer from NADH. Binding and transformation of unnatural 2,4-dichloroacetophenone is not as good, although it is reduced with very high catalytic efficiency. STD NMR indicates a reasonable amount to leave the ternary complex in unreduced form. The molecular docking calculation confirms this result, as only a couple of the investigated ternary complexes allow reduction of the substrates.

The Synthesis and X-ray Studies of 6-pyrrolidinyl-2-triazolyl Purine Arabinonucleoside

Abstract: C(6)-Pyrrolidinyl derivative with triazolyl moiety at C(2)-position was obtained from 2,6-bis-triazolylpurine arabinonucleoside via C(6)-regioselective nucleophilic substituon of 1,2,3-triazolyl moiety with pyrrolidine. The obtained compound was studied by NMR, X-ray, UV/VIS and emission spectra. Pyranose form of arabinose residue and α-configuration of the obtained compound were unambiguously proven by NMR and X-ray studies.

Microwave-Assisted FeCl3·6H2O-Catalyzed Regioselective Deprotection of Pyranose Anomeric O-Acetyl Group

Abstract: Treatment of peracetylated pyranoses with FeCl3·6H2O in acetonitrile under microwave conditions provides an efficient and mild method for regioselective deprotection of anomeric O-acetyl group. The experimental results indicated that the employment of microwave could notably improve the reaction efficacy compared with the conventional heating condition.

Cement slurries having pyranose polymers

Abstract: A composition includes a cement component and an amidyl pyranose component. A method of making the composition includes mixing a cement component with an amidyl pyranose component.

2,4-o-bridged pyranose inversion compound

Abstract: PROBLEM TO BE SOLVED: To provide a pyranose compound to be used in a method for producing β-O-pyranoside with high selectivity and simply.SOLUTION: A 2,4-O-bridged pyranose inversion compound is a compound represented by general formula (1) or its enantiomer.

Structural Properties of Polysaccharides for the Mycelium of Hericium caput-medusae

Abstract: Water extraction polysaccharides and alkali extraction polysaccharides for the mycelium of Hericium caput-medusae were studied on the structural properties.The results showed that HMP-w1.1 is α pyranose with the relative molecular weights of 36.3 kD,containing protein and no uronic acid,and is composed of Man,Glc,Gal and Fuc.HMP-a1.1 is β pyranose with the relative molecular weights of 42.8 kD,containing protein and uronic acid,and is composed of Man,GalUA,Glc,Gal and Fuc.The structural analysis showed that HMP-w1.1 glycoside bond configuration might be 1→,1→4,1→4,6,1→6,1→2,1→2,6,and HMP-w1.1 glycoside bond configuration might be 1→6,1→2,1→2,6.

Synthesis of β-C-glycosidic nitrate esters

Abstract: A series of novel β-C-glycosidic nitrate esters were synthesized from β-C-glycosidic ketones,through selective protection of the 4,6-position hydroxyl of pyranose ring and nitration reaction using fuming nitric acid in acetic anhydride,which are new candidate compounds for new drug development and structure-activity relationship study.

Sequential Norrish Type II Photoelimination and Intramolecular Aldol Cyclization of α-Diketones: Synthesis of Polyhydroxylated Cyclopentitols by Ring Contraction of Hexopyranose Carbohydrate Derivatives.

Abstract: The excitation of the innermost carbonyl of nono-2,3-diulose derivatives by irradiation with visible-light initiates a sequential Norrish typeII photoelimination and aldol cyclization process that finally gives polyfunctionalized cyclopentitols. The rearrangement has been confirmed by the isolation of stable acyclic photoenol intermediates that can be independently cyclized by a thermal 5-(enolexo)-exo-trig uncatalyzed aldol reaction with high diastereoselectivity. In this last step, the large deuterium kinetic isotope effect found for the 1,5-hydrogen atom transfer seems to indicate that the aldol reaction runs through a concerted pericyclic mechanism. Owing to the ready availability of pyranose sugars of various configurations, this protocol has been used to study the influence of pyranose ring-substituents on the diastereoselectivity of the aldol cyclization reaction. In contrast with other pyranose ring contraction methodologies no transition-metal reagents are needed and the sequential rearrangement occurs simply by using visible light and moderate heating (0 to 60 degrees C).

Cutaneous light aging inhibitor

Abstract: PROBLEM TO BE SOLVED: To provide means for inhibiting cutaneous light aging, and to provide means for utilizing this in the fields of cosmetics, health foods, or medicines.SOLUTION: A cutaneous light aging inhibitor contains, as active ingredients, acid mucopolysaccharides with structure expressed by the general formulas (1), or a physiologically acceptable salt or a derivative thereof. (In the constitutional formula, GalNAcp is a pyranose type N-acetyl galactosamine residue, GlcUAp is a pyranose type glucuronic acid residue, D is a D form, L is an L-form, Pyr is pyruvic acid, and n is a repeated number which expresses that the average molecular weight measured by gel filtration chromatography is 1,000,000-1,500,000 based on pullulan.)

Pyranose derivative containing carbonyl groups, and preparation method of pyranose derivative

Abstract: The invention relates to synthesis of a sugar compound, namely carbohydrate, and particularly relates to an o-dicarbonyl sugar compound and a preparation method of the o-dicarbonyl sugar compound The method comprises the steps of: firstly, protecting carbonyl groups at 2,3-site or 3,4-site of alpha-methyl glucoside which serves as a main raw material, so as to protect the rest carbonyl groups by benzyl groups; secondly, removing 2,3-butanedione to release a pair of adjacent hydroxyl groups; and jointly oxidizing the adjacent hydroxyl groups by trifluoroacetic anhydride and dimethyl sulfoxide, wherein the product mainly exists in an enol form

Synthesis, Characterization, and Crystal Structure of a-Glucosimino-pyranose Anthranilic Acid

Abstract: The new secondary amine, build of glucose and anthranilic acid—a-glucosiminopyranose anthranilic acid (1)—has been synthesized and characterized by elemental analyses, FT-IR and 1 H NMR spectroscopy. Crystal and molecular structure of the hydrate of 1 has been determined by means of X-ray diffraction. 1� H2O crystallizes in monoclinic P21 space group, with a = 15.584(3) A u , b = 4.992(1) A u ,c = 18.928(4) and b = 107.63(3)8. The studies prove that a cyclic secondary amine is formed instead of open chain Schiff base, and only one anomer, a is produced. There are two symmetry-independent mole- cules of 1� H2O in the asymmetric part of the unit cell, and these independent molecules create complicated hydrogen bonded structures—starting with the homomolecular chains which in turn are joined into three dimensional structure. The differences in the supramolecular structures are correlated with the differences in the bond angles pat- terns, which result from the different orientations of certain O-H bonds. The antibacterial activities of 1 were also tested but the results were negative.