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Currently, there are no specific drugs for treating acute pancreatitis. Soluble epoxide hydrolase (sEH) inhibitors show promise, but face challenges like low blood drug concentrations and potential adverse effects on CYP enzymes and the human ether-a-go-go-related gene (hERG). In this study, an approach involving scaffold hopping and structure-activity guided optimization was employed to design a series of phenylquinoline-based sEH inhibitors. Among these compounds, DJ-53 exhibited potent in vitro and in vivo effects in alleviating pain and reducing inflammation. The in vivo mechanism of action involved inhibiting sEH enzyme activity, thereby increasing levels of anti-inflammatory epoxyeicosatrienoic acids (EETs) and decreasing levels of proinflammatory dihydroxyeicosatrienoic acids (DHETs). Importantly, DJ-53 showed exceptional oral bioavailability and pharmacokinetics, while avoiding inhibition of CYP enzymes or the hERG channel. These results highlight DJ-53's potential as a new lead compound for anti-inflammatory and analgesic applications and provide a safe and effective scaffold for developing sEH inhibitors.

An efficient and mild protocol for the visible light-induced radical cascade difluoromethylation/cyclization of imidazoles with unactivated alkenes using easily accessible and bench-stable difluoromethyltriphenylphosphonium bromide as the precursor of the -CF 2 H group has been developed to afford CF 2 H-substituted polycyclic imidazoles in moderate to good yields. This strategy, along with the construction of Csp 3 -CF 2 H/C-C bonds, is distinguished by mild conditions, no requirement of additives, simple operation, and wide substrate scope. In addition, the mechanistic experiments have indicated that the difluoromethyl radical pathway is essential for the methodology., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Described herein is an efficient copper-catalyzed tandem alkyne indolylcupration-initiated 1,2-indole migration/6π-electrocyclic reaction of allene-ynamides with indoles by the in situ-generated metal carbenes. This method allows the efficient synthesis of valuable indole-fused spirobenzo[ f ]indole-cyclohexanes with high regio- and stereoselectivity. In addition, this reaction affords rapid access to the functionalized spirobenzo[ f ]indole-cyclohexanes in the absence of indoles by a presumable 5-exo-dig cyclization/Friedel-Crafts alkylation via copper-containing all-carbon 1,4-dipoles.

A highly convenient copper(I)-catalyzed oxidation-initiated cyclopropanation of indolyl ynamide for the rapid construction of indole-fused cyclopropane-lactams is described, which represents, to the best of our knowledge, the first non-noble-metal-catalyzed indolyl ynamide oxidation/dearomatization by the in situ generated α-oxo copper carbenes. Compared to hydrazone and diazo, the use of alkynes as carbene precursors allows cyclopropanation to occur under a safe and convenient pathway. Moreover, this transformation can lead to the divergent synthesis of pentacyclic spiroindolines involving the reversal of ynamide regioselectivity by engineering substrate structures.

Pyridalyl, as a novel insecticide with an unknown mode of action, has shown excellent control efficacy against lepidopterous larvae and thrips. Previous modifications of this compound have mostly focused on the pyridine moiety, with limited information available about modifications to other parts of pyridalyl. In this paper, we report the synthesis and insecticidal activity of a series of azidopyridryl-containing dichlorolpropene ether derivatives, based on modifications to the middle alkyl chain of pyridalyl. Screening results for insecticidal activity indicate that our synthesized compounds show moderate to high activities at the tested concentrations against P. xylostella . Particularly, compound III-10 exhibits a LC 50 value of 0.831 mg L -1 , compared to the LC 50 value of pyridalyl at 2.021 mg L -1 . Furthermore, compound III-10 also displays a relatively broad insecticidal spectrum against Lepidoptera pests M. separata , C. suppressalis , O. nubilalis , and C. medinalis . Finally, in field trials, III-10 demonstrates better control efficiency against Chilo suppressalis compared to pyridalyl. Overall, our findings suggest that the modification of the middle alkyl chain of pyridalyl may be a promising approach for developing insecticides with improved efficacy.

The significant health implications of e-waste toxicants have triggered the global tightening of regulation on informal e-waste recycling sites (ER) but with disparate governance that requires effective monitoring. Taking advantage of the opportunity to implement e-waste control in the Guiyu ER since 2015, we investigated the temporal variations in levels of oxidative DNA damage, 25 volatile organic compound metabolites (VOCs), and 16 metals/metalloids (MeTs) in urine in 918 children between 2016 and 2021 to demonstrate the effectiveness of e-waste control in reducing population exposure risks. The hazard quotients of most MeTs and levels of 8-hydroxy-2'-deoxyguanosine in children decreased significantly during this time, indicating that e-waste control effectively reduces the noncarcinogenic risks of MeT exposure and levels of oxidative DNA damage. Using mVOC-derived indexes as a feature, a bagging-support vector machine algorithm-based machine learning model was constructed to predict the extent of e-waste pollution (EWP). The model exhibited excellent performance with accuracies >97.0% in differentiating between slight and severe EWP. Five simple functions established using mVOC-derived indexes also had high accuracy in predicting the presence of EWP. These models and functions provide a novel human exposure monitoring-based approach for assessing e-waste governance or the presence of EWP in other ERs.

An efficient and facile visible-light-mediated tandem difluoromethylation/cyclization of alkenyl aldehydes, with easily accessible and air-stable [Ph 3 PCF 2 H] + Br - as the difluoromethylation reagent, has been established. A range of CF 2 H-substituted chroman-4-one skeletons and their derivatives, such as 2,3-dihydroquinolin-4(1 H )-ones, chroman, 3,4-dihydronaphthalen-1(2 H )-one, 2,3-dihydrobenzofuran, and 2,3-dihydro-1 H -inden-1-one, are efficiently produced in moderate to good yields with excellent chemoselectivity under mild reaction conditions.

The abnormal angiogenesis and insufficient oxygen supply in solid tumors lead to intratumoral hypoxia, which severely limits the efficacy of traditional photodynamic therapy (PDT). Here, a multifunctional nanoplatform (ZDZP@PP) based on a zeolitic imidazolate framework-67 (ZIF-67) core as a hydrogen peroxide catalyst, a zeolitic imidazolate framework-8 (ZIF-8) shell with a pH-responsive property, and a polydopamine-poly(ethylene glycol) (PDA-PEG) layer for improving the biocompatibility is fabricated for not only relieving tumor hypoxia but also enhancing the efficacy of combination chemo-photodynamic therapy. The chemotherapy drug doxorubicin (DOX) and photosensitizer protoporphyrin IX (PpIX) are encapsulated in different layers independently; thus, a unique two-stage stepwise release becomes possible. Moreover, the nanoplatform can effectively decompose hydrogen peroxide to produce oxygen and thus relieve tumor hypoxia, which further facilitates the production of cytotoxic reactive oxygen species (ROS) by PpIX under laser irradiation. Both in vitro and in vivo experimental results confirm that the combination chemo-photodynamic therapy with the ZDZP@PP nanoplatform can provide more effective cancer treatment than chemotherapy or PDT alone. Consequently, the oxygen self-sufficient multifunctional nanoplatform holds promising potential to overcome hypoxia and treat solid tumors in the future.

Responsive nanocarriers with biocompatibility and precise drug releasing capability have emerged as a prospective candidate for anticancer treatment. However, the challenges imposed by the complicated preparation process and limited loading capacities have seriously impeded the development of novel multifunctional drug delivery systems. Here, we developed a novel and dual-responsive nanocarrier based on a nanoscale ZIF-8 core and an organosilica shell containing disulfide bridges in its frameworks through a facile and efficient strategy. The prepared ZIF-8@DOX@organosilica nanoparticles (ZDOS NPs) exhibited a well-defined structure and excellent doxorubicin (DOX) loading capability (41.2%) with pH and redox dual-sensitive release properties. The degradation of the organosilica shell was observed after 12 h incubation with a 10 mM reducing agent. Confocal imaging and flow cytometry analysis further proved that the nanocarriers can efficiently enter cells and complete intracellular DOX release under the low pH and high glutathione concentrations, which resulted in an enhanced cytotoxicity of DOX for cancer cells. Meanwhile, subcellular localization experiments revealed that the ZDOS NPs entered cells mainly by endocytosis and then escaped from lysosomes into the cytosol. Moreover, in vivo assays also demonstrated that the ZDOS NPs exhibited negligible systemic toxicity and significantly enhanced anticancer efficiencies compared with free DOX. In summary, our prepared pH and redox dual-responsive nanocarriers provide a potential platform for controlled release and cancer treatment.

The concept of high-performance excited-state intramolecular proton transfer (ESIPT)-based fluorescent metal-organic framework (MOF) probes for Al 3+ is proposed in this work. By regulating the hydroxyl groups on the organic linker step by step, new fluorescent magnesium-organic framework (Mg-MOF) probes for Al 3+ ions were established based on the ESIPT fluorescence mechanism. It is observed for the first time that the number of intramolecular hydrogen bonds between adjacent hydroxyl and carboxyl groups can effectively adjust the ESIPT process and lead to tunable fluorescence sensing performance. Together with the well-designed porous and anionic framework, the Mg-TPP-DHBDC probe decorating with a pair of intramolecular hydrogen bonds exhibits extra-high quantitative fluorescence response to Al 3+ through an unusual turn-off (0-1.2 μM) and turn-on (4.2-15 μM) luminescence sensing mechanism. Notably, the 28 nM limit of detection value represents the lowest record among all reported MOF-based Al 3+ fluorescent sensors up to now. Benefited from the unique turn-off-on ESIPT fluorescence detection process, the Mg-TPP-DHBDC MOF sensor exhibits single Al 3+ detection compared with other 16 common metal ions including Ga 3+ , In 3+ , Fe 3+ , Cr 3+ , Ca 2+ , and Mg 2+ . Impressively, such an Al 3+ selective sensing process can even be fulfilled by the reusable MOF test paper detected by naked eyes. Overall, the quantitative Al 3+ detection, together with the extraordinary sensitivity, selectivity, fast response, and good reusability, strongly supports our concept of ESIPT-based fluorescent MOF Al 3+ probes and makes Mg-TPP-DHBDC one of the most powerful Al 3+ fluorescent sensors.

Vacancy control can significantly enhance the performance of photocatalytic semiconductors for water purification. However, little is known about the mechanisms and approaches that could generate stable large vacancies. Here, we report a new mechanism to induce vacancy formation on nanocrystals for enhanced photocatalytic activity: the introduction of mesopores. We synthesized two nanosheet-assembled hierarchical 3D BiOCl mesoporous nanostructures with similar morphology and exposed facets but different nanosheet thickness. Positron annihilation analysis detected unprecedentedly large V Bi ‴ V O •• V Bi ‴ V O •• V Bi ‴ vacancy associates (as well as V Bi ‴ V O •• V Bi ‴ ) on BiOCl assembled from 3-6 nm nanosheets but only V Bi ‴ V O •• V Bi ‴ vacancy associates on BiOCl assembled from thicker (10-20 nm) nanosheets. Comparison of vacancy properties with 2D ultrathin 2.7 nm nanosheets (with V Bi ‴ V O •• V Bi ‴ and V Bi ‴ ) indicates that nanosheet thinness alone cannot explain the formation of such large atom vacancies. On the basis of density functional theory computations of formation energy of isolated Bi vacancy, we show that mesopores facilitate the formation of large vacancies to counterbalance thermodynamic instability caused by incompletely coordinated Bi and O atoms along the mesopore perimeters. We corroborate that the extraordinarily large V Bi ‴ V O •• V Bi ‴ V O •• V Bi ‴ vacancy associates facilitate photoexcitation of electrons and prevent the recombination of electron-hole pairs, which significantly enhances photocatalytic activity. This is demonstrated by the rapid mineralization of bisphenol A (10 -5 M) with low photocatalyst loading (1 g L -1 ), as well as enhanced bacterial disinfection. Improved electron-hole separation is also corroborated by enhanced photocatalytic reduction of nitrate.

The discovery of triplet excitons participating in the photoluminescent processes in a growing number of pure organic emitters represents an exciting impetus for a diversity of promising opto, bio, and optoelectronic applications. In this contribution, we have studied a small-molecule dithienylbenzothiadiazole-based red-emitting dye red-1b, which shows clearly delayed fluorescence under optical and electrical excitation. The OLED device that contained red-1b as a nondoped solution-processable emitter exhibited a moderately high utilization of exciton amounting to ≈31% and slow efficiency roll-off. Magnetoelectroluminescence measurements revealed the coexistence of reverse intersystem crossing from the lowest triplet state to singlet state (RISC, E-type triplet to singlet up-conversion) and triplet-triplet annihilation (TTA, P-type triplet to singlet up-conversion). Specifically, in low current-density regime, the moderately high exciton utilization is attributed to RISC (i.e., thermally activated delayed fluorescence, TADF), whereas in high current-density regime, TTA may contribute to suppressing efficiency roll-off. Furthermore, the results showed that red-1b may represent a new kind of organic red emitters that display delayed fluorescence in a way differing from the few red emitters investigated so far.

We report here the electrochemistry, spectroscopy, and electrogenerated chemiluminescence (ECL) from a solution, film, and nanoparticles (NPs) of a red-emitting dithienylbenzothiadiazole molecular fluorophore [4,7-bis(4-(n-hexyl)-5-(3,5-di(1-naphthyl)phenyl)thiophen-2-yl)-2,1,3-benzothiadiazole, 1a], which has a donor-acceptor-donor configuration. In addition, the quenching of the fluorescence of the organic NPs by KI was investigated. The 1a film and NPs exhibit two absorbance peaks at 350 and ~504 nm that are red-shifted compared to those of 1a dissolved in solution (340 and 486 nm). Fluorescence quenching of 1a NPs does not follow a linear Stern-Volmer relationship; i.e., the fluorescence emission with excitation wavelength at either 350 or 504 nm decreased with increasing concentration of KI. Static quenching and heterogeneity related to the size distribution of the 1a NPs are proposed to explain the nonlinearity. A lifetime of 4.49 ± 0.04 ns was found for 1a organic NPs in water saturated with N2. After addition of KI, the fluorescence lifetime decreased to 3.1 ns. The fluorescence emission of 1a film/NPs is red-shifted (~17 nm) compared with that of 1a solution in dichloromethane (DCM). Solution ECL was generated in DCM through an annihilation reaction, while film and NP ECL could be generated in water through oxidation with a coreactant, tri-n-propylamine (TPrA). A film of 1a with thickness of 100-900 nm was prepared by drop-casting 1a in DCM on fluorine-doped tin oxide, and the ECL of the 1a film was found in phosphate-buffered saline solution with TPrA. Both 1a in solution and the 1a film produce strong ECL (I(film) = 0.14I(solution)). The ECL spectrum of 1a in solution, produced by electron-transfer annihilation of the reduced and oxidized forms, consists of a single peak with maximum emission at about 637 ± 4 nm, ~20 nm red-shifted from its fluorescence, while the ECL spectrum of 1a film produced by reaction with TPrA consists of a single peak with maximum emission at 642 ± 3 nm, a 10 nm red shift compared with the fluorescence of 1a film. Organic fluorescent 1a NPs were prepared by a reprecipitation method in water saturated with N2, and they were characterized by transmission electron microscopy, absorbance, fluorescence, and ECL. Strong ECL was also generated from the organic NPs in water by reduction with K2S2O8 coreactant.

We report here the electrochemistry and electrogenerated chemiluminescence (ECL) of a red-emitting dithienylbenzothiadiazole-based molecular fluorophore (4,7-bis(4-(4-sec-butoxyphenyl)-5-(3,5-di(1-naphthyl)phenyl)thiophen-2-yl)-2,1,3-benzothiadiazole, 1b). 1b contains two substituted thiophene groups as strong electron donors at the ends connected directly to a strong electron acceptor, 2,1,3-benzothiadiazole, in the center. Each thiophene moiety is substituted in position 2 by 3,5-di(1-naphthyl)phenyl and in position 3 by 4-sec-butoxyphenyl. Cyclic voltammetry of 1b, with scan rate ranging from 0.05 to 0.75 V/s, shows a single one-electron reduction wave (E°(red) = -1.18 V vs SCE) and two nernstian one-electron oxidation waves (E°(1,ox) = 1.01 V, E°(2,ox) = 1.24 V vs SCE). Reduction of the unsubstituted 2,1,3-benzothiadiazole center shows nernstian behavior with E°(red) = -1.56 V vs SCE. By comparison to a digital simulation, the heterogeneous electron-transfer rate constant for reduction, k(r)° = 1.5 × 10(-3) cm/s, is significantly smaller than those for the oxidations, k(o)° > 0.1 cm/s, possibly indicating that the two substituted end groups have a blocking effect on the reduction of the benzothiadiazole center. The ECL spectrum, produced by electron-transfer annihilation of the reduced and oxidized forms, consists of a single peak with maximum emission at about 635 nm, consistent with the fluorescence of the parent molecule. Relative ECL intensities with respect to 9,10-diphenylanthracene are 330% and 470% for the radical anion-cation and radical anion-dication annihilation, respectively. Radical anion (A(-•))-cation (A(+•)) annihilation produced by potential steps shows symmetric ECL transients during anodic and cathodic pulses, while for anion (A(-•))-dication (A(2+•)) annihilation, transient ECL shows asymmetry in which the anodic pulse is narrower than the cathodic pulse. Digital simulation of the transient ECL experiments showed that the origin of the observed asymmetry is asymmetry in the amount of generated charges rather than instability of the electrogenerated species.

Asymmetrically 4,7-disubstituted benzothiadiazole derivatives involving a carbazolyl moiety at one end and a solubilizing dendron at the opposite end have been synthesized and characterized. A two-layer electroluminescent device based on one of these solution-processed molecular emitters revealed a maximal luminous efficiency of approximately 10.6 cd A(-1) and green light emission with CIE coordinates (0.34, 0.58).

New soluble and intrinsic amorphous red emitters 1 and 2 were obtained by Suzuki coupling. Due to the close molecular polarities, separation of target products from monocoupling impurities presents a challenge. The results showed highly pure 2 would be a potentially valuable fluorophore for solution-processed pure red electroluminescence in terms of visual sensitivity with respect to 1.

A series of carbazol-9-yl end-capped red-emitting heteroleptic iridium complexes was readily synthesized using post Suzuki coupling. The appealing solubility, photoluminescent characteristics, and morphological stability enabled the current heteroleptic iridium complexes to be highly desirable phosphorescent dopant emitters in doped light-emitting diodes for the purpose of resisting molecular aggregations in the doped emitting layers.

The chelate phosphine oxide ligand bis(2-(diphenylphosphino)phenyl) ether oxide (DPEPO) was used as a unit neutral ligand to prepare the complex Eu(TTA)(3)(DPEPO) 1 (TTA = 2-thenoyltrifluoroacetonate). Compound 1 has a photoluminescence (PL) quantum yield of 55.3%, which is more than the twice of the PL quantum yield of Eu(TTA)(3)(TPPO)(2) (TPPO = triphenylphosphine oxide). Investigation indicated that DPEPO in 1 has the mezzo first triplet excited energy level (T(1)) between the first singlet excited energy level (S(1)) and T(1) of TTA, which may support one more additional energy transfer routines from the T(1) energy level of DPEPO to that of TTA, and consequently results in the improvement of energy transfer in the Eu(III) complex. DPEPO forms a complex with a more rigid and compact structure that can improve energy transfer between ligands and the center Eu(III) ion, support the higher saturation level by the coordinating ability of the oxygen atom in the ether moiety, and consequently enhance the PL intensity and efficiency of the corresponding Eu(III) complex. The multilayered electroluminescent (EL) device of 1 used as the red dopant exhibited an impressive brightness of 632 cd m(-2) at 25 V. The device had the excellent voltage-independent spectral stability with an emission peak at 615 nm. To the best of our knowledge, this luminescence is the brightest emission among Eu complexes with phosphine oxide ligands. The maximum external quantum yield (eta(ext)) of 2.89% and the maximum current and power efficiency of 4.58 cd A(-1) and 2.05 lm W(-1) were achieved at a low turn-on voltage of 7 V and current density of 0.021 mA cm(-2). These properties demonstrate that the chelate phosphine oxides ligand DPEPO can not only be favorable to form the rigid and compact complex structure and increase the efficiency of devices, but also reduce the ability of the formation of exciplex. DPEPO shows much better performance compared with the ordinary phosphine oxide ligand triphenylphosphine oxide.

2,2'-bithiophene derivatives, 5-ammoniumethylsulfanyl-2,2'-bithiophene (AESBT) and 5,5'-bis(ammoniumethylsulfanyl)-2,2'-bithiophene (BAESBT), have been designed for their incorporation in organic-inorganic materials based on iodometalates. Three layered compounds, (BAESBT)PbI(4), (AESBT)(4)Pb(3)I(10), and (AESBT)(3)Bi(2)I(9), have been synthesized as crystals from slowly cooled aqueous solution containing metal halide and bithiophene derivative salts. When starting from the diammonium cation, (BAESBT)PbI(4) hybrid perovskite is obtained. (BAESBT)PbI(4) adopts a triclinic cell (P1) with the lattice parameters a = 8.4741(5) A, b = 8.9255(6) A, c = 16.876(1) A, alpha = 88.328(5) degrees, beta = 81.806(4) degrees, gamma = 88.864(5) degrees, Z = 2. In the structure, PbI(4)(2)(-) perovskite sheets and diammonium cation layers alternate along c. The incorporation of the corresponding monoammonium cation (AESBT) leads to a head to tail arrangement of the molecules in the (AESBT)(4)Pb(3)I(10) hybrid, precluding the formation of the perovskite layers. (AESBT)(4)Pb(3)I(10) is orthorhombic, Pna2(1), with a = 38.333(4) A, b = 22.239(3) A, c = 8.448(2) A, Z = 4. The structure consists of corrugated layers of Pb(3)I(10)(4)(-) separated by organic layers of monoammonium cations. A similar relative situation of molecules in organic layers is observed in (AESBT)(3)Bi(2)I(9), with the inorganic sheets being built up from Bi(2)I(9)(3)(-) entities. (AESBT)(3)Bi(2)I(9) crystallizes in an orthorhombic cell (P2(1)2(1)2(1)) with a = 8.4564(6) A, b = 21.368(2) A, c = 30.747(2) A, Z = 4. In the three compounds, the molecular packings appear different, underlining the interplay between both organic and inorganic components. New packings are stabilized, as illustrated by an original mixed kappa-alpha type arrangement of the bithiophene units in (AESBT)(3)Bi(2)I(9). Furthermore, molecular interactions, especially of S.S type, appear stronger in the hybrids based on the monoammonium cations. The electrical conductivity of a (BAESBT)PbI(4) single crystal has also been investigated, revealing a semiconductive behavior with a characteristic energy of E(g) = 2.535 eV.

We have examined the cross-relaxation behavior among the protons of oyster glycogen using nuclear Overhauser enhancement (NOE). Steady-state and transient NOEs were generated using low-power CW irradiation and frequency-selective inversions. In D2O, saturation of glycogen H2 and H4' at 3.64 ppm gave a strong negative NOE (eta = -0.74) at H1. The NOE was similar to the value predicted by the correlation time (tau c) calculated from the T1 and T2 of glycogen H1 in D2O assuming an isotropic rigid motor dipole-dipole model. Selective inversion of H2 and H4' gave a transient NOE at H1. In D2O, selective inversion of H1 also led to negative transient NOEs in the H2 + H4', H3, and H5 resonances. The magnitude and rates of appearance of the NOEs in H3 and H5 were too large to arise from direct H1-H3 and H1-H5 dipolar interactions, but were consistent with very efficient cross-relaxation leading to large second-order NOEs. The glycogen H1 NOE in H2O was also studied. Replacement of D2O with H2O as solvent significantly reduced the steady-state NOE at H1 following saturation of H2 + H4'. Saturation of the water resonance caused a large negative NOE at H1 (eta = -0.55) consistent with our earlier study which indicated that there was no direct dipolar interaction between H1 and free H2O.

The NMR relaxation properties of the H1 proton of oyster glycogen in D2O and H2O solutions have been studied using nonselective, semiselective, and selective inversion recovery and Hahn spin-echo pulse sequences. The data were analyzed in terms of an isotropic, rigid-rotor dipole-dipole model including cross-relaxation. At 8.4 T in D2O, p = 5.4 +/- 0.4 s-1 and sigma = -4.5 +/- 0.4 s-1. The large, negative sigma value is consistent with strong cross-relaxation and a long correlation time. The relaxation data can be explained by a single correlation time, tau c = 2.7 x 10(-9) s, indicating significant internal mobility. With this value of tau c, and assuming that the structure of the glucose moieties was the same as in alpha-D-glucose crystals, the dipole sum contributing to T1 relaxation was calculated. The intra-ring relaxation was dominated by dipole fields from the H2 proton, but these only accounted for approximately 18% of the total relaxation. Most of the relaxation comes from inter-glucose relaxation. From modeling, this is dominated by the H4' across the alpha-1,4-glycosidic bond. The H1 longitudinal relaxation rates were significantly enhanced in H2O compared with D2O. This enhancement is not due to direct dipolar interaction between H1 and bulk water. Transverse relaxation rates were not significantly enhanced in H2O.