Antioxidant properties of rare sugar D-allose: Effects on mitochondrial reactive oxygen species production in Neuro2A cells

Antioxidants of commercial interest from Homalium tomentosum attenuates hepatocellular necrosis: Insights from experimental and computational studies

Homalium tomentosum (Vent.) Benth, is a valuable agroforestry species and has industrial importance high-quality wood is used for malas, the manufacture of matches, and is suitable for making a wide range of articles. Nevertheless, leaves and bark are relatively rich in phenols and flavonoids, used for medicinal purposes. In this study, phenols and flavonoids rich in bio-privileged antioxidants in ethyl-acetate extracted fractions of bark (HTEB), and leaves (HTEL) at 300, and 400 mg/kg were examined in carbon tetrachloride (CCl4)-induced hepatotoxicity in experimental rats. HTEB and HTEL (400) showed improvement in liver structural integrity, but, HTEB400 significantly improved serum (total protein, TP; alkaline phosphatase, ALP; total bilirubin, TB; serum glutamate oxaloacetate transaminase, SGOT, and serum glutamate pyruvate transaminase, SGPT), and hepatic oxidative (catalase, CAT; thiobarbituric acid reactive species, TBARS; reduced glutathione, GSH; superoxide dismutase, SOD), and inflammatory (transforming growth factor, TGF-β; ineterleukin-6, IL-6) biomarkers accompanied by histopathological improvements of the liver. GC-MS analysis of HTEB and HTEL identified 14 and 18 compounds, but physicochemical properties of 3-major antioxidants of HTEB (levoglucosenone, (+)-borneol, α-N-normethadol), and HTEL (2-coumaranone, salicyl alcohol, D-allose) were satisfied for the parameters molecular weight, no. of H-acceptor and H-donor, partition co-efficient (clogP), and topological polar surface area (tPSA) of Lipinski's rule. ADME-Tox properties were directly related to the biological activities of HTEB and HTEL. Molecular docking investigation of α-N-normethadol showed the highest binding energy against TGF-β and IL-6 than other antioxidants. HTEB and HTEL were powerful antioxidant potential, but levoglucosenone, (+)-borneol, and α-N-normethadol of HTEB demonstrated better activities in neutralizing reactive oxygen species (ROS) to preserve cellular membrane integrity in liver cirrhosis as found evidence in restoring the liver inflammatory cytokines. This study confirmed the economic interest of H. tomentosum bark as crude material for the preparation of biobased materials for the pharmaceutical and food industries.

Effects of D-Allose on experimental cardiac hypertrophy

The hallmark of pathological cardiac hypertrophy is the decline in myocardial contractility caused by an energy deficit resulting from metabolic abnormalities, particularly those related to glucose metabolism. Here, we aim to explore whether D-Allose, a rare sugar that utilizes the same transporters as glucose, may restore metabolic equilibrium and reverse cardiac hypertrophy. Isolated neonatal rat cardiomyocytes were stimulated with phenylephrine and treated with D-Allose simultaneously for 48 h. D-Allose treatment resulted in a pronounced reduction in cardiomyocyte size and cardiac remodelling markers accompanied with a dramatic reduction in the level of intracellular glucose in phenylephrine-stimulated cells. The metabolic flux analysis provided further insights revealing that D-Allose exerted a remarkable inhibition of glycolysis as well as glycolytic capacity. Furthermore, in mice subjected to a 14-day continuous infusion of isoproterenol (ISO) to induce cardiac hypertrophy, D-Allose treatment via drinking water notably reduced ISO-induced cardiac hypertrophy and remodelling markers, with minimal effects on ventricular wall thickness observed in echocardiographic analyses. These findings indicate that D-Allose has the ability to attenuate the progression of cardiomyocyte hypertrophy by decreasing intracellular glucose flux and inhibiting glycolysis.

Novel Strategy for Human Deep Vein Thrombosis Diagnosis Based on Metabolomics and Stacking Machine Learning

Deep vein thrombosis (DVT) is a serious health issue that often leads to considerable morbidity and mortality. Diagnosis of DVT in a clinical setting, however, presents considerable challenges. The fusion of metabolomics techniques and machine learning methods has led to high diagnostic and prognostic accuracy for various pathological conditions. This study explored the synergistic potential of dual-platform metabolomics (specifically, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS)) to expand the detection of metabolites and improve the precision of DVT diagnosis. Sixty-one differential metabolites were identified in serum from DVT patients: 22 from GC-MS and 39 from LC-MS. Among these, five key metabolites were highlighted by SHapley Additive exPlanations (SHAP)-guided feature engineering and then used to develop a stacking diagnostic model. Additionally, a user-friendly interface application system was developed to streamline and automate the application of the diagnostic model, enhancing its practicality and accessibility for clinical use. This work showed that the integration of dual-platform metabolomics with a stacking machine learning model enables faster and more accurate diagnosis of DVT in clinical environments.

Long-term d-allose administration ameliorates age-related cognitive impairment and loss of bone strength in male mice

Age-related physical and cognitive decline may be ameliorated by consuming functional foods. d-Allose, reported to have multiple health benefits, may temper aging phenotypes, particularly brain function. We investigated whether d-allose supplementation improves cognitive function. A standard battery of behavioral tests was administered to 18-month-old male mice after consuming diet containing 3 % d-allose for 6 months. Following a wire-hanging test, an open-field test, Morris water maze, fear-conditioning, and an analgesia test were sequentially performed. Bone density and strength were assessed afterwards. Possible mechanism(s) under-lying memory changes in hippocampus were also examined with a DNA microarray. d-Allose failed to influence muscle strength, locomotor activity and anxiety, fear memory, or pain sensitivity. However, d-allose improved hippocampus-dependent spatial learning and memory, and it may contribute to increase bone strength. d-Allose also changed the expression of some genes in hippocampus involved in cognitive functions. Long-term d-allose supplementation appears to modestly change aging phenotypes and improve spatial memory.

Effects of d-allose on anti-brain edema effects and reduction of tumor necrosis factor-alpha and interleukin-6 in the water intoxication model

Rare sugars, which exist only in very small quantities in nature, have recently attracted attention for their various biological functions in medicine. Among them, d-allose is known to have cytoprotective effects by antioxidant effects. In this study, we investigated whether the antioxidant effects of d-allose reduce brain edema in a water intoxication model of cytotoxic brain edema. Methods: Mice were injected intraperitoneally with distilled water (10 % of body weight) to create a model of brain edema. d-allose was administered orally at 400 mg/kg 30 min before the model was created. Two hours later, the degree of brain edema was measured by the dry-weight method to determine whether d-allose reduced brain edema. As an index of antioxidant effects, we measured changes over time in inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6) induced by the water intoxication model, and whether d-allose reduced inflammatory cytokines 4 h after model creation. Results: Administration of d-allose significantly suppressed brain edema formation of the water-intoxication model. And it significantly reduced inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6). These results suggest that the antioxidant effect of d-allose exerts an anti-inflammatory effect and reduces brain edema.

D-allose, a typical rare sugar: properties, applications, and biosynthetic advances and challenges

D-allose, a C-3 epimer of D-glucose and an aldose-ketose isomer of D-allulose, exhibits 80% of sucrose's sweetness while being remarkably low in calories and nontoxic, making it an appealing sucrose substitute. Its diverse physiological functions, particularly potent anticancer and antitumor effects, render it a promising candidate for clinical treatment, garnering sustained attention. However, its limited availability in natural sources and the challenges associated with chemical synthesis necessitate exploring biosynthetic strategies to enhance production. This overview encapsulates recent advancements in D-allose's physicochemical properties, physiological functions, applications, and biosynthesis. It also briefly discusses the crucial role of understanding aldoketose isomerase structure and optimizing its performance in D-allose synthesis. Furthermore, it delves into the challenges and future perspectives in D-allose bioproduction. Early efforts focused on identifying and characterizing enzymes responsible for D-allose production, followed by detailed crystal structure analysis to improve performance through molecular modification. Strategies such as enzyme immobilization and implementing multi-enzyme cascade reactions, utilizing more cost-effective feedstocks, were explored. Despite progress, challenges remain, including the lack of efficient high-throughput screening methods for enzyme modification, the need for food-grade expression systems, the establishment of ordered substrate channels in multi-enzyme cascade reactions, and the development of downstream separation and purification processes.

Foliar Application of Nanoparticles Reduced Cadmium Content in Wheat (Triticum aestivum L.) Grains via Long-Distance "Leaf-Root-Microorganism" Regulation

Foliar application of beneficial nanoparticles (NPs) exhibits potential in reducing cadmium (Cd) uptake in crops, necessitating a systematic understanding of their leaf-root-microorganism process for sustainable development of efficient nano-enabled agrochemicals. Herein, wheat grown in Cd-contaminated soil (5.23 mg/kg) was sprayed with different rates of four commonly used NPs, including nano selenium (SeNPs)/silica (SiO2NPs)/zinc oxide/manganese dioxide. SeNPs and SiO2NPs most effectively reduced the Cd concentration in wheat grains. Compared to the control, Cd concentration in grains was significantly decreased by 35.0 and 33.3% by applying 0.96 mg/plant SeNPs and 2.4 mg/plant SiO2NPs, and the grain yield was significantly increased by 33.9% with SeNPs application. Down-regulated gene expression of Cd transport proteins (TaNramp5 and TaLCT1) and up-regulated gene expression of vacuolar Cd fixation proteins (TaHMA3 and TaTM20) were observed with foliar SeNPs and SiO2NPs use. SeNPs increased the levels of leaf antioxidant metabolites. Additionally, foliar spray of SeNPs resulted in lower abundances of rhizosphere organic acids and reduced Cd bioavailability in rhizosphere soil, and soil microorganisms related to carbon and nitrogen (Solirubrobacter and Pedomicrobium) were promoted. Our findings underscore the potential of the foliar application of SeNPs and SiO2NPs as a plant and rhizosphere soil metabolism-regulating approach to reduce Cd accumulation in wheat grains.

Effects of D-allose on ATP production and cell viability in neonatal rat cardiomyocytes

2-Deoxy-d-glucose (2DG) induces anticancer effects through glycolytic inhibition but it may raise the risk of arrhythmia. The rare monosaccharide d-allose also has anticancer properties, but its cardiac effects are unknown. We examined the effects of d-allose on adenosine triphosphate (ATP) production in neonatal rat cardiomyocytes. We showed that 25 mM d-allose selectively reduced glycolytic ATP, but had minimal impact on mitochondrial ATP, while 1 mM 2DG strongly inhibited both. Furthermore, d-allose had less impact on cell viability and was less cytotoxic than 2DG; neither compound caused apoptosis. Thus, d-allose selectively diminished glycolytic ATP production with no apparent effects on cardiomyocytes.

A comprehensive review of recent advances in the characterization of L-rhamnose isomerase for the biocatalytic production of D-allose from D-allulose

D-Allose and D-allulose are two important rare natural monosaccharides found in meager amounts. They are considered to be the ideal substitutes for table sugar (sucrose) for, their significantly lower calorie content with around 80 % and 70 % of the sweetness of sucrose, respectively. Additionally, both monosaccharides have gained much attention due to their remarkable physiological properties and excellent health benefits. Nevertheless, D-allose and D-allulose are rare in nature and difficult to produce by chemical methods. Consequently, scientists are exploring bioconversion methods to convert D-allulose into D-allose, with a key enzyme, L-rhamnose isomerase (L-RhIse), playing a remarkable role in this process. This review provides an in-depth analysis of the extractions, physiological functions and applications of D-allose from D-allulose. Specifically, it provides a detailed description of all documented L-RhIse, encompassing their biochemical properties including, pH, temperature, stabilities, half-lives, metal ion dependence, molecular weight, kinetic parameters, specific activities and specificities of the substrates, conversion ratio, crystal structure, catalytic mechanism as well as their wide-ranging applications across diverse fields. So far, L-RhIses have been discovered and characterized experimentally by numerous mesophilic and thermophilic bacteria. Furthermore, the crystal forms of L-RhIses from E. coli and Stutzerimonas/Pseudomonas stutzeri have been previously cracked, together with their catalytic mechanism. However, there is room for further exploration, particularly the molecular modification of L-RhIse for enhancing its catalytic performance and thermostability through the directed evolution or site-directed mutagenesis.

D-allose Inhibits TLR4/PI3K/AKT Signaling to Attenuate Neuroinflammation and Neuronal Apoptosis by Inhibiting Gal-3 Following Ischemic Stroke

BACKGROUND

Ischemic stroke (IS) occurs when a blood vessel supplying the brain becomes obstructed, resulting in cerebral ischemia. This type of stroke accounts for approximately 87% of all strokes. Globally, IS leads to high mortality and poor prognosis and is associated with neuroinflammation and neuronal apoptosis. D-allose is a bio-substrate of glucose that is widely expressed in many plants. Our previous study showed that D-allose exerted neuroprotective effects against acute cerebral ischemic/reperfusion (I/R) injury by reducing neuroinflammation. Here, we aimed to clarify the beneficial effects D-allose in suppressing IS-induced neuroinflammation damage, cytotoxicity, neuronal apoptosis and neurological deficits and the underlying mechanism in vitro and in vivo.

METHODS

In vivo, an I/R model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R) in C57BL/6 N mice, and D-allose was given by intraperitoneal injection within 5 min after reperfusion. In vitro, mouse hippocampal neuronal cells (HT-22) with oxygen-glucose deprivation and reperfusion (OGD/R) were established as a cell model of IS. Neurological scores, some cytokines, cytotoxicity and apoptosis in the brain and cell lines were measured. Moreover, Gal-3 short hairpin RNAs, lentiviruses and adeno-associated viruses were used to modulate Gal-3 expression in neurons in vitro and in vivo to reveal the molecular mechanism.

RESULTS

D-allose alleviated cytotoxicity, including cell viability, LDH release and apoptosis, in HT-22 cells after OGD/R, which also alleviated brain injury, as indicated by lesion volume, brain edema, neuronal apoptosis, and neurological functional deficits, in a mouse model of I/R. Moreover, D-allose decreased the release of inflammatory factors, such as IL-1β, IL-6 and TNF-α. Furthermore, the expression of Gal-3 was increased by I/R in wild-type mice and HT-22 cells, and this factor further bound to TLR4, as confirmed by three-dimensional structure prediction and Co-IP. Silencing the Gal-3 gene with shRNAs decreased the activation of TLR4 signaling and alleviated IS-induced neuroinflammation, apoptosis and brain injury. Importantly, the loss of Gal-3 enhanced the D-allose-mediated protection against I/R-induced HT-22 cell injury, inflammatory insults and apoptosis, whereas activation of TLR4 by the selective agonist LPS increased the degree of neuronal injury and abolished the protective effects of D-allose.

CONCLUSIONS

In summary, D-allose plays a crucial role in inhibiting inflammation after IS by suppressing Gal-3/TLR4/PI3K/AKT signaling pathway in vitro and in vivo.

Safety evaluation and maximum use level for transient ingestion in humans of allitol

Allitol is a hexitol produced by reducing the rare sugar D-allulose with a metal catalyst under hydrogen gas. To confirm the safe level of allitol, we conducted a series of safety assessments. From the results of Ames mutagenicity assay using Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537, Escherichia coli strain WP2uvrA, and an in vitro chromosomal aberration test on cultured Chinese hamster cells, allitol did not show any significant genotoxic effect. No significant effects on general condition, urinalysis, hematology, physiology, histopathology, or at necropsy were observed at a dose of 1500 mg/kg body weight of allitol in the acute and 90-day subchronic oral-toxicity assessments for rats. A further study performed on healthy adult humans showed that the acute use level of allitol for diarrhea was 0.2 g/kg body weight for both men and women. The results of current safety assessment studies suggest that allitol is safe for human consumption.

Indian jujube a potential fruit tree to improve the livelihood

Indian Jujube, also known as Ber or Ziziphus Mauritiana Lam., is a fruit-bearing tree endemic to South Asia, including India, Pakistan, Bangladesh, and Sri Lanka. The tree belongs to the buckthorn family and is known for its fruit, a tiny, round, or oblong-shaped drupe roughly the size of a cherry or a small plum. Indian Jujube has been growing for thousands of years. It is a popular fruit throughout the tropical and subtropical regions of Asia, Africa, and South America. Despite the fruit's delicious flavour and health benefits, it is also known for its therapeutic value. Many studies have suggested that various components of ber trees, such as fruit, seed leaves, roots, and flowers, include bioactive substances that demonstrate the potential for antioxidant activity and have anticancer, antibacterial, and antidiabetic effects. Due to the crop's minimal management requirements, it may slow down climate change and the threat of extreme soil and weather conditions, such as drought resistance, strong winds, erosion, high salt, and floods. The main objectives of the current systematic review are to understand Ber's chemical compositions, health benefits, culinary uses, major nutraceutical features, and its function in fostering livelihoods and climatic tolerance.

The gut microbiome promotes arsenic metabolism and alleviates the metabolic disorder for their mammal host under arsenic exposure

Gut microbiome can participate in arsenic metabolism. However, its efficacy in the host under arsenic stress is still controversial. To clarify their roles in fecal arsenic excretion, tissue arsenic accumulation, host physiological states and metabolism, in this study, ninety-six C57BL/6 male mice were randomly divided to four groups, groups A and B were given sterile water, and groups C and D were given the third generation of broad-spectrum antibiotic (ceftriaxone) to erase the background gut microbiome. Subsequently, groups B and D were subchronicly exposed to arsenic containing feed prepared by adding arsenical mixture (rice arsenic composition) into control feed. In group D, the fecal total arsenic (C_tAs) decreased by 25.5 %, iAs^III composition increased by 46.9 %, unclarified As (uAs) composition decreased by 92.4 %, and the liver C_tAs increased by 26.7 %; the fecal C_tAs was positively correlated with microbial richness and some metabolites (organic acids, amino acids, carbohydrates, SCFAs, hydrophilic bile acids and their derivatives); and fecal DMA was positively correlated with microbial richness and some metabolites (ferulic acid, benzenepropanoic acid and pentanoic acid); network analysis showed that the numbers of modules, nodes, links were decreased and vulnerability was increased; some SCFAs and hydrophilic bile acid decreased, and hydrophobic bile acids increased (Ps < 0.05). In the tissue samples of group D, Il-18 and Ifn-γ gene expression increased and intestinal barrier-related genes Muc2, Occludin and Zo-1 expression decreased (Ps < 0.05); serum glutathione and urine malondialdehyde significantly increased (Ps < 0.05); urine metabolome significantly changed and the variation was correlated with six SCFAs-producing bacteria, and some SCFAs including isobutyric acid, valeric acid and heptanoic acid decreased (Ps < 0.05). Therefore, the normal gut microbiome increases fecal arsenic excretion and biotransformation, which can maintain a healthier microbiome and metabolic functions, and alleviate the metabolic disorder for their mammal host under arsenic exposure.

Engineering of Escherichia coli for D-allose fermentative synthesis from D-glucose through izumoring cascade epimerization

D-Allose is a potential alternative to sucrose in the food industries and a useful additive for the healthcare products in the future. At present, the methods for large-scale production of D-allose are still under investigation, most of which are based on in vitro enzyme-catalyzed Izumoring epimerization. In contrast, fermentative synthesis of D-allose has never been reported, probably due to the absence of available natural microorganisms. In this work, we co-expressed D-galactose: H+ symporter (GalP), D-glucose isomerase (DGI), D-allulose 3-epimerase (DAE), and ribose-5-phosphate isomerase (RPI) in Escherichia coli, thereby constructing an in vivo Izumoring pathway for yielding D-allose from D-glucose. The carbon fluxes and carbon catabolite repression (CCR) were rationally regulated by knockout of FruA, PtsG, Glk, Mak, PfkA, and PfkB involved in the pathways capable of phosphorylating D-fructose, D-glucose, and fructose-6-phosphate. Moreover, the native D-allose transporter was damaged by inactivation of AlsB, thus driving the reversible Izumoring reactions towards the target product. Fermentation was performed in the M9 medium supplemented with glycerol as a carbon source and D-glucose as a substrate. The results show that the engineered E. coli cell factory was able to produce approximately 127.35 mg/L of D-allose after 84 h. Our achievements in the fermentative production of D-allose in this work may further promote the green manufacturing of rare sugars.

Immunomodulatory effects of D-allose on cytokine production by plasmacytoid dendritic cells

D-Allose is classified as a 'rare sugar,' i.e., part of the group of monosaccharides that are present in low quantities in the natural world. D-Allose has been demonstrated to exert many physiological functions. The effects of the rare sugars on immune responses are largely unexplored. Here, we investigated the physiological effects of D-allose on murine dendritic cells' cytokine production. When plasmacytoid dendritic cells (pDCs) were stimulated with a Toll-like receptor 7 (TLR7) ligand, a single-stranded RNA (ssRNA), or a TLR9 ligand, CpG DNA, in the medium containing D-allose, the productions of both interferon-alpha (IFN-α) and interleukin (IL)-12p40 were severely decreased. In contrast, a normal production of these cytokines was observed when pDCs were stimulated with other TLR7 ligands, an imidazoquinoline, or a guanosine analog. In contrast to the pDCs, conventional dendritic cells (cDCs) produced IL-12p40 and tumor necrosis factor-alpha (TNF-α) in response to an imidazoquinoline or CpG DNA even though D-allose was present in the medium. D-Allose did not induce pDC death, and not inhibit the endocytic uptake of fluorophore-labeled CpG DNA into pDCs. These results suggested that D-allose exerts its inhibitory effects after CpG DNA is internalized. We analyzed the TLR7/9 signal-induced activation of downstream signaling molecules in pDCs and observed that when pDCs were stimulated with a ssRNA or CpG DNA, the phosphorylation status of the MAPK family, which includes Erk1/2, JNK/SAPK, and p38 MAPK, was attenuated in the presence of D-allose compared to D-glucose controls. The stimulation of pDCs with an imidazoquinoline induced a strong phosphorylation of these MAPK family members even in the presence of D-allose. These findings reveal that D-allose can inhibit the cytokine production by pDCs stimulated with ssRNA or CpG DNA via an attenuation of the phosphorylation of MAPK family members.

D-Allose, a rare sugar. Synthesis of D-allopyranosyl acceptors from glucose, and their regioselectivity in glycosidation reactions

Although D-allose (D-All) is a sugar with low natural abundance, it has great pharmacological and alimentary potential due to its biological properties. However, its chemistry, regarding the regioselectivity in protective reactions and glycosidations, has been scarcely explored. Glycobiological studies require appreciable quantities of carbohydrates with defined structures and high purity. Thus, the development of efficient strategies for their synthesis is crucial. In this frame, the knowledge of the regioselectivity between different hydroxyl groups of glycosyl acceptors is valuable because it allows minimizing the use of protecting groups. We have long been interested in the relative reactivity of OH-3 and OH-4 of glycosyl acceptors in glycosidation reactions. In this paper we synthesized D-allose glycopyranosyl acceptors with free OH-3 and OH-4 from D-Glc precursors. We assessed glycosidations with galactose trichloroacetimidates as donors and the experimental results were compared with those obtained by molecular modeling. Axial O-3 was the preferred site of glycosylation for α-anomers, whereas equatorial O-4 was the preferred site for a β-anomer. A good correlation between the experimental and modeling results was observed using atomic charges and cationic intermediates, although Fukui indices did not predict adequately the experimental results. The achieved regioselectivities are useful for the efficient design of oligosaccharide synthesis containing D-All moieties.

Biochemical and metabolic responses of the deep-sea mussel Bathymodiolus platifrons to cadmium and copper exposure

Greater interest in commercial deep-sea mining has been accompanied by mounting environmental concerns, including metal contamination resulting from mining activities. However, little is known about the toxic effects of metal exposure on deep-sea life. Given its ability to accumulate metals from the surrounding environment, its wide distribution at both vents and seeps, and its high abundance, the deep-sea mussel Bathymodiolus platifrons could serve as an ideal model to investigate the toxicological responses of deep-sea organisms to metal exposure. Here, we evaluated metal accumulation, traditional metal-related biomarkers, namely acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase, catalase, reduced glutathione, metallothioneins, and malondialdehyde, as well as metabolic profiles in the gills of B. platifrons after a 7-day exposure to copper (100 μg/L), cadmium (500 μg/L), or copper-plus-cadmium treatments (100 μg/L Cu and 500 μg/L Cd). Metal exposure concentrations selected in this study can be found in deep-sea hydrothermal environments. Metal exposure resulted in significant metal accumulation in the gills of the mussel, indicating that B. platifrons has promise for use as an indicator of deep-sea metal pollution levels. Traditional biomarkers (AKP, ACP, and measured antioxidants) revealed cellular injury and oxidative stress in mussels following metal exposure. Metabolic responses in the three treatment groups indicated that metal exposure perturbed osmoregulation, energy metabolism, and nucleotide metabolism in mussels, in a response marked by differentially altered levels of amino acids, hypotaurine, betaine, succinate, glucose 6-phosphate, fructose 6-phosphate, guanosine, guanosine 5'-monophosphate, and inosine. Nevertheless, several uniquely altered metabolites were found in each treatment exposure group, suggesting dissimilar modes of toxicity between the two metal types. In the Cd-exposed group, the monosaccharide D-allose, which is involved in suppressing mitochondrial ROS production, was downregulated, a response consistent with oxidative stress in Cd-exposed B. platifrons. In the Cu-exposed group, the detected alterations in dopamine, dopamine-related, and serotonin-related metabolites together suggest disturbed neurotransmission in Cu-exposed B. platifrons. In the Cu-plus-Cd group, we detected a decline in fatty acid levels, implying that exposure to both metals jointly exerted a negative influence on the physiological functioning of the mussel. To the best of our knowledge, this is the first study to investigate changes in metabolite profiles in Bathymodiolus mussels exposed to metal. The findings reported here advance our understanding of the adverse impact of metal exposure on deep-sea life and can inform deep-sea mining assessments through the use of multiple biomarkers.

Kefir metabolites in a fly model for Alzheimer's disease

Alzheimer's Disease (AD) is the most common cause of dementia among elderly individuals worldwide, leading to a strong motor-cognitive decline and consequent emotional distress and codependence. It is traditionally characterized by amyloidogenic pathway formation of senile plaques, and recent studies indicate that dysbiosis is also an important factor in AD's pathology. To overcome dysbiosis, probiotics-as kefir-have shown to be a great therapeutic alternative for Alzheimer's disease. In this present work, we explored kefir as a probiotic and a metabolite source as a modulator of microbiome and amyloidogenic pathway, using a Drosophila melanogaster model for AD (AD-like flies). Kefir microbiota composition was determined through 16S rRNA sequencing, and the metabolome of each fraction (hexane, dichloromethane, ethyl acetate, and n-butanol) was investigated. After treatment, flies had their survival, climbing ability, and vacuolar lesions accessed. Kefir and fraction treated flies improved their climbing ability survival rate and neurodegeneration index. In conclusion, we show that kefir in natura, as well as its fractions may be promising therapeutic source against AD, modulating amyloidogenic related pathways.

Characteristics of rice starch film blended with sugar (trehalose/allose) and oil (canola oil/coconut oil): Part I - Filmogenic solution behavior and mechanical properties

The concentrations effects of sugars (trehalose and allose) and oils (canola and coconut oil) on the characteristics of rice starch suspension and mechanical properties of rice starch film were studied. The samples were prepared using 3% (w/w) rice starch, with 10% or 30% (w/w) sugar (trehalose or allose) added and 10% or 30% (w/w) oil (canola or coconut). The droplet size of the film suspension increased with increasing oil concentration both in trehalose and allose, which blended with oil. The flow behavior of the film suspensions showed shear-thinning behavior as calculated by the Power Law model. The apparent viscosity tended to increase with the addition of sugar and oil. The breaking stress of the films blended with sugar and oil was less than that of control. On preparation day and after 7 days' storage, the breaking strain tended to increase more with the addition of coconut oil than with that of canola oil. However, breaking stress and breaking strain decreased after 28 days' storage. Adding sugar had correlation with mechanical properties whereas adding oil had correlation with film suspension characteristics, allowed the sugar and oil to interact and inhibited starch chain mobility due to concentration, sugar type, and oil type. PRACTICAL APPLICATION: Trehalose, allose, canola oil, and coconut oil could be used as a plasticizer in a starch edible/biodegradable film system. The preparation process of filmogenic solution was depended on the combination of sugar and oil that could change the flow behavior and affected the mechanical properties of the edible film. The sugar and oil might improve the mechanical properties of the film by a hydroxyl group of sugar and lubricating properties of the oil.

Rare mono- and disaccharides as healthy alternative for traditional sugars and sweeteners?

Obesity and type 2 diabetes are major health problems affecting hundreds of millions of people. Caloric overfeeding with calorie-dense food ingredients like sugars may contribute to these chronic diseases. Sugar research has also identified mechanisms via which conventional sugars like sucrose and fructose can adversely influence metabolic health. To replace these sugars, numerous sugar replacers including artificial sweeteners and sugar alcohols have been developed. Rare sugars became new candidates to replace conventional sugars and their health effects are already reported in individual studies, but overviews and critical appraisals of their health effects are missing. This is the first paper to provide a detailed review of the metabolic health effects of rare sugars as a group. Especially allulose has a wide range of health effects. Tagatose and isomaltulose have several health effects as well, while other rare sugars mainly provide health benefits in mechanistic studies. Hardly any health claims have been approved for rare sugars due to a lack of evidence from human trials. Human trials with direct measures for disease risk factors are needed to allow a final appraisal of promising rare sugars. Mechanistic cell culture studies and animal models are required to enlarge our knowledge on understudied rare sugars.

D-Allose, a Stereoisomer of D-Glucose, Extends the Lifespan of Caenorhabditis elegans via Sirtuin and Insulin Signaling

D-Allose (D-All), C-3 epimer of D-glucose, is a rare sugar known to suppress reactive oxygen species generation and prevent hypertension. We previously reported that D-allulose, a structural isomer of D-All, prolongs the lifespan of the nematode Caenorhabditis elegans. Thus, D-All was predicted to affect longevity. In this study, we provide the first empirical evidence that D-All extends the lifespan of C. elegans. Lifespan assays revealed that a lifespan extension was induced by 28 mM D-All. In particular, a lifespan extension of 23.8 % was achieved (p < 0.0001). We further revealed that the effects of D-All on lifespan were dependent on the insulin gene daf-16 and the longevity gene sir-2.1, indicating a distinct mechanism from those of other hexoses, such as D-allulose, with previously reported antiaging effects.

Searching for diagnostic properties of novel fluorine-18-labeled D-allose

OBJECTIVE

Two fluorine-18-labeled analogues, 3-deoxy-3-[¹⁸F]fluoro-D-allose (3-[¹⁸F]FDA) and 6-deoxy-6-[¹⁸F]fluoro-D-allose (6-[¹⁸F]FDA), were synthesized and their potentials of diagnostic property were characterized.

METHODS

In vitro rat red blood cell (RBC) transport and phosphorylation by yeast hexokinase were evaluated in comparison with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG). The rate of protein binding in pooled human serum was measured by an ultrafiltration method. In vivo metabolite analysis in mice was also performed. Biodistribution, urine excretion, and in vivo renal kinetics in mice were compared with 2-deoxy-2-[¹⁸F]fluorosorbitol ([¹⁸F]FDS).

RESULTS

Rat RBC uptake of 3- and 6-[¹⁸F]FDA (7.8 ± 2.5%ID and 10.2 ± 4.8%ID, respectively) was significantly lower than that of [¹⁸F]FDG (44.7 ± 8.7%ID). RBC uptake of 3-[¹⁸F]FDA was inhibited by D-glucose (30%) and cytochalasin B (40%), indicating the involvement of GLUT1-dependent transport. In contrast, 6-[¹⁸F]FDA transport was not inhibited by D-glucose and cytochalasin B. 3- and 6-[¹⁸F]FDA were not phosphorylated by yeast hexokinase under the conditions that result in 60% conversion of [¹⁸F]FDG into [¹⁸F]FDG-6-phosphate within 30 min. Serum protein binding of 3- and 6-[¹⁸F]FDA was negligible. Metabolic transformation of both tracers was not detected in plasma and urine at 30 min after injection. The highest tissue uptake of both tracers was observed in kidneys. Heart and brain uptake of both tracers was below blood levels throughout the biodistribution studies (until 120 min after injection). No significant uptake in the bone was observed, indicating the absence of de-fluorination in mice. In vivo PET imaging visualized rapid excretion of the administered 3- and 6-[¹⁸F]FDA from the kidneys, with minimal tracer accumulation in other organs. The urine excretion rate of 3-[¹⁸F]FDA was much lower than that of 6-[¹⁸F]FDA and [¹⁸F]FDS.

CONCLUSIONS

3- and 6-[¹⁸F]FDA might be unsatisfactory for tumor imaging. In contrast, these tracers demonstrated high levels of kidney uptake and excretion, low serum protein binding, and high metabolic stability as preferable properties for renal imaging. Notably, the urine excretion rate and kidney uptake kinetics of 6-[¹⁸F]FDA were comparable with those of the potential renal imaging agent [¹⁸F]FDS. Further validation studies in animal models are required to confirm the feasibility of 6-[¹⁸F]FDA as a functional renal imaging agent.

The leaves of Crataeva nurvala Buch-Ham. modulate locomotor and anxiety behaviors possibly through GABAergic system

Background

Crataeva nurvala Buch-Hum is an indigenous herb, extensively used in traditional medicines of the South Asian countries to treat inflammation, rheumatic fever, gastric irritation, and constipation. Despite this wide range of uses, very little information is known regarding its effects on the central nervous system (CNS). Therefore, this study evaluated the neuropharmacological properties of methanolic extract of Crataeva nurvala leaves (MECN) using a number of behavioral models in animals. This study also identified potentially active phytochemicals in MECN.

Methods

Following MECN administration (at 50, 100 and 200 mg/kg; b.w.) the animals (male Swiss albino mice) were employed in hole-cross test (HCT), open field test (OFT), and rota-rod test (RRT) to evaluate sedative properties, where anxiolytic activities were investigated using elevated plus maze (EPM), light dark box (LDB), and marble burying test (MBT). The involvement of GABAergic system was evaluated using thiopental sodium (TS)-induced sleeping time determination test. Moreover, colorimetric phytochemical tests as well as GC/MS-MS were also conducted to define the phytochemical constituents of MECN.

Results

MECN possesses sedative properties indicated through the dose-dependent inhibition of locomotor activities of the animals in HCT and OFT and motor coordination in RRT. MECN also exhibited prominent anxiolytic properties through decreased burying behavior in MBT, increased time spent and transitions in open arm of EPM, and increased time spent in light compartment of LDB. In addition, the treatments potentiated TS-mediated hypnosis indicating a possible participation of GABAergic system in the observed sedative and anxiolytic activities. Phytochemical screening of MECN revealed 48 different compounds in it. We reviewed and conceive that the sedative and anxiolytic effects could be due to the presence of neuroactive compounds such as phytol, D-allose, and α-Tocopherol in MECN.

Conclusion

The present study showed that MECN possesses sedative and anxiolytic potential which could be beneficial in treatment of anxiety and insomnia associated with different psychological disorders.

Recent research on the physiological functions, applications, and biotechnological production of D-allose

D-Allose is a rare monosaccharide, which rarely appears in the natural environment. D-Allose has an 80% sweetness relative to table sugar but is ultra-low calorie and non-toxic and is thus an ideal candidate to take the place of table sugar in food products. It displays unique health benefits and physiological functions in various fields, including food systems, clinical treatment, and the health care fields. However, it is difficult to produce chemically. The biotechnological production of D-allose has become a research hotspot in recent years. Therefore, an overview of recent studies on the physiological functions, applications, and biotechnological production of D-allose is presented. In this review, the physiological functions of D-allose are introduced in detail. In addition, the different types of D-allose-producing enzymes are compared for their enzymatic properties and for the biotechnological production of D-allose. To date, very little information is available on the molecular modification and food-grade expression of D-allose-producing enzymes, representing a very large research space yet to be explored.

Synthesis and inhibitory activity of deoxy-d-allose amide derivative against plant growth

1,2,6-Trideoxy-6-amido-d-allose derivative was synthesized and found to exhibit higher growth-inhibitory activity against plants than the corresponding deoxy-d-allose ester, which indicates that an amide group at C-6 of the deoxy-d-allose amide enhances inhibitory activity. In addition, the mode of action of the deoxy-d-allose amide was significantly different from that of d-allose which inhibits gibberellin signaling. Co-addition of gibberellin GA₃ restored the growth of rice seedlings inhibited by the deoxy-d-allose amide, suggesting that it might inhibit biosynthesis of gibberellins in plants to induce growth inhibition.

Metabolic responses of the growing Daphnia similis to chronic AgNPs exposure as revealed by GC-Q-TOF/MS and LC-Q-TOF/MS

Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials. Their fast-growing utilization has increased the occurrence of AgNPs in the environment, posing potential health and ecological risks. In this study, we conducted chronic toxicity tests and investigated the metabolic changes of the growing Daphna similis with exposure to 0, 0.02, and 1 ppb AgNPs, using non-targeted mass spectrometry-based metabolomics. To the best of our knowledge, this study is the first to report the baseline metabolite change of a common aquatic organism Daphnia crustacean through its life-cycle. The results show a dynamic kinetic pattern of the growing Daphnia's metabolome underwent a cycle from day 0 to day 21, with the level of metabolites gradually increasing from day 0 to day 13, before falling back to the baseline level of day 0 on day 21. As for the samples exposed to environmental concentrations of AgNPs, although without morphological or structural changes, numerous metabolite changes occurred abruptly during the first 10 days, and these changes reached steady state by day 13. The significant changes in certain metabolites, such as amino acids (serine, threonine and tyrosine), sugars (d-allose) and fatty acids (arachidonic acid) revealed new insights into how these metabolites in Daphnia respond to chronic AgNPs stress. These findings highlight the capability of metabolomics to discover early metabolic responses to environmental silver nanoparticles.

Phenolic Isomers from Plantago Catharinea Leaves: Isolation, Identification, Quantification and in Vitro Antioxidant Activity

In this study we isolated two polyphenolic acids of m/z 639, called catharinol A and catharinol B, from Plantago catharinea L. (Plantaginaceae) leaves. Although presenting very similar structures, catharinol A showed higher antioxidant activity when compared with gallic acid and quercetin standards. These compounds are position isomers and present in their chemical structure the rare sugar D-allose. Molecules with similar constitution are known to have important biological activities such as antitumor and immunosuppressive. These compounds were isolated by high-performance liquid chromatography (HPLC) and characterized by mass spectrometry (FIA-ESI-IT-MS/MS) and nuclear magnetic resonance (NMR). This work is the first study on the chemical composition of P. catharinea and encourages the production of Plantago species as a good source of bioactive molecules.

D-Allose Inhibits Cancer Cell Growth by Reducing GLUT1 Expression

Glucose is a major energy source for mammalian cells and is transported into cells via cell-specific expression of various glucose transporters (GLUTs). Especially, cancer cells require massive amounts of glucose as an energy source for their dysregulated growth and thus over-express GLUTs. d-allose, a C-3 epimer of d-glucose, is one of rare sugars that exist in small quantities in nature. We have shown that d-allose induces the tumor suppressor gene coding for thioredoxin interacting protein (TXNIP) and inhibits cancer cell growth by G1 cell cycle arrest. It has also been reported that GLUTs including GLUT1 are over-expressed in many cancer cell lines, which may contribute to larger glucose utilization. Since d-allose suppresses the growth of cancer cells through the upregulation of TXNIP expression, our present study focused on whether d-allose down-regulates GLUT1 expression via TXNIP expression and thus suppresses cancer cell growth. Western blot and real-time PCR analyses revealed that d-allose significantly induced TXNIP expression and inhibited GLUT1 expression in a dose-dependent manner in three human cancer cell lines: hepatocellular carcinoma (HuH-7), Caucasian breast adenocarcinoma (MDA-MB-231), and neuroblastoma (SH-SY5Y). In these cell lines, d-allose treatment inhibited cell growth. Importantly, d-allose treatment decreased glucose uptake, as measured by the uptake of 2-deoxy d-glucose. Moreover, the reporter assays showed that d-allose decreased the expression of luciferase through the hypoxia response element present in the tested promoter region. These results suggest that d-allose may cause the inhibition of cancer growth by reducing both GLUT1 expression and glucose uptake.

Involvement of reactive oxygen species derived from mitochondria in neuronal injury elicited by methylmercury

Methylmercury induces oxidative stress and subsequent neuronal injury. However, the mechanism by which methylmercury elicits reactive oxygen species (ROS) production remains under debate. In this study, we investigated the involvement of mitochondrial ROS in methylmercury-induced neuronal cell injury using human neuroblastoma SH-SY5Y-derived ρ⁰ cells, which have a deletion of mitochondrial DNA and thus decreased respiratory activity. SH-SY5Y cells were cultured for 60 days in the presence of ethidium bromide to produce ρ⁰ cells. Our ρ⁰ cells showed decreases in the cytochrome c oxidase expression and activity as well as oxygen consumption compared with original SH-SY5Y cells. Methylmercury at a concentration of 1 µM induced cell death with oxidative stress in original SH-SY5Y cells, but not ρ⁰ cells, indicating that ρ⁰ cells are resistant to methylmercury-induced oxidative stress. ρ⁰ cells also showed tolerance against hydrogen peroxide and superoxide anion, suggesting that ρ⁰ cells are resistant to total ROS. These data indicate that mitochondrial ROS are clearly involved in oxidative stress and subsequent cell death induced by methylmercury. Considering that the dominant mechanism of ROS generation elicited by methylmercury is due to direct antioxidant enzyme inhibition, mitochondria might play a role in amplifying ROS in methylmercury-induced neurotoxicity.

d-Allose Attenuates Overexpression of Inflammatory Cytokines after Cerebral Ischemia/Reperfusion Injury in Gerbil

BACKGROUND

The present study investigates the effects of d-allose, a rare sugar, on the inflammatory response after transient forebrain ischemia in the gerbil and whether it reduces oxidative stress (8-hydroxyl-2'-deoxyguanosine levels) and behavioral deficits.

METHODS

Transient forebrain ischemia was induced by occlusion of the bilateral common carotid arteries for 5 minutes. d-Allose was intraperitoneally injected immediately after ischemia (400 mg/kg). Inflammatory cytokines and oxidative damage in the hippocampus and behavioral deficits were examined 3 days after ischemia.

RESULTS

d-Allose administration reduced ischemia-induced cytokine production, oxidative stress, and behavioral deficits (motor and memory related).

CONCLUSIONS

The present results suggest that d-allose reduces brain injury after transient global ischemia by suppressing inflammation as well as by inhibiting oxidative stress.

Syntheses and biological activities of deoxy-d-allose fatty acid ester analogs

We describe the syntheses of three different deoxy-D-allose analogs [2-deoxy-d-allose (2-DOAll), 1,2-dideoxy-d-allose (1,2-DOAll), and 1,2-didehydro-1,2-dideoxy-d-allose (1,2-DHAll)] and their fatty acid esters via regioselective lipase-catalyzed transesterification. Among them, 2-DOAll and its decanoate (2-DOAll-C10) showed higher inhibitory activity on plant growth, which is similar to d-allose (All) [corrected] and its decanoate (All-C10). Bioassay results of deoxy-All-C10 on four plant species suggest that the hydroxy group at the C-1 position might be important showing growth inhibitory activity. In addition, co-addition of gibberellin (GA3) with 1,2-DHAll-C10 and 2-DOAll-C10 recovered plant growth, suggesting that they might mainly inhibit biosynthesis of gibberellin.

The anti-tumor efficacy of 2-deoxyglucose and D-allose are enhanced with p38 inhibition in pancreatic and ovarian cell lines

PURPOSE

The anti-tumor activity of glucose analogs 2-deoxy-glucose (2-DG) and D-allose was investigated alone or in combination with p38 mitogen-activated protein kinase (MAPK) inhibitor SB202190 or platinum analogs as a strategy to pharmacologically target glycolytic tumor phenotypes.

METHODS

Hypoxia inducible factor-1 alpha (HIF-1α) protein accumulation in pancreatic cell lines treated with SB202190 alone and in combination with glucose analogs was analyzed by Western blot. HIF-1α transcriptional activity was measured in MIA PaCa-2 cells stably transfected with a hypoxia response element luciferase reporter following treatment with glucose analogs alone, and in combination with SB202190. Induction of cleaved poly(ADP-ribose) polymerase (PARP) was measured by Western blot in the MIA PaCa-2 cells. In vitro anti-proliferative activity of 2-DG and D-allose alone, or in combination with oxaliplatin (pancreatic cell lines), cisplatin (ovarian cell lines), or with SB202190 were investigated using the MTT assay.

RESULTS

SB202190 decreased HIF-1α protein accumulation and transcriptional activity. 2-DG demonstrated greater anti-proliferative activity than D-allose. Pre-treatment with SB202190 enhanced activity of both 2-DG and D-allose in MIA PaCa-2, BxPC-3, ASPC-1, and SK-OV-3 cells. The combination of D-allose and platinum agents was additive to moderately synergistic in all but the OVCAR-3 and HEY cells. SB202190 pre-treatment further enhanced activity of D-allose and 2-DG with platinum agents in most cell lines investigated.

CONCLUSIONS

SB202190 induced sensitization of tumor cells to 2-DG and D-allose may be partially mediated by inhibition of HIF-1α activity. Combining glucose analogs and p38 MAPK inhibitors with chemotherapy may be an effective approach to target glycolytic tumor phenotypes.

Biosynthesis of rare hexoses using microorganisms and related enzymes

Rare sugars, referred to as monosaccharides and their derivatives that rarely exist in nature, can be applied in many areas ranging from foodstuffs to pharmaceutical and nutrition industry, or as starting materials for various natural products and drug candidates. Unfortunately, an important factor restricting the utilization of rare sugars is their limited availability, resulting from limited synthetic methods. Nowadays, microbial and enzymatic transformations have become a very powerful tool in this field. This article reviews the biosynthesis and enzymatic production of rare ketohexoses, aldohexoses and sugar alcohols (hexitols), including D-tagatose, D-psicose, D-sorbose, L-tagatose, L-fructose, 1-deoxy-L-fructose, D-allose, L-glucose, L-talose, D-gulose, L-galactose, L-fucose, allitol, D-talitol, and L-sorbitol. New systems and robust catalysts resulting from advancements in genomics and bioengineering are also discussed.

Biochemical composition and antioxidant capacity of extracts from Podophyllum hexandrum rhizome

BACKGROUND

Podophyllum hexandrum Royle (P. hexandrum) is a perennial herb and widely used in clinic. The present study was designed to separate and identify the biochemical composition and antioxidant capacity of extracts from P. hexandrum rhizome.

METHODS

The ethyl acetate and ethanol extracts from P. hexandrum rhizome were analyzed by GC-MS (gas chromatography-mass spectrometry), and the antioxidant capacity of the extracts and the components was tested by using the DPPH (2, 2-diphenylpicrylhydrazyl) and FRAP (Ferric reducing/antioxidant power) assays.

RESULTS

The rhizome extracts had greater antioxidant capacity than the petiole extracts in DPPH and FRAP assays. About 16 kinds of main reactive oxygen components were identified in the extracts. Components of PADE (Phthalic acid, diisobutyl ester), BADE (1,2-Benzenedicarboxylic acid, diisooctyl ester), Polyneuridine, PODD (Podophyllotoxin, deoxy), β-Sitosterol and POD (Podophyllotoxin) showed the antioxidant capacity in some degree. PODD, POD, and Polyneuridine showed stronger antioxidant capacity with the IC50 and FRAP values of 9.61 ± 0.81 and 2923.98 ± 21.89 μM, 9.98 ± 0.24 and 2847.27 ± 14.82 μM, and 13.37 ± 0.35 and 2404.32 ± 36.88 μM, respectively, than the positive control ASA (Ascorbic acid) with the values of 60.78 ± 1.22 and 1267.5 ± 30.24 μM (P < 0.01).

CONCLUSIONS

PODD, POD, and Polyneuridine are very critical for the antioxidant capacity in the extract of P. hexandrum rhizome. These results provide useful biochemical basis and information for the potential use of this plant.

Structural confirmation of oligosaccharides newly isolated from sugar beet molasses

Background

Sugar beet molasses is a viscous by-product of the processing of sugar beets into sugar. The molasses is known to contain sucrose and raffinose, a typical trisaccharide, with a well-established structure. Although sugar beet molasses contains various other oligosaccharides as well, the structures of those oligosaccharides have not been examined in detail. The purpose of this study was isolation and structural confirmation of these other oligosaccharides found in sugar beet molasses.

Results

Four oligosaccharides were newly isolated from sugar beet molasses using high-performance liquid chromatography (HPLC) and carbon-Celite column chromatography. Structural confirmation of the saccharides was provided by methylation analysis, matrix-assisted laser desorption/ionaization time of flight mass spectrometry (MALDI-TOF-MS), and nuclear magnetic resonance (NMR) measurements.

Conclusion

The following oligosaccharides were identified in sugar beet molasses: β-D-galactopyranosyl-(1- > 6)-β-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named β-planteose), α-D-galactopyranosyl-(1- > 1)-β-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named1-planteose), α-D-glucopyranosyl-(1- > 6)-α-D-glucopyranosyl-(1 <-> 2)-β-D-fructofuranoside (theanderose), and β-D-glucopyranosyl-(1- > 3)-α-D-glucopyranosyl-(1 <-> 2)-β-D-fructofuranoside (laminaribiofructose). 1-planteose and laminaribiofructose were isolated from natural sources for the first time.