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Two experiments were conducted to evaluate the effect of different levels of sugars (glucose, lactose and raffinose) and the effect of those sugars (C(3) to C(6)) or their correspondent sugar alcohols on the dialysis of bovine semen. First, the effect of isosmotic solutions of glucose, lactose or raffinose at five different levels (0, 25, 50, 75, 95% V/V) on sperm motility of semen dialyzed prior to freezing were studied. These levels were used in extenders and dialysates, and the final volume was complemented with Piperazine-N-N-BIS (2-ethane sulfonic acid (PIPES) titrated to pH 7.0 with TRIS (hydroxymethyl) amino-methane (TRIS) to form PIPEST or a 1:1 (V/V) combination between PIPEST and sodium citrate solutions. In the second experiment, 30% of the buffer volume contained solutions of sugars (C(3) or C(6)) or their correspondent sugar alcohol, and the final volume was completed with PIPEST-citrate buffer. Semen aliquots were extended (1:10) and dialyzed (1:50) for 2 h while cooling from 37 to 5 degrees C in semipermeable dialysis bags of 12,000 to 14,000 molecular weight cut off. The samples were frozen in pellets 1 h after dialysis was terminated. Sperm survival was significantly higher in PIPEST-citrate than in PIPEST buffer alone (P0.05). No significant difference (P0.05) was obtained between the use of glucose or lactose or between lactose and raffinose. High levels of sugar appeared to be detrimental to sperm motility of fresh and thawed semen samples. Motility of cells extended in buffers containing 30% (V/V) isosmotic solutions of glucose, galactose, ribose, xylose, arabinose or their correspondent sugar alcohols was significantly higher (P0.05) than their motility in extenders without sugar.

The uptake of different sugars was studied in segments of isolated phloem from petioles of celery (Apium graveolens L.) in order to determine the kinetics and specificity of phloem loading in this highly uniform conductive tissue. The uptake kinetics of sucrose and the sugar alcohol, mannitol, which are both phloem-translocated, indicated presence of a single saturable system, while uptake of non-phloem sugars (glucose and 3-O-methylglucose) exhibited biphasic kinetics with lower uptake rates than those for sucrose and mannitol. The presence of unlabeled mannitol, 3-O-methylglucose and maltose in the incubation solution did not cause inhibition of labeled-sucrose uptake, indicating high carrier specificity and lack of sucrose hydrolysis in vivo. The pH optimum for sucrose uptake was 5-6. Furthermore, a rapid and transient alkalinization of the external media by sucrose indicated a sugar/H(+)-cotransport mechanism. Dual-labeling experiments showed that sucrose influx continued at a constant rate (V max=15 μmol·h(-1)·(g FW)(-1)), whereas sucrose efflux was low and insensitive to external concentration. Therefore, the saturable uptake kinetics for sucrose did not appear to be the result of an equilibrium between rates of sucrose influx and efflux.

Lycurium [1,4-di-(methylsulfonyloxy-ethylamino)-1,4-didesoxy-erythrioldimethylsulfonate; R-74; NSC-122402] undergoes rapid hydrolysis in aqueous solutions. The concentration of the alkylating compound(s), demonstrated by the 4-(4'-nitrobenzyl)pyridine reaction, decreases approximately by 80% in 10 min following the dissolution of the drug in saline. In patients peak plasma concentration of radioactivity after the intracavitary injection of 14C-labelled Lycurim is observed between 4 and 6 h. It is assumed, therefore, that only a negligible amount of pharmacologically active alkylating compounds reaches the circulation after intracavitary application. This conclusion is supported by clinical experience showing that intracavitary administration of the same amount of Lycurim causes much milder systemic side-effects than intravenous injection. A dose escalation study was started to determine the applicability of Lycurim in the form of high volume intraperitoneal instillation ('belly bath') for the treatment of ovarian cancer.

The effects of several environmental factors on the production of viable zoospores by Lagenidium giganteum were determined by counts of germlings produced after induction of zoosporogenesis by suspension of mycelium in various substances. NaCl at a concentration of 0.6 g/liter virtually eliminated zoosporogenesis. At 0.2 g/liter NaCl there was a significant reduction in four of the five fungal isolates tested. Transmission of fungus between mosquito larvae at 0.8 g/liter NaCl suggests that estimates of solute effects from in vitro studies are exaggerated. Zoosporogenesis took place from pH 4.5 to 8.4 by three isolates and from 4.5 to 8 by two other isolates (±0.2). Anaerobic conditions halted zoosporogenesis. Reintroduction of oxygen within 7 days allowed the process to resume, but with reduced production for each day under anaerobic conditions. Five species of bacteria inhibited zoosporogenesis at concentrations of 107–108 cells/ml. The yeast, Saccharomyces cerevisiae, was inhibitory at 106 cells/ml. Three sugars, a sugar alcohol, three amino acids, and peptone all reduced zoosporogenesis at levels that generally correlated positively with their nutritional values for the fungus. Peptone, which can support lush vegetative growth of L. giganteum in the absence of other nutrients, was far more effective in inhibiting zoosporogenesis than the other solutes.

A report of glucose translocation, an apparent exception to the hypothesis that sucrose is the major carbohydrate translocated in plants, was investigated. Carbon-14 studies of the carbohydrates in the bark of apple suggest that rather than glucose the sugar alcohol, sorbitol, in addition to sucrose, is a principal compound translocated in this species.

During the study of aerobic dissimilation of galactose by yeasts, polyhydric products were isolated in crystalline form from the fermented broths and identified. Yeast species may be divided into two groups on basis of sugar alcohol production: type I yeasts form the same end products from galactose as from glucose; type II yeasts produce dulcitol from galactose with or without other sugar alcohols but they produce no dulcitol from glucose. Isolation of dulcitol from microorganism has not been previously described.

Publisher Summary This chapter reviews the metabolism of the sugar alcohols that emphasis mainly on the isomeric hexitols. Substances such as methyl alcohol and ethylene glycol are studied under categories other than the sugar alcohols. The sugar alcohol refers to the hexahydric alcohols and their availability as food in the human diet warrants special study of their metabolic patterns. Biological metabolic processes attack most of the sugar alcohols. Glycerol, sorbitol, and mannitol are nontoxic precursors of glycogen and hence are metabolizable in the animal body. The respective anhydrides of the sugar alcohols studied in the chapter are not metabolized in the animal body.

Heterogeneous populations acclimated to sorbitol or mannitol were subjected to shock loading with glucose during growth on the sugar alcohol. Under these severe shock-loading conditions, glucose caused immediate cessation of sorbitol or mannitol removal. Metabolism of these compounds was renewed subsequent to glucose exhaustion. Under similar shock-loading conditions, with the use of cells operationally defined as “old,” the sugar alcohols were removed concurrently with glucose. In the absence of a nitrogen source with old cells, the added glucose was removed slowly in the presence of sorbitol and not at all in the mannitol-acclimated system. These results indicate the potential variability in purification efficiency attributable to substrate interaction.

It is generally accepted that xylitol administered to adult in various conditions including normal and diseased state, such as diabetes mellitus and hepatic disease, is rapidly metabolized and effectively utilized as a source of energy and that it exhibits a strong antiketogenic action. However, only few studies have been reported in the pediatric age group. The present studies were undertaken to examine whether xylitol administered to children is utilized as effectively as observed in adults and if there is any advantage in using this sugar alcohol for treatment of certain diseases of children.

Modifications have been made to a periodate oxidation procedure originally described by Rappaport et al.1,2 These have resulted in a procedure suited to the routine determination of a wide range of carbohydrates in solution, including soluble sugars, sugar alcohols, oligosaccharides and the hydrolysis products of reserve polysaccharides. A reasonably accurate estimate of fructose in a mixture of sugars is possible by the determination of the periodate consumption of aliquots before and after the destruction of fructose. An improved ferricyanide method is suited to the determination of reducing sugars. Both methods may be applied with equal success to hexose and pentose sugars. When used in conjunction, the two methods enable the estimation of fructose, reducing sugar, sucrose and sugar alcohol in aliquots of the same extract.

Publisher Summary This chapter discusses the role of sorbitol pathway in neuropathy. The role of the sorbitol pathway in cataract formation has been proved by the finding that aldose reductase inhibitors, which block the increased formation of sugar alcohol in experimental diabetes and galactosemia, also prevent cataract development both in vitro and in vivo. In peripheral nerve aldose reductase has been localized to the Schwann cell, which is the cell responsible for the formation and maintenance of the myelin sheath. Recent investigations with the galactose-fed rat model provide evidence for a role of sugar alcohol in causing neuropathy. The chapter describes a study involving a sample of rats. In this study, the insulin dose was subsequently reduced from 10 to 4 U per rat daily, and in the following three weeks, an increase in blood sugar to a mean of 250 mg% was observed. A nerve conduction velocity defect again appeared. Insulin dosage was again increased to an average dose of 8 U per rat, a dose lower than was initially required to eliminate glycosuria but unexpectedly sufficient to eliminate several experimental animals secondary to hypoglycemia, as evidenced by a mean blood glucose value of 59 mg% in the surviving group.

The application range of existing real scale mobile thermal storage units with phase change materials (PCM) is restricted by the low phase change temperature of 58 ∘ C for sodium acetate trihydrate, which is a commonly used storage material. Therefore, only low temperature heat sinks like swimming pools or greenhouses can be supplied. With increasing phase change temperatures, more applications like domestic heating or industrial process heat could be operated. The aim of this study is to find alternative PCM with phase change temperatures between 90 and 150 ∘ C . Temperature dependent thermophysical properties like phase change temperatures and enthalpies, densities and thermal diffusivities are measured for the technical grade purity materials xylitol (C 5 H 12 O 5 ), erythritol (C 4 H 10 O 4 ) and magnesiumchloride hexahydrate (MCHH, MgCl 2 · 6H 2 O). The sugar alcohols xylitol and erythritol indicate a large supercooling and different melting regimes. The salt hydrate MgCl 2 · 6H 2 O seems to be a suitable candidate for practical applications. It has a melting temperature of 115.1 ± 0.1 ∘ C and a phase change enthalpy of 166.9 ± 1.2 J / g with only 2.8 K supercooling at sample sizes of 100 g . The PCM is stable over 500 repeated melting and solidification cycles at differential scanning calorimeter (DSC) scale with only small changes of the melting enthalpy and temperature.

Surfactants, such as glycolipids, are specialty compounds that can be encountered daily in cleaning agents, pharmaceuticals or even in food. Due to their wide range of applications and, more notably, their presence in hygiene products, the demand is continuously increasing worldwide. The established chemical synthesis of glycolipids presents several disadvantages, such as lack of specificity and selectivity. Moreover, the solubility of polyols, such as sugars or sugar alcohols, in organic solvents is rather low. The enzymatic synthesis of these compounds is, however, possible in nearly water-free media using inexpensive and renewable building blocks. Using lipases, ester formation can be achieved under mild conditions. We propose, herein, a “2-in-1” system that overcomes solubility problems, as a Deep Eutectic System (DES) made of sorbitol and choline chloride replaces either a purely organic or aqueous medium. For the first time, 16 commercially available lipase formulations were compared, and the factors affecting the conversion were investigated to optimize this process, owing to a newly developed High-Performance Liquid Chromatography-Evaporative Light Scattering Detector (HPLC-ELSD) method for quantification. Thus, using 50 g/L of lipase formulation Novozym 435® at 50 °C, the optimized synthesis of sorbitol laurate (SL) allowed to achieve 28% molar conversion of 0.5 M of vinyl laurate to its sugar alcohol monoester when the DES contained 5 wt.% water. After 48h, the de novo synthesized glycolipid was separated from the media by liquid–liquid extraction, purified by flash-chromatography and characterized thoroughly by one- and two-dimensional Nuclear Magnetic Resonance (NMR) experiments combined to Mass Spectrometry (MS). In completion, we provide initial proof of scalability for this process. Using a 2.5 L stirred tank reactor (STR) allowed a batch production reaching 25 g/L in a highly viscous two-phase system.

Commercially available lipases (Candida antarctica lipase B, Novozyme 435, Thermomyces lanuginosus lipase, and Lipozyme TL IM), as well as sol-gel immobilized lipases, have been screened for their ability to acylate regioselectively xylitol, sorbitol, and mannitol with a phenolic ester in a binary mixture of t-butanol and dimethylsulfoxide. HPLC and MALDI-TOF MS analysis revealed the exclusive formation of monoesters for all studied sugar alcohols. The lipases immobilized by the sol-gel entrapment method proved to be efficient catalysts, leading to high conversions (up to 60%) in the investigated acylation reactions. From a sequence of silane precursors with different nonhydrolyzable groups in their structure, the presence of octyl and i-butyl group was most beneficial for the catalytic activity of sol-gel entrapped lipases in the studied process., {"references":["H. Stamatis, V. Sereti, and F. N. Kolisis, \"Enzymatic synthesis of\nhydrophilic and hydrophobic derivatives of natural phenolic acids in\norganic media\", Journal of Molecular Catalysis B: Enzymatic, vol. 11,\npp. 323-328, 2001.","C. Vafiadi, E. Topakas, K. K. Y. Wong, I. D. Suckling, and P.\nChristakopoulos, \"Mapping the hydrolytic and synthetic selectivity of a\ntype C feruloyl esterase (StFaeC) from Sporotrichum thermophile using\nalkyl ferulates\", Tetrahedron: Asymmetry, vol. 16, pp. 373-379, 2005.","I. S. Yoo, S. J. Park, and H. H. Yoon, \" Enzymatic synthesis of sugar\nfatty acid esters\", J. Ind. Eng. Chem., vol. 13, no. 1, pp. 1-6, 2007.","J. Piao, S. Adachi, \"Stability of O/W emulsions prepared using various\nmonoacyl sugar alcohols as an emulsifier\", Innovat. Food Sci. Emerg.\nTechnol., vol. 7, pp. 211-216, 2006.","B. Guyot, B. Bosquette, M. Pina, and J. Graille, \"Esterification of\nphenolic acids from green coffee with an immobilized lipase from\nCandida antarctica in solvent-free medium \", Biotechnol. Let., vol. 19,\nno. 6, pp. 529-532, 1997.","H. Stamatis, V. Sereti, and F. N. Kolisis, \"Studies on the enzymatic\nsynthesis of lipophilic derivatives of natural antioxidants\", JAOCS, vol.\n76, no. 12, pp. 1505-1510, 1999.","A. M. B. Rahman, N. B. Chaibakhsh, M. A. B. Salleh, and R. N. Z. R. A.\nRahman, \" Application of artificial neural network for yield prediction\nof lipase-catalyzed synthesis of dioctyl adipate \", Appl. Biochem.\nBiotechnol., vol. 158, no. 3, pp. 722-735, 2009.","F. Ganske, U. T. Bornscheuer, \"Optimization of lipase-catalyzed glucose\nfatty acid ester synthesis in a two-phase system containing ionic liquids\nand t-BuOH \", J. Mol. Catal. B: Enzym., vol. 36, pp. 40-42, 2005.","J. Piao, S. Adachi, \"Enzymatic preparation of fatty acid esters of sugar\nalcohols by condensation in acetone using a packed-bed reactor with\nimmobilized Candida antarctica lipase\", Biocat. Biotrans., vol. 22, pp.\n269-274, 2004.\n[10] A. F. Artamanov, L. F. Burkovskaya, F. S. Nigmatullina, and B. Z.\nDzhiembaev, \"Synthesis of monoesters of d-sorbitol and aromatic\nacids\", Chem. Nat. Comp., vol. 33, no. 5, pp. 571-573, 1998.\n[11] F. Peter L. Poppe, C. Kiss, E. Szocs-Bíro, G. Preda, C. Zarcula, and A.\nOlteanu, \"Influence of precursors and additives on microbial lipases\nstabilized by sol-gel entrapment\", Biocat. Biotrans., vol. 23, pp. 251-\n260, 2005.\n[12] M. M. Bradford, \"A rapid and sensitive method for the quantitation of\nmicrogram quantities of protein utilizing the principle of protein-dye\nbinding\", Anal Biochem., vol. 72, pp. 248-254, 1976.\n[13] R. ter Haar, H. A. Schols, L. A. M. van den Broek, D. Sağlam, A. E.\nFrissen, C. G. Boeriu, and H. Gruppen, \"Molecular sieves provoke\nmultiple substitutions in the enzymatic synthesis of fructose\noligosaccharide-lauryl esters\", J. Mol. Catal. B: Enzymatic, vol. 62, pp.\n183-189, 2010.\n[14] C. Zarcula, C. Kiss, L. Corîci, R. Croitoru, C. Csunderlik, and F. Peter,\n\"Combined sol-gel entrapment and adsorption method to obtain solidphase\nlipase biocatalyts\", Rev. Chim.(Bucharest), vol. 60, no. 9, pp. 922-\n927, 2009.\n[15] C. Zarcula, R. Croitoru, L. Corîci, C. Csunderlik, and F. Peter,\n\"Improvement of lipase catalytic properties by immobilization in hybrid\nmatrices\", Int. J. Chem. Biomol. Eng., vol. 2, no. 3, pp. 138-143, 2009.\n[16] S. Naik, A. Basu, R. Saikia, Bhawna Madan, Pritish Paul, Robin\nChaterjee, Jesper Brask, and Allan Svendsen, \"Lipases for use in\nindustrial biocatalysis: Specificity of selected structural groups of\nlipases\", J. Mol. Catal. B: Enzymatic, vol. 65, pp. 18-23, 2010.\n[17] F. Peter, C. Zarcula, S. Kakasi-Zsurka, R. Croitoru, C. Davidescu, and C.\nCsunderlik, \"Solid-phase lipase biocatalysts for kinetic resolutions\", J.\nBiotechnol., 136S, S356-S401, 2008.\n[18] R. T. Otto, H. Scheib, U. T. Bornscheuer, J. Pleiss, C. Syldatk, and R.\nD. Schmid, \"Substrate specificity of lipase B from Candida antarctica in\nthe synthesis of arylaliphatic glycolipids\", J. Mol. Catalysis B:\nEnzymatic, vol. 8, pp. 201-211, 2000."]}

Acetogenic microorganisms utilize organic substrates such as sugars in addition to hydrogen (H2) + carbon dioxide (CO2). Electrons from the oxidation of organic substrates are still removed by CO2 reduction through the Wood-Ljungdahl pathway (WLP), a process which has been called “homoacetogenesis” with respect to the fermentation of sugars. But how are more reduced substrates such as the sugar alcohol mannitol metabolized? Are acetogens then restricted to utilize additional carbon dioxide (CO2) or can they utilize protons as electron acceptors, similar to some fermentative microorganisms? Recently, we reported that the thermophilic acetogenic microorganism Thermoanaerobacter kivui is among the few acetogens that utilize mannitol, dependent on a gene cluster encoding mannitol uptake, phosphorylation and oxidation of mannitol-1-phosphate to fructose-6-phosphate. Here, we studied mannitol metabolism with resting cells of T. kivui; and found that mannitol was “fermented” in a homoacetogenic manner, i.e. acetate was the sole product if HCO3– was present. We found an acetate:mannitol ratio higher than 3, indicating the requirement of external CO2, and the involvement of the WLP as terminal electron accepting pathway. In the absence of CO2 (or bicarbonate, HCO3–), however, the cells still converted mannitol to acetate, but slowly and with stoichiometric amounts of H2 formed in addition, resulting in a “mixed” fermentation. This showed that – in addition to the WLP – the cells used an additional electron sink – protons, making up for the “missing” CO2 as electron sink. Growth was 2.5-fold slower in the absence of external CO2, while the addition of formate completely restored the growth rate. A model for mannitol metabolism is presented, involving the major 3 hydrogenases, to explain how [H] make their way from glycolysis into the products acetate or acetate+H2.

d-Galacturonic acid (GalA) is the major constituent of pectin-rich biomass, an abundant and underutilized agricultural byproduct. By one reductive step catalyzed by GalA reductases, GalA is converted to the polyhydroxy acid l-galactonate (GalOA), the first intermediate of the fungal GalA catabolic pathway, which also has interesting properties for potential applications as an additive to nutrients and cosmetics. Previous attempts to establish the production of GalOA or the full GalA catabolic pathway in Saccharomyces cerevisiae proved challenging, presumably due to the inefficient supply of NADPH, the preferred cofactor of GalA reductases. Here, we tested this hypothesis by coupling the reduction of GalA to the oxidation of the sugar alcohol sorbitol that has a higher reduction state compared to glucose and thereby yields the necessary redox cofactors. By choosing a suitable sorbitol dehydrogenase, we designed yeast strains in which the sorbitol metabolism yields a “surplus” of either NADPH or NADH. By biotransformation experiments in controlled bioreactors, we demonstrate a nearly complete conversion of consumed GalA into GalOA and a highly efficient utilization of the co-substrate sorbitol in providing NADPH. Furthermore, we performed structure-guided mutagenesis of GalA reductases to change their cofactor preference from NADPH towards NADH and demonstrated their functionality by the production of GalOA in combination with the NADH-yielding sorbitol metabolism. Moreover, the engineered enzymes enabled a doubling of GalOA yields when glucose was used as a co-substrate. This significantly expands the possibilities for metabolic engineering of GalOA production and valorization of pectin-rich biomass in general.

Glycolipids are non-ionic surfactants occurring in numerous products of daily life. Due to their surface-activity, emulsifying properties, and foaming abilities, they can be applied in food, cosmetics, and pharmaceuticals. Enzymatic synthesis of glycolipids based on carbohydrates and free fatty acids or esters is often catalyzed using certain acyltransferases in reaction media of low water activity, e.g., organic solvents or notably Deep Eutectic Systems (DESs). Existing reports describing integrated processes for glycolipid production from renewables use many reaction steps, therefore this study aims at simplifying the procedure. By using microwave dielectric heating, DESs preparation was first accelerated considerably. A comparative study revealed a preparation time on average 16-fold faster than the conventional heating method in an incubator. Furthermore, lipids from robust oleaginous yeast biomass were successfully extracted up to 70% without using the pre-treatment method for cell disruption, limiting logically the energy input necessary for such process. Acidified DESs consisting of either xylitol or sorbitol and choline chloride mediated the one-pot process, allowing subsequent conversion of the lipids into mono-acylated palmitate, oleate, linoleate, and stearate sugar alcohol esters. Thus, we show strong evidence that addition of immobilized Candida antarctica Lipase B (Novozym 435®), in acidified DES mixture, enables a simplified and fast glycolipid synthesis using directly oleaginous yeast biomass.

1. Introduction||2. Effect of hemicellulose-derived sugar alcohols on the growth and metabolites biosynthesis of Euglena gracilis||3. Application of Lignosulfonate as the Growth Promotor for Euglena gracilis to Increase Productivity of Biomass and Lipids||4. Effect of phenolic acids from the basic structures of lignin on the growth and metabolism of Euglena gracilis||5. Enhancement of biomass yield and lipid accumulation of freshwater microalga Euglena gracilis by phenolic aldehydes from basic structures of lignin||6. Summary and prospect, 九州工業大学博士学位論文 学位記番号：生工博甲第393号 学位授与年月日：令和3年3月25日, 令和2年度

Increased blood sugar levels may influence the refractive power of the lens in juvenile diabetics, and can lead to the rare true diabetic cataract ("snow-storm cataract"). Surplus glucose induces accumulation of the sugar alcohol within the cells, thus generating disturbances of the osmotic balance and finally causing cataract. The enzyme aldose reductase catalyzes the formation of sorbitol. Experiments with animals have shown that aldose reductase inhibitors can prevent the formation of such opacities with streptozotocin-induced diabetes in rats. Numerous aldose reductase inhibitors are now known, but we still have insufficient knowledge to determine whether systemic or local administration is preferable. The mechanisms reported here are not relevant with respect to the frequent occurrence of senile cataract in older diabetics, which has often been described.

In a sample of fruits of 57 cultivated species (25 temperate and 32 tropical/subtropical) we found that sugar concentrations did not significantly differ. Furthermore, percentages of disaccharides did not significantly differ between the New World and Old World groups in either the tropical/subtropical or temperate samples. The tropical/subtropical species, however, produce fruits significantly higher in disaccharides (and consequently lower in hexoses) than fruits of temperate species. A CONSIDERABLE OLDER LITERATURE concerning the occurrence, concentration, and composition of sugars in economically important fruits has developed during this century (e.g., Widdowson & McCance 1935; and the reviews by Whiting 1970; Nagy & Shaw 1980; Wrolstad & Shallenberger 1981). More recently, fruit sugars have been studied by Eheart and Mason (1967), Kline et al. (1970), Van Handel et al. (1972), Chan and Kwok (1975), Chan et al. (1975), Chan and Lee (1975), Chan and Heu (1975), Chan et al. (1979), Richmond et al. (1981), and Kader et al. (1982). Sugar parameters have been found to vary widely, but the dominant fruit sugars are the hexoses fructose and glucose and the disaccharide sucrose. The occasional occurrence of maltose has also been noted, as well as the sugar alcohol sorbitol within the family Rosaceae. During a cursory examination of this literature we noticed that tropical/subtropical fruits seemed to have a sugar composition higher in disaccharides than do temperate fruits. This observation led us to the following questions concerning these cultivated fruits. (1) Do tropical/subtropical fruits and temperate fruits differ in relative sugar composition? (2) Do these two groups differ in total sugar concentration as a percentage of fresh weight? (3) Are there compositional differences between New World and Old World tropical/subtropical fruits or between New World and Old World temperate fruits?

BAKER1 has described the isolation of dulcitol, a non-reducing sugar alcohol, from the exudate of the leaves of Euonymus japonica. An investigation of this exudate by partition chromatography on strips of filter paper, employing the usual solvents for sugar analysis, revealed that dulcitol gives rise to a discrete dark brown spot on the paper chromatogram when it is sprayed with an ammoniacal solution of silver nitrate and heated. Other polyhydric alcohols, such as mannitol, sorbitol, glycerol and ethylene glycol, also reduce ammoniacal silver nitrate under these conditions, a most surprising and unpredictable result. In view of the importance of partition chromatography for the analysis of intimate mixtures of the reducing sugars2, an examination of the properties of the polyhydric alcohols on the paper chromatogram was necessary in order to avoid any confusion between these closely related substances. It is of interest to note that Partridge3 has encountered inositol, a cyclic hexitol, along with glucose and fructose in an extract of the fœtal blood of sheep, since he found that it also gives rise to a discrete brown spot on the paper chromatogram with the ammoniacal silver nitrate reagent.

Background To meet the growing demand and market for protein supplements, sports nutrition companies and manufacturers have developed protein supplements in several forms, such as RTDs, bars, and powders. Recently, candy bar-like protein supplements have been developed using sugar alcohols instead of sugar to lessen the glycemic response. However, these candy bar-like substitutes usually have a high concentration of total fat, saturated fat, and cholesterol. It is the purpose of this study therefore to determine the acute glycemic and blood lipid response to ingesting a candy bar-like protein supplement compared to its candy bar counterpart.

Background We have previously shown that lipophilic components (LPC) of the brown seaweed Ascophyllum nodosum (ANE) improved freezing tolerance in Arabidopsis thaliana. However, the mechanism(s) of this induced freezing stress tolerance is largely unknown. Here, we investigated LPC induced changes in the transcriptome and metabolome of A. thaliana undergoing freezing stress. Results Gene expression studies revealed that the accumulation of proline was mediated by an increase in the expression of the proline synthesis genes P5CS1 and P5CS2 and a marginal reduction in the expression of the proline dehydrogenase (ProDH) gene. Moreover, LPC application significantly increased the concentration of total soluble sugars in the cytosol in response to freezing stress. Arabidopsis sfr4 mutant plants, defective in the accumulation of free sugars, treated with LPC, exhibited freezing sensitivity similar to that of untreated controls. The 1H NMR metabolite profile of LPC-treated Arabidopsis plants exposed to freezing stress revealed a spectrum dominated by chemical shifts (δ) representing soluble sugars, sugar alcohols, organic acids and lipophilic components like fatty acids, as compared to control plants. Additionally, 2D NMR spectra suggested an increase in the degree of unsaturation of fatty acids in LPC treated plants under freezing stress. These results were supported by global transcriptome analysis. Transcriptome analysis revealed that LPC treatment altered the expression of 1113 genes (5%) in comparison with untreated plants. A total of 463 genes (2%) were up regulated while 650 genes (3%) were down regulated. Conclusion Taken together, the results of the experiments presented in this paper provide evidence to support LPC mediated freezing tolerance enhancement through a combination of the priming of plants for the increased accumulation of osmoprotectants and alteration of cellular fatty acid composition.