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Artificial sweetener reduces nociceptive reaction in term newborn infants.

BACKGROUND: Sucrose has been shown to have an analgesic effect in preterm and term neonates. Sucrose, however, has a high osmolarity and may have deleterious effects in infants with fructose intolerance. Furthermore, it may favour caries. We therefore investigated the effects of a commercially available artificial sweetener (10 parts cyclamate and 1 part saccharin), glycine (sweet amino acid) or breast milk in reducing reaction to pain as compared with a placebo. SUBJECTS: Eighty healthy term infants, four days old, with normal birth weight. INTERVENTIONS: The infants were randomly assigned to one of four groups: 2 ml sweetener, glycine, expressed breast milk or water were given 2 min before a heel prick for the Guthrie test. The procedure was filmed with a video camera and analysed by two observers who did not know which medication the infant had received. RESULTS: Using a multivariate regression analysis, the following variables had significant correlation with relative crying time and recovery time: behavioural state before the intervention, the pricking nurse, and the type of medication. Relative crying time and recovery time were significantly less in the sweetener group but not in the glycine and the breast milk group. CONCLUSIONS: The artificial sweetener used in our study reduces pain reaction to a heel prick in term neonates, and thus provides an alternative to sucrose. In contrast, glycine tends to increase pain reaction whereas breast milk has no effect.

Analgesics↗

Is the negative charge on RNHSO3-M+ an essential requirement for sulfamate sweetness?

Although many structure-taste studies have been carried out on sulfamate (cyclamate) sweeteners, there are still some unanswered questions-notably whether the sulfamate anion, -NHSO(3)(-), is essential for sweetness in this class of compounds. The literature is contradictory on this point; therefore, 14 sulfamate esters RNHSO(3)R', which contain the sulfamate moiety but without the negative charge, i.e., -NHSO(3)(-), have been synthesized and tasted under standard conditions. Almost all of the esters were found to possess strong sweetness accompanied by bitterness. Because the esters had to be heated in water to 60 degrees C to dissolve them, it was necessary to check for partial hydrolysis to the free sulfamic acids, RNHSO(3)H, since they would be sweet and would invalidate the tasting results if formed. This was done by monitoring (gas-liquid chromatography) the formation of alcohol after heating. Negligible or very low hydrolysis to acid was found for all 14 esters. This work, in addition to answering an important structure-taste question, points the way to the potential use of suitable sulfamate esters as additives in situations where the more usual sodium sulfamate salts are unsuitable, for example, in hydrophobic media.

Anions↗

Development of structure-taste relationships for monosubstituted phenylsulfamate sweeteners using classification and regression tree (CART) analysis.

Twenty monosubstituted phenylsulfamates (cyclamates) have been synthesized and have had their taste portfolios determined. These have been combined with 63 compounds already in the literature to give a database of 83 ortho, meta, and para compounds. A training set of 75 compounds was randomly selected leaving eight compounds as a test set. A series of nine predictors determined with Corey-Pauling-Koltun models, calculated from the PC SPARTAN PRO program and Hammett sigma values taken mainly from the literature, have been used to establish structure-taste relationships for these types of sweeteners. The taste panel data for all compounds were categorized into three classes, namely, sweet (S), nonsweet (N), and sweet/nonsweet (N/S), and a novel "sweetness value" or weighting was also calculated for each compound. Linear and quadratic discriminant analysis were first used with the S, N, and N/S data, but the results were somewhat disappointing. Classification and regression tree analysis using the sweetness values for all 75 compounds was more successful, and only 14 were misclassified and six of the eight test set compounds were correctly classified. For the 29 meta compounds, one subset using just two parameters classified 83% of these compounds. Finally, using various methods, predictions were made on the likely tastes of a number of meta compounds and a striking agreement was found between the tree prediction and those given by earlier models. This appears to offer a strong vindication of the tree approach.

Cyclamates↗

Solution properties and sweetness response of selected bulk and intense sweeteners.

Two bulk sweeteners (sucrose and maltitol) and four intense sweeteners (acesulfame K, aspartame, sodium cyclamate, and sodium saccharin) are used in this study. Densities and sound velocity values of the sweeteners in solution are measured at 20 degrees C, and their apparent molar and specific volumes, their isentropic apparent molar and specific compressibilities, as well as their compressibility hydration numbers are calculated and reported. The introduction of solute molecules in water results in a volume change of the solvent as a result of attractive forces exerted by the solute molecules; such forces are in the form of electrostrictive or hydrogen-bonding forces, or charge-dipole attraction. Changes of molar volumes with increasing concentration give an indication of the extent of solute-solute interaction, whereas isentropic compressibilities give a direct measurement of the state of hydration of the solute molecules. The compressibility hydration numbers reported give an indication of the number of water molecules disturbed by the presence of each solute molecule in solution. Isentropic compressibilities seem to be a more sensitive parameter for distinguishing the bulk sweeteners from the artificial sweeteners. The sweetness response of the sweeteners is then explained in terms of their solution behaviors.

Aspartame↗

Quantitative structural activity relationship study of bis-tetraazacyclic compounds. A novel series of HIV-1 and HIV-2 inhibitors.

This work describes a study of quantitative structural activity relationships (QSAR) of bis-tetraazamacrocyclic compounds. These compounds represent a novel class of very potent and selective anti-HIV inhibitors, with a new mode of action. The QSAR study correlates structural features of the compounds with anti-HIV activity, resulting in a model which has a high predictive capacity (predictive r2 = 0.79). This predictive model will be of major importance for the design of new anti-HIV inhibitors of this class. Use is made of partial least-squares (PLS) analysis, with the novelty being that structural features derived by inclusion of all sterically allowed conformations for each molecule are included in the analysis. PLS analysis was made of descriptors, including structural parameters, macrocyclic ring size, metal chelating ability, etc., and those features necessary for the observed antiviral activities of these compounds were deduced from the models. Since all sterically allowed conformations are included in the analysis, the flexibility of the molecules is also taken into account. In addition, a correlation is found (indicated by a predictive r2 value of 0.61) between inhibition of HIV-1 (HIV-2) and syncytium formation inhibition in the presence of bis-cyclam analogues, leading to the suggestion of a common target, namely, gp120, being involved in both inhibition of virus replication and syncytium formation.

Antiviral Agents↗

Configurationally restricted bismacrocyclic CXCR4 receptor antagonists.

A zinc(II) containing configurationally restricted analogue of bismacrocyclic cyclam-type CXCR4 chemokine receptor antagonists has been synthesized and shown to adopt only one configuration in solution. The single crystal X-ray structure reveals favorable binding to acetate via a bidentate chelation that can be related to the proposed interaction with aspartate on the receptor protein surface. The zinc(II) complex is highly active against HIV infection in vitro.

Anti-HIV Agents↗

Measurement of the relative sweetness of stevia extract, aspartame and cyclamate/saccharin blend as compared to sucrose at different concentrations.

Special diets are used to mitigate many human diseases. When these diets require changes in carbohydrate content, then sweetness becomes an important characteristic. The range of low-calorie sweeteners available to the food industry is expanding. It is essential to have an exact knowledge of the relative sweetness of various sweeteners in relation to different sucrose concentrations. The objective of this study was to determine the variation on the relative sweetness of aspartame (APM), stevia [Stevia rebaudiana (Bert.) Bertoni] leaf extract (SrB) and the mixture cyclamate/saccharin--two parts of cyclamate and one part of saccharin--(C/S) with the increase in their concentrations, and in neutral and acid pH in equisweet concentration to 10% sucrose, using magnitude estimation. Sweetness equivalence of SrB in relation to sucrose concentrations of 20% or higher and of APM and C/S to sucrose concentrations of 40% or higher could not be determined, because a bitter taste predominated. The potency of all sweeteners decreased as the level of sweetner increased. In equi-sweet concentration of sucrose at 10%, with pH 7.0 and pH 3.0, the potency was practically the same for all sweeteners evaluated.

Aspartame↗

Taste rejection of nonnutritive sweeteners in cats.

Cats reject saccharin and cyclamate and are indifferent to dulcin, although they, like other mammals, prefer sucrose. The rejection threshold for saccharin found in this experiments, .0001 M, is about 2 log steps lower than a previously reported rejection threshold for sodium saccharin. Water produces a taste in cats adapted to their own saliva. The high sodium saccharin threshold may have resulted because the taste of the sodium saccharin was masked by the taste of the water solvent; however, saccharin may also be somewhat more aversive to the cat than sodium saccharin. Saccharin may produce an aversive taste because it stimulates receptor sites sensitive to substances bitter to man as well as those sensitive to sugars. In addition, saccharin may not be an effective stimulus for all sugar-sensitive sites.

Animals↗

Use of artificial sweeteners to promote alcohol consumption by rats.

Cirrhosis may be reliably produced in rats by exposing them intermittently to low levels of carbon tetrachloride vapour while feeding alcohol in the Lieber-DeCarli liquid diet. Providing the alcohol in drinking water that has been sweetened with sucrose is a cheaper and more convenient method but it does not yield reliable results. This study aimed to determine whether alcohol in drinking water sweetened with artificial sweeteners would give adequate alcohol intake to achieve the desired hepatic effects. Rats were fed alcohol (8% v/v) in drinking water sweetened with sucrose (5% w/v) (n = 12), or with one of the artificial sweeteners aspartame (0.025%), saccharin (0.025%) or cyclamate (0.05%) (n = 8 per agent). During the alcohol treatment the animals were exposed to carbon tetrachloride vapour, 40 ppm, six hours per night for five nights per week, over a period of 14 weeks. All groups achieved good alcohol intakes of 5-6 g/kg/day. Only one rat, in the aspartame group, became cirrhotic; all the others had varying degrees of fibrosis which did not differ significantly among the treatments. Although it was not effective in reliably achieving cirrhosis, sweetening the alcohol solution with artificial sweeteners led to reasonable alcohol intakes with resultant hepatic fibrosis, and without the high carbohydrate intake which occurs when sucrose is used.

Alcohol Drinking↗

Acceptable daily intake and the regulation of intense sweeteners.

At the present time there are four intense sweeteners that are available in a number of countries: acesulfame-K, aspartame, cyclamate and saccharin. Extensive toxicity databases are available on each sweetener and these have been assessed by both national and international regulatory authorities. This review considers briefly the critical toxicity of each sweetener that is the basis for establishing the no adverse effect level in animal studies. The calculation of an acceptable daily intake (ADI) for human intake employs a large safety factor applied to the no-effect level. The magnitude of the safety factor for each sweetener is discussed in relation to the ADI values recommended by the Scientific Committee for Food in 1985.

Animals↗

Toxins and carcinogens in the environment: an observation in the tropics.

The incidence of primary liver cancer in the countries of tropical Africa is the highest in the world. There is a growing belief that the relatively high prevalence of hepatocellular carcinoma in Nigeria may have a multiple chemical factor etiology in such forms as food contaminants, herbal teas, and environmental chemicals. Major chemical toxins and carcinogens that have been identified so far in the tropical environment include sapotoxin, cycasin, mushroom toxin, capsaicin, oxalic acid, prussic acid, fluorooleic acid, N-nitroso compounds, aflatoxin, palmotoxin, pyrrolizidine alkaloids, quinine, DDT, and cyclamate.

Carcinogens, Environmental↗

Purification and some properties of cyclohexylamine oxidase from a Pseudomonas sp.

Cyclohexylamine oxidase was purified 90-fold from cell-free extracts of Pseudomonas sp. capable of assimilating sodium cyclamate. The purified enzyme was homogeneous in disc electrophoresis, and the molecular weight was found to be approximately 80,000 by gel filtration. The enzyme catalyzed the following reaction: cyclohexylamine+O2+H2O leads to cyclohexanone+NH3+H2O2. The enzyme thus can be classified as an amine oxidase; it utilized oxygen as the ultimate electron acceptor. The pH optimum of the reaction was 6.8 and the apparent Km value for cyclohexylamine was 2.5 X 10(-4) M. The enzyme was highly specific for the deamination of alicyclic primary amines such as cyclohexylamine, but was found to be inactive toward ordinary amines used as substrates for amine oxidases. The enzyme solution was yellow in color and showed a typical flavoprotein spectrum; the addition of cyclohexylamine under anaerobic conditions caused reduction of the flavin in the native enzyme. The flavin of the prosthetic group was identified as FAD by thin layer chromatography. The participation of sulfhydryl groups in the enzymic action was also suggested by the observation that the enzyme activity was inhibited in the presence of PCMB and could be recovered by the addition of glutathione.

Amines↗

Aspartylphenylalanine methyl ester: a low-calorie sweetener.

Sensory evaluation indicated that aspartylphenylalanine methyl ester is about 160 times sweeter than sucrose in aqueous solution. Blends of this dipeptide with (i) sodium saccharin, (ii) sodium saccharin and sucrose, and (iii) sodium saccharin, sucrose, and calcium cyclamate did not differ significantly from 4 or 12 percent sucrose in bitterness, off-flavors, or aftertaste.

Analysis of Variance↗

Determinants for sensitivity of human immunodeficiency virus coreceptor CXCR4 to the bicyclam AMD3100.

The bicyclam AMD3100 is a potent and selective inhibitor of the replication of human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2). It was recently demonstrated that the compound inhibited HIV entry through CXCR4 but not through CCR5. Selectivity of AMD3100 for CXCR4 was further indicated by its lack of effect on HIV-1 and HIV-2 infection mediated by the CCR5, CCR3, Bonzo, BOB, and US28, coreceptors. AMD3100 completely blocked HIV-1 infection mediated by a mutant CXCR4 bearing a deletion of most of the amino-terminal extracellular domain. In contrast, relative resistance to AMD3100 was conferred by different single amino acid substitutions in the second extracellular loop (ECL2) or in the adjacent membrane-spanning domain, TM4. Only substitutions of a neutral residue for aspartic acid and of a nonaromatic residue for phenylalanine (Phe) were associated with drug resistance. This suggests a direct interaction of AMD3100 with these amino acids rather than indirect effects of their mutation on the CXCR4 structure. The interaction of aspartic acids of ECL2 and TM4 with AMD3100 is consistent with the positive charge of bicyclams, which might block HIV-1 entry by preventing electrostatic interactions between CXCR4 and the HIV-1 envelope protein gp120. Other features of AMD3100 must account for its high antiviral activity, in particular the presence of an aromatic linker between the cyclam units. This aromatic group might engage in hydrophobic interactions with the Phe-X-Phe motifs of ECL2 or TM4. These results confirm the importance of ECL2 for the HIV coreceptor activity of CXCR4.

Amino Acid Sequence↗

Ionic requirements of proximal tubular sodium transport. III. Selective luminal anion substitution.

The effect of substitution of luminal anions on sodium and fluid absorption in rat renal proximal convoluted tubules was studied with continuous luminal microperfusion methods. Substitution of bicarbonate in the control Ringer perfusion fluid by 25 mM acetate reduced net sodium reabsorption by 40%; substitution by chloride reduced it by 25%; and substitution by cyclamate reduced it by 70%. Infusion of acetazolamide reduced net sodium and fluid transport in all cases except chloride-Ringer perfusion. Cyanide added to the perfusion fluid inhibited fluid and sodium movement completely when there was no imposed chloride concentration gradient, but only reduced fluid and solute movement by 68% when a nominal 36 mM transepithelial chloride concentration gradient existed. We conclude from these observations that passive forces for sodium reabsorption can account for a moderate amount of sodium transport, that the effects of acetazolamide in low concentrations are dependent on the presence of bicarbonate in the lumen, and that some anions alter net sodium transport either by reducing the availability of permeant anion for co-transport with sodium or by a direct effect on the sodium and/or chloride transport systems.

Acetazolamide↗

Luminal and peritubular ionic substitutions and intracellular potential of the rabbit proximal convoluted tubule.

Transepithelial (psi T) and basolateral (psi BL) potential difference was measured in rabbit proximal convoluted tubules perfused in vitro. In control solution without protein, the mean psi BL was -54 +/- 2.2 mV (n = 57). Luminal substitution of K by Na had no effect. Complete luminal substitution of glucose and alanine, 110 mM substitution of Na or NaCl produced transient hyperpolarizations of psi BL of 14, 10, and 13 mV, respectively, with a return close to the control value within 4-8 min in all cases. Returning to control solution produced similar time-course transient depolarizations of psi BL of 17, 11, and 16 mV, respectively, again with a return to the control value in 4-10 min. Omission of glucose and alanine in the perfusate produced a decrease in cell volume of 14% that was maximal in 4 min with a complete recovery in the post-control period. A 110 mM luminal or peritubular substitution of Cl by cyclamate produced no significant effect on psi BL after taking into account the large psi T generated by the diffusion of Cl across the paracellular pathway. On the other hand, complete peritubular substitution of K by Na and 110 mM substitution of Na or NaCl produced sustained but reversible depolarizations of psi BL of 37.5, 10.2, and 20.4 mV, respectively. The transient nature of the hyperpolarization following luminal substitution of glucose, alanine, or Na can be interpreted in terms of changes in the intracellular sodium activity that would affect the Na-K-ATPase pump. Similarly, the sustained depolarization seen after a peritubular substitution of K and Na would also be compatible with a decrease in the basolateral ionic pump activity.

Alanine↗

[Analysis of nine kinds of sweeteners in foods by LC/MS].

A simple and rapid method for the simultaneous determination of nine kinds of sweeteners (acesulfame potassium, AK; sucralose, SUC; saccharin, SA; cyclamate, CYC; aspartame, APM; dulcin, DU; glycyrrhizic acid, GA; stevioside, STV; rebaudioside A, REB) in various foods by high-performance liquid chromatography-electrospray mass spectrometry (LC/ESI-MS) was developed. The LC separation was performed on a ZORBAX Eclipse XDB-C18 (2.1 mm x 150 mm) with a mobile phase of 5 mmol/L dibutylammonium acetate (DBAA) and acetonitrile-water (8: 2). Mass spectral acquisition was done in the negative ion mode by applying selected ion monitoring (SIM). The sweeteners were extracted from foods with 0.08 mol/L phosphate buffer (pH 7.0)- ethanol (1:1), and the extract was cleaned up on a Sep-pak Vac C18 cartridge after the addition of tetrabutylammonium bromide and phosphate buffer (pH 3.0). The recovery of the nine kinds of sweeteners from five kinds of foods fortified at the level 0.01 g/kg, 0.05 g/kg and 0.20 g/kg was 75.7-109.2%, and the between-day SD values were 0.5-10.9%. The quantification limits of AK, SA, CYC, APM and STV were 0.001 g/kg, and those of SUC, DU, GA and REB were 0.005 g/kg. A recovery test from each cleaned-up sample solution was necessary to detect ionization suppression.

Aspartame↗

Coffee drinking and cancer of the lower urinary tract.

The relationship between coffee drinking and cancer of the lower urinary tract (LUT) was investigated by a case-control study of white women identified from hospitals in urban areas of Massachusetts and Rhode Island. Data on coffee drinking, tea drinking, use of coffee additives, and cigarette smoking were obtained by mail questionnaire. Information was available for 135 women with LUT cancer and 390 controls. For women who usually drank 1+ cups of coffee per day, the risk ratio of having LUT cancer was 2.1 (95 percent confidence limits, 1.1-4.3), compared to a risk of 1 for women who drank less or not at all. However, no dose-response relationship was demonstrated between LUT cancer and usual daily coffee consumption or "cup-years" of coffee drinking. The association of coffee with disease was no different, whether decaffeinated, nondecaffeinated, regular, or instant coffee had been drunk, or whether the coffee was brewed strong or weak. Use of nondairy creamers, saccharin, or cyclamates was not associated with increased risk of disease. The risk of LUT cancer for cigarette smokers relative to nonsmokers was 1.6 (1.0-2.4). The attendant dose-response relationship was statistically significant. The absence of a dose-response relationship between coffee drinking and LUT cancer suggested that the association observed was noncasual.

Aged↗