Evaluation of the relative available energy of cyclic nigerosylnigerose using breath hydrogen excretion in healthy humans.

Cyclic nigerosylnigerose (CNN) is a cyclic tetrasaccharide with properties distinct from those of other conventional cyclodextrins. We investigated the relative available energy of CNN in healthy humans. CNN digestibility was determined using brush border membrane vesicles from the small intestines of rats. CNN was not hydrolyzed by rat intestinal enzymes. To investigate breath hydrogen excretion, 13 human subjects were included in a double-blind cross-over, randomized, placebo-controlled study. The effects of CNN on hydrogen excretion were compared with those of a typical nondigestible, fermentable fructooligosaccharide (FOS). In the study participants, hydrogen excretion hardly increased upon CNN and was remarkably lower than for FOS. The available energy value was determined using the fermentability based on breath hydrogen excretion and was evaluated as 0 kcal/g for CNN. CNN was hardly metabolized and hence may be used as a low-energy dietary fiber.

Profiling of volatile compounds in APC(Min/+) mice blood by dynamic headspace extraction and gas chromatography/mass spectrometry.

Various volatile compounds as well as hydrophilic compounds exist in the blood. For example, 2-alkenals, 4-hydroxy-2-alkenals, and ketoaldehydes have been reported as oxidized lipid-derived volatiles in blood. These specific volatiles have been associated with diseases; however, multi-volatile analyses have not been performed. In this study, volatile profiling of APC(Min/+) mouse plasma by dynamic headspace extraction was performed for multi-volatile analysis. In total, 19 volatiles were detected in the plasma of mice, based on information regarding oxidized lipid-derived volatile compounds, and eight of these compounds differed significantly between normal and diseased mice. 2-Methyl-2-butanol and benzyl alcohol were previously unreported in blood samples. Furthermore, 3,5,5-trimethyl-2(5H)-furanone was only detected in normal mice. 5-Methyl-3-hexanone and benzaldehyde have been detected in subjects with gastrointestinal diseases and lung cancer, respectively. Therefore, volatile profiling can be used to detect differences between samples and to identify compounds associated with diseases.

Multi-Component Profiling of Trace Volatiles in Blood by Gas Chromatography/Mass Spectrometry with Dynamic Headspace Extraction.

A dynamic headspace extraction method (DHS) with high-pressure injection is described. This dynamic extraction method has superior sensitivity to solid phase micro extraction, SPME and is capable of extracting the entire gas phase by purging the headspace of a vial. Optimization of the DHS parameters resulted in a highly sensitive volatile profiling system with the ability to detect various volatile components including alcohols at nanogram levels. The average LOD for a standard volatile mixture was 0.50 ng mL(-1), and the average LOD for alcohols was 0.66 ng mL(-1). This method was used for the analysis of volatile components from biological samples and compared with acute and chronic inflammation models. The method permitted the identification of volatiles with the same profile pattern as in vitro oxidized lipid-derived volatiles. In addition, the concentration of alcohols and aldehydes from the acute inflammation model samples were significantly higher than that for the chronic inflammation model samples. The different profiles between these samples could also be identified by this method. Finally, it was possible to analyze alcohols and low-molecular-weight volatiles that are difficult to analyze by SPME in high sensitivity and to show volatile profiling based on multi-volatile simultaneous analysis.

Metabolic profiling of oxidized lipid-derived volatiles in blood by gas chromatography/mass spectrometry with in-tube extraction.

Once lipids are oxidized, various volatiles are produced by cleavage of the fatty acid side chain. Considering the variety of lipids present in the body, a large number of possible volatiles might originate from oxidized lipids. However, only specific volatiles such as aldehydes are exclusively examined in current studies, and there is no reported method for the exhaustive analysis of all volatiles. We developed a sensitive analytical method for the detection of all possible volatiles for multimarker profiling, applying a new extraction method called in-tube extraction. Oxidized phosphatidyl choline standards were prepared in vitro and analyzed in order to determine the potential variety of volatiles. Over 40 compounds, including alcohols, ketones, and furanones, were identified in addition to the aldehydes reported previously. Based on this result, we applied our analytical method to mouse plasma and identified 12 volatiles, including 1-octen-3-ol, which is correlated to disease states. To determine the volatile profile after oxidation, we oxidized plasma in vitro under various conditions and identified 27 volatiles, including 1-octen-3-ol and benzaldehyde. The generation capacity of each volatile was different. This method allows sensitive and exhaustive analysis of various volatiles in addition to aldehydes.