Low Molecular Weight Carbohydrates Research Articles

Gas chromatographic-based techniques for the characterization of low molecular weight carbohydrates and phenylalkanoid glycosides of Sedum roseum root supplements

An extensive characterization of low molecular weight carbohydrates (LMWC) and phenylalkanoid glycosides (PAG) of Sedum roseum root supplements has been carried out for the first time by gas chromatography coupled to mass spectrometry (GC–MS) and by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-ToF MS). Optimization of the required derivatization procedure for improved determination of PAG showed the combined use of trimethylsilylimidazole and trimethylchlorosilane as the most appropriate reagents. Up to 37 compounds were qualitative- and quantitatively characterized in different dietary supplements of S. roseum by GC–MS. In addition to the well-known rosin, rosarin, rosavin and salidroside, other carbohydrates, polyalcohols, acids, etc. were determined. Among them, several seven-carbon monosaccharides such as coriose and 2,7-anhydro-β-d-altro-heptulose were detected for the first time in S. roseum root supplements. Sedoheptulose was found to be the most abundant compound (9–151 mg g−1), followed by rosiridin (20–81 mg g−1) and rosavin (11–56 mg g−1). The use of GC × GC-ToF MS allowed the detection and tentative assignation of 48 additional compounds mainly belonging to the phenylalkanoid glycoside, pentosyl-hexose and hexosyl-hexose families.

Polytetrafluoroethylene (PTFE) hollow fiber AnMBR performance in the treatment of organic wastewater with varying salinity and membrane cleaning behavior

PTFE hollow fiber anaerobic membrane bio-reactor (AnMBR) performance was investigated in the treatment of organic wastewater, with varying salinity and PTFE membrane cleaning behavior. The AnMBR was operated for 226 days, with a total and biological COD removal efficiency of 97.2% and 89.9% respectively, at a NaCl concentration of 35 g L−1. A high number of Proteobacteria (38.2%) and Bacteroidetes (25.9%) were present in the system, with an increase in membrane fouling rate from 1.88 × 1011 to 2.63 × 1011 m−1 d−1 with higher salinity. The effects of soluble microbial products (SMP), extracellular polymeric substances (EPS), low molecular-weight (LMW) carbohydrates, sludge particle size and inorganic element accumulation, were evaluated on membrane fouling. Flux recovery of fouled PTFE membranes reached 91.6% with offline cleaning. Overall, results indicate that PTFE hollow fiber AnMBR provides a promising method for the treatment of saline organic wastewater.

Case Report of Integrated Medicine Approach Mainly with Depolymerized Low Molecular Weight Fucoidan and Carbohydrate Restricted Diet Resulting in Improved Anti-P53 Antibody Values

Case Report of Integrated Medicine Approach Mainly with Depolymerized Low Molecular Weight Fucoidan and Carbohydrate Restricted Diet Resulting in Improved Anti-P53 Antibody Values

Profiling, quantification and classification of cocoa beans based on chemometric analysis of carbohydrates using hydrophilic interaction liquid chromatography coupled to mass spectrometry

Fifty-six cocoa bean samples from different origins and status of fermentation were analyzed by a validated hydrophilic interaction liquid chromatography-electrospray ionization-time of flight-mass spectrometry (HILIC-ESI-TOF-MS) method. The profile of the low molecular weight carbohydrate (LMWC) was analyzed by high resolution and tandem mass spectrometry, which allowed the identification of mono-, di-, tri- and tetrasaccharides, sugar alcohols and iminosugars.This study provides, for the first time in a large set of samples, a comprehensive absolute quantitative data set for the carbohydrates identified in cocoa beans (fructose, glucose, mannitol, myo-inositol, sucrose, melibiose, raffinose and stachyose). Differences in the content of carbohydrates were observed between unfermented (range of 0.9–4.9 g/g DM) and fermented (range 0.1–0.5 g/g DM) cocoa beans.The use of multivariate statistical tools allowed the identification of biomarkers suitable for cocoa bean classification according to the status of fermentation, procedure of fermentation employed and number of days of fermentation.

Towards speciation of organically bound tritium and deuterium: Quantification of non-exchangeable forms in carbohydrate molecules

An original methodology to quantitatively explore exchangeability of hydrogen isotopes in carbohydrate molecules is proposed. To access the speciation of organically bound hydrogen isotopes, isotopic exchanges were carried out under a soft path regime in the vapor phase at 20 °C with set (D,T/H) vapor pressure ratios. When steady states were reached, the fraction of exchangeable hydrogen of microcrystalline cellulose, alpha-cellulose and wheat grains were obtained and ranged from 13 to 31% (versus a theoretical value of 30%). In cellulose, and more specifically in microcrystalline cellulose, the molecular hydrogen bonds as well as the different conformations of the network seemed to decrease the hydroxyl groups of glucose units available for isotopic exchange. On the contrary, the assumed enzymatic hydrolysis of the constitutive molecules of wheat starch into low-molecular weight carbohydrate molecules enhanced the exchangeable pool. An average value of the activity between non-exchangeable organically bound tritium (NE-OBT) and non-exchangeable organically bound hydrogen was calculated for wheat grains, (TH)NE = 0.55 ± 0.03 Bq.g−1 of hydrogen atoms.

Nanostructural, Chemical, and Thermal Changes of Oil Palm Empty Fruit Bunch Cellulose Nanofibers Pretreated with Different Solvent Extractions

The aim of this study was to analyze the effect of different extraction solvents in cellulose nanofibers (CNFs) isolation and properties, including nanostructures, chemical functional groups, chemical substances, and thermal stabilities. Physical oven-dried CNFs had a varied diameter of self-aggregated nanofibers from 2 to 20 µm with different aggregate shapes of nanofibers, whereas individual nanostructure of CNFs suspension was akin to grape-like flocking nanofibers with a diameter of about 50 nm. FTIR spectra showed that hot water extraction for CNFs isolation was able to remove low-molecular weight carbohydrates (hemicellulose and pectin), whereas ethanol and ethanol/benzene extraction for CNFs isolation was able to remove tannin, fatty acids, and waxes. However, amorphous lignin was still present indicated with IR transmission peak at 1558 cm−1. Carboxylic acids, esters, ketones, and benzoyl units were the chemical compounds of CNFs, indicating the presence of cellulose, hemicellulose, and lignin in which long-chain fatty acids were the most dominant compounds. There were five thermal degradation peaks for ethanol- and hot water-pretreated CNFs thermal stability, whereas ethanol/benzene- and non-extraction-pretreated CNFs had four thermal degradation peaks. Solvent-pretreated CNFs had better thermal stability and higher char residue obtained above 8.51% than that of non-extracted-pretreated CNFs.

Prebiotic Oligosaccharides: Special Focus on Fructooligosaccharides, Its Biosynthesis and Bioactivity.

The bacterial groups in the gut ecosystem play key role in the maintenance of host's metabolic and structural functionality. The gut microbiota enhances digestion processing, helps in digestion of complex substances, synthesizes beneficial bioactive compounds, enhances bioavailability of minerals, impedes growth of pathogenic microbes, and prevents various diseases. It is, therefore, desirable to have an adequate intake of prebiotic biomolecules, which promote favorable modulation of intestinal microflora. Prebiotics are non-digestible and chemically stable structures that significantly enhance growth and functionality of gut microflora. The non-digestible carbohydrate, mainly oligosaccharides, covers a major part of total available prebiotics as dietary additives. The review describes the types of prebiotic low molecular weight carbohydrates, i.e., oligosaccharides, their structure, biosynthesis, functionality, and applications, with a special focus given to fructooligosaccharides (FOSs). The review provides an update on enzymes executing hydrolytic and fructosyltransferase activities producing prebiotic FOS biomolecules, and future perspectives.

Moisture deficit effects on kale (Brassica oleracea L. var. acephala) biomass, mineral, and low molecular weight carbohydrate concentrations

Abstract Kale (Brassica oleracea L. var. acephala) contains essential minerals and a range of low molecular weight carbohydrates (LMWC), but the presence of these nutrients can be affected by moisture stress. This study aimed to determine the response of kale genotypes commonly grown in southern US regions to moisture stress in terms of mineral concentrations, LMWC concentrations, and biomass loss. Kale transplants were grown in a greenhouse under normal growing conditions for 4 weeks, followed by 2 weeks of moisture stress (drought: 40% moisture; control: 80% moisture), and 2 weeks of recovery. Moisture stress significantly reduced kale biomass (by 19–35%) compared to controls. For minerals, Ca, Mg, and Zn concentrations in the leaf did not change but concentrations of K, P, Fe, Mn, and Cu significantly decreased as a result of moisture stress. Sorbitol, sucrose, and verbascose + kestose concentrations increased with moisture stress. Kale genotypes ‘Black Magic’, ‘Darkibor’, and ‘Vates’ had the least relative biomass reduction response to moisture stress compared to the other genotypes. Further, ‘Beira’, ‘Black Magic’, ‘Darkibor’, and ‘Lacinato’ did not change individual mineral content in response to moisture stress, and visual symptoms of water stress were not evident. These data confirm that kale biomass production and nutritional quality are greatly affected by moisture stress. By genetic sourcing, drought tolerance and nutritional quality of kale could be further enhanced. Overall, inter-varietal variation of kale nutritional quality under conditions of moisture stress may also allow Brassica vegetable breeders to incorporate these traits towards “field biofortification” to benefit North American consumers.

The effect of cold acclimation on the low molecular weight carbohydrate composition of safflower.

Understanding cold acclimation and identifying the low molecular weight carbohydrates that support the development of freezing tolerant safflower seedlings will aid in breeding winter-hardy cultivars for temperate cropping systems. Three field selected lines of winter safflower (WSRC01: PI 651878; WSRC02: PI 651879; WSRC03: PI 651880) were cold acclimated for four weeks at 4 °C and compared to seedlings grown for two weeks at 20 °C. The commercial spring-type cultivar, Olé, served as a non-hardy check. Leaf, stem, and root fructose, glucose, sucrose, raffinose, and stachyose concentrations all increased to variable extents across the PI accessions after cold acclimation. In comparison with Olé, winter safflower accessions tended to be more responsive to cold acclimation by increasing metabolite concentration. Verbascose was only recovered within leaf tissue and PI 651880 was the only entry to show a substantial alteration in verbascose concentration due to cold acclimation. Based on these data, no specific low molecular carbohydrate was responsive or responsible for the accumulation of freezing tolerance, but a concert of metabolites and their responsiveness may help explain the observed differences in development, freezing tolerance, and ultimately winterhardiness among safflower germplasm.

Diversity of the composition and content of soluble carbohydrates in seeds of the genus Vicia (Leguminosae)

Low molecular weight carbohydrates of seeds of 10 species of Vicia, namely: V. angustifolia, V. articulata, V. cordata, V. ervilia, V. johannis, V. macrocarpa, V. monantha, V. narbonensis, V. pannonica and V. sativa were analyzed by the high resolution gas chromatography method. Seeds of the investigated species contain common (glucose, fructose, myo-inositol, sucrose, galactinol, di-galactosyl myo-inositol and raffinose family oligosaccharides—RFOs) and species-specific carbohydrates (d-pinitol and its α-d-galactosides—in V. articulata, V. monantha and V. pannonica or d-ononitol and its galactoside—in V. ervilia). Among the species containing in seeds RFOs as the main α-d-galactosides (V. angustifolia, V. cordata, V. johanensis, V. macrocarpa, V. narbonensis and V. sativa), an additional subgroup can be separated, which contains a set of unknown compounds (found in V. angustifolia, V. cordata and V. macrocarpa). Moreover, several other unidentified carbohydrate-containing compounds were detected exclusively in seeds of V. ervilia. The concentrations of total soluble carbohydrates (TSCs), including sugars, RFOs, cyclitols and galactosyl cyclitols and unknown compounds, in seeds differ significantly (P < 0.05) among the species. RFOs and sucrose are the main fractions in TSCs, with the exception of V. pannonica seeds, containing more galactosyl pinitols, and V. ervilia, in which unknown compounds account for 50% of TSCs. In V. ervilia RFOs occur at the lowest concentration (9.32 mg g−1 seeds), and the concentration of DGMI (di-galactosyl myo-inositol) is comparable with that of RFOs, which is unusual among all the investigated Vicia species.

Unraveling the Photoprotective Response of Lichenized and Free-Living Green Algae (Trebouxiophyceae, Chlorophyta) to Photochilling Stress.

Lichens and free-living terrestrial algae are widespread across many habitats and develop successfully in ecosystems where a cold winter limits survival. With the goal of comparing photoprotective responses in free-living and lichenized algae, the physiological responses to chilling and photochilling conditions were studied in three lichens and their isolated algal photobionts together as well as in a fourth free-living algal species. We specifically addressed the following questions: (i) Are there general patterns of acclimation in green algae under chilling and photochilling stresses? (ii) Do free-living algae exhibit a similar pattern of responses as their lichenized counterparts? (iii) Are these responses influenced by the selection pressure of environmental conditions or by the phylogenetic position of each species? To answer these questions, photosynthetic fluorescence measurements as well as pigment and low molecular weight carbohydrate pool analyses were performed under controlled laboratory conditions. In general, photochemical efficiency in all free-living algae decreased with increasing duration of the stress, while the majority of lichens maintained an unchanged photochemical activity. Nevertheless, these patterns cannot be generalized because the alga Trebouxia arboricola and the lichen Ramalina pollinaria (associated with Trebouxia photobionts) both showed a similar decrease in photochemical efficiency. In contrast, in the couple Elliptochloris bilobata-Baeomyces rufus, only the algal partner exhibited a broad physiological performance under stress. This study also highlights the importance of the xanthophyll cycle in response to the studied lichens and algae to photochilling stress, while the accumulation of sugars was not related to cold acclimation, except in the alga E. bilobata. The differences in response patterns detected among species can be mainly explained by their geographic origin, although the phylogenetic position should also be considered, especially in some species.

Molecular phylogeny and taxonomic revision of the genus Wittrockiella (Pithophoraceae, Cladophorales), including the descriptions of W.australis sp. nov. and W.zosterae sp. nov.

Wittrockiella is a small genus of filamentous green algae that occurs in habitats with reduced or fluctuating salinities. Many aspects of the basic biology of these algae are still unknown and the phylogenetic relationships within the genus have not been fully explored. We provide a phylogeny based on three ribosomal markers (ITS, LSU, and SSU rDNA) of the genus, including broad intraspecific sampling for W.lyallii and W.salina, recommendations for the use of existing names are made, and highlight aspects of their physiology and life cycle. Molecular data indicate that there are five species of Wittrockiella. Two new species, W.australis and W.zosterae, are described, both are endophytes. Although W.lyallii and W.salina can be identified morphologically, there are no diagnostic morphological characters to distinguish between W.amphibia, W.australis, and W.zosterae. A range of low molecular weight carbohydrates were analyzed but proved to not be taxonomically informative. The distribution range of W.salina is extended to the Northern Hemisphere as this species has been found in brackish lakes in Japan. Furthermore, it is shown that there are no grounds to recognize W.salina var. kraftii, which was described as an endemic variety from a freshwater habitat on Lord Howe Island, Australia. Culture experiments indicate that W.australis has a preference for growth in lower salinities over full seawater. For W.amphibia and W.zosterae, sexual reproduction is documented, and the split of these species is possibly attributable to polyploidization.

Chromium (VI) Adsorption Study Using Bio-Adsorbent Material Derived from Tamarind-Seed Testa

In this research, the chromium (VI) adsorption in potassium chromate (K2CrO4) and potassium dichromate (K2Cr2O7) was studied with the low-cost adsorbent derived from sweet tamarind seeds obtained from the food processing industry in Thailand. The tamarind-seed testa was prepared by decoloring the tamarind-seed husks in boiling water and 1% NaOH solution followed by bleaching in H2O2 solution. The major components found in the tamarind-seed testa were alkali hydrolysable, low molecular-weight carbohydrates. The study found that the adsorbent material derived from tamarind–seed testa could well adsorb chromium ions in both chromium compound solutions at pH 2. The adsorption took place rapidly within the first 4 hours and then gradually declined until reaching adsorption equilibrium in 12 hours. Adsorption of chromium (VI) from potassium chromate solution was superior to that from potassium dichromate. Chromium adsorption at pH 2 fitted well with Langmuir and Freundlich isotherms. The adsorption mechanism in both solutions was a monolayer chemical adsorption rather than multilayer physical adsorption. The adsorbent could almost completely remove chromium in potassium chromate (90% removal) while it could remove 57% chromium from potassium dichromate solution when the initial chromium concentration of 100 mg/l was employed.

Ingestion of High Molecular Weight Carbohydrate Enhances Subsequent Repeated Maximal Power: A Randomized Controlled Trial.

Athletes in sports demanding repeat maximal work outputs frequently train concurrently utilizing sequential bouts of intense endurance and resistance training sessions. On a daily basis, maximal work within subsequent bouts may be limited by muscle glycogen availability. Recently, the ingestion of a unique high molecular weight (HMW) carbohydrate was found to increase glycogen re-synthesis rate and enhance work output during subsequent endurance exercise, relative to low molecular weight (LMW) carbohydrate ingestion. The effect of the HMW carbohydrate, however, on the performance of intense resistance exercise following prolonged-intense endurance training is unknown. Sixteen resistance trained men (23±3 years; 176.7±9.8 cm; 88.2±8.6 kg) participated in a double-blind, placebo-controlled, randomized 3-way crossover design comprising a muscle-glycogen depleting cycling exercise followed by ingestion of placebo (PLA), or 1.2 g•kg•bw-1 of LMW or HMW carbohydrate solution (10%) with blood sampling for 2-h post-ingestion. Thereafter, participants performed 5 sets of 10 maximal explosive repetitions of back squat (75% of 1RM). Compared to PLA, ingestion of HMW (4.9%, 90%CI 3.8%, 5.9%) and LMW (1.9%, 90%CI 0.8%, 3.0%) carbohydrate solutions substantially increased power output during resistance exercise, with the 3.1% (90% CI 4.3, 2.0%) almost certain additional gain in power after HMW-LMW ingestion attributed to higher movement velocity after force kinematic analysis (HMW-LMW 2.5%, 90%CI 1.4, 3.7%). Both carbohydrate solutions increased post-exercise plasma glucose, glucoregulatory and gut hormones compared to PLA, but differences between carbohydrates were unclear; thus, the underlying mechanism remains to be elucidated. Ingestion of a HMW carbohydrate following prolonged intense endurance exercise provides superior benefits to movement velocity and power output during subsequent repeated maximal explosive resistance exercise. This study was registered with clinicaltrials.gov (NCT02778373).

Low molecular weight carbohydrates released from Okara by enzymatic treatment under high hydrostatic pressure

Okara is an abundant, inexpensive and rich in dietary fibre by-product from soybean with potential prebiotic effect, although an increase in soluble dietary fibre (SDF) and low molecular weight carbohydrates (LMWC) would be desirable. Therefore, a simultaneous treatment with food-grade enzymes (Ultraflo® L or Viscozyme® L) and high hydrostatic pressure (HHP) was used to improve LMWC profile. Release of LMWC from Okara was monitored and estimated using a newly calibrated and validated HPLC method with an ion-exchange column and evaporative light scattering detection (HPLC-ELSD). Both enzymes improved the effect of the HHP treatment. Treatment at 600 MPa, 40 °C for 30 min achieved a decrease in the average molecular weight of polysaccharides from 12.74 ± 3.97 kDa to 3.85 ± 1.33 or 1.59 ± 0.40 kDa when Ultraflo® L or Viscozyme® L were used, respectively. Ultraflo® L (15 min) and Viscozyme® L (30 min) at 600 MPa, were the most effective treatments. Using industrial by-products as a source of nutraceuticals is interesting from an economical point of view. The content of low molecular weight polysaccharides of Okara has been maximized to increase its value as a prebiotic. An industrial adapted treatment with high hydrostatic pressure assisted by food-grade enzymes has been employed. In addition, a new HPLC-ELDS method has been calibrated for monitorizating the process.

Diapause and Cold Hardiness of the Almond Wasp, Eurytoma amygdali (Hymenoptera: Eurytomidae), Two Independent Phenomena.

The almond wasp, Eurytoma amygdali Enderlein (Hymenoptera: Eurytomidae), a key pest of almond, is a univoltine pest diapausing as last instar larvae inside the damaged fruits for almost nine months in a year. In this study, changes in the amount of total simple sugars, lipid, protein, glycogen, trehalose, glucose, supercooling points (SCPs), and cold hardiness of the diapausing larvae were measured from October to March for first year diapause-destined and in August and September for second year diapause-destined larvae. Changes in glycogen content were reversely proportional to changes in total simple sugars and low molecular weight carbohydrates. These changes reflect the interconversion of glycogen to sugar alcohol in order to increase the insect cold tolerance. We found that cold hardiness and diapause of the last instar larvae of the almond wasp have evolved separately. Cold hardiness was highly associated with physiological changes (accumulation of cryoprotectants), but no physiological changes occurred in early diapause of first year diapause-destined and second year diapause-destined larvae. The almond wasp larvae were found to be a freeze-avoidant insect, as no larva survived after SCP determination and crystallization of its body fluids.

Carbohydrate composition of mature and immature faba bean seeds

Faba bean is a valuable pulse crop for human consumption. The low molecular weight carbohydrates (LMWC): glucose, fructose, sucrose (GFS), raffinose, stachyose, and verbascose (RFO- raffinose family oligosaccharides) in faba bean seeds contribute to the flavor and prebiotic nature of this edible bean. Understanding the variation of these compounds across the species would aid plant breeders in their selection efforts to release improved varieties. Therefore, this study was conducted to quantify LMWCs from a diverse collection of faba bean germplasm. The LMWCs of mature and immature seed from 40 faba bean populations across a range of seed sizes (26.2–172.0g100seed−1) were quantified with an Agilent 1260 Infinity LC (size exclusion chromatography/gel permeation chromatography) system with refractive index detection. Sucrose was the predominant constituent LMWC of immature seeds ranging from 5.9 to 22.6% DW for cotyledons and 6.7 to 16.7% DW for seed coats, while total RFO averaged <1% DW across populations. The sucrose content of mature seeds was relatively stable across population with a mean of 2.4% DW, while RFO content ranged from 2.5 to 7.5% DW. The apparent positive relationship between seed size and GFS of immature seed and sucrose and RFO of mature seed indicates that selection for seed size may also affect LMWC concentration.

Carbon Isotope Composition of Carbohydrates and Polyols in Leaf and Phloem Sap of Phaseolus vulgaris L. Influences Predictions of Plant Water Use Efficiency.

The use of carbon isotope abundance (δ(13)C) to assess plant carbon acquisition and water use has significant potential for use in crop management and plant improvement programs. Utilizing Phaseolus vulgaris L. as a model system, this study demonstrates the occurrence and sensitivity of carbon isotope fractionation during the onset of abiotic stresses between leaf and phloem carbon pools. In addition to gas exchange data, compound-specific measures of carbon isotope abundance and concentrations of soluble components of phloem sap were compared with major carbohydrate and sugar alcohol pools in leaf tissue. Differences in both δ(13)C and concentration of metabolites were found in leaf and phloem tissues, the magnitude of which responded to changing environmental conditions. These changes have inplications for the modeling of leaf-level gas exchange based upon δ(13)C natural abundance. Estimates of δ(13)C of low molecular weight carbohydrates and polyols increased the precision of predictions of water use efficiency compared with those based on bulk soluble carbon. The use of this technique requires consideration of the dynamics of the δ(13)C pool under investigation. Understanding the dynamics of changes in δ(13)C during movement and incorporation into heterotrophic tissues is vital for the continued development of tools that provide information on plant physiological performance relating to water use.

The effects of carbohydrate supply and host genetic background on Epichloë endophyte and alkaloid concentrations in perennial ryegrass

The ecological effects of novel grass–endophyte associations used in agriculture have not been widely studied. Previous studies of asexual Epichloe-infected Lolium perenne suggest that endophyte concentration is altered in high sugar grasses (HSGs) selectively bred to produce higher concentrations of water-soluble carbohydrates relative to conventional cultivars. We investigated whether differences are due to the effects of altered carbohydrates, or genetic background, by growing multiple cultivars in both high-sugar trait expression and non-expression conditions (using light/temperature treatments). Endophyte and alkaloid concentrations were measured in three HSG and three NSG (normal-sugar grass) cultivars infected with Lp19 or AR37 endophyte strains. Low molecular weight (LMW) carbohydrates had a small effect, explaining <6% of the variation in endophyte concentration. Endophyte concentrations were strongly dependent on plant genotype and fungal strain, with the highest concentrations seen in Lp19, suggesting that the interaction is highly dependent on genetic compatibility. Changes in endophyte concentration due to altered environmental variables and genetic compatibility may have consequences for persistence, toxicity, and invasive potential of endophyte-infected plants.

Analysis of iminosugars and other low molecular weight carbohydrates in Aglaonema sp. extracts by hydrophilic interaction liquid chromatography coupled to mass spectrometry

A method by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS2) has been successfully developed for the simultaneous analysis of bioactive iminosugars and other low molecular weight carbohydrates in Aglaonema leaf extracts. Among other experimental chromatographic conditions, mobile phase eluents, additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry provided for target carbohydrates. In general, narrow peaks (wh: 0.2–0.6min) with good symmetry (As: 0.9–1.3) and excellent resolution (Rs>1.8) were obtained for iminosugars using an acetonitrile:water gradient with 5mM ammonium acetate in both eluents at 55°C. Tandem mass spectra were used to confirm the presence of previously detected iminosugars in Aglaonema extracts and to tentatively identify for the first time others such as miglitol isomer, glycosyl–miglitol isomers and glycosyl–DMDP isomers. Concentration of total iminosugars varied from 1.35 to 2.84mgg−1 in the extracts of the different Aglaonema samples analyzed. To the best of our knowledge, this is the first time that a HILIC-MS2 method has been proposed for the simultaneous analysis of iminosugars and other low molecular weight carbohydrates of Aglaonema sp. extracts.