Modification of the Antibiotic, Colistin, with Dextrin Causes Enhanced Cytotoxicity and Triggers Apoptosis in Myeloid Leukemia.

Introduction: Acute myeloid leukemia (AML) remains difficult to treat due to its heterogeneity in molecular landscape, epigenetics and cell signaling alterations. Precision medicine is a major goal in AML therapy towards developing agents that can be used to treat patients with different 'subtypes' in combination with current chemotherapies. We have previously developed dextrin-colistin conjugates to combat the rise in multi-drug resistant bacterial infections and overcome dose-limiting nephrotoxicity. Recent evidence of colistin's anticancer activity, mediated through inhibition of intracellular lysine-specific histone demethylase 1 (LSD1/KDM1A), suggests that dextrin-colistin conjugates could be used to treat cancer cells, including AML. This study aimed to evaluate whether dextrin conjugation (which reduces in vivo toxicity and prolongs plasma half-life) could enhance colistin's cytotoxic effects in myeloid leukemia cell lines and compare the intracellular uptake and localization of the free and conjugated antibiotic. Results: Our results identified a conjugate (containing 8000 g/mol dextrin with 1 mol% succinoylation) that caused significantly increased toxicity in myeloid leukemia cells, compared to free colistin. Dextrin conjugation altered the mechanism of cell death by colistin, from necrosis to caspase 3/7-dependent apoptosis. In contrast, conjugation via a reversible ester linker, instead of an amide, had no effect on the mechanism of the colistin-induced cell death. Live cell confocal microscopy of fluorescently labelled compounds showed both free and dextrin-conjugated colistins were endocytosed and co-localized in lysosomes, and increasing the degree of modification by succinoylation of dextrin significantly reduced colistin internalization. Discussion: Whilst clinical translation of dextrin-colistin conjugates for the treatment of AML is unlikely due to the potential to promote antimicrobial resistance (AMR) and the relatively high colistin concentrations required for anticancer activity, the ability to potentiate the effectiveness of an anticancer drug by polymer conjugation, while reducing side effects and improving biodistribution of the drug, is very attractive, and this approach warrants further investigation.

Structural characteristics and emulsifying properties of linear dextrin/eicosapentaenoic acid composites: Effect of the degree of polymerization.

This work aimed at building functional emulsions based on the linear dextrins (LDs) emulsion system. The gradient polyethylene glycol (PEG) precipitaion method was used to fractionate LDs into fractions with different degrees of polymerization (DP). A package, and co-precipitation procedure of LDs, and eicosapentaenoic acid (EPA) was used to fabricate LDs-EPA composites. The gas chromatograph, Fourier transform infrared spectroscopy, X-ray diffraction and differential scanning calorimetry analyses affirmed the formation of the LDs-EPA composites. The sizes of these composites were 38.55 nm, 59.14 nm to 80.62 nm, respectively, and they had good amphiphilicity. Compared with LDs, these LDs-EPA composites stabilized Pickering emulsion had higher stability and antioxidant capacity. Their emulsifying ability was positively correlated with the DP values of LDs. Furthermore, the oxidation stability results showed that LDsF10-EPA emulsion had the lowest lipid hydroperoxide (LHs) content, malondioxide (MDA) content and hexal concentration, which were 138.75 mmol kg-1 oil, 15.50 mmol kg-1 oil and 3.83 µmol kg-1 oil, respectively. The study provided a new idea and application values for the application of LDs in emulsion.

Dextrin-assisted gel electromembrane extraction of chiral drugs: Improving the extraction efficiency and investigation of enantioselectivity of extraction.

The present study investigates the use of dextrins (maltodextrin, ß-cyclodextrin, and hydroxypropyl-ß-cyclodextrin) to improve the efficiency of the agarose-based gel electromembrane extraction technique for extracting chiral basic drugs (citalopram, hydroxyzine, and cetirizine). Additionally, it examines the enantioselectivity of the extraction process for these drugs. To achieve these, dextrins were incorporated into either the sample solution, the membrane, or the acceptor solution, and then the extraction procedure was performed. Enantiomers were separated and analyzed using a capillary electrophoresis device equipped with a UV detector. The results obtained under the optimal extraction conditions (sample solution pH: 4.0, acceptor solution pH: 2.0, gel membrane pH: 3.0, agarose concentration: 3 % w/v, stirring rate: 1000 rpm, gel thickness: 4.4 mm, extraction voltage: 62.3 V, and extraction time: 32.1 min) indicated that incorporating dextrins into either the sample solution, membrane or the acceptor solution enhances extraction efficiency by 17.3-23.1 %. The most significant increase was observed when hydroxypropyl-ß-cyclodextrin was added to the acceptor solution. The findings indicated that the inclusion of hydroxypropyl-ß-cyclodextrin in the sample solution resulted in an enantioselective extraction, yielding an enantiomeric excess of 6.42-7.14 %. The proposed method showed a linear range of 5.0-2000 ng/mL for enantiomers of model drugs. The limit of detection and limit of quantification for all enantiomers were found to be < 4.5 ng/mL and <15.0 ng/mL, respectively. Intra- and inter-day RSDs (n = 4) were less than 10.8 %, and the relative errors were less than 3.2 % for all the enantiomers. Finally, the developed method was successfully applied to determine concentrations of enantiomers in a urine sample with relative recoveries of 96.8-99.2 %, indicating good reliability of the developed method.

Casein/butyrylated dextrin nanoparticles and chitosan stabilized bilayer emulsions as fat substitutes in sponge cakes.

This study aimed to evaluate the potential of the bilayer emulsions stabilized with casein/butyrylated dextrin nanoparticles and chitosan as fat substitutes in preparing low-calorie sponge cakes. Among the different cake groups, the substitution of bilayer emulsions at 60% exhibited comparable baking properties, appearance, texture characteristics and stable secondary structure to fat. The specific volume and height were increased by 36.94% and 22%, respectively, while the cake showed higher lightness (L*) in the cores and softer hardness in the crumb. In addition, the moisture content of cakes was increased while the water activity remained unchanged. These results showed that casein/butyrylated dextrin bilayer emulsion was a potential fat substitute for cake products at the ratio of 60% with the desirable characteristics.

Interfacial engineering method to regulate the performances of bilayer emulsions co-stabilized by casein/butyrylated dextrin nanoparticles and chitosan.

In present study, bilayer emulsions with different interfacial structures stabilized by casein/butyrylated dextrin nanoparticles (CDNP), chitosan (CS) and chitosan nanoparticles (CSNP) were prepared to overcome the limitations of conventional emulsions. The effects of chitosan morphology and incorporation sequences on the bilayer emulsions were examined. Bilayer emulsions prepared with CDNP as the inner layer and CS/CSNP as the outer layer were observed to have smaller droplet sizes (1.39 ± 86.74 um and 1.45 ± 7.87 um). Bilayer emulsions prepared with CDNP as the inner layer and CS as the outer layer exhibited the lowest creaming index (2.38 %) after 14 days of storage, indicating excellent stability. Furthermore, bilayer emulsion prepared with CDNP as the inner layer and CS as the outer layer also exhibited a uniform water distribution, excellent protein oxidative stability, and uniformly distributed droplets by the measurement of Low-field NMR, intrinsic tryptophan fluorescence and laser confocal laser scanning microscopy. These results indicated that the study provided a theoretical basis for the development and design of bilayer emulsions with different interfacial structures. This study also provides a new material for the preparation of delivery systems that protect biologically active compounds. Bilayer emulsions are promising for applications in traditional and manufactured food products.

Characterization, health benefits, and food applications of enzymatic digestion- resistant dextrin: A review.

Resistant dextrin or resistant maltodextrin (RD), a short-chain glucose polymer that is highly resistant to hydrolysis by human digestive enzymes, has shown broad developmental prospects in the food industry and has gained substantial attention owing to its lack of undesirable effects on the sensory features of food or the digestive system. However, comprehensive fundamental and application information on RD and how RD improves anti-diabetes and obesity have not yet been received. Therefore, the characterization, health benefits and application of RD in various fields are summarized and discussed in the current study. Typically, RD is prepared by the acid thermal method and possesses excellent physicochemical properties, including low viscosity, high solubility, storage stability, and low retro-gradation, which are correlated with its low molecular weight (Mw) and non-digestible glycosidic linkages. In contrast, RD prepared by the simultaneous debranching and crystallization method has low solubility and high crystallinity. The ingestion of RD can positively affect metabolic diseases (diabetes and obesity) in animals and humans by producing short-chain fatty acids (SCFAs), and facilitating the inflammatory response. Moreover, RD has been widely used in the beverage, dairy products, and dessert industries due to its nutritional value and textural properties without unacceptable quality loss. More studies are required to further explore RD application potential in the food industry and its role in the management of different chronic metabolic disorders.

Molecular structure of lotus seed amylopectins and their beta-limit dextrins.

Investigation on amylopectin molecular structure is gaining importance for understanding starch property. Lotus seeds are a novel starch source with high apparent amylose content. Current understanding on the molecular structure of amylopectin in lotus seed starch is scarce. This study compared the molecular structure of a range of lotus seed amylopectins with those of maize and potato amylopectins. Internal structures of these amylopectins were compared via investigating the chain length distribution of their ß-limit dextrins. The average lengths and molar compositions of unit chains in lotus seed amylopectins and their ß-limit dextrins fell generally between those of maize and potato. The average chain lengths of lotus seed, maize, and potato amylopectins were 19.95 (on average), 19.11, and 21.19 glucosyl residues, respectively. Lotus seed amylopectins had higher weight proportion of clustered unsubstituted chains (44.94 % on average) than those of potato (43.99 %) and maize amylopectins (42.95 %). Results of correlation analysis indicated that apparent amylose content of LS was related to structural characteristics of its amylopectin due to the presence of long external chains. The results of this study are of fundamental importance for the utilization of lotus seed starch as a novel starch source.

Effects of Resistant Dextrin from Potato Starch on the Growth Dynamics of Selected Co-Cultured Strains of Gastrointestinal Bacteria and the Activity of Fecal Enzymes.

Preparations of resistant dextrins have become an interesting topic of research due to their properties, which bear resemblance those of prebiotics, e.g., the improvement of metabolic parameters, increased efficiency of the immune system and induction of vitamin production. The aim of this study was to investigate the effects of the resistant dextrin produced from potato starch on the growth dynamics of typical gastrointestinal microbiota and the activity of fecal enzymes in order to assess a possible exhibition of prebiotic properties. In the study, in vitro cultivation of co-cultures of Lactobacillus, Bifidobacterium, E. coli, Enterococcus, Clostridium and Bacteroides spp. was conducted on media enriched with the resistant dextrin. The CFU/mL for each strain was measured in time periods of 24, 48, 72, 96 and 168 h. Furthermore, the activities of α-glucosidase, α-galactosidase, ß-glucosidase, ß-galactosidase and ß-glucuronidase were determined using spectrophotometric methods at a wavelength of 400 nm. The results show that the resistant dextrin can be utilized as a source of carbon for the growth of intestinal bacteria. Moreover, the results revealed that, after 168 h of cultivation, it enhances the viability of probiotic strains of Lactobacillus and Bifidobacterium spp. and decreases the growth of other intestinal strains (Clostridium, Escherichia coli, Enterococcus and Bacteroides), which is demonstrated by a high Prebiotic Index (p < 0.05). Furthermore, there was no significant change in the pH of the cultures; however, the pace of the pH decrease during the cultivation was slower in the case of culture with resistant dextrin. Furthermore, it was revealed that usage of the resistant dextrin as a medium additive noticeably lowered the activities of ß-glucosidase and ß-glucuronidase compared to the control (p < 0.05), whereas the activities of the other fecal enzymes were affected to a lesser degree. The resistant dextrins derived from potato starch are a suitable prebiotic candidate as they promote the growth of beneficial strains of gut bacteria and improve health markers, such as the activity of fecal enzymes. Nevertheless, additional in vivo research is necessary to further assess the suspected health-promoting properties.

Diverse prebiotic effects of isomaltodextrins with different glycosidic linkages and molecular weights on human gut bacteria in vitro.

Isomaltodextrin (IMD) is a novel dietary fiber enzymatically produced by reconstructing the molecular chain structure of starch using glycosyltransferases. In this study, the specific prebiotic effects of α-1,6 linear and α-1,2 or α-1,3 branched IMDs with different molecular weights (Mw) on human intestinal bacteria were investigated by pure culture of single strains and mixed fermentation of human fecal microflora in vitro. The results showed that α-1,6 linear IMDs markedly promoted beneficial Bifidobacterium and Lactobacillus in both pure culture and mixed fermentation. α-1,3 branching exhibited similar selectivity with α-1,6 linkage but yielded more butyrate in pure cultures. In contrast, IMDs containing α-1,2 branches were utilized efficiently only during mixed fermentation, which was speculated to result from metabolic cross-feeding. Regarding Mw, IMDs with lower Mw showed better prebiotic effects in pure cultures but no differences in mixed culture. These findings provide a theoretical basis for their application as functional foods.

Slowly digestible property of highly branched α-limit dextrins produced by 4,6-α-glucanotransferase from Streptococcus thermophilus evaluated in vitro and in vivo.

Starch molecules are first degraded to slowly digestible α-limit dextrins (α-LDx) and rapidly hydrolyzable linear malto-oligosaccharides (LMOs) by salivary and pancreatic α-amylases. In this study, we designed a slowly digestible highly branched α-LDx with maximized α-1,6 linkages using 4,6-α-glucanotransferase (4,6-αGT), which creates a short length of α-1,4 side chains with increasing branching points. The results showed that a short length of external chains mainly composed of 1-8 glucosyl units was newly synthesized in different amylose contents of corn starches, and the α-1,6 linkage ratio of branched α-LDx after the chromatographical purification was significantly increased from 4.6% to 22.1%. Both in vitro and in vivo studies confirmed that enzymatically modified α-LDx had improved slowly digestible properties and extended glycemic responses. Therefore, 4,6-αGT treatment enhanced the slowly digestible properties of highly branched α-LDx and promises usefulness as a functional ingredient to attenuate postprandial glucose homeostasis.

Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production.

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

Physically cross-linked chitosan/dextrin cryogels entrapping Thymus vulgaris essential oil with enhanced mechanical, antioxidant and antifungal properties.

Herein, we entrapped Thymus vulgaris essential oil (EO) within the physically cross-linked sponge-like architecture of cryogels by ice template-assisted freeze-drying. Their 3D cryogenically-structured network was built through hydrogen bonding formed by blending two naturally-derived polysaccharides, chitosan and dextrin. The embedment of EOs within the cryogel matrix generates porous films with an increased elasticity that allows their fast shape recovery after full compression. Thus, the swollen EOs-loaded cryogel films exhibited an elastic modulus of 3.00 MPa, which is more than 40 times higher than that of polysaccharide films without EOs (an elastic modulus of only 0.07 MPa). In addition, the encapsulation of bioactive compounds endows the bio-based films with both antioxidant and antifungal properties, showing a radical scavenging activity of 65% and a zone inhibition diameter of 40 mm for Candida parapsilosis fungi. Our results recommend the entrapment of EOs into bio-based cryogel carriers as a straightforward approach to provide 'green' polysaccharide-based films having both improved physicochemical properties and remarkable antifungal activity.

A physicochemical assessment of the thermal stability of dextrin-colistin conjugates.

Attachment of polysaccharide carriers is increasingly being used to achieve precision delivery and improved effectiveness of protein and peptide drugs. Although it is clear that their clinical effectiveness relies on the purity and integrity of the conjugate in storage, as well as following administration, instability of polysaccharide-based conjugates can reduce the protective efficacy of the polymer, which may adversely affect the bioactive's potency. As a model, these studies used dextrin-colistin conjugates, with varying degrees of polymer modification (1, 2.5 and 7.5 mol% succinoylation) to assess the effect of storage temperature (- 20, 4, 21 and 37 °C) and duration (up to 12 months) on saccharide and colistin release and antimicrobial activity. Estimation of the proportion of saccharide release (by comparison of area under the curve from size exclusion chromatograms) was more pronounced at higher temperatures (up to 3 and 35% at - 20 °C and 37 °C, respectively after 12 months), however, repeated freeze-thaw did not produce any measurable release of saccharides, while addition of amylase (20, 100, 500 IU/L) caused rapid release of saccharides (> 70% total within 24 h). At all temperatures, conjugates containing the lowest degree of succinoylation released the highest proportion of free colistin, which increased with storage temperature, however no trend in saccharide release was observed. Despite the clear physical effects of prolonged storage, antimicrobial activity of all samples was only altered after storage at 37 °C for 12 months (> threefold decreased activity). These results demonstrate significant release of saccharides from dextrin-colistin conjugates during prolonged storage in buffered solution, especially at elevated temperature, which, in most cases, did not affect antimicrobial activity. These findings provide vital information about the structure-activity relationship of dextrin-colistin conjugates, prior to full-scale commercial development, which can subsequently be applied to other polysaccharide-protein and -peptide conjugates.

Synthesis of dextrin-polyacrylamide and boric acid based tough and transparent, self-healing, superabsorbent film.

Stretchabiliy, transparency and self-healing ability of bio-based materials are some of the important features for their utilization in the biomedical field. Recently, robust self-healing super porous materials possessing multifunctional nature have raised enormous interest among the researchers in order to design different materials which can be used in industrial, biomedical and pharmaceutical fields. Herein, a novel self-healing, stretchable and transparent superabsorbent film based on Dextrin-polyacrylamide and Boric Acid (DEX-cl-polyAAm) was synthesized using a free radical reaction mechanism. In distilled water, the maximum water absorptivity of the synthesized film was reported to be 3156% after the optimization of various reaction parameters. The film was also found to show structural integrity in urea solution, phosphate buffer and solutions of different pH. Lastly, the viscoelastic and self-healing analysis of the film suggested its utility towards biomedical field.

A novel dextrin produced by the enzymatic reaction of 6-α-glucosyltransferase. I. The effect of nonreducing ends of glucose with by α-1,6 bonds on the retrogradation inhibition of high molecular weight dextrin.

We prepared a high-molecular-weight modified dextrin (MWS-1000) from a partial hydrolysate of waxy corn starch with a weight average molecular weight of 1 × 106 (WS-1000) using Paenibacillus alginolyticus PP710 α-glucosyltransferase. The gel permeation chromatography showed that the weight average molecular weight of MWS-1000 was almost the same as that of WS-1000. The side chain lengths of WS-1000 and MWS-1000 after isomaltodextranase digestion were also shown to be similar to each other by high-performance anion exchange chromatography with pulsed amperometric detection. Since MWS-1000 confirmed the presence of α-1,6 bonds by enzyme digestibility, methylation, and 1H-NMR analyses, it was presumed that the structure of MWS-1000 was based on the introduction of α-1,6 glucosyl residues at the nonreducing ends of the partial hydrolysate of waxy corn starch. Furthermore, the MWS-1000 solution was not retrograded even during refrigerated storage or after repeated freeze-thaw cycles.

Sustainable plant and microbes-mediated preparation of Fe3O4 nanoparticles and industrial application of its chitosan, starch, cellulose, and dextrin-based nanocomposites as catalysts.

Iron oxide nanoparticles (Fe3O4 NPs) attracted significant scientific interest, considering their immense diversity of usage and biocompatibility. Perceiving the growing importance of sustainable chemistry, many efforts have been made to prepare these NPs using naturally occurring materials mostly plant extracts and microbes. Magnetic NPs (MNPs) are commonly used as composites and are considered in two matters: synthesis and modification of their functional groups. Biopolymeric nanocomposites are a group of hybrid materials composed of natural polymers and inorganic nanomaterials. Biopolymers such as alginate, cellulose, starch, gelatin, chitosan, etc. have been considered extensively and provided composites with better electrical and mechanical thermal properties. Fe3O4 NPs incorporated in a polymer and biopolymer matrix is a good instance of the functional nanostructure, which has been able to enhance the properties of both ingredients. These hybrids can have impressive applications in various scopes such as magneto-optical storage, electromagnetic interference shielding, catalyst, water remediation, biomedical sensing, and so on. In this study, we have tried to briefly introduce Fe3O4 NPs, investigate the green and sustainable methods that have been suggested for its synthesis and review recent utilization of their biopolymeric nanocomposite (NC) including starch, chitosan, dextrin, etc. as catalysts and photocatalysts.

Oxidized polysaccharides for anticancer-drug delivery: What is the role of structure?

Study provides an in-depth analysis of the structure-function relationship of polysaccharide anticancer drug carriers and points out benefits and potential drawbacks of differences in polysaccharide glycosidic bonding, branching and drug binding mode of the carriers. Cellulose, dextrin, dextran and hyaluronic acid have been regioselectively oxidized to respective dicarboxylated derivatives, allowing them to directly conjugate cisplatin, while preserving their major structural features intact. The structure of source polysaccharide has crucial impact on conjugation effectiveness, carrier capacity, drug release rates, in vitro cytotoxicity and cellular uptake. For example, while branched structure of dextrin-based carrier partially counter the undesirable initial burst release, it also attenuates the cellular uptake and the cytotoxicity of carried drug. Linear polysaccharides containing ß-(1→4) glycosidic bonds and oxidized at C2 and C3 (cellulose and hyaluronate) have the best overall combination of structural features for improved drug delivery applications including potentiation of the cisplatin efficacy towards malignances.

Injectable hydrogels of newly designed brush biopolymers as sustained drug-delivery vehicle for melanoma treatment.

Novel biocompatible and brush copolymers have been developed for cancer treatment using its controlled drug-release potential. Polyurethane graft on linear dextrin has been synthesized to control the hydrophilic-hydrophobic balance for regulated drug delivery. The properties of the graft copolymers have been tuned through graft density. The prepared grafts are thermally stable and mechanically strong. An injectable hydrogel has been developed by embedding the drug-loaded brush copolymers in methyl cellulose to better control the release for a prolonged period, importantly by keeping the drug release at a constant rate. Cellular studies indicate the biocompatible nature of the brush copolymers whose controlled and slow release of drug exhibit significant cytotoxic effects on cancer cells. Endocytosis of drug tagged contrast agent indicates greater transport of biologically active material inside cell as observed through cellular uptake studies. In vivo studies on melanoma mice exhibit the real efficacy of the controlled drug release from the injectable hydrogel with significant melanoma suppression without any side effects as opposed to severe toxic effects observed in conventional chemotherapy. Special application method of drug-loaded hydrogel just beneath the tumor makes this system incredibly effective through confinement. Thus, brush copolymer injectable hydrogel is a promising vehicle for control release of drug for cancer treatment in future.

Structural comparisons of pyrodextrins during thermal degradation process: The role of hydrochloric acid.

Hydrochloric acid (HCl) is widely used to prepare pyrodextrins, especially the water-soluble pyrodextrin. In this study, the structural difference between pyrodextrins as affected by HCl is compared by characterizing the molecular size, chain-length distributions (CLDs), crystallinity, and solubility. It is found that: 1) dry heating of starch granules without HCl mainly degrades long-amylose chains while slightly affects amylopectin branches; 2) the presence of HCl during dry heating decreases the degree of polymerization (DP) range of amylose chains upon degradation from DP ~ 833-1267 to DP ~ 206-432, suggesting that the presence of HCl accelerates the breakdown of long-amylose chains; 3) both pyroconversion processes have slight effects on A-(DP ~ 6-12) and B1- chains (DP ~ 12-24), which might explain the retained granular and crystalline structure during the process. This study could improve the understanding of the role of HCl in affecting the structure and property during pyroconversion of native starch.

A simplified method of determining the internal structure of amylopectin from barley starch without amylopectin isolation.

To determine the internal structure of barley starch without amylopectin isolation, whole starch was hydrolyzed using ß-amylase to remove the linear amylose and obtain ß-limit dextrins (ß-LDs). The ß-LDs were treated with extensive α-amylase to prepare α-limit dextrins (α-LDs), and the α-LDs were further hydrolyzed with ß-amylase into building blocks. The chain-length distribution of ß-LD and building block composition were analyzed by size-exclusion chromatography and anion-exchange chromatography. The internal structure of the barley whole starches had similar pattern to barley amylopectins analyzed by conventional methods. The starch of barley amo1-mutated varieties contained more short internal B-chains and less long internal B-chains than that of other varieties. The starch from amo1-mutated varieties had more large building blocks than that from waxy varieties. The simplified method presented in this study can effectively characterize starch internal structure that relates to physicochemical properties of starch, although some details of amylopectin structure are not assessable.