Publications by authors named "Daham Jeong"

24 Publications

  • Page 1 of 1

Azobenzene-grafted carboxymethyl cellulose hydrogels with photo-switchable, reduction-responsive and self-healing properties for a controlled drug release system.

Int J Biol Macromol 2020 Nov 10;163:824-832. Epub 2020 Jul 10.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea; Department of Systems Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea. Electronic address:

In this study, multifunctional hydrogels containing host-guest complex formation between azobenzene-grafted carboxymethyl cellulose (CMC-Azo) and β-cyclodextrin (CD) dimers connected by disulfide bonds with agarose for structural support were prepared. The obtained hydrogels exhibited self-healing properties by host-guest complexation as well as gel-sol phase transition in response to ultraviolet (UV) light and reducing agents. Photo-switchable properties of the hydrogels depend on changes in the complex formation of CD-dimers through the trans(450 nm) to cis(365 nm) photo-isomerization of azobenzene. The tensile and strain sweep tests confirmed that the hydrogel's self-healing ability was 79.44% and 81.59%, respectively. In addition, drug release from the hydrogels was controlled to accelerate to 80% in 3 h using UV light or reducing agent. Since the suggested photo-switchable, reduction-responsive, and self-healable hydrogels are non-cytotoxic, they can be potentially applied as biomedical materials in the development of hydrogel-based drug release systems.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.07.071DOI Listing
November 2020

Production of L-Theanine Using Whole-Cell Overexpressing γ-Glutamylmethylamide Synthetase with Bakers Yeast.

J Microbiol Biotechnol 2020 May;30(5):785-792

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.

L-Theanine, found in green tea leaves has been shown to positively affect immunity and relaxation in humans. There have been many attempts to produce L-theanine through enzymatic synthesis to overcome the limitations of traditional methods. Among the many genes coding for enzymes in the L-theanine biosynthesis, glutamylmethylamide synthetase (GMAS) exhibits the greatest possibility of producing large amounts of production. Thus, GMAS from No. 9 was overexpressed in several strains including vectors with different copy numbers. BW25113(DE3) cells containing the pET24ma:: was selected for strains. The optimal temperature, pH, and metal ion concentration were 50°C, 7, and 5 mM MnCl, respectively. Additionally, ATP was found to be an important factor for producing high concentration of L-theanine so several strains were tested during the reaction for ATP regeneration. Bakers yeast was found to decrease the demand for ATP most effectively. Addition of potassium phosphate source was demonstrated by producing 4-fold higher L-theanine. To enhance the conversion yield, GMAS was additionally overexpressed in the system. A maximum of 198 mM L-theanine was produced with 16.5 mmol/l/h productivity. The whole-cell reaction involving GMAS has greatest potential for scale-up production of L-theanine.
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http://dx.doi.org/10.4014/jmb.1910.10044DOI Listing
May 2020

Preparation of Succinoglycan Hydrogel Coordinated With Fe Ions for Controlled Drug Delivery.

Polymers (Basel) 2020 Apr 22;12(4). Epub 2020 Apr 22.

Department of Systems Biotechnology & Dept. of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.

Hydrogel materials with a gel-sol conversion due to external environmental changes have potential applications in a wide range of fields, including controlled drug delivery. Succinoglycans are anionic extracellular polysaccharides produced by various bacteria, including species, which have diverse applications. In this study, the rheological analysis confirmed that succinoglycan produced by Rm 1021 binds weakly to various metal ions, including Fe cations, to maintain a sol form, and binds strongly to Fe cations to maintain a gel form. The Fe-coordinated succinoglycan (Fe-SG) hydrogel was analyzed by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, circular dichroism (CD), and field-emission scanning electron microscopy (FE-SEM). Our results revealed that the Fe cations that coordinated with succinoglycan were converted to Fe by a reducing agent and visible light, promoting a gel-sol conversion. The Fe-SG hydrogel was then successfully used for controlled drug delivery based on gel-sol conversion in the presence of reducing agents and visible light. As succinoglycan is nontoxic, it is a potential material for controlled drug delivery.
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http://dx.doi.org/10.3390/polym12040977DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7240483PMC
April 2020

Utilization of Water-Soluble Aminoethylamino-β-Cyclodextrin in the Pfitzinger Reaction-Catalyzed to the Synthesis of Diversely Functionalized Quinaldine.

Polymers (Basel) 2020 Feb 9;12(2). Epub 2020 Feb 9.

Department of Systems Biotechnology & Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.

In this study we describe the use of an aminoethylamino-β-cyclodextrin (AEA-β-CD) as a supramolecular homogeneous catalyst for the synthesis of a series of diversely substituted quinaldine derivatives which are medicinally important, via Pfitzinger reaction. This supramolecular catalyst exhibited remarkable catalytic activity with high substrate scope to achieve the synthetic targets in good to excellent yield, 69-92%. The structural and morphological properties of the synthesized AEA-β-CD were determined through MALDI-TOF mass spectrometry, NMR, FT-IR, and SEM analysis. Possible reaction mechanisms were determined through molecular host-guest complexation and proposed based on 2D NMR (ROESY) spectroscopy, FT-IR, FE-SEM, and DSC.
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http://dx.doi.org/10.3390/polym12020393DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7077625PMC
February 2020

Succinoglycan dialdehyde-reinforced gelatin hydrogels with toughness and thermal stability.

Int J Biol Macromol 2020 Apr 23;149:281-289. Epub 2020 Jan 23.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea; Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, South Korea. Electronic address:

Pure gelatin hydrogel (PG) has limited practical applications due to their thermal instability and unfavorable mechanical properties. To overcome these limitations, dually crosslinked hydrogels were developed by imparting chemical crosslinking to existing physically crosslinked gelatin hydrogel networks using succinoglycan dialdehyde (SGDA) as a macromolecular crosslinker. SGDA-reinforced gelatin hydrogels (SGDA/Gels) displayed an 11 times higher compressive stress under identical deformation strain and a 1040% improvement in storage modulus (G') than PG. In addition, chemical crosslinking induced by SGDA increased the thermal stability of SGDA/Gels, such that they did not decompose at 60 °C, as confirmed by oscillatory temperature ramp experiments. The newly synthesized SGDA/Gels with reinforced networks and thermal stability exhibit potential for long-term use as controlled drug delivery carriers and 3D cell culture scaffolds for tissue engineering.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.01.228DOI Listing
April 2020

Mono-6-Deoxy-6-Aminopropylamino--Cyclodextrin on Ag-Embedded SiO Nanoparticle as a Selectively Capturing Ligand to Flavonoids.

Nanomaterials (Basel) 2019 Sep 20;9(10). Epub 2019 Sep 20.

Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Korea.

It has been increasingly important to develop a highly sensitive and selective technique that is easy to handle in detecting levels of beneficial or hazardous analytes in trace quantity. In this study, mono-6-deoxy-6-aminopropylamino--cyclodextrin (pr--CD)-functionalized silver-assembled silica nanoparticles (SiO@Ag@pr--CD) for flavonoid detection were successfully prepared. The presence of pr--CD on the surface of SiO@Ag enhanced the selectivity in capturing quercetin and myricetin among other similar materials (naringenin and apigenin). In addition, SiO@Ag@pr--CD was able to detect quercetin corresponding to a limit of detection (LOD) as low as 0.55 ppm. The relationship between the Raman intensity of SiO@Ag@pr--CD and the logarithm of the Que concentration obeyed linearity in the range 3.4-33.8 ppm (R = 0.997). The results indicate that SiO@Ag@pr--CD is a promising material for immediately analyzing samples that demand high sensitivity and selectivity of detection.
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http://dx.doi.org/10.3390/nano9101349DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6835478PMC
September 2019

Cyclodextrin functionalized agarose gel with low gelling temperature for controlled drug delivery systems.

Carbohydr Polym 2019 Oct 20;222:115011. Epub 2019 Jun 20.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea; Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul, 05029, South Korea. Electronic address:

Conventional agaroses with high gelling temperature are limited to apply to the field of drug delivery. In this study, β-cyclodextrin (βCD) functionalized agarose (CFA) with low gelling temperature was successfully prepared from ethylenediamine-functionalized agarose using mono-succinyl βCD. The gelling temperature of CFA dramatically decreased to 26.7 °C from 65 °C and the melting temperature declined from 95 °C to 66.1 °C. Upon drug loading, CFA can be used at 30 °C because of its low gelling temperature compared to agarose. CFA gel could be used both for bovine serum albumin as a full release, and for the doxorubicin (DOX) for sustained release, via inclusion complexation of βCD. Furthermore, cytotoxicity tests revealed that CFA was noncytotoxic. DOX in the CFA gel could retain the anti-cancer activity. Newly synthesized CFA with low gelling temperature offer a new means for the development of hydrogel-based delivery systems for a variety of therapeutic drugs.
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http://dx.doi.org/10.1016/j.carbpol.2019.115011DOI Listing
October 2019

Efficient Adsorption on Benzoyl and Stearoyl Cellulose to Remove Phenanthrene and Pyrene from Aqueous Solution.

Polymers (Basel) 2018 Sep 19;10(9). Epub 2018 Sep 19.

Department of Systems Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.

Benzoyl and stearoyl acid grafted cellulose were synthesized by a simple chemical grafting method. Using these as chemical adsorbents, polycyclic aromatic hydrocarbons (PAHs), like pyrene and phenanthrene, were effectively removed from aqueous solution. The structural and morphological properties of the synthesized adsorbents were determined through X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), FE-SEM, and NMR analyses. Through this method, it was confirmed that benzoyl and stearoyl acid were successfully grafted onto the surface of cellulose. The 5 mg of stearoyl grafted cellulose (St⁻Cell) remove 96.94% pyrene and 97.61% phenanthrene as compared to unmodified cellulose, which adsorbed 1.46% pyrene and 2.99% phenanthrene from 0.08 ppm pyrene and 0.8 ppm phenanthrene aqueous solution, suggesting that those results show a very efficient adsorption performance as compared to the unmodified cellulose.
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http://dx.doi.org/10.3390/polym10091042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6403814PMC
September 2018

Solubility Enhancement of Atrazine by Complexation with Cyclosophoraose Isolated from biovar TA-1.

Polymers (Basel) 2019 Mar 12;11(3). Epub 2019 Mar 12.

Department of Systems Biotechnology & Dept. of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.

biovar TA-1, a kind of soil bacteria, produces cyclosophoraoses (Cys). Cyclosophoraoses contain various ring sizes with degrees of polymerization ranging from 17 to 23. Atrazine is a hardly-soluble herbicide that contaminates soil and drinking water, and remains in soil for a long time. To remove this insoluble contaminant from aqueous solutions, we have enhanced the solubility of atrazine by complexation with Cys. The complex formation of Cys and atrazine was confirmed using ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), rotating frame nuclear overhauser spectroscopy (ROESY), and molecular modeling studies. The aqueous solubility of atrazine was enhanced 3.69-fold according to the added concentrations (20 mM) of Cys, compared to the 1.78-fold enhancements by β-cyclodextrin (β-CD). Cyclosophoraoses as an excellent solubility enhancer with long glucose chains that can effectively capture insoluble materials showed a potential application of microbial polysaccharides in the removal of hazardous hardly-soluble materials from aqueous solutions in the fields of biological and environmental industry.
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http://dx.doi.org/10.3390/polym11030474DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473739PMC
March 2019

Triple-crosslinkedβ-cyclodextrin oligomer self-healing hydrogel showing high mechanical strength, enhanced stability and pH responsiveness.

Carbohydr Polym 2018 Oct 28;198:563-574. Epub 2018 Jun 28.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea; Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, South Korea. Electronic address:

A novel self-healing hydrogel was prepared from a cationic β-cyclodextrin oligomer allyl ether [C(βCD-OM)AE] using a triple cross-linking strategy combining electrostatic interaction, host-guest complexation, and CC bonds as the macrocrosslinker. Here, the C(βCD-OM)AE@Ad gel was successfully prepared by polymerization of synthesized C(βCD-OM)AE, 1-adamantyl acrylate, and acrylic acid. The triple cross-linked hydrogel shows multi-functionality of high mechanical strength, enhanced stability, cytocompatibility, pH responsiveness as well as self-healing ability. Based on the cooperative and synergetic forces of non-covalent and covalent bonds, the C(βCD-OM)AE@Ad gel shows a high tensile strain up to 1,590%, and the self-healed gel could restore up to 84% of its initial length within 24 h. Furthermore, drug release in the hydrogel was controlled by the surrounding pH and slowly released. The present work reveals the cooperativity of multiple cross-links for a 3D structured polymeric material, and the developed self-healable hydrogel can possibly be applied in various biomedical applications.
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http://dx.doi.org/10.1016/j.carbpol.2018.06.117DOI Listing
October 2018

Carboxymethyl cyclosophoraoses as a flexible pH-responsive solubilizer for pindolol.

Carbohydr Polym 2017 Nov 9;175:493-501. Epub 2017 Aug 9.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea. Electronic address:

In the present study, cyclosophoraoses (CyS) (β-1,2 linked cyclic glucans, with glucopyranose units ranging from 17 to 23) isolated from Rhizobium leguminosarum biovar viciae VF-39 were modified with carboxymethyl (CM) groups, and the pH-sensitive complexation of CM CyS with pindolol was investigated. The solubility of pindolol increased 32-fold by its complexation with 5mM CM CyS at pH 10, whereas it shows no significant change at pH 3. Pindolol, a β-adrenergic blocking agent, has a hydrophobic nature at non-ionized state, and CM CyS could solubilize efficiently pindolol in a high alkaline solution. The carboxymethylation of flexible CyS allows them to present a more suitable cavity for the hydrophobic pindolol at pH 10, which is differentiated from CM β-cyclodextrin (β-CD). It can be interpreted as that the anionic repulsion effectively modulates the flexible and distorted conformation of CyS rather than rigid annular shape of β-CD. Resultingly, the highly solubilized CM CyS/pindolol complex was characterized by UV-vis, T1 relaxation, ROESY, DOSY NMR spectroscopy, FT-IR spectroscopy, SEM, and molecular modeling studies. The antioxidant activity of pindolol was also improved 260% in the complex compared to free pindolol. The use of flexible host molecules with pH-responsive substituents would be applied in the development of smart systems for sensing or in biomedical fields.
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http://dx.doi.org/10.1016/j.carbpol.2017.08.026DOI Listing
November 2017

Carbohydrate-Based Host-Guest Complexation of Hydrophobic Antibiotics for the Enhancement of Antibacterial Activity.

Molecules 2017 Aug 8;22(8). Epub 2017 Aug 8.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea.

Host-guest complexation with various hydrophobic drugs has been used to enhance the solubility, permeability, and stability of guest drugs. Physical changes in hydrophobic drugs by complexation have been related to corresponding increases in the bioavailability of these drugs. Carbohydrates, including various derivatives of cyclodextrins, cyclosophoraoses, and some linear oligosaccharides, are generally used as host complexation agents in drug delivery systems. Many antibiotics with low bioavailability have some limitations to their clinical use due to their intrinsically poor aqueous solubility. Bioavailability enhancement is therefore an important step to achieve the desired concentration of antibiotics in the treatment of bacterial infections. Antibiotics encapsulated in a complexation-based drug delivery system will display improved antibacterial activity making it possible to reduce dosages and overcome the serious global problem of antibiotic resistance. Here, we review the present research trends in carbohydrate-based host-guest complexation of various hydrophobic antibiotics as an efficient delivery system to improve solubility, permeability, stability, and controlled release.
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http://dx.doi.org/10.3390/molecules22081311DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6152325PMC
August 2017

SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand.

Nanomaterials (Basel) 2017 Jan 6;7(1). Epub 2017 Jan 6.

Center for Biotechnology Research in UBITA (CBRU), Institute for Ubiquitous Information Technology and Application (UBITA), Konkuk University, Seoul 05029, Korea.

Ethylenediamine-modified β-cyclodextrin (Et-β-CD) was immobilized on aggregated silver nanoparticle (NP)-embedded silica NPs (SiO₂@Ag@Et-β-CD NPs) for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS) signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO₂@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin. In particular, luteolin was detected more strongly in the linear range 10 to 10 M than various organic molecules, namely ethylene glycol, β-estradiol, isopropyl alcohol, naphthalene, and toluene. In addition, the SERS signal for luteolin captured by the SiO₂@Ag@Et-β-CD NPs remained even after repeated washing. These results indicated that the SiO₂@Ag@Et-β-CD NPs can be used as a rapid, sensitive, and selective sensor for flavonoids.
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http://dx.doi.org/10.3390/nano7010008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5295198PMC
January 2017

Solubility and bioavailability enhancement of ciprofloxacin by induced oval-shaped mono-6-deoxy-6-aminoethylamino-β-cyclodextrin.

Carbohydr Polym 2017 May 22;163:118-128. Epub 2017 Jan 22.

Department of Systems Biotechnology, Microbial Carbohydrate Resource Bank (MCRB) & Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul, Republic of Korea. Electronic address:

Ciprofloxacin is a broad-spectrum fluoroquinolone antibiotic used to treat bacterial infections; however, its limited aqueous solubility inhibits its broader clinical uses. This study investigated the complexation effect of mono-6-deoxy-6-aminoethylamino-β-cyclodextrin on the aqueous solubility and bioavailability of ciprofloxacin. During complexation, the oval-shaped cavity induced by mono-aminoethylamine substitution on the primary rim of β-cyclodextrin, was considered to be a key factor according to NMR spectroscopy and molecular modeling studies. The ciprofloxacin with mono-6-deoxy-6-aminoethylamino-β-cyclodextrin complex was characterized using FE-SEM, DSC, FT-IR, T1 relaxation, 2D NOESY, and DOSY NMR spectroscopy and molecular modeling studies. The solubility property of ciprofloxacin complexed with mono-6-deoxy-6-aminoethylamino-β-cyclodextrin was enhanced by seven-fold compared to that of pure ciprofloxacin. Furthermore antibacterial activity of that complex against methicillin-resistant Staphylococcus aureus was enhanced and it clearly showed the growth inhibition. The mono-6-deoxy-6-aminoethylamino-β-cyclodextrin has the potential to be utilized for other oblong guest molecules besides ciprofloxacin based on the novel induced elliptical cavity.
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http://dx.doi.org/10.1016/j.carbpol.2017.01.073DOI Listing
May 2017

Pentynyl Ether of β-Cyclodextrin Polymer and Silica Micro-Particles: A New Hybrid Material for Adsorption of Phenanthrene from Water.

Polymers (Basel) 2017 Jan 4;9(1). Epub 2017 Jan 4.

Center for Biotechnology Research in UBITA (CBRU), Institute for Ubiquitous Information Technology and Applications (UBITA), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea.

A new hybrid material for the removal of polycyclic aromatic hydrocarbons (PAH) from water was prepared by the polymerization of pentynyl beta-cyclodextrin (PyβCD) and silica micro-particles (SMP). Phenanthrene, being one of the important members of the PAH family and a potential risk for environmental pollution, was selected for this study. Results show that phenanthrene removal efficiency of the SMP was improved significantly after hybridization with PyβCD-polymer. Approximately 50% of the phenanthrene was removed in the first 60 min and more than 95% was removed in less than 7 h when 25 mL of the 2 ppm aqueous phenanthrene solution was incubated with the 100 mg of SMP-PyβCD-polymer material. Infrared spectroscopy and thermal gravimetric analysis show that the enhanced efficiency of the SMP-PyβCD-polymer compared to the unmodified SMP was due to the formation of the inclusion complexation of phenanthrene with the PyβCD. These results indicate that SMP-PyβCD polymers have a potential to be applied as molecular filters in water purification systems and also for waste water treatment.
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http://dx.doi.org/10.3390/polym9010010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6432442PMC
January 2017

Enhancing bio-availability of β-naphthoflavone by supramolecular complexation with 6,6'-thiobis(methylene)-β-cyclodextrin dimer.

Carbohydr Polym 2016 Oct 18;151:40-50. Epub 2016 May 18.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MBRC) & Center for Biotechnology Research in UBITA (CBRU), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea. Electronic address:

The aryl hydrocarbon receptor (AhR) is a ligand activated transcriptional regulator, which governs key biological processes including detoxification of carcinogens. β-Naphthoflavone (β-NF) is a non-toxic flavonoid, and a potent AhR agonist. Thus, β-NF can induce the representative detoxifying enzyme cytochrome P4501A1, thereby enhancing the detoxification potential. However, its low water solubility hampers the use. We found that supramolecular complexation of β-NF with the synthetic 6,6'-thiobis(methylene)-β-cyclodextrin (β-CD-S) dimer significantly enhanced β-NF's role as an AhR agonist. The water solubility of β-NF was increased to 469 fold by effective supramolecular complexation with the β-CD-S dimer, and caused significant induction of cytochrome P4501A1. Stable formation of the supramolecular complex of β-NF with β-CD-S-dimer was verified by various analyses. In summary, supramolecular complexation of β-NF with β-CD-S dimer greatly enhanced bio-availability of β-NF as an AhR agonist. Our findings provide an easy, non-destructive, and alternative approach to enhance the bio-availability of therapeutics.
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http://dx.doi.org/10.1016/j.carbpol.2016.05.046DOI Listing
October 2016

Synthesis, Characterization, and Retinol Stabilization of Fatty Amide-β-cyclodextrin Conjugates.

Molecules 2016 Jul 22;21(7). Epub 2016 Jul 22.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea.

Amphiphilic cyclodextrin (CD) has been the object of growing scientific attention because of its two recognition sites, the cavity and the apolar heart, formed by self-assembly. In the present study, mono[6-deoxy-6-(octadecanamido)]-β-CD and mono[6-deoxy-6-(octadecenamido)]-β-CD were successfully synthesized by reacting mono-6-amino-6-deoxy-β-CD with N-hydroxysuccinimide esters of corresponding fatty acids in DMF. The structures were analyzed using nuclear magnetic resonance spectroscopy and mass spectrometry. The amphiphilic β-CDs were able to form self-assembled nano-vesicles in water, and the supramolecular architectures were characterized using fluorescence spectroscopy, dynamic light scattering, and transmission electron microscopy. Using the cavity-type nano-vesicles, all-trans-retinol was efficiently encapsulated; it was then stabilized against the photo-degradation. Therefore, the present fatty amide-β-CD conjugate will be a potential molecule for carrier systems in cosmetic and pharmaceutical applications.
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http://dx.doi.org/10.3390/molecules21070963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273423PMC
July 2016

Functionalized β-cyclodextrin as supramolecular ligand and their Pd(OAc)2 complex: highly efficient and reusable catalyst for Mizoroki-Heck cross-coupling reactions in aqueous medium.

Carbohydr Res 2016 Jul 29;430:85-94. Epub 2016 Apr 29.

Institute for Ubiquitous Information Technology and Applications (UBITA) & Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 143-701, South Korea; Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, Seoul 143-701, South Korea. Electronic address:

A novel class of water soluble palladium complexes with recognition abilities based on functionalized β-cyclodextrin has been synthesized. The complex demonstrated high catalytic activity and a supramolecular platform for phosphine-free Mizoroki-Heck cross-coupling reactions in water. The efficient arylation of alkenes was carried out using different iodo- and bromo-arenes with good to excellent yields (up to 96%). The advantages, like recyclability of catalysts, operational simplicity and accessibility in aqueous medium, make this protocol eco-friendly.
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http://dx.doi.org/10.1016/j.carres.2016.04.024DOI Listing
July 2016

β-CD Dimer-immobilized Ag Assembly Embedded Silica Nanoparticles for Sensitive Detection of Polycyclic Aromatic Hydrocarbons.

Sci Rep 2016 05 17;6:26082. Epub 2016 May 17.

Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea.

We designed a β-CD dimer on silver nanoparticles embedded with silica nanoparticles (Ag@SiO2 NPs) structure to detect polycyclic aromatic hydrocarbons (PAHs). Silica NPs were utilized as a template for embedding silver NPs to create hot spot structures and enhance the surface-enhanced Raman scattering (SERS) signal, and a thioether-bridged dimeric β-CD was immobilized on Ag NPs to capture PAHs. The assembled Ag NPs on silica NPs were confirmed by TEM and the presence of β-CD dimer on Ag@SiO2 was confirmed by UV-vis and attenuated total reflection-Fourier transform infrared spectroscopy. The β-CD dimer@Ag@SiO2 NPs were used as SERS substrate for detecting perylene, a PAH, directly and in a wide linearity range of 10(-7) M to 10(-2) M with a low detection limit of 10(-8) M. Also, the β-CD dimer@Ag@SiO2 NPs exhibited 1000-fold greater sensitivity than Ag@SiO2 NPs in terms of their perylene detection limit. Furthermore, we demonstrated the possibility of detecting various PAH compounds using the β-CD dimer@Ag@SiO2 NPs as a multiplex detection tool. Various PAH compounds with the NPs exhibited their distinct SERS bands by the ratio of each PAHs. This approach of utilizing the assembled structure and the ligands to recognize target has potential for use in sensitive analytical sensors.
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http://dx.doi.org/10.1038/srep26082DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4869113PMC
May 2016

Regioselective self-acylating cyclodextrins in organic solvent.

Sci Rep 2016 Mar 29;6:23740. Epub 2016 Mar 29.

Center for Biotechnology Research in UBITA (CBRU), Institute for Ubiquitous Information Technology and Applications (UBITA), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, South Korea.

Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods.
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http://dx.doi.org/10.1038/srep23740DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4810458PMC
March 2016

Colorimetric Detection of Some Highly Hydrophobic Flavonoids Using Polydiacetylene Liposomes Containing Pentacosa-10,12-diynoyl Succinoglycan Monomers.

PLoS One 2015 23;10(11):e0143454. Epub 2015 Nov 23.

Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB) & Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul, South Korea.

Flavonoids are a group of plant secondary metabolites including polyphenolic molecules, and they are well known for antioxidant, anti-allergic, anti-inflammatory and anti-viral propertied. In general, flavonoids are detected with various non-colorimetric detection methods such as column liquid chromatography, thin-layer chromatography, and electrochemical analysis. For the first time, we developed a straightforward colorimetric detection system allowing recognition of some highly hydrophobic flavonoids such as alpha-naphthoflavone and beta-naphthoflavone, visually using 10,12-pentacosadiynoic acid (PCDA) derivatized with succinoglycan monomers isolated from Sinorhizobium meliloti. Besides changes in visible spectrum, we also demonstrate fluorescence changes using our detection system in the presence of those flavonoids. The succinoglycan monomers attached to PCDA molecules may function as an unstructured molecular capturer for some highly hydrophobic flavonoids by hydrophobic interactions, and transmit their molecular interactions as a color change throughout the PCDA liposome.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0143454PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4658141PMC
June 2016

Hydroxypropyl cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimers as effective carbohydrate-solubilizers for polycyclic aromatic hydrocarbons.

Carbohydr Res 2015 Jan 13;401:82-8. Epub 2014 Nov 13.

Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center & Institute of Ubiquitous Information Technology and Applications (CBRU), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea. Electronic address:

The removal of polycyclic aromatic hydrocarbons by soil washing using water is extremely difficult due to their intrinsic hydrophobic nature. In this study, the effective aqueous solubility enhancements of seven polycyclic aromatic hydrocarbons by chemically modified hydroxypropyl rhizobial cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimer have been investigated for the first time. In the presence of hydroxypropyl cyclic β-(1 → 2)-D-glucans, the solubility of benzo[a]pyrene is increased up to 38 fold of its native solubility. The solubility of pyrene and phenanthrene dramatically increased up to 160 and 359. Coronene, chrysene, perylene, and fluoranthene also show an increase of 11, 23, 23, and 97 fold, respectively, of enhanced solubility by complexation with synthetic epichlorohydrin β-cyclodextrin dimer. The physicochemical properties of the complex are characterized by Fourier-transform infrared spectra and differential scanning calorimetry. Utilizing a scanning electron microscopy, the morphological structures of native benzo[a]pyrene, pyrene, phenanthrene, coronene, chrysene, perylene, fluoranthene and their complex with novel carbohydrate-solubilizers are studied. These results elucidate that polycyclic aromatic hydrocarbons are able to form an efficient complex with hydroxypropyl cyclic β-(1 → 2)-D-glucans and β-cyclodextrin dimer, suggesting the potential usage of chemically modified novel carbohydrate-solubilizers.
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http://dx.doi.org/10.1016/j.carres.2014.10.025DOI Listing
January 2015

Complexation of fisetin with novel cyclosophoroase dimer to improve solubility and bioavailability.

Carbohydr Polym 2013 Aug 2;97(1):196-202. Epub 2013 May 2.

Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center & Institute for Ubiquitous Information Technology and Applications (CBRU), Konkuk University, Seoul 143-701, South Korea.

Rhizobium species produce cyclosophoraose (Cys), which is an unbranched cyclic β-(1,2)-glucan. We synthesized novel cationic cyclosophoraose dimer (Cys dimer) and its structure was confirmed via NMR spectroscopy and MALDI-TOF mass spectrometry analysis. In this study, we investigated the complexation of hardly soluble drug fisetin (3,3',4',7-tetrahydroxyflavone) with Cys dimer to improve the solubility of fisetin, and its solubility was increased up to 6.5-fold. The solubility of fisetin with Cys dimer showed 2.4-fold better than with β-cyclodextrin. The fisetin-Cys dimer complex was characterized by using, phase solubility diagram, 2D NMR, FT-IR spectroscopy, SEM, DSC analysis and molecular modeling. Through the molecular docking simulations, complexation ability of fisetin with host molecules were in the following order: Cys dimer>Cys monomer>β-CD. The fisetin-Cys dimer complex showed also higher cytotoxicity to HeLa cells than free fisetin, indicating that the Cys dimer to improve bioavailability of fisetin.
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http://dx.doi.org/10.1016/j.carbpol.2013.04.066DOI Listing
August 2013

Cholesterol reduction from milk using β-cyclodextrin immobilized on glass.

J Dairy Sci 2013 Jul 28;96(7):4191-6. Epub 2013 Apr 28.

Department of Bioscience and Biotechnology & Center for Biotechnology Research in UBITA, Konkuk University, Seoul 143-701, Republic of Korea.

β-Cyclodextrin (β-CD) was converted into β-CD-undecenyl ether by chemical modification and subsequently covalently attached to a glass surface. The functionalized glass surface was characterized by static water contact angle and x-ray photoelectron spectroscopy. Both techniques confirmed that an excellent monolayer of β-CD was formed on the glass surface. The β-CD solid surface was used to reduce cholesterol levels in milk. In 4h, 73.6% of the cholesterol was extracted at 25°C with shaking at 170rpm. This is the highest value ever reported for milk using β-CD immobilized on a solid surface. The same surface was repeatedly used for 10 cycles and maintained its efficiency with 72±2% cholesterol reduction observed in all the cycles. X-ray photoelectron spectroscopy analysis completed after 5 and 10 cycles of cholesterol reduction showed that the β-CD on the glass surface was not degraded. The high efficiency and long-term stability of the functional monolayer was attributed to the specific structure of β-CD, which is composed of a relatively low number of functional groups and long spacer chain lengths that provide great flexibility.
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http://dx.doi.org/10.3168/jds.2012-6355DOI Listing
July 2013