• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.04a
• /
• pp.255-256
• /
• 2022

We synthesized catechol-conjugated chitosan (CCC) to study its usefulness as a construction material additive in cement mortar. The degree of catechol conju-gation (DOC_cat) of the synthesized CCC was determined to be approximately14% by UV-vis and ¹H NMR spectroscopy. Furthermore, the hydroxyl and amine groups in CCC could play a crucial role in hydrogen bonding, metal coordination, and cross-linking processes via interaction with adducts from cement mortar. In this study, we observedanimprovement in the compressive strength and absorption rate, suggesting that CCC is a promising candidateforhigh-performance cement mortar.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.12
• /
• pp.1293-1294
• /
• 2001

• Journal of Adhesion and Interface
• /
• v.17 no.4
• /
• pp.149-154
• /
• 2016

In this study, natural polymer-based virus neutralizing agent was developed in an attempt to replace the conventional sterilization method for mammalian cell culture. A catechol conjugated heparin was synthesized by using EDC chemistry, and it show unique binding ability to virus which has heparin affinity (adenovirus, adeno-associated virus). To evaluate neutralization ability of catechol conjugated heparin, adeno-associated virus was used for test model, instead of using a pathogenic virus. The catechol conjugated heparin exhibited resistance to high concentration of salt and complete inactivation of adeno-associated virus. The result suggests that the catechol conjugated heparin, which is biocompatible and efficiency, may replace conventional sterilization method for mammalian cell culture.

• Korean Journal of Weed Science
• /
• v.17 no.3
• /
• pp.334-344
• /
• 1997

Inhibitory substance in the water extracts from lilac(Syringa vulgaris) leaves was determined in terms of the allelopathic chemicals. The water extracts from S. vulgaris leaves inhibited the germination and root growth of Digitaria sanguinalis and L. sativa, indicating that a biological substances are presented in the lilac leaves. The phenolic acids were separated and tentatively identified from S. vulgaris leaves by gas chromatography and there were composed of higher contents of p-coumaric acid, salicylic acid, pyrogallol, and catechol. Polyphenolic compounds such as rutin (5.3%), scopoletin (3.3%), kaempferol (2.9%), and other polyphenolic compotmds were detected from lilac leaves. The mixtures of $10^{-6}M$ of pyrogallol with all the concentrations of catechol had high inhibition of the shoot growth on D. sanguinalis and E. crus-galli regardless of the catechol concentrations.

• Journal of Korean Society of Forest Science
• /
• v.32 no.1
• /
• pp.21-28
• /
• 1976

This paper reports on seasonal variation of tannin, catechol tannin, pyrogallol tannin, sugar, starch and protein contained in new shoots of four races of Castanea crenata in relation to their resistance to gall-wasps. The four races were Ginyose, Shimokatsugi, Taisyo-wase and Tsuguba. 1. Tannin contents showed the lowest level during June and September, and they gradually increased afterwards. Generally tannin contents were higher in gall-wasp resistant races than in its susceptible races. Mean annual tannin contents were 0.73%, 0.845%, 0.507%, and 0.520%, respectively, in Tsuguba, Ginyose, Shimokatsugi and Taisyo-wase. 2. Catechol tannin contents did not change from February to October, however, increased after that period. Catechol tannin contents in gall-wasp resistant races (Tsuguba and Ginyose) more than doubled those in the susceptible races (Shimokatsugi and Taisyo-wase) all the year round, indicating that there may be a correlation between quantitative differences in catechol tannin and the resistance to gall-wasps. 3. Pyrogallol tannin contents were rather lower in the gall-wasp resistant races than in the susceptible races on the contrary to the above results. 4. Seasonal variation of sugar contents showed similar tendency with catechol tannin. Gall-wasp resistant races contained higher sugar contents than those susceptible races. 5. Starch contents were significantly higher during dormant period. Gall-wasp susceptible races showed higher starch contents than the resistant races did, however, this tendency varied with season. 6. There were not significant differences in protein between races but there was a tendency of higher protein in gall-wasp susceptible races. The seasonal change of protein was similar to that of starch. 7. From the above results it seems that seasonal variation of contents of tannin, catechol and pyrogallol tannin, sugar, starch and protein in new shoots of chestnut trees have some relation to their resistance to gall-wasp.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.11a
• /
• pp.89-89
• /
• 2012

• Korean Journal of Microbiology
• /
• v.39 no.1
• /
• pp.1-7
• /
• 2003

The aim of this work was to investigate the characterization and sequence of catechol 2,3-dioxygenase isolated from Delfia sp. JK-2, which could utilize aniline as sole carbon, nitrogen and energy source. In initial experiments, several characteristics of C2,3O separated with ammonium sulfate precipitation, DEAE-sepharose were investigated. Specific activity of C2,3O was approximately 4.72 unit/mg. C2,3O demonstrated its enzyme activity to other substrates, catechol and 4-methylcatechol. The optimum temperature of C2,3O was $$Cu^{2+}$^{\circ}C$, and the optimal pH was approximately 8. Metal ions such as $Ag^{+}$, $Hg^{+}$, and $Cu^{2+}$ showed inhibitory effect on the activity of C2,3O. Molecular weight of the enzyme was determined to approximately 35 kDa by SDS-PAGE. N-terminal amino acid sequence of C2,3O was analyzed as $^{1}MGVMRIG-HASLKVMDMDA- AVRHYENV^{26}$, and exhibited high sequence homology with that of C2,30 from Pseudomonas sp. AW-2, Comamonas sp. JS765, Comamonas testosteroni and Burkholderia sp. RPO07. PCR product was amplified with the primers derived from N-terminal amino acid sequence. In this work, we found that the amino acid sequence of Delftia sp. JK-2 showed high sequence homology of C2,3O from Pseudomonas sp. AW-2 (100%) and Comamonas sp. JS765 (97%).

• Korean Journal of Microbiology
• /
• v.38 no.2
• /
• pp.74-80
• /
• 2002

The purpose of this work was to investigate the characterization and sequence of catechol 1,2-dioxygenase (Cl,2O) purified from Acinetobacter sp. KS-1 which was grown on benzoate as a sole carbon source. Cl,2O demonstrated its enzyme activity to catechol and 4-methylcatechol. The optimum temperature of Cl,2O was $35^{\circ}C$, and the optimal pH was in the range from pH 7.5 to 9.0. $Ag^{+}$, $Hg^{+}$, and $Cu^{2+}$ showed inhibitory effect on the activity of Cl,2O. Molecular weight of the enzyme was determined to approximately 36 kDa by SDS-PAGE and 7-terminal amino acid sequence of Cl,2O was analyzed as $^{1}MNYQQIDALVKQMNVDTAKG^{20}$and exhibited 95% sequence homology with that of Cl,2O from Acinetobacter radioresistens In addition, trypsin digestion and peptide mapping were performed for internal sequencing analysis. Molecular weights of three digested peptide fragments were analyzed as 966.3 Da, 1933.8 Da and 2081.7 Da by MALDI-TOF, which were matched with each internal sequences $^{1}SQSDFNLRR^{9}\, ^{1}HGNRPSHVHYFNSAPGYR^{18}\, ^{1}TIEGPLYVAGAPESVGFAR^{19}$) of. A. radioresistens. PCR product was amplified with the degenerated primers derived from N-terminal and each internal amino acid sequences.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.9
• /
• pp.1956-1962
• /
• 2009

The binding abilities of two multidentate tripodal amine catechol ligands, cis,cis-1,3,5-tris[(2,3-dihydroxybenzylamino) aminomethyl]cyclohexane (TMACHCAT, $L^1)\;and\;N^1,N^3,N^5$-tris(2-(2,3-dihydroxybenzylamino) ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, $L^2$) with Ga(III) and In(III) have been investigated by potentiometric and spectrophotometric methods in an aqueous medium of 0.1 M KCl at 25 ${\pm}\;1\;{^{\circ}C}.$ The ligands $L^1\;and\;L^2$ formed various monomeric species $MLH_3,\;MLH_2$, MLH and ML (M = $Ga^{+3}\;and\;In^{+3}$) and showed potential to form strong encapsulated tris(catechol) type complexes. The coordination modes, binding ability and selectivity of the ligands towards Ga(III) and In(III) have been discussed with the help of experimental evidences, and supported with molecular modeling calculations.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2002.05b
• /
• pp.209-212
• /
• 2002

The heavy use of petroleum products in modern livings has brought ubiquitous environmental contaminants of aromatic compounds, which persist in aquatic and geo-environment without the substantial degradation. The persistence and accumulation of the aromatic compounds, which include xylene, phenol, toluene, phthalate, and so on are known to cause serious problems in our environments. Some of soil and aquatic microorganisms facilitate their growth by degrading aromatic compounds and utilizing degrading products as growth substrates, the biodegradation helps the reentry of carbons of aromatic compounds, preventing their accumulation in our environments. The metabolic studies on the degradation of aromatic compounds by microoganlsms were extensively carried out along with their genetic studies. A Rhodococcus sp. isolated in activated sludges has shown the excellent ability to grow on phenol as a sole carbon source. In the present study investigated a gene encoding phenol-degrading enzymes from a Rhodococcus sp.