• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.126-128
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• 2002

Monascus pigment-dipeptide derivatives were synthesized by Monascus in 48-well plates. Monascus pigment-dipeptides derivatives were identified as antibacterial agents. The antibacterial activities against 20strains were tested with ELISA Reader and 96-well plate.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.121-121
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• 1993

Angiotensin Converting Enzyme (ACE)의 효과적인 억제제를 합성하기 위하여 ketomethylene dipeptide isoster와 2-isoxazoline dipeptide isoster를 얻는 방법을 확립하였다. 상기 등입체성 분자들은 아미노산으로부터 유도된 아미노 니트릴 옥사이드의 고리더함반응을 이용하여 효율적으로 합성하였다. 얻어진 이 화합물로부터 ACE 억제제 후보물질 (1, 2)의 합성이 연구되고 있다.

• Journal of the Korean Chemical Society
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• v.21 no.3
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• pp.171-179
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• 1977

Proton magnetic resonance spectra of five glycine-containing dipeptides glycyl-L-valine, L-valyl-glycine, glycyl-DL-alanine, glycyl-DL-serine and glycyl-L-aspartic acid in $D_2O$ were investigated as a function of pH at room temperature. From the analysis of the spectra, it was found that the chemical shift of the $C_{\alpha}H,\;C_{\beta}H\;and\;C_rH$protons varies with pH as a one-step titration curve, and that the spin-spin coupling constant remains almost unchanged. Two distinct values of the chemical shift for $C_{\alpha}H,\;C_{\beta}H\;or\;C_rH$protons of constituent amino acids in dipeptide solutions indicate the existence of two magnetically non-equivalent sites in solution. From this study, the structures of the five dipeptides have been confirmed by proton magnetic resonance spectra and it has been suggested that the structural change, conformation and sequence determination can be explored for oligopeptides by an analysis of proton magnetic resonance spectra.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1091-1096
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• 2003

The effects of different polarization conditions on vibrational echo signals are systematically explored for the rigid cyclic dipeptide 2,5-diazabicyclo[2,2,2]octane-3,6-dione. An anharmonic vibrational Hamiltonian is constructed by computing energy derivatives to fourth order using density functional theory. Molecular frame transition dipole orientations are then used to calculate polarization dependent orientational factors corresponding to various Liouville space pathways. Enhancement and elimination of specific peaks in twodimensional correlation plots is accomplished by identifying appropriate pulse configurations.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.158-162
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• 2006

Cyclic dipeptides isolated from Streptomyces sp. have been shown to have antimicrobial activity as well as other potentially useful biological activities. The purpose of this study was to compare the in vitro activity of two cyclic dipeptides combined against anaerobic bacteria with the activity of other antimicrobial agents. Specifically, the in vitro activity of the combination of two cyclic dipeptides was investigated against 140 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of erythromycin, cefoxitin, imipenem, clindamycin, and metronidazole. The cyclic dipeptide combination and imipenem were the most active antimicrobial agents tested. In addition, the cyclic dipeptide combination had a radioprotective effect on five normal human lung fibroblast cells, showing survival rates higher $(>90\%)$ than either of the two cyclic dipeptides alone $(<80\%)$.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.273-277
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• 2005

Dynamic resolution of $\alpha$-bromo tertiary acetamides in asymmetric nucleophilic substitution reaction is described. Intermolecular substitution of $\alpha$-bromo tertiary acetamides with dibenzylamine in the presence of TBAI and $Et_3N$ gave the dipeptide analogues 7-10 with high stereoselectivities up to 90 : 10 dr. Also, cyclic dipeptide analogues 20-29 were produced by the intramolecular nucleophilic cyclization of $\alpha$-bromo tertiary acetamides with low stereoselectivities in 84-42% yields.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.300-303
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• 1985

To understand the nature of the linkage between chromophore and apoprotein in the photoreceptor of Stentor coeruleus, a conformational analysis has been carried out on the dipeptide amides linked to the chromophore hypericin using an empirical potential function. The conformational energies for the dipeptide amides of Glu (OHyp)-X-NHMe, where X = Leu, Phe, Asp, and Tyr, have been calculated to investigate the influence of peptide residues in stabilizing conformers. It was found that the increase of acidity of hypericin upon photoexcitation may be facilitated by the formation of intramolecular hydrogen bonds between hydroxyl groups of hypericin and carbonyl groups of peptide backbone, and that the stabilities of dipeptide amides do not significantly depend on peptide residues directly linked to chromophore.

• Journal of Pharmaceutical Investigation
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• v.25 no.4
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• pp.291-298
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• 1995

The purpose of this study is to verify the interaction between food and ampicillin which is one of the aminopenicillins known to be absorbed by a specified dipeptide transporter in the small intestine. The absorption of ampicillin was measured in the presence of the high carbohydrate food, high fat food, and high protein food, and compared with that in the presence of the control normal food. In situ single-pass perfusion method was chosen in these experiments using two jejunal segments in the rat. Reduction in the absorption of ampicillin was not shown, when both high carbohydrate food and high fat food were co-perfused with ampicillin. When the high protein food was co-perfused with ampicillin, the difference of $C_{out}/C_{in}$ of ampicillin ratio was $0.084\;{\pm}\;0.082$, showing a trend of reduced absorption without a significance. Further, glyclysarcosine (Gly-Sar) which is a stable dipeptide in the small intestine was used in order to see the direct competitive inhibition with ampicillin on the dipeptide transporter. The difference of $C_{out}/C_{in}$ ratio was $0.078\;{\pm}\;0.020$ in the presence of 10 mM Cly-Sar, showing a significant inhibition of ampicillin absorption (p < 0.02). It suggests that dietary di- and tripeptides, the digestive products of protein food, might have influence on the absorption of ampicillin, and that ampicillin could be given at the lasting state for better absorption.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.283-288
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• 2011

The jellyfish Nemopilema nomurai was hydrolyzed with papain and a novel dipeptide purified via ultrafiltration, gel filtration chromatography with Sephadex LH-20, and reverse phase chromatography using $C_{18}$ and $C_{12}$ columns. The IR, 1H NMR, 13C NMR, and MS spectrometer analyses showed that the dipeptide comprised tyrosine-isoleucine (Tyr-Ile). The $IC_{50}$ and $K_i$ values were $6.56{\pm}1.12$ and $3.10{\pm}0.28\;{\mu}M$, respectively, indicating competitive inhibition of angiotensin-I-converting enzyme (ACE). As a novel ACE-inhibitory active peptide, Tyr-Ile may have potential for use in antihypertensive therapy.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.775-781
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• 2022

As part of research to develop a permanent wave-reducing agent for hair, in the current study, 0.1%-1.0% of Polyquaternium-10 was added to a permanent reagent containing Nicotinoyl Dipeptide-23 to prepare the agent, which was tested on damaged hair. The pH change was relatively stable even after a date, but due to the hair's natural composition, 0.1%-0.6% of the Polyquaternium-10 concentration according to pH was suitable. The temperature safety experiment demonstrated it to be stable at a high temperature and at room temperature, but when a Polyquaternium-10 concentration of 0.9% or higher was added at 0℃, coagulation occurred. In terms of the force efficiency of permanent wave formation, wave efficiency lowered as the concentration increased: the longer the wave lasts, the lower the Polyquaternium-10 concentration. The permanent moisture content was found to be higher as the concentration of Polyquaternium-10 increased. Therefore, when Polyquaternium-10 is applied to the permanent wave-reducing agent, considering stability, permanent formation, durability, and moisture rate, the most suitable concentration was found to be that of Polyquaternium-10 in the cysteine-reducing agent. A novel finding from this study is that as the concentration of Polyquaternium-10 increases, the consistency of the permanent wave-reducing agent changes, shifting from a liquid to a viscous liquid formulation.