• Archives of Pharmacal Research
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• 제14권4호
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• pp.342-345
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• 1991

Synthesis of series of 3-benzalphthalidyl-amino acids and their corresponding methyl esters, dipeptides and tripeptide methyl esters 2a-7c is decribed. All 3-benzalphthalidynamino acids 2a-g were found to possess a remarkable antimicrobial properties against a number of microorganisms and fungi.

• BMB Reports
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• 제45권2호
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• pp.114-119
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• 2012

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) is a compound derived from dopamine metabolism and is capable of causing dopaminergic neurodegeneration. Oxidative modification of neurofilament proteins has been implicated in the pathogenesis of neurodegenerative disorders. In this study, oxidative modification of neurofilament-L (NF-L) by salsolinol and the inhibitory effects of histidyl dipeptides on NF-L modification were investigated. When NF-L was incubated with 0.5 mM salsolinol, the aggregation of protein was increased in a time-dependent manner. We also found that the generation of hydroxyl radicals (${\bullet}OH$) was linear with respect to the concentrations of salsolinol as a function of incubation time. NF-L exposure to salsolinol produced losses of glutamate, lysine and proline residues. These results suggest that the aggregation of NF-L by salsolinol may be due to oxidative damage resulting from free radicals. Carnosine, histidyl dipeptide, is involved in many cellular defense processes, including free radical detoxification. Carnosine, and anserine were shown to significantly prevent salsolinol-mediated NF-L aggregation. Both compounds also inhibited the generation of ${\bullet}OH$ induced by salsolinol. The results indicated that carnosine and related compounds may prevent salsolinol-mediated NF-L modification via free radical scavenging.

• Biomolecules & Therapeutics
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• 제16권4호
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• pp.356-363
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• 2008

A bacterial strain with good antibacterial activities against Staphylococus aureus and Escherichia coli was isolated from a marine sponge Stelleta sp., and it was identified as a Psychrobacter sp. by comparative 16S rDNA sequence analysis. In our search for bioactive secondary metabolites from this psychrophillic and halotolerent bacterium, sixteen cyclic dipeptides (1-16) were isolated and their structures were identified on the basis of NMR analysis. In the test of the compounds for the protective effect against Vibrio vulnificusinduced cytotoxicity in human intestinal epithelial cells, cyclo-(L-Pro-L-Phe) (5) exhibited significant protective effect. Compounds 2, 6, and 11, which contain D-amino acid, were first isolated from bacteria.

• 대한화학회지
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• 제19권3호
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• pp.169-173
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• 1975

Aminobenzylphosphonic acid를 포함하고 있는 dipeptide들의 합성을 carbodimide법으로 시도하여 다음과 같은 새로운 화합물들을 얻었다. Glycyl-dl-1-aminobenzylphosphonic acid, alanyl-dl-1-aminobenzylphosphonic acid, L-alanyl-dl-1-aminobenzylphosphonic acid, N-phthalyl-L-phenylalanyl-dl-1-aminobenzylphosphonic acid diethyl ester, N-carbobenzoxyglycyl-dl-1-aminobenzylphosphonic acid diethyl ester, N-carbobenzoxy-alanyl-dl-1-aminobenzylphosphonic acid diethyl ester, N-carbobenzoxy-L-alanyl-dl-1-aminobenzylphosphonic acid diethyl ester, glycyl-dl-1-aminobenzylphosphonic acid diethyl ester hydobromide, alanyl-dl-1-aminobenzylphosphonic acid diethyl ester hydrobromide 및 L-alanyl-dl-1-aminobenzylphosphonic aciddiethyl ester hydrobromide.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.409-414
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• 2009

Novel binol aldehydes derivatized at 2' hydroxy position with both uryl and acetamide groups (2), and diuryl groups (3) have been synthesized. Both were designed for streospecific binding and chirality conversion of general dipeptides with support of multiple hydrogen bonding donor sites in the receptors. The receptors, 2 and 3, converted the chirality of N-terminal amino acids of peptides such as Ala-Gly, Met-Gly, Leu-Gly and His-Gly with stereoselectivity on D-form over L-form. The stereoselectivity ratios were in the range of 5-11, somewhat higher than those of the binol receptor with mono uryl group (1). The DFT calculation at the B3LYP/6-31G$^*$//MPWB1K/6-31G$^*$ level revealed that 3-D-Ala-Gly was 2.2 kcal/mol more stable than 3-L-Ala-Gly. The considerable steric hindrance between the methyl group of the alanine and the imine CH moiety of the receptor seems to be the main contributing factor for the thermodynamic preference.

• Natural Product Sciences
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• 제29권2호
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• pp.59-66
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• 2023

The anti-melanogenic activity of 259 actinomycete strains was tested, and based on the results for the inhibition of mushroom tyrosinase activity and the reduction in melanin content, Micromonospora sp. JCS1 and JCS7 were selected as the strains with the highest anti-melanogenic potential. The activity-guided fractionation of extracts from JCS1 and JCS7 led to the isolation of the dipeptides cyclo(ʟ-Phenyl alanine (Phe)-ʟ-Proline (Pro)) (1) and cyclo(ʟ-Tryptophan (Trp)-ʟ-Proline (Pro)) (2). These two compounds were tested for their inhibition of mushroom tyrosinase by monitoring ʟ-DOPA levels and melanin production. Cyclo(ʟ-Phe-ʟ-Pro) (1) and cyclo(ʟ-Trp-ʟ-Pro) (2) were thus confirmed to have the potential for use in functional whitening cosmetics containing actinomycete-derived secondary metabolites.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.229-242
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• 2018

본 연구에서는 발효 돈태반 (fermented porcine placenta, FPP)과 그의 주요 다이펩타이드인 L-Leucyl-Glycine (Leu-Gly), Glycyl-L-Leucine (Gly-Leu)의 섭취가 UVB 조사에 의한 무모 쥐의 피부 주름 생성에 미치는 효능을 알아보았다. Human Primary Dermal fibroblasts-Neonatal (HDF-N) 세포에서 세포 독성을 나타내지 않는 농도를 설정하여 평가하였을 때, FPP, Leu-Gly, Gly-Leu 처리 시 procollagen의 증가 및 MMP-1 (matrix metalloproteinase-1)의 감소를 확인하였다. 또한 무모 생쥐에 주 3회 UVB를 조사하여 광노화를 유도하였고, FPP 10, 100 mg/kg, Leu-Gly 10 mg/kg, Gly-Leu 10 mg/kg을 매일 총 8주간 경구투여 한 후, 주름생성, 홍반및 MMPs의 발현량을 측정하였다. 8주간 진행된 동물 실험 결과 UVB만 조사한 군과 비교하여 UVB를 조사하고 FPP, Leu-Gly, Gly-Leu을 섭취시킨 군에서 주름생성과 홍반이 감소하였고 피부 수분함량과 콜라겐 생합성이 증가하였다. 뿐만 아니라 FPP, Leu-Gly, Gly-Leu 섭취군에서 콜라겐 분해효소인 MMP-3, MMP-13의 mRNA 발현량이 감소하였고, MMP-2와 MMP-9의 활성이 감소하였다. 결과를 종합하였을 때, FPP의 주요 다이펩타이드인 Leu-Gly과 Gly-Leu은 자외선에 의한 주름 생성을 억제하고, 피부 손상을 회복시키는 효능을 갖는 피부미용식품 소재로서 활용 가능성이 클 것으로 사료된다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1996년도 정기총회 및 학술발표회
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• pp.15-15
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• 1996

In order to investigate the conformational preferences to elicit the tastes, conformational free energy calculations using the empirical potential ECEPP/3 and the hydration shell model were carried out on the L-aspartyl dipeptide methyl esters, L-$\^$+/HAsp$\^$-/-D-Xaa-OMe, in the unhydrated state, where Xaa includes sweet (Ala, Abu, Ser, Thr, Val, and lle), bitter (Phe, Trp, and Leu), and tasteless (Tyr and Met) residues. (omitted)

• Archives of Pharmacal Research
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• 제15권3호
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• pp.204-207
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• 1992

Glycylglycine, alanylalanine and alanylglycine were synthesized, their free carboxylic and amino groups were converted to methyl esters of N-acetylglycyglycine, N-acetylalanylglycine and N-acetylalanylalanine. The synthesized compounds were evaluated for antiepileptic activity, plasmaprotein binding, $TD_{50}$ and potentiating effect of phenobarbitone sodium.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1997년도 춘계학술대회
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• pp.119-119
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• 1997

Valacyclovir is a L-valyl ester prodrug of acyclovir which is a highly effective and selective antiviral agent in the treatment of herpes virus diseases. Valacyclovir is rapidly and almost completely converted to acyclovir and increases the oral bioavailability of acyclovir three to five fold. However, the intestinal absorption mechanism of valacyclovir is not clear. If the improved absorption mechanism of valacyclovir is fully understood, it will provide a rationale of designing the amino acid ester prodrugs of polar drugs containing hydroxyl group. The main objective of our present study is to characterize the membrane transport mechanism of valacyclovir. Methods : Intestinal absorption of valacyclovir was investigated by using in-situ rat perfusion study and its wall permeability was estimated by modified boundary layer model. The membrane transport mechanism was also investigated through the uptake study in Caco-2 cells and in CHO-hPepTl cells. Results : In the rat perfusion study, the wall permeability of valacyclovir was ten times higher than acyclovir and showed concentration dependency, Valacyclovir also demonstrated a D,L stereo-selectivity with L-isomer having an approximately five-fold higher permeability than D-isomer. Mixed dipeptides and cephalexin, which are transported by dipeptide carriers, strongly competed with valacyclovir for the intestinal absorption, while L-valine did not show any competition with valacyclovir. This indicated that the intestinal absorption of valacyclovir could be dipeptide carrier-mediated. In addition, the competitive uptake study in Caco-2 cells presented that dipeptides reduced the valacyclovir uptake but valine did not. Also, in IC$\sub$50/ study, valacyclovir showed strong inhibition on the $^3$H-gly-sar uptake in CHO-hPepTl cells over-expressing a human intestinal peptide transporter. Taken together, the result from our present study indicated that valacyclovir utilized the peptide transporter for the intestinal absorption.