• Bulletin of the Korean Chemical Society
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• 제22권4호
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• pp.388-394
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• 2001

Quantitative Structure-Activity Relationship (QSAR) have been established of 57 fluorovinyloxyacetamides compounds to correlate and predict EC50 values. Genetic algorithm (GA) and multiple linear regression analysis were used to select the descriptors and to generate the equations that relate the structural features to the biological activities. This equation consists of three descriptors calculated from the molecular structures with molecular mechanics and quantum-chemical methods. The results of MLR and GA show that dipole moment of z-axis, radius of gyration and logP play an important role in growth inhibition of barnyard grass.

• Natural Product Sciences
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• 제19권1호
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• pp.8-14
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• 2013

The inhibitory effect and the structure-activity relationships of luteolin and its related derivatives isolated from Taraxacum mongolicum against MAO activities were investigated. The activity-guided isolation of extract from Taraxacum mongolicum led to the isolation of three flavonoids, luteolin, diosmetin, and luteolin-7-glucoside, a polyphenol, chlorogenic acid, a tyrosine and a uridine. The inhibitory activities of luteolin and its related derivatives against MAOs activities are dependent on their molecular structures. The presence of the phenolic hydroxy group at para-position is the active site for MAO-A inhibition as well as of MAO-B. The methoxy group has no potential on MAO-A inhibition. An additional phenolic hydroxy group at the ortho-position alleviates about 4-fold MAO-A inhibitory activity of phenolic hydroxy group at para-position. A carboxylic group seems to be critical for DBH inhibition and has no effects on MAO.

• Journal of the Korean Wood Science and Technology
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• 제34권2호
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• pp.88-94
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• 2006

The purpose of this study is to examine the relationship between antioxidant activities and chemical structures of various chalcones. Twenty-two chalcones were assessed for their radical scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Of 22 compounds tested, the most active on DPPH radical was 2',4-dihydroxy-3,3'5-trimethoxy-5'-propylchacone (4) (72.6% at 100 ppm). It was followed by 3',4'-dihydroxy-3,4,5-trimethoxy-6'-methylchalcone (6), 2',4,4'-trihydroxy-3-methoxy-5-propenylchalcone (7) and 2',4,4'-trihydroxy-3,5-dimethoxychalcone (13). Based on the results, we concluded that the scavenging activity is controlled by the number and the position of the substitution in the compound.

• Archives of Pharmacal Research
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• 제27권9호
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• pp.937-943
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• 2004

Recent investigations have shown that certain flavonoids, especially flavone derivatives, inhibit nitric oxide (NO) production by inducible NO synthase (iNOS) in macrophages, which contrib-ute their anti-inflammatory action. For the purpose of finding the optimized chemical structures of flavonoids that inhibit NO production, various A- and B-ring substituted flavones were syn-thesized and evaluated for their inhibitory activity using lipopolysaccharide-treated RAW 264.7 cells. It was found that the optimal chemical structures were A-ring 5,7-dihydroxyflavones hav-ing the B-ring 2＇,3＇-dihydroxy or 3＇,4＇-dihydroxy or 3＇,4＇-hydroxy/methoxy (methoxy/hydroxy) groups. These structurally optimized compounds were revealed to be down-regulators of iNOS induction, but not direct iNOS inhibitors. Of these derivatives that were evaluated, 2＇,3＇,5,7-tet-rahydroxyflavone and 3＇,4＇,5,7-tetrahydroxyflavone (Iuteolin) showed the strongest inhibition. The $IC_{50}$/ values for these compounds were 19.7 and 17.1 11M, respectively. Therefore, these compounds may have a potential as new anti-inflammatory agents.

• Journal of Ginseng Research
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• 제31권2호
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• pp.69-73
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• 2007

Since chemical structures of ginsenoside as active ingredient of Panax ginseng are known, accumulating evidence have shown that ginsenoside is one of bio-active ligands through the diverse physiological and pharmacological evaluations. Chemical structures of ginsenoside could be divided into three parts depending on diol or triol ginsenoside: Steroid- or cholesterol-like backbone structure, carbohydrate portions, which are attached at the carbon-3, -6 or -20, and aliphatic side chain coupled to the backbone structure at the carbon-20. Ginsenosides also exist as stereoisomer at the carbon-20. Bioactive ligands usually exhibit the their structure-function relationships. In ginsenosides, there is little known about the relationship of chemical structure and biological activity. Recent reports have shown that ginsenoside $Rg_3$, one of active ginsenosides, exhibits its differential physiological or pharmacological actions depending on its chemical structure. This review will show how ginsenoside $Rg_3$, as a model compound, is functionally coupled to voltage-gated ion channel or ligand-gated ion channel regulations in related with its chemical structure.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.143-146
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• 2002

Saponins are glycosidic compounds present in many edible and inedible plants. Structurally, they are composed of a lipid-soluble aglycone consisting of either a sterol or, more commonly, a triterpenoid and water-soluble sugar residues differing in type and amount of sugars ［1］. Because of their amphiphilic nature, they are highly surface-active. Their biological activity is closely related to the chemical structures that determine the polarity, hydrophobicith and acidity of compounds ［1］. (omitted)

• 약학회지
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• 제13권2_3호
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• pp.97-100
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• 1969

As a part of an effort to find a relationship between metal chelation and its chemotherapeutic activity change for sulfa drugs, Sulfadimethoxine, Sulfamerazine Sulfamethoxy-pyridazine-Cu(II) complex compounds were studied through IR spectra.

• Journal of the Korean Wood Science and Technology
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• 제32권3호
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• pp.66-70
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• 2004

The antioxidant activities of six isoflavonoids isolated from Sophora japonica wood and bark were examined by DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging method. This study was focused on the relationship between antioxidant activity of isoflavonoids and their chemical structures. From the results of this study, it could be concluded that the hydroxyl groups that linked at ring B and ring A in isoflavonoids have importance in the antioxidant activity. Additionally, the absence of the 2,3-double bond on the isoflavonoid enhances its antioxidant activity.

• Natural Product Sciences
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• 제17권2호
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• pp.108-112
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• 2011

Several isoquinoline alkaloids (1 - 18), which have basic chemical structures as protoberberine and aporphine skeletones, were evaluated for their inhibitory activities on AChE and BuChE. Among them, compounds 3, 4, 6, 8 and 12 showed the potent AchE activity with the $IC_{50}$ values ranging from $10.2{\pm}0.5\;{\mu}M$ to $24.5{\pm}1.6\;{\mu}M$, meanwhile, compound 14 - 17 exhibited strong inhibitory activity with $IC_{50}$ values from $2.1{\pm}0.2$ to $5.5{\pm}0.3\;{\mu}M$. Compounds 14 - 17 exhibited selective inhibition for AChE compared with BuChE. The isoquinoline alkaloid possesses aromatic methylenedioxy groups and quaternary nitrogen atoms are crucial for the anti-cholinesterase inhibitory activity.

• 디지털융복합연구
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• 제17권1호
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• pp.443-447
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• 2019

방향성탄화수소 수용체(Arylhydrocarbon Receptor, AhR)은 리간드에 의해 활성화되어 체내 외래물질의 대사를 조절하는 전사인자다. 생체 내에서 AhR의 생리학적 역할은 오랜 기간 연구되어 왔으나 활성화를 유발하지 않는 길항제를 비롯하여 유효한 화학적 도구가 아직 개발되지 않아 기능 연구가 제한적이다. AhR이 다양한 질병의 발병기전에서 중요한 역할을 수행한다는 것이 보고됨에 따라 약물 표적으로서 유효하다고 판단되나 치료나 예방을 위한 유효한 약물은 아직 개발되지 않았다. 길항제로 알려진 화합물들은 낮은 농도에서는 활성이 있어 연구 목적으로 활용되고 있으나 높은 농도에서는 방향성 탄화수소를 활성화하는 부분적 agonist로 작용한다. 이에 AhR 활성화를 유도하지 않는 순수한 길항제의 개발이 필요하다. 본 연구에서는 이미 알려진 AhR 길항제의 골격인 phenyldiazenylphenylpicolinamide의 세 고리구조 중 두 고리구조에 존재하는 메틸 기들을 변형하여 활성을 평가하는 구조-활성 관계 연구를 통하여 새로운 길항제를 개발하고자 하였다.