• 생약학회지
• /
• 제31권4호
• /
• pp.430-433
• /
• 2000

Five compounds have been isolated from the stem of Caesalpinia japonica. On the basis of spectral evidences, the structures of these compounds were identified as 4',7-dihydroxyflavone, 3,4',7-trihydroxyflavone, cathechin, 3',4',7-trihydroxyflavone and 2',3,4',5,6,7-hexahydroxyflavone.

• Archives of Pharmacal Research
• /
• 제4권2호
• /
• pp.129-131
• /
• 1981

From the steambark of Albizzia julibrissin, 3', 4' 7-trihydroxyflavone and .alpha.-spinasteryl-D-glucoside were isolated.

• Natural Product Sciences
• /
• 제16권4호
• /
• pp.217-222
• /
• 2010

A phytochemical investigation of the ethanolic extract of Erythrina caffra flowers from an Egyptian origin yielded three C-flavonoidal glycosides; 5,7,4'-trihydroxyflavone-8-C-$\beta$-D-glucopyranoside (vitexin) (1), 5,7,4'-trihydroxyflavone-6-C-$\beta$-D-glucopyranosyl-(1 $\rightarrow$ 2)-$\beta$-D-glucopyranoside (isovitexin-2"-$\beta$-D-glucopyranoside) (2), 5, 7, 4'-trihydroxyflavone-6, 8-di-C-$\beta$-D-glucopyranoside (vicenin-2) (3) and one O-flavonoidal glycoside; kaempferol-3-O-$\beta$-D.glucopyranosyl) (1 $\rightarrow$ 2)-$\beta$-D-glucopyranoside (4). The structures of the isolated compounds (1 - 4) were elucidated using different spectral techniques (UV, 1D and 2D NMR and HRESIMS). This is the first report for the isolation of flavonoidal glycosides from Erythrina caffra. The antibacterial, antifungal, antimalarial, and antileishmanial activities of the isolates were evaluated. In addition, the cytotoxic activity of the ethanolic extract and the main fractions were tested using brine shrimp bioassay.

• Archives of Pharmacal Research
• /
• 제26권6호
• /
• pp.458-462
• /
• 2003

The antioxidant activity of the stem bark from Albizzia julibrissin was evaluated for its potential to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, to inhibit the generation of the hydroxyl radical ($\cdot OH$), total reactive oxygen species (ROS) and to scavenge authentic peroxynitrites ($ONOO^{-}$). The methanol extract of A. julibrissin exhibited strong antioxidant activity in the tested model systems. Therefore, it was further fractionated using several solvents. The antioxidant activity of the individual fractions were in the order of ethyl acetate (EtOAc) ＞ n-butanol (n-BuOH) ＞ dichloromethane ($CH_2 CI-2$) ＞ and water ($H_2O$). The ethyl acetate soluble fraction, which exhibited strong antioxidant activity, was further purified by repeated silicagel, Sephadex LH-20 and RP-18 gel column chromatography. Sulfuretin (1) and 3 ,4 ,7-trihydroxyflavone (2) were isolated as the active principles. Compounds 1 and 2 exhibited good activity in all tested model systems. Compound 1 exhibited five times more inhibitory activity on the total ROS than Trolox. Compound 2 showed six times stronger DPPH radical scavenging activity than L-ascorbic acid. These results show the possible antioxidant activity of the A. julibrissin crude extract and its major constituents.

• Food Science and Biotechnology
• /
• 제17권3호
• /
• pp.578-586
• /
• 2008

Phytochemicals study from the leaves of soybean [Glycine max (L.) Merr.], one of Korean edible plant materials were investigated through various chromatographic procedures. The methanolic leaves extracts of soybean yielded 16 phytochemicals, including 5 isoflavones 1-5, 3 flavones 6-8, 1 flavonol 9, 2 pterocarpans 10 and 11, 2 phenolic compounds 12 and 13, 2 phytosterols 14 and 15, and 1 sugar alcohol 16. The structures were fully characterized by analysis of physical and spectral data and were defined clearly as 4,5,7-trihydroxyisoflavone (1), 4,5,7-trihydroxyisoflavone-7-O-$\beta$-D-glucopyranoside (2), 4,7-dihydroxy-6-methoxyisoflavone (3), 4,7-dihydroxyisoflavone (4), 4,7-dihydroxyisoflavone-7-O-$\beta$-D-glucopyranoside (5), 5,7,4'-trihydroxyflavone (6), 3',4',5,7-tetrahydroxyflavone (7), 3',4',5-trihydroxyflavone-7-O-$\beta$-D-glucopyranoside (8), 3,4',5,7-tetrahydroxyflavonol (9), coumestrol (10), glyceofuran (11), 4-hydroxybenzoic acid (12), methyl-4-hydroxybenzoate (13), soyasapogenol B (14), stigmasterol (15), and D-mannitol (16), respectively. Among them, phytochemicals 7-16 were reported for the first time on the isolation and confirmation from the leaves of this species. These results suggest that the leaves extracts of soybean may possess possible health related benefits to human due to the isolated phytochemicals 1-16 which have been well known potential effects on various chronic diseases.

• 약학회지
• /
• 제32권2호
• /
• pp.125-128
• /
• 1988

Geranylation of some synthetic and natural flavones have yielded cytotoxic products against L1210 coll; 5,2´-dihydroxy-6,7,8-trimethoxy-6´-geranyloxyflavone 4$(8.5{\mu}g/ml)$, 5,6-dihydroxy-7-gerenyloxyflavone 9$(2.3{\mu}g/ml)$. 2 has showed the same range of cytotoxicity as the starting material, 5,2´-dihydroxy-6,7,8-trimethoxy-6´-benzyloxyflavone$(17.0{\mu}g/ml)$. The cytotoxicity of 4 was lower than its starting substance, 5,2´,6´-trihydroxy-6,7,8-trimethoxyflavone $(4.5{\mu}g/ml)$. On geranylating 5,6,7-trihydroxyflavone(baicalein, $15.0{\mu}g/ml$) the cytotoxic activity has been strongly potentiated($2.3{\mu}g/ml$ of 9). The presence of at least a free hydroxy group in B-ring of Skullkapflavone II-type flavones. was essential for a high activity. A larger RD-group than methoxy in the B-ring has weakened the activity. The cytotoxicities of baicalein series could not be correlated to their structures.

• 생명과학회지
• /
• 제19권8호
• /
• pp.1009-1015
• /
• 2009

Flavonoid류와 진정제의 시험관 내 암세포증식억제효과를 관찰하기 위하여, 암세포의 말초형 benzodiazepine 수용체(이하 PBR로 약함) 활성도와 포도당 활용도에 대한 효과를 유방암 세포를 대상으로 검색하였다. 동시에 이미 항암활성이 잘 알려진 flavonoid류와의 상호작용도 관찰하였다. Fisetin (3,7,3',4'-tetrahydroxyflavone)과 diazepam의 암세포 증식 억제 효과는 악성도가 높은 MDA-MB-231 유방암 세포에서 MCF-7 유방암세포보다 저명하게 관찰되었다. MDA-MB-231 유방암세포에서, Apigenin (4',5,7-Trihydroxyflavone)과 fisetin 같은 flavonoid류처럼, $10^{-6}$ M 농도의 dazepam을 3일간 처치하였을 때 암세포 증식 억제효과를 나타내었으며, 이는 PBR 배위자들의 암세포 증식 증진효과와는 차이를 나타낸 것이다. Flavonoid 류처럼, MDA-MB-231 유방암세포에서, $10^{-6}$ M dazepam의 3일간 처치는 암세포의 PBR mRNA 발현에 큰 영향을 미치지 않았다. $10^{-6}$ M diazepam의 6 일간 처치는 암세포의 증식억제 효과가 증가되어 나타났으며, 암세포의 PBR mRNA 발현도 억제되었다. MDA-MB-231 유방암 세포에서, apigenin, fisetin과 diazepam은 포도당 유용도를 억제하였으며, 인슐린에 의한 포도당 유용도 증강효과도 억압하였다. Apigenin은 diazepam의 암세포 증식 억제 효과를 부가적으로 증강시켰다. 요약하면, 본 연구결과는 flavonoid류와 진정제의 시험관내 암세포 증식 억제효과와 부가적인 상호작용을 보여주고 있다. 결론적으로, 본 연구는 향후 좀더 진척된 시험을 위한 실험적인 기반 정보이다.

• Bulletin of the Korean Chemical Society
• /
• 제35권11호
• /
• pp.3219-3223
• /
• 2014

Ochnaflavone, a naturally occurring biflavonoid composed of two units of apigenin (5,7,4'-trihydroxyflavone) joined via a C-O-C linkage, was first synthesized and evaluated its inhibitory activity on $PGE_2$ production. Total synthesis was accomplished through modified Ullmann diaryl ether formation as a key step. Coupling reactions of 4'-halogenoflavones and 3'-hydroxy-5,7,4'-trimethoxyflavone were explored in diverse reaction conditions. The reaction of 4'-fluoro-5,7-dimethoxyflavone (2c) and 3'-hydroxy-5,7,4'-trimethoxyflavone (2d) in N,N-dimethylacetamide gave the coupled compound 3 in 58% yield. Synthetic ochnaflavone strongly inhibited PGE2 production ($IC_{50}=1.08{\mu}M$) from LPS-activated RAW 264.7 cells, which was due to reduced expression of COX-2. On the contrary, the inhibition mechanism of wogonin was somewhat different from that of ochnaflavone although wogonin, a natural occurring anti-inflammatory flavonoid, showed strong inhibitory activity of $PGE_2$ production ($IC_{50}=0.52{\mu}M$), and seems to be COX-2 enzyme inhibition. Our concise total synthesis of ochnaflavone enable us to provide sufficient quantities of material for advanced biological studies as well as to efficiently prepare derivatives for structure-activity relationship study.

• Archives of Pharmacal Research
• /
• 제18권6호
• /
• pp.415-422
• /
• 1995

Twenty-four flavones were synthesized with various hydroxyl and/or methoxyl groups on A and B rings. Their antimutagenic properties were evaluated against ben:w(a)pyrene (BaP) and a pool of mutagenic urine concentrate (U) using a modified liquid incubation method of Ames test. The tester strain was Salmonella typhimurium TA98+S9 Mix. The antimutagenic activities were calculated by non linear regression analysis and the doses of flavones (in nmoles) required for a 50% reduction of induced revertants with BaP and U were defined as the inhibition doses (TEX>$ID_{508}{\;}and{\;}ID_{508}$ respectively). Seventeen flavones possessed significant antimutagenic activity against BaP. $ID_{508}$ ranged from 15.1 nmoles (F22) to 1000.6 nmoles (F13). Eighteen f1avones showed significant antimutagenic activity against U. $ID_{50U}$ ranged from 23.5 nmoles (F22) to 354.6 nmoles (F3). The 2',3',4'-trihydroxyflavone (F22, $ID_{508}=15.1$ nmoles, $ID_{50U}=23.5$ nmoles) and the 2',3',4',7-tetrahydroxyflavone (F20, $ID_{508}=37.8$ nmoles; $ID_{50U}=62.3$ nmoles) had antimutagenic activities similar to those of chlorophyllin ($ID_{508}=19.6$ nmoles and $ID_{50U}=44.2$ nmoles) and were evaluated against B(alP 7,8-dihydrodiol-9,10-epoxide. Against this last mutagen, the flavones which included three OH in B ring showed the highest activity and this property seemed independent of the substituent groups on A ring.

• Biomolecules & Therapeutics
• /
• 제25권4호
• /
• pp.427-433
• /
• 2017

Previously, we demonstrated that galangin (3,5,7-trihydroxyflavone) protects human keratinocytes against ultraviolet B (UVB)-induced oxidative damage. In this study, we investigated the effect of galangin on induction of antioxidant enzymes involved in synthesis of reduced glutathione (GSH), and investigated the associated upstream signaling cascades. By activating nuclear factor-erythroid 2-related factor (Nrf2), galangin treatment significantly increased expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS). This activation of Nrf2 depended on extracellular signal-regulated kinases (ERKs) and protein kinase B (AKT) signaling. Inhibition of GSH in galangin-treated cells attenuated the protective effect of galangin against the deleterious effects of UVB. Our results reveal that galangin protects human keratinocytes by activating ERK/AKT-Nrf2, leading to elevated expression of GSH-synthesizing enzymes.