• Archives of Pharmacal Research
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• 제28권8호
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• pp.877-884
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• 2005

A number of wogonin derivatives have been synthesized as congeners of wogonin and evaluated for their inhibitory activities of $PGE_2$ production. Wogonin derivatives modified at the B ring of wogonin were obtained from 2,4-Dihydroxy-3,6-dimethoxyacetophenone (1) via several steps. Most wogonin derivatives exhibited much reduced inhibitory activities against COX-2 catalyzed $PGE_2$ production compared to that of wogonin. Alkylation of 5,7-phenol groups and substitution at the B ring of wogonin generally caused reduction of inhibitory activity.

• Archives of Pharmacal Research
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• 제28권2호
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• pp.216-219
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• 2005

Wogonin (5,7-dihydroxy-8-methoxyflavone) has been reported to exhibit a variety of biological properties including anti-inflammatory and neuroprotective functions. In this study, biological activities of diverse synthetic wogonin derivatives have been evaluated in two experimental cell culture models. Inhibitory activities of wogonin derivatives on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV2 microglial cells and on hydrogen peroxide ($H_{2}O_2$)-induced neuronal cell death in SH-SY5Y human neuroblastoma were examined. Wogonin derivatives such as WS2 and WS3 showed more potent suppressive activities on LPS-induced NO production and $H_{2}O_2$-induced cytotoxicity than wogonin itself. In addition, thiol substitution played a minor role in enhancing the activities of the derivatives. These findings may contribute to the development of novel anti-inflammatory and neuroprotective agents derived from wogonin.

• Archives of Pharmacal Research
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• 제22권1호
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• pp.18-24
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• 1999

Various flavonoid derivatives were previously reported to possess the inhibitory activity on cyclooxygenase/lipoxygenase. And these properties of flavonoids might contribute to their anti-inflammatory activity in vivo. In this study, several polyhydroxylated/methoxylated flavonoid derivatives such as oroxylin A. wogonin, skullcapflavone II, tectorigenin and iristectorigenin A were isolated from the medicinal plants. these compounds were evaluated fro their inhibitory effects on cyclooxygenase/lipoxygenase from the homogenate of human platelets in vitro. It was found that isoflavones including daidzein and tectorigenin possessed the inhibitory activity on cycloooxygenase, although the potency of inhibition was far less than that of indomethacin. In addition, oroxylin A, baicalein and wogonin inhibited 12-lipoxygenase activity without affecting cyclooxygenase, which suggested that 5,6,7- or 5,7,8-trisubstitutions of A-ring of flavone gave favorable results. The IC50 values of oroxylin A and NDGA against 12-lipoxygenase were found to be 100 and 1.5 uM, respectively.

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