• Bulletin of the Korean Chemical Society
• /
• 제22권10호
• /
• pp.1156-1158
• /
• 2001

• Bulletin of the Korean Chemical Society
• /
• 제25권2호
• /
• pp.221-225
• /
• 2004

A series of 2',3'-dideoxy-3'-fluoro-D-apiosyl nucleosides 15, 16, 17 and 18 were synthesized enantiomerically with L-Gulonic- ${\gamma}$-lactone as the starting material. The reduction of butenolide 1 with DIBAL-H followed by the Luche procedure afforded the allylic alcohol 2. Ozonolysis and the reduction of compound 4 induced the cyclized lactol, which was acetylated to give the acetate 7. Condensation of the acetate 7 with silylated pyrimidine ($N^4$-benzoyl cytosine) and a purine base (6-chloropurine) under Vorbruggen conditions and deblocking afforded a series of fluorinated apiosyl nucleosides.

• 대한화학회지
• /
• 제47권3호
• /
• pp.229-236
• /
• 2003

Cyclobutenedions을 lithium trimethylsilylacetylene과 반응시키고 물로 반응을 정지시키면 butenolides가 생성된다. 이 색다른 반응을 위해 allene을 intermediate로 하는 기전을 제안하였다. 이는 trimethylsilyl group이 너무 크기 때문에 보통의 diradical intermediate는 형성이 어렵고, allene이 ${\alpha}$-silyl group에 의해 안정화되기 때문이라고 사료된다.

• Natural Product Sciences
• /
• 제27권4호
• /
• pp.293-299
• /
• 2021

The ethyl acetate fractions prepared from the leaves of Thuja orientalis significantly inhibited nitric oxide (NO) production in lipopolysaccharide-stimulated BV2 microglial cells. According to bioassay-coupled LC-QTOF MS/MS, the components near 22 and 25 mins in the mass chromatogram highly inhibited NO production and were expected to be labdane diterpenes, and the active components were characterized via further isolation. The results of the NO production inhibitory assay of the isolated compounds correlated well with the results of bioassay-coupled LC-QTOF MS/MS. Among the identified constituents, NO production inhibitory activities of 16-hydroxy-labda-8(17),13-diene-15,19-dioic acid butenolide (2) and 15-hydroxypinusolidic acid (3) were newly reported. Taken together, these results demonstrated that LC-QTOF MS/MS coupled with NO production inhibition assay was a powerful tool for accurately predicting new anti-inflammatory constituents in the extracts from natural products. Moreover, it provided a potential basis for broadening the application of bioassay-coupled LC-QTOF MS/MS in natural product research.