• Archives of Pharmacal Research
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• v.9 no.1
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• pp.11-13
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• 1986

In addition to the previous reported furoquinoline alkaloids, skimmianine, kokusaginine and confusameline, a rate furoquinoline alkaloid, heliparifoline, mp 241-$3^{\circ}$ was isolated from the leaves of Melcope contusa and characterized by spectral data.

• Archives of Pharmacal Research
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• v.28 no.6
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• pp.675-679
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• 2005

Eight furoquinoline alkaloids were purified from two plants belonging to the Rutaceae family. Kokusaginine. skimmianine, evolitrine, and confusameline were purified from Melicope confusa, and haplopine, robustine, dictamine, and $\gamma$-fagarine from Dictamnus albus. In this study, the eight furoquinoline alkaloids were examined for inhibitory potency against human phos-phodiesterase 5 (hPDE5A) in vitro. DNA encoding the catalytic domain of human PDE5A was amplified from the mRNA of T24 cells by RT-PCR and was fused to GST in an expression vector. GST-tagged PDE5A was then purified by glutathione affinity chromatography and used in inhibition assays. Of the eight alkaloids, $\gamma$-fagarine was the most potent inhibitor of PDE5A, and its single methoxy group at the C-8 position was shown to be critical for inhibitory activity. These results clearly illustrate the relationship between PDE5A inhibition and the methoxy group position in furoquinoline alkaloids.