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Biomedical subjects

E Eich

Publications and source records attributed to E Eich.

49 records · Page 3Linked to original sources
PubMedDate not supplied

Differential in vitro anti-HIV activity of natural lignans.

Two naturally occurring lignanolides, isolated from the tropical climbing shrub Ipomoea cairica, (-)-arctigenin and (-)-trachelogenin, were found to inhibit strongly replication of human immunodeficiency virus type 1 (HIV-1; strain HTLV-III B) in vitro. At a concentration of 0.5 microM, (-)-arctigenin and (-)-trachelogenin inhibited the expression of HIV-1 proteins p17 and p24 by 80-90% and 60-70%, respectively. The reverse transcriptase activity in the culture fluids was reduced by 80-90% when the cells (HTLV-III B/H9) were cultivated in the presence of 0.5 microM (-)-arctigenin or 1 microM (-)-trachelogenin. At the same concentrations, the formation of syncytia in the HTLV-III B/H9-Jurkat cell system was inhibited by the compounds by more than 80%. A series of other lignan type compounds displayed no anti-HIV activity. Studying the molecular mechanism of action of (-)-arctigenin and (-)-trachelogenin we found that both compounds are efficient inhibitors of the nuclear matrix-associated DNA topoisomerase II activity, particularly of the enzyme from HIV-1-infected cells. Our results suggest that both compounds prevent the increase of topoisomerase II activity, involved in virus replication, after infection of cells with HIV-1.

Animals↗
PubMedDate not supplied

Iseluxine: a novel isoquinolinone alkaloid from Iseia luxurians.

A novel isoquinolinone alkaloid, iseluxine (1), has been isolated from the epigeal parts of Iseia luxurians (MORIC.) O'DONELL (Convolvulaceae), a climber indigenous to the tropical Americas. Structural elucidation was achieved by HRMS, 1H NMR, 13C NMR, and HMBC spectroscopy. N- and/or O-methyl derivatives of 1 are already known from certain Magnoliidae families, e.g., the Fumariaceae, the Lauraceae, or the Papaveraceae. Iseluxine, the "missing link" in the biosynthesis of these methyl derivatives from dopamine, is the first isoquinolinone alkaloid characterized by a catechol substructure.

Alkaloids↗