Design, Synthesis, and Structure--Activity Relationship of New 2-Aryl-3,4-dihydro-ß-carbolin-2-ium Salts as Antifungal Agents.

Twenty-two 2-aryl-9-methyl-3,4-dihydro-ß-carbolin-2-ium bromides along with four 9-demethylated derivatives were synthesized and characterized by spectroscopic analysis. By using the mycelium growth rate method, the compounds were evaluated for antifungal activities in vitro against six plant pathogenic fungi, and structure-activity relationships (SAR) were derived. Almost all of the compounds showed obvious inhibition activity on each of the fungi at 150 µM. For all of the fungi, 10 of the compounds showed average inhibition rates of >80% at 150 µM, and most of their EC50 values were in the range of 2.0-30.0 µM. SAR analysis showed that the substitution pattern of the N-aryl ring significantly influences the activity; N9-alkylation improves the activity, whereas aromatization of ring-C reduces the activity. It was concluded that the present research provided a series of new 2-aryl-9-alkyl-3,4-dihydro-ß-carbolin-2-iums with excellent antifungal potency and structure optimization design for the development of new carboline antifungal agents.

Cytotoxic constituents from the leaves of Broussonetia papyrifera / 中国天然药物

AIM@#To investigate the chemical constituents from the leaves of Broussonetia papyrifera.@*METHODS@#The chemical constituents were isolated and purified by macroporous adsorptive resin D101, silica gel, and ODS column chromatography and preparative HPLC. Their structures were elucidated on the basis of 1D and 2D NMR analyses. In addition, their cytotoxic activity against human hepatoma carcinoma cells (HepG-2) were evaluated by the MTT method. Furthermore, RP-HPLC and colorimetric methods were used for the analysis of cosmosiin and total flavonoids.@*RESULTS@#A new lignan, together with five known compounds were obtained, and their structures were characterized as (+)-pinoresinol-4'-O-β-D-glucopyranosyl-4″-O-β-D-apiofuranoside (1), cosmosiin (2), luteolin-7-O-β-D-glucopyranoside (3), liriodendrin (4), 3, 5, 4'-trihydroxy-bibenzyl-3-O-β-D-glucoside (5), and apigenin-6-C-β-D-glucopyranside (6). Furthermore, RP-HPLC and colorimetric methods were established for the analysis of cosmosiin and total flavonoids.@*CONCLUSION@#Compound 1 was a new lignan, and compounds 5 and 6 were isolated for the first time from the title plant. Compounds 1, 4 and 6 showed definite activities against HepG-2, while the other compounds didn't show inhibitory effects. The optimal harvest time of B. papyrifera (L.) Vent. is September.