Isoflavonoids from the roots of Campylotropis hirtella.

From the dried roots of Campylotropis hirtella (Franch.) Schindl., five novel isoflavonoids, 3( S)-7,2',4'-trihydroxy-5,5'-dimethoxy-6-(3-methylbut-2-enyl)-isoflavan ( 1), 3( S)-2',4'-dihydroxy-5,5'-dimethoxy-(6'',6''-dimethylpyrano)-(2'',3'':7,6)-isoflavan ( 2), 3( R)-5,4'-dihydroxy-2'-methoxy-3'-(3-methylbut-2-enyl)-(6'',6''-dimethylpyrano)-(7,6 : 2'',3'')-isoflavanone ( 3), 3( R)-5,4'-dihydroxy-2'-methoxy-(6'',6''-dimethylpyrano)-(7,6: 2'',3'')-isoflavanone ( 4), and 3( R)-5,4'-dihydroxy-7,2'-dimethoxy-6-geranylisoflavanone ( 5) were isolated. The structures of the compounds were elucidated on the basis of spectroscopic analysis. All isolates exhibited good immunosuppressive activities on mitogen-induced splenocyte proliferation, and their cytotoxicity on splenic lymphocytes was also tested.

Two 22S-solanidine-type steroidal alkaloids from Fritillaria anhuiensis.

Phytochemical investigation of the fresh bulbs of Fritillaria anhuiensis S. C. Chen et S. E. Yin, resulted in the isolation of a known steroidal alkaloid solanidine of (22S,25S)-solanid-5-en-3beta-ol (1), which has never yet been found as a natural substance, and of a new steroidal alkaloid (22S,25S)-solanid-5,20(21)-dien-3beta-ol. Compounds 1 and 2 were the first solanidine-type alkaloids with 22-S configuration discovered from nature. Their structures were elucidated based on spectroscopic analysis, including 1D and 2D NMR experiments.

Geranylated flavonoids from the roots of Campylotropis hirtella and their immunosuppressive activities.

In an effort to identify new immunosuppressive agents from natural sources, 12 new geranylated flavonoids, 5,7,4'-trihydroxy-3'-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]isoflavone (1), a racemate of 5,7,2',4'-tetrahydroxy-3'-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]isoflavanone (2), 2''(S)-5,7-dihydroxy-[2''-methyl-2''-(4-methyl-3-pentenyl)pyrano]-5'',6'':3',4'-isoflavone (3), (2''S,3''R,4''S)-5,7,3'',4''-tetrahydroxy[2''-methyl-2''-(4-methyl-3-pentenyl)pyrano]-5'',6'':3',4'-isoflavone (4), a racemate of 3'-geranyl-5,7,2',4'-tetrahydroxyisoflavanone (5), a racemate of 3'-geranyl-4'-methoxy-5,7,2'-trihydroxyisoflavanone (6), 3'-geranyl-5,7,4',5'-tetrahydroxyisoflavone (8), 3'-geranyl-5,7,2',5'-tetrahydroxyisoflavone (9), 3'-geranyl-4'-methoxy-5,7,2'-trihydroxyisoflavone (10), 2(R),3(R)-3'-geranyl-2,3-trans-5,7,4'-trihydroxyflavonol (12), (2R,3R)-6-methyl-3'-geranyl-2,3-trans-5,7,4'-trihydroxyflavonol (13), and 5,7-dihydroxy-4'-O-geranylisoflavone (14), were isolated from the roots of Campylotropis hirtella (Franch.) Schindl. together with three previously described flavonoids. Their structures were elucidated by spectroscopic measurements, including two-dimensional nuclear magnetic resonance (NMR) techniques. The immunosuppressive effects of these compounds were assessed using mitogen-induced splenocyte proliferation, and the cytotoxicity of the compounds was also examined. The IC50 values of the compounds were found to be in the range of 1.49-61.23 microM for T lymphocyte suppression and 1.16-73.07 microM for B lymphocyte suppression. An analysis of their structure-activity relationships revealed that an isoflavonoid carbon skeleton with a C10 substituent at the C3' position was necessary for the activity. As many of the compounds exhibited good immunosuppressive activities, they may be promising as novel immunosuppressive agents.

Hirtellanines A and B, a pair of isomeric isoflavonoid derivatives from Campylotropis hirtella and their immunosuppressive activities.

A pair of isomeric isoflavonoid derivatives, Hirtellanines A (1) and B (2), has been isolated from the roots of Campylotropis hirtella (Franch.) Schindl. and their structures were elucidated on the basis of spectroscopic methods, with special emphasis on 1D and 2D NMR techniques. The in vitro assay showed that Hirtellanine A had strong B lymphocyte suppression activity (IC(50): 0.06microM) and T lymphocyte suppression activity (IC(50): 0.92microM). Hirtellanine B showed moderate B lymphocyte suppression activity (IC(50): 3.00microM) and T lymphocyte suppression activity (IC(50): 9.55microM). Due to the potent immunosuppressive activities and lower cytotoxicity, Hirtellanine A could be a promising lead towards novel immunosuppressive agents.