Studies On Chemical Constituents Of The Light Leaves The Saddle Tree

Maackia tenuifolia (Hemsl.) Hand-Mazz distributed in Jiangsu, Zhejiang, Jiangxi, Henan and Hubai provinces of China, has been used for injuries and as fungicide in Zhejiang folk medicine. Some bioactive phenolic compounds were isolated from the plant of another species, M. amurensis, while only a few studies reported on this plant, which prompted us to investigate the chemical constituents of the title plant in order to elucidate the substance base responsible for folk medicine usage. Also, the occurrence of prenylated flavonoids in this plant enhanced our interest. Prenylated flavonoids were widely found in nature, which have a wide structure variety and extensive biological activities. Our investigation of the CHCl₂ soluble portion of ethanolic extract of the roots of the title plant afforded 18 new compounds, 14 known compounds and 4 pair of new isoflavan diastereoisomers (N9～12), their structures were determined on the basis of spectroscopic analysis and comparison with known compounds. Compounds N1～8, N13～16 are prenylated isoflavans, N19, N22 are two biflavonoids of new type skeleton. N20 is a 4-Aryl substituted isoflavan, which was not encountered in isoflavonoids except for [4-5']biisoflavans. Simple phenolic compounds K10, K11, N18 are structurally part of some prenylated isoflavans, compound N17, N8 hold part structure of N19, N22, which suggests that they should be closely relevant in biosynthesis.Part of these compounds were subjected to antifungal, anti-HIV and antitumor tests. Compounds N3, N5, N6, N13, K11 showed promising antifungal activity in vitro against Candida albicans, Cryptococcus neoformas and Aspergillus fumigatus. N4 and N13 exhibited anti-HIV activity. In antitumor tests, N22 is effective against HL-60, N7 and N19 are effective against U937, N22 showed week activity on U937.