Brahin, a New Lipoxygenase Inhibiting Triterpene from Spiraea brahuica

Brahin ( 1 ), a new ursene-type triterpene, has been isolated from the CHCl 3 -soluble fraction of Spiraea brahuica together with β -sitosterol ( 2 ), 3-(3,4-dimethoxyphenyl)-2-propenal ( 3 ), and cinnamic acid ( 4 ), which are reported for the first time from this species. The structures of these compounds were elucidated by 1D and 2D NMR spectroscopic techniques. Brahin showed moderate inhibitory activity against the enzyme lipoxygenase.