Powell R G, Weisleder D, Smith C R
J Nat Prod. 1985 Jan-Feb;48(1):102-7. doi: 10.1021/np50037a018.
An alcoholic extract of Diarthron vesiculosum seed has yielded two novel daphnane diterpene esters, vesiculosin and isovesiculosin. Compounds 1 and 2 undergo rapid interconversion to an equilibrium mixture containing approximately 80% 1 and 20% 2 in solution at elevated temperatures. At 25 degrees or below, 1 and 2 may be isolated and stored for extended periods with minimal interconversion. Excoecariatoxin and simplexin are the major daphnane orthoesters present in D. vesiculosum, and 1 and 2 apparently are biosynthetic precursors of 3. Isolation of these compounds was monitored by bioassay against PS leukemia (in vivo), and structures were determined by 1H nmr, 13C nmr, ms, and comparison with known compounds.
地锦草种子的乙醇提取物已产生两种新型瑞香烷二萜酯，即地锦草素和异地锦草素。化合物1和2在高温下会迅速相互转化，形成溶液中含有约80%的1和20%的2的平衡混合物。在25摄氏度或更低温度下，1和2可以被分离并长时间储存，相互转化极少。异株荨麻毒素和单叶豆素是地锦草中主要的瑞香烷原酸酯，而1和2显然是3的生物合成前体。这些化合物的分离通过对PS白血病（体内）的生物测定进行监测，其结构通过1H核磁共振、13C核磁共振、质谱以及与已知化合物的比较来确定。
