Longiberine and <i>O</i>-Methyllongiberine, Dimeric Protoberberine-Benzyl Tetrahydroisoquinoline Alkaloids from <i>Thalictrum </i><i>l</i><i>ongistyl</i><i>um</i>
作者:Shoei-Sheng Lee、Wu、John H. Wilton、Jack L. Beal、Raymond W. Doskotch
DOI:10.1021/np9902284
日期:1999.10.1
isolated from the roots of Thalictrum longistylum and represent a new class of dimeric alkaloids. The structure of longiberine (1) was established by spectral and chemical methods. Reductive cleavage of O-ethyllongiberine (4) with Na/liquid NH(3) yielded (+)-(S)-N-methylcoclaurine (5), which determined one-half of the dimer, and 1D and 2D NMR studies arranged the substituents on the protoberberine nucleus