Departamento de Química Orgânica, Instituto de Química, Universidade Estadual Paulista (UNESP), Araraquara, SP 14800-900, Brazil.
J Nat Prod. 2011 May 27;74(5):1154-60. doi: 10.1021/np200085h. Epub 2011 Apr 20.
Gaudichaudianic acid, a prenylated chromene isolated from Piper gaudichaudianum, has been described as a potent trypanocidal compound against the Y-strain of Trypanosoma cruzi. We herein describe its isolation as a racemic mixture followed by enantiomeric resolution using chiral HPLC and determination of the absolute configuration of the enantiomers as (+)-S and (-)-R by means of a combination of electronic and vibrational circular dichroism using density functional theory calculations. Investigation of the EtOAc extract of the roots, stems, and leaves from both adult specimens and seedlings of P. gaudichaudianum revealed that gaudichaudianic acid is biosynthesized as a racemic mixture from the seedling stage onward. Moreover, gaudichaudianic acid was found exclusively in the roots of seedlings, while it is present in all organs of the adult plant. Trypanocidal assays indicated that the (+)-enantiomer was more active than its antipode. Interestingly, mixtures of enantiomers showed a synergistic effect, with the racemic mixture being the most active.
古地屈酸，一种从 Piper gaudichaudianum 中分离出来的被烃基化的色烯，已被描述为一种针对 Y 株 Trypanosoma cruzi 的强效杀锥虫化合物。本文描述了其作为外消旋混合物的分离，然后使用手性 HPLC 对其进行对映体拆分，并通过使用密度泛函理论计算的电子和振动圆二色性的组合确定对映体的绝对构型为 (+)-S 和 (-)-R。对成年植株和幼苗的根、茎和叶的 EtOAc 提取物进行研究表明，古地屈酸从幼苗阶段开始就作为外消旋混合物进行生物合成。此外，古地屈酸仅存在于幼苗的根部，而在成年植物的所有器官中都存在。杀锥虫试验表明，(+)-对映体比其对映体更具活性。有趣的是，对映体混合物表现出协同作用，而外消旋混合物的活性最高。
