Figueroa Mario, Gonzalez Maria Del Carmen, Mata Rachel
Departamento de Farmacia, Instituto de Biologia Universidad Nacional Autonoma de Mexico, Mexico City, Mexico.
Nat Prod Res. 2008 May 20;22(8):709-14. doi: 10.1080/14786410802012361.
A new indole alkaloid, namely malbrancheamide B (2), was isolated from the culture medium and mycelia of the ascomycete Malbranchea aurantiaca along with malbrancheamide (1). Structural elucidation of 2 was carried out by a combination of mass spectrometry (MS) and (1)H and (13)C NMR spectroscopy analyses, as well as by comparison of the NMR data with those of 1. According to the conformational studies using molecular mechanics analyses, compound 2 exists in one preferred conformation, which was optimised by density functional theory (DFT) calculations. Compound 2 is the second chlorinated indole alkaloid possessing a bicyclo [2.2.2] ring with an unusual relative configuration at C12a in the bicyclo [2.2.2] diazaoctane ring system. So far, these structural features seem to be unique for the alkaloids biosynthesised by the fungus M. aurantiaca.
从子囊菌橙色马尔布兰奇菌（Malbranchea aurantiaca）的培养基和菌丝体中分离出一种新的吲哚生物碱，即马尔布兰奇酰胺B（2），同时还分离出了马尔布兰奇酰胺（1）。通过质谱（MS）、（1）H和（13）C核磁共振光谱分析，并将核磁共振数据与化合物1的数据进行比较，对化合物2进行了结构解析。根据使用分子力学分析的构象研究，化合物2以一种优势构象存在，该构象通过密度泛函理论（DFT）计算得到了优化。化合物2是第二种具有双环[2.2.2]环的氯化吲哚生物碱，在双环[2.2.2]二氮杂辛烷环系统的C12a处具有不寻常的相对构型。到目前为止，这些结构特征对于由橙色马尔布兰奇菌生物合成的生物碱来说似乎是独一无二 的。
