Abstract The title compounds platyphylline (C18H29NO5.0.5H2O) and integerrimine (C18H25NO6) have been isolated from the serial parts of the Senecio species. the crystal and molecular structures of platyphylline have been determined. the compound crystallises in orthorhombic space group, P212121. the pyrrolizidine nucleus exhibits exo-buckling conformation. the molecular geometry was stabilized by C-H[ddot]O and C-H[ddot]N hydrogen bonds. a search for the low energy conformations of integerrimine as a similar alkaloid was also carried out. Force field calculations were undertaken by the MM3 program and some particular conformations were computed with the semi-emprical molecular orbital methods by the AMI and PM3 programs.

中文翻译：

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桔梗碱的晶体结构和整数亚胺的分子构象分析

摘要 标题化合物 platyphylline (C18H29NO5.0.5H2O) 和 integerrimine (C18H25NO6) 已从千里光物种的系列部分中分离出来。已经确定了柏叶碱的晶体和分子结构。该化合物在正交空间群 P212121 中结晶。吡咯里西啶核呈现外屈曲构象。分子几何结构由 CH[ddot]O 和 CH[ddot]N 氢键稳定。还进行了对作为类似生物碱的整数亚胺的低能量构象的研究。MM3 程序进行了力场计算，AMI 和 PM3 程序使用半经验分子轨道方法计算了一些特定的构象。