An alkaloid with a novel skeleton, oxazonigelladine (1), and four new dolabellane-type diterpenes, damasterpenes I (2) – IV (5), were isolated from the seeds of Nigella damascena. Oxazonigelladine has an isoxazolidinone partial structure bearing a direct bond between a nitrogen atom and an oxygen atom. This small and simple structure is quite rare in the nature. Surprisingly, despite the unstable bond between nitrogen and oxygen, oxazonigelladine was isolated with good stability. On the other hand, damasterpenes are dolabellane-type diterpenes with phenylacetyl, benzoyl, acetyl or nicotinoyl moieties. This report deals with the structure determination including the absolute configuration by X-ray crystallographic analysis and CD analysis.

从烟草（Nigella damascena）的种子中分离出了一种具有新骨架的生物碱恶唑酮（1）和四个新的dolabellane型二萜，damasterpenes I（2）-IV（5）。。恶唑尼拉汀具有在氮原子和氧原子之间带有直接键的异恶唑烷酮部分结构。这种小而简单的结构在自然界中是很少见的。出乎意料的是，尽管氮和氧之间的键不稳定，但仍以良好的稳定性分离出恶唑尼拉定。另一方面，达马斯汀为具有苯乙酰基，苯甲酰基，乙酰基或烟酰基的部分的多马兰型二萜。该报告涉及结构确定，包括通过X射线晶体学分析和CD分析的绝对构型。