ABSTRACT Leptospermum scoparium J. R. et G. Forst. (Myrtaceae), called mānuka or kahikātoa by Māori, shows distinct foliage chemotypes in different regions of Aotearoa New Zealand, including one with rare antimicrobial triketones. To extend knowledge of mānuka chemotypes geographically and historically, we have developed a miniaturised method for analyses of herbarium samples needing just a few small leaves analysed by headspace solid phase microextraction gas chromatography (HS-SPME-GC). This method was validated on herbarium samples of known chemotypes. Geographical knowledge was extended by analysing herbarium samples collected on New Zealand's offshore islands, ranging from the Manawa/Three Kings in the North to Rakiura/Stewart Island in the South. The chemotypes were generally similar to the nearest populations on the main North or South islands. Historically, volatiles were identified from herbarium samples collected by the first botanists from Europe in 1769, showing that the oil glands in mānuka leaves act as ‘chemical time capsules’.

中文翻译：

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化学时间胶囊：十八世纪麦卢卡植物标本中的生物活性挥发物，Leptospermum scoparium

摘要 Leptospermum scoparium JR et G. Forst。（桃金娘科）被毛利人称为 mānuka 或 kahikātoa，在新西兰 Aotearoa 的不同地区显示出不同的叶子化学型，其中一种含有罕见的抗菌三酮。为了在地理和历史上扩展对麦卢卡化学型的了解，我们开发了一种小型化方法，用于分析标本馆样品，只需通过顶空固相微萃取气相色谱 (HS-SPME-GC) 分析几片小叶子。该方法在已知化学型的植物标本中得到验证。通过分析在新西兰离岸岛屿（从北部的 Manawa/三王岛到南部的 Rakiura/Stewart 岛）收集的植物标本馆样本，扩展了地理知识。化学型通常与主要北岛或南岛最近的种群相似。从历史上看，挥发性物质是从 1769 年欧洲第一批植物学家收集的植物标本中鉴定出来的，表明麦卢卡叶子中的油腺起到了“化学时间胶囊”的作用。