The Carrot psyllid, Trioza apicalis Förster (Homoptera: Psylloidea: Triozidae) is one of the major insect pests of carrots (Daucus carota L.) in parts of northern and central Europe. Gas chromatography–single-sensillum recording (GC–SSR) previously confirmed several active compounds in a carrot leaf extract, but the most active compound remained unidentified. Mass fragmentation patterns observed from the unidentified active compound when analyzed by gas chromatography and mass spectrometry (GC–MS) was used to propose β-sesquiphellandrene and α-cis-bergamotene to be candidates as the unidentified compound. The compounds were synthesized and their mass spectra were nearly identical with the unknown active compound. But, the retention times differed from the compound in the carrot leaf extract. Thus, to obtain the unidentified compound pure enough and in adequate amounts for nuclear magnetic resonance (NMR) analysis, preparative gas chromatography was applied to separate and concentrate this biologically active compound. Analysis by liquid chromatography quadrupole time of flight mass spectrometry (LC–QTOF) confirmed the unidentified compound to be a compound with the formula of C₁₅H₂₄ and together with GC–MS, ¹H and ¹³C NMR analysis sesquisabinene B was identified as the unidentified compound in the extract. GC–SSR was then used to finally confirm the biological activity of sesquisabinene B isolated from the carrot leaf extract via preparative GC.

中文翻译：

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鉴定胡萝卜（Daucus carota L.）叶中的倍半萜烯B是对胡萝卜木虱（Trioza apicalisFörster）具有电生理活性的化合物

胡萝卜木虱，Trioza apicalisFörster（Homooptera：Psylloidea：Triozidae）是北欧和中欧部分地区的胡萝卜（Daucus carota L.）的主要害虫之一。气相色谱-单敏记录（GC-SSR）先前在胡萝卜叶提取物中证实了几种活性化合物，但最具活性的化合物仍未确定。通过气相色谱和质谱分析（GC-MS）从未知的活性化合物中观察到的质谱碎片图被用于提出β-倍半萜烯和α-顺式-佛手柑将被用作未知化合物。合成了这些化合物，其质谱与未知的活性化合物几乎相同。但是，保留时间不同于胡萝卜叶提取物中的化合物。因此，为了获得足够纯净和足够数量的未鉴定化合物用于核磁共振（NMR）分析，应用了制备型气相色谱法来分离和浓缩这种生物活性化合物。通过液相色谱四极杆飞行时间质谱（LC-QTOF）分析，确认了该未知化合物为分子式为C ₁₅ H ₂₄的化合物，以及GC-MS，¹ H和¹³13 C NMR分析倍半萜烯B被鉴定为提取物中的未鉴定化合物。然后使用GC–SSR来确定通过制备性GC从胡萝卜叶提取物中分离出的倍半萜烯B的生物活性。