Leaves, flowers, fruits and stems (44 sample groups) were collected from mature Camptotheca acuminate during 2017.3-2018.3 and classified by ultra-high performance liquid chromatography coupled with quadrupole-time of flight-mass spectrometry based metabolomics. One hundred metabolites including forty-seven alkaloids, fifteen terpenes, thirty-two polyphenols and six other metabolites were rapidly identified through the in-house database alignment at first glance. Thirty-three alkaloids classified into five groups including camptothecin group (CG1-13), pumiloside group (PG1-5), strictosidinic acid group (SG1-3), vincosamide group (VG1-7), and a new hybrid group, vincosamide-camptothecin group (VC1-5) were mined and further characterized by MS/MS analyses. The identification of two untapped biosynthetic precursors, 2-hydroxypumiloside (PG2) and 16‑hydroxy‑15, 16-dihydrocamptothecoside (CG3), along with sixteen new alkaloids enables us for a better understanding of camptothecin biogenetic reasoning. The underlying enzymes involved in camptothecin biosynthesis were also proposed according to the guiding metabolic map, thus purposefully mining of enzymes involved in the downstream biosynthetic pathway of camptothecin could be initiated with the help of this map.

中文翻译：

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利用超高效液相色谱结合四极杆飞行时间质谱，生物合成启发性挖掘和鉴定喜树中未开发的生物碱，以发现酶。

在2017.3-2018.3期间从成熟的喜树形喜树中采集叶，花，果实和茎（44个样品组），并通过超高效液相色谱结合基于飞行时间质谱的四极杆时间质谱法进行分类。乍一看，通过内部数据库比对，可快速鉴定出一百多种代谢物，包括四十七种生物碱，十五种萜烯，三十二种多酚和六种其他代谢物。33种生物碱分为五个组，包括喜树碱组（CG1-13），普米洛赛德组（PG1-5），丁二酸组（SG1-3），长春酰胺组（VG1-7）和新的杂种组长春酰胺-喜树碱组（VC1-5）进行了挖掘，并通过MS / MS分析进一步表征。鉴定两种尚未开发的生物合成前体，2-羟基油苷（PG2）和16-羟基15、16-二氢喜树碱（CG3）以及16种新生物碱使我们能够更好地了解喜树碱的生物遗传学原理。还根据指导性代谢图谱提出了喜树碱生物合成中涉及的潜在酶，因此可以借助该图谱来有目的地挖掘喜树碱下游生物合成途径中涉及的酶。