School of Agriculture, Food and Wine, and Waite Research Institute, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia.
CSIRO Agriculture and Food, Waite Campus, Locked Bag No. 2, Glen Osmond, South Australia 5064, Australia.
J Agric Food Chem. 2023 May 3;71(17):6717-6726. doi: 10.1021/acs.jafc.3c00306. Epub 2023 Apr 20.
Methoxypyrazines (MPs) are potent aroma compounds that have been predominately studied in grape berries but can also be detected in other vine tissues. The synthesis of MPs in berries from hydroxypyrazines by VvOMT3 is well established, but the origin of MPs in vine tissues that have negligible gene expression is unknown. This research gap was addressed through the application of stable isotope tracer 3-isobutyl-2-hydroxy-[H]-pyrazine (-IBHP) to the roots of Pinot Meunier L1 microvines and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) quantification of HPs from grapevine tissues following a novel solid-phase extraction method. Four weeks post-application, -IBHP and its -methylated product 3-isobutyl-2-methoxy-[H]-pyrazine (-IBMP) were present in excised cane, berry, leaf, root, and rachis material. Translocation of -IBHP and -IBMP was investigated, but results were inconclusive. Nonetheless, knowledge that -IBHP, and potentially -IBMP, are translocated from roots to other vine organs, including the berries, could provide opportunities for controlling MP accumulation in grapevine tissues pertinent to winemaking.
甲氧基吡嗪（MPs）是一种强效香气化合物，主要在葡萄浆果中进行研究，但也可以在其他葡萄藤组织中检测到。通过 VvOMT3 由羟基吡嗪合成浆果中的 MPs 已经得到充分证实，但在基因表达可忽略不计的藤组织中 MPs 的来源尚不清楚。通过将稳定同位素示踪剂 3-异丁基-2-羟基-[H]-吡嗪（-IBHP）应用于 Pinot Meunier L1 微型葡萄藤的根部，并采用新型固相萃取法对葡萄藤组织中的 HPs 进行高效液相色谱-串联质谱（HPLC-MS/MS）定量分析，解决了这一研究空白。-IBHP 及其 - 甲基化产物 3-异丁基-2-甲氧基-[H]-吡嗪（-IBMP）在 4 周后出现在切割的嫩枝、浆果、叶片、根和穗轴材料中。对 -IBHP 和 -IBMP 的转运进行了研究，但结果不确定。尽管如此，-IBHP，以及可能的 -IBMP，从根部转运到其他葡萄藤器官，包括浆果的知识，为控制与酿酒相关的葡萄藤组织中 MPs 的积累提供了机会。
