From linden flower to linden honey -: Part 2 -: Glycosidic precursors of cyclohexa-1,3-diene-1-carboxylic acids
From linden flower to linden honey -: Part 2 -: Glycosidic precursors of cyclohexa-1,3-diene-1-carboxylic acids
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DOI：
10.1002/cbdv.200690012
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发表时间：
2006-01-01
影响因子：
2.9
通讯作者：
Naef, R
中科院分区：
文献类型：
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作者：
Frérot, E;Velluz, A;Naef, R
经过固相萃取和高效液相纯化，现在也证实了(瑞士)梧桐蜂蜜中存在两种不寻常的新近发现的萜烯酸，即4-(1-hydroxy-1-methylethyl)cyclohexa-1，3-diene-1-carboxylic酸(1)和4-(I-methylethenyl)cyclohexa-1，3-diene-1-carboxylic酸(2)。核磁共振谱结合UPLC/MS分析表明，1的几种糖苷的含量约为蜂蜜的0.6%，经UPLC-UV定量。通过2D-核磁共振实验，可以分离出化合物5的主要糖苷，并鉴定为相应的β-龙胆二糖酯(而不是经典的具有苷元羟基和糖之间的糖苷键的化合物)。在梧桐蜜中发现的相同的二糖苷也在梧桐花蜜中被检测到；此外，板栗和冷杉蜂蜜中含有少量的这些糖苷，但不包括甘蓝、金合欢或蒲公英蜂蜜(表2)。
The presence of two unusual, recently identified terpene acids, i.e., 4-(1-hydroxy-1-methylethyl)cyclohexa-1,3-diene-1-carboxylic acid (1) and 4-(I-methylethenyl)cyclohexa-1,3-diene-1-carboxylic acid (2), was now also confirmed in (Swiss) linden honey, after solid-phase extraction and HPLC purification. NMR Spectroscopy, in combination with UPLC/MS analysis, showed the presence of several glycosides of 1, which accounted for ca. 0.6 weight-% of the honey, as quantified by UPLC-UV. The major 'glycoside' of 1, compound 5, could be isolated and identified by 2D-NMR experiments as the corresponding beta-gentiobiosyl ester (rather than the classical compound with a glycosidic bond between an aglycone OH group and the sugar). The same diglycosides found in linden honey were also detected in linden nectar; also, chestnut and fir honeys contained these glycosides in minor quantities, but not colza, acacia, or dandelion honeys (Table 2).