Identification of tuliposide G, a novel glucoside ester-type tuliposide, and its distribution in tulip
Identification of tuliposide G, a novel glucoside ester-type tuliposide, and its distribution in tulip
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DOI：
10.1515/znc-2019-0176
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发表时间：
2020-03-01
影响因子：
2
通讯作者：
Kato, Yasuo
中科院分区：
文献类型：
--
作者：
Nomura, Taiji;Kato, Yasuo
郁金香糖苷是郁金香属植物的主要防御性次生代谢产物，在D-葡萄糖的C-1和/或C-6位含有4-羟基-2-亚甲基丁酰基和/或(3S)-3，4-二羟基-2-亚甲基丁酰基。C-6位的酰基被郁金香糖苷转换酶(Tce)转化为抗微生物内酯，即郁金香素。在调查郁金香组织提取物以鉴定新的POS的过程中，我们发现一个微小的高效液相色谱峰在TCE作用后消失，其保留时间与已知POS的保留时间不同。光谱分析表明其结构为5‘’-O-(6-O-(4‘-hydroxy-2’-methylenebutanoyl))-beta-D-glucopyranosyl-(2‘R)-2’‘-羟甲基-4’‘-丁内酯，是一种新的糖苷酯型POS。我们把这种化合物简单地命名为“郁金香G”(Posg)。POSG在鳞茎中积累，水平明显低于6-POSA(鳞茎中的主要POS)，但在任何其他组织中均未发现。对包括30个郁金香品种和22个野生郁金香种在内的52种郁金香种球中的POSG进行了定量，结果在28个品种中检测到POSG，而只在郁金香亚属的3个野生种中检测到POSG，表明POSG作为郁金香的化学分类标记具有潜在的应用价值。
Tuliposides (Pos) are major defensive secondary metabolites in tulip (genus Tulipa), having 4-hydroxy-2-methylenebutanoyl and/or (3S)-3,4-dihydroxy-2-methylenebutanoyl groups at the C-1 and/or C-6 positions of D-glucose. The acyl group at the C-6 position is converted to antimicrobial lactones, tulipalins, by tuliposide-converting enzymes (TCEs). In the course of a survey of tulip tissue extracts to identify novel Pos, we found a minute high-performance liquid chromatography peak that disappeared following the action of a TCE, and whose retention time differed from those of known Pos. Spectroscopic analyses of the purified compound, as well as its enzymatic degradation products, revealed its structure as 5 ''-O-(6-O-(4'-hydroxy-2'-methylenebutanoyl))-beta-D-glucopyranosyl-(2 '' R)-2 ''-hydroxymethyl-4 ''-butyrolactone, which is a novel glucoside ester-type Pos. We gave this compound the trivial name 'tuliposide G' (PosG). PosG accumulated in bulbs, at markedly lower levels than 6-PosA (the major Pos in bulbs), but was not found in any other tissues. Quantification of PosG in bulbs of 52 types of tulip, including 30 cultivars (Tulipa gesneriana) and 22 wild Tulipa spp., resulted in the detection of PosG in 28 cultivars, while PosG was present only in three wild species belonging to the subgenus Tulipa, the same subgenus to which tulip cultivars belong, suggesting the potential usefulness of PosG as a chemotaxonomic marker in tulip.