Margl Lilla, Ettenhuber Christian, Gyurján István, Zenk Meinhart H, Bacher Adelbert, Eisenreich Wolfgang
Biozentrum-Pharmazie, Universität Halle, Weinbergweg 22, D-06120 Halle/Saale, Germany.
Phytochemistry. 2005 Apr;66(8):887-99. doi: 10.1016/j.phytochem.2005.02.022.
Root cultures of Tagetes patula L. cv. Carmen were grown with a mixture of unlabeled glucose and [U-(13)C(6)]glucose or [1-(13)C(1)]glucose as carbon source. Isoeuparin and (-)-4-hydroxytremetone were isolated by solvent extraction of the cultured tissue, purified by chromatography and analysed by (1)H and (13)C NMR spectroscopy. Amino acids obtained by hydrolysis of protein from the same experiments were used for the reconstruction of the labelling patterns in central metabolic intermediates. These labelling patterns were used for the prediction of isotopolog compositions in the benzofuranone derivatives via different hypothetical pathways. Comparison with the experimentally observed isotopolog distributions showed that the benzenoid ring and the acetoxy group are exclusively or predominantly (>98%) derived from phenylalanine and not from acetyl-CoA via a polyketide-type biosynthesis. The isopropylidene side chain and two carbon atoms of the furan and dihydrofuran moiety, respectively, originate from an isoprenoid building block obtained exclusively or predominantly (>98%) via the deoxyxylulose phosphate pathway. The exomethylene atom of the isopropylidene side chain is biosynthetically equivalent to the (Z)-methyl group of dimethylallyl diphosphate. The data indicate that isoeuparin and (-)-4-hydroxytremetone are assembled from 4-hydroxyacetophenone and dimethylallyl diphosphate via prenyl-substituted 4-hydroxyacetophenone and dihydrobenzofurans as intermediates.
孔雀草品种卡门的根培养物以未标记的葡萄糖与[U-(13)C(6)]葡萄糖或[1-(13)C(1)]葡萄糖的混合物作为碳源进行培养。通过对培养组织进行溶剂萃取分离出异欧前胡素和(-)-4-羟基百里香醌，经色谱法纯化后，用(1)H和(13)C核磁共振光谱进行分析。从相同实验中蛋白质水解得到的氨基酸用于重建中心代谢中间体中的标记模式。这些标记模式通过不同的假设途径用于预测苯并呋喃酮衍生物中的同位素异构体组成。与实验观察到的同位素异构体分布进行比较表明，苯环和乙酰氧基完全或主要（>98%）源自苯丙氨酸，而非通过聚酮类生物合成途径源自乙酰辅酶A。异亚丙基侧链以及呋喃和二氢呋喃部分的两个碳原子分别源自一种类异戊二烯结构单元，该结构单元完全或主要（>98%）通过磷酸脱氧木酮糖途径获得。异亚丙基侧链的亚甲基原子在生物合成上等同于二甲基烯丙基二磷酸的(Z)-甲基。数据表明，异欧前胡素和(-)-4-羟基百里香醌是由4-羟基苯乙酮和二甲基烯丙基二磷酸通过异戊烯基取代的4-羟基苯乙酮和二氢苯并呋喃作为中间体组装而成。
