Rocha Daniele F O, Wouters Felipe C, Machado Glauco, Marsaioli Anita J
Chemistry Institute, State University of Campinas, POB 6154, 13083-970 Campinas, SP, Brazil.
Sci Rep. 2013 Nov 6;3:3156. doi: 10.1038/srep03156.
Arthropods produce a great variety of natural compounds, many of which have unexplored biosynthesis. Among the armored harvestmen (Arachnida: Opiliones) of the suborder Laniatores, the defensive gland exudates contain vinyl ketones and other constituents of supposed polyketide origin. We have studied the biosynthesis of 1-hepten-3-one in the Neotropical harvestman Iporangaia pustulosa by feeding individuals with ¹³C-labeled precursors, demonstrating its mixed acetate/propionate origin. ¹³C NMR spectroscopy showed an unusual labeling pattern suggesting different propionate sources for starting and extender units. Our analysis also indicates the presence of methylmalonyl-CoA mutase, converting acetate into propionyl-CoA via succinyl-CoA, together with other C₃ unit routes. This is the first biosynthetic study of alkyl vinyl ketones in arthropods. Our results shed light on the origin and diversification of chemical compounds in a major arthropod group.
节肢动物能产生种类繁多的天然化合物，其中许多化合物的生物合成尚未得到探索。在鞭蛛亚目（蛛形纲：盲蛛目）的带甲盲蛛中，防御腺分泌物含有乙烯基酮和其他推测为聚酮来源的成分。我们通过用¹³C标记的前体喂养新热带盲蛛Iporangaia pustulosa个体，研究了1-庚烯-3-酮的生物合成，证明了其混合的乙酸盐/丙酸盐来源。¹³C核磁共振光谱显示出一种不寻常的标记模式，表明起始单元和延伸单元的丙酸盐来源不同。我们的分析还表明存在甲基丙二酰辅酶A变位酶，它通过琥珀酰辅酶A将乙酸盐转化为丙酰辅酶A，以及其他C₃单元途径。这是节肢动物中烷基乙烯基酮的首次生物合成研究。我们的结果揭示了一个主要节肢动物类群中化合物的起源和多样化。
