The homologous and phylogenetically old scent glands of harvestmen—also called defensive or repugnatorial glands—represent an ideal system for a model reconstruction of the evolutionary history of exocrine secretion chemistry (“phylogenetic chemosystematics”). While the secretions of Laniatores (mainly phenols, benzoquinones), Cyphophthalmi (naphthoquinones, chloro-naphthoquinones, methyl-ketones) and some Eupnoi (naphthoquinones, ethyl-ketones) are fairly well studied, one open question refers to the still largely enigmatic scent gland chemistry of representatives of the suborder Dyspnoi and the relation of dyspnoan chemistry to the remaining suborders. We here report on the secretion of a nemastomatid Dyspnoi, Nemastoma triste, which is composed of straight-chain methyl-ketones (heptan-2-one, nonan-2-one, 6-tridecen-2-one, 8-tridecen-2-one), methyl-branched methyl-ketones (5-methyl-heptan-2-one, 6-methyl-nonan-2-one), naphthoquinones (1,4-naphthoquinone, 6-methyl-1,4-naphthoquinone) and chloro-naphthoquinones (4-chloro-1,2-naphthoquinone, 4-chloro-6-methyl-1,2-naphthoquinone). Chemically, the secretions of N. triste are remarkably reminiscent of those found in Cyphophthalmi. While naphthoquinones are widely distributed across the scent gland secretions of harvestmen (all suborders except Laniatores), methyl-ketones and chloro-naphthoquinones arise as linking elements between cyphophthalmid and dyspnoan scent gland chemistry.

中文翻译：

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Opiliones 气味腺中的甲基酮：在呼吸困难的 Nemastoma triste 中检索到的 cyphophthalmi 的化学特征。

收割者的同源和系统发育上古老的气味腺 - 也称为防御性或反抗性腺体 - 代表了一个理想的系统，用于模型重建外分泌化学进化史（“系统发育化学系统学”）。虽然对 Laniatores（主要是苯酚、苯醌）、Cyphophthalmi（萘醌、氯萘醌、甲基酮）和一些 Eupnoi（萘醌、乙基酮）的分泌物进行了相当充分的研究，但一个悬而未决的问题是指仍然很大程度上是神秘的气味腺呼吸困难亚目代表的化学以及呼吸困难化学与其余亚目的关系。我们在这里报告了一种线虫 Dyspnoi、Nemastoma triste 的分泌，由直链甲基酮（庚烷-2-酮、壬烷-2-酮、6-十三烯-2-酮、8-十三烯-2-酮）、甲基支链甲基酮（5-甲基-heptan-2-one, 6-methyl-nonan-2-one), 萘醌 (1,4-naphthoquinone, 6-methyl-1,4-naphthoquinone) 和氯代萘醌 (4-chloro-1,2-naphthoquinone) , 4-chloro-6-methyl-1,2-naphthoquinone)。从化学上讲， N. triste的分泌物与在 Cyphophthalmi 中发现的分泌物非常相似。虽然萘醌广泛分布于收割者的气味腺分泌物中（除 Laniatores 外的所有亚目），但甲基酮和氯萘醌作为环苯胺和呼吸困难气味腺化学之间的连接元素而出现。