QOPNA, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
J Chromatogr A. 2013 Nov 8;1315:152-61. doi: 10.1016/j.chroma.2013.09.049. Epub 2013 Sep 19.
Metabolomics represents an emerging topic that can be valuable in the knowledge of organism responses to different stimuli. Metabolomic studies of bivalves may reveal the constraints they are subjected to, and may help clarifying the functions most affected and the tolerance mechanisms triggered. In response to this approach, two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-ToFMS) combined with headspace solid phase microextraction (HS-SPME) was applied, for the first time to our knowledge, to the untargeted and comprehensive study of the volatile composition of clam species. Firstly, experimental parameters that influence the SPME extraction efficiency were evaluated: sample preparation mode, sample volume and SPME fiber coating. Taking into account the results from the optimization step, the metabolomic profiles were performed using 1 ml of clam soft tissues homogenized with N2 and diluted in deionised water (1:2, w/v), using the PDMS/DVB fiber coating. From a total of more than 200 compounds detected per sample, 63 were tentatively identified and distributed over the chemical families of hydrocarbons, ketones, aldehydes, alcohols, and terpenoids, which seems to arise from clams own metabolism, and/or from their activity as filter-feeders. The potential of this methodology to discriminate close related species was explored by comparing the volatile profiles of Venerupis philippinarum and Venerupis decussata from Ria de Aveiro, two clams belonging to the same genus. Both species experience different environment conditions, and physiological and biochemical characteristics, which may explain the observed differentiation between their metabolic profiles. To our knowledge, this is the most detailed information available so far about clam volatile composition, which represents a valuable data for future advanced studies in the ecology, toxicology and physiology of bivalves based on clams fingerprinting.
代谢组学是一个新兴的研究领域，可以帮助我们了解生物体对不同刺激的反应。双壳贝类的代谢组学研究可以揭示它们所受到的限制，并有助于阐明受影响最大的功能和触发的耐受机制。为此，我们首次应用二维气相色谱-飞行时间质谱联用（GC×GC-ToFMS）结合顶空固相微萃取（HS-SPME）技术，对贻贝类物种的挥发性成分进行非靶向和全面的研究。首先，评估了影响 SPME 萃取效率的实验参数：样品制备方式、样品量和 SPME 纤维涂层。考虑到优化步骤的结果，使用 1ml 用 N2 匀浆并稀释在去离子水中（1:2，w/v）的贻贝软组织，采用 PDMS/DVB 纤维涂层进行代谢组学分析。从每个样品中检测到的 200 多种化合物中，有 63 种被初步鉴定，并分布在烃类、酮类、醛类、醇类和萜烯类等化学家族中，这些化合物似乎来自贻贝自身的代谢，以及/或者来自它们作为滤食者的活动。通过比较来自阿威罗泻湖的菲律宾帘蛤和糙耳鲍的挥发性图谱，探讨了该方法区分亲缘关系密切的物种的潜力。这两种贻贝属于同一属，但经历着不同的环境条件、生理和生化特征，这可能解释了它们代谢图谱的差异。据我们所知，这是迄今为止关于贻贝挥发性成分的最详细信息，为基于贻贝指纹的双壳贝类生态学、毒理学和生理学的未来高级研究提供了有价值的数据。
