University of Hohenheim, Institute of Food Chemistry (170b), Garbenstraße 28, D-70599 Stuttgart, Germany.
University of Hohenheim, Institute of Food Chemistry (170b), Garbenstraße 28, D-70599 Stuttgart, Germany.
Sci Total Environ. 2020 Sep 20;736:139680. doi: 10.1016/j.scitotenv.2020.139680. Epub 2020 May 25.
MHC-1 is a halogenated natural product (HNP) produced by the red seaweed Plocamium cartilagineum. MHC-1 concentrations of 550-2700 μg/g dry weight were found in Plocamium collected by divers at Heligoland (Germany). Compared to that MHC-1 concentrations were much lower in samples collected on beaches in Ireland and Portugal. Exposure of leaves of Plocamium to sunlight showed that MHC-1 was readily transformed by hydrodebromination. At Heligoland in March, MHC-1 (δC value -45.2‰) was lighter in carbon by ~15‰ compared to the bulk δC value (‰) of Plocamium (-30.7‰). Collected at the same time and location at Heligoland, samples of Halichondria and Mastocarpus sp. were richer in carbon (by ~10‰) as Plocamium. However, the δC value of MHC-1 in Halichondria (-44.6‰) and Mastocarpus sp. (-42.1‰) was as negative as in Plocamium. This was indirect proof that MHC-1 was produced by Plocamium and then released into the water phase from where it then was bioconcentrated by Halichondria and Mastocarpus sp. In agreement with that, concentrations of MHC-1 in Halichondria and Mastocarpus sp. were much lower than in Plocamium. In addition, a potential isomer of MHC-1 (compound X) was detected in all samples from Heligoland at ~2% of the MHC-1 level.
MHC-1 是一种卤代天然产物 (HNP)，由红海藻类 Plocamium cartilagineum 产生。在德国 Heligoland 潜水员采集的 Plocamium 中发现 MHC-1 的浓度为 550-2700μg/g 干重。与德国 Heligoland 相比，在爱尔兰和葡萄牙海滩采集的样本中 MHC-1 的浓度要低得多。暴露于阳光下的 Plocamium 叶片表明，MHC-1 很容易通过氢脱溴转化。在 3 月的 Heligoland，与 Plocamium 的 bulk δC 值（‰）相比，MHC-1（δC 值为-45.2‰）的碳含量轻约 15‰。在 Heligoland 同一时间和地点采集的 Halichondria 和 Mastocarpus sp. 的碳含量比 Plocamium 更丰富（约 10‰）。然而，Halichondria（-44.6‰）和 Mastocarpus sp.（-42.1‰）中 MHC-1 的 δC 值与 Plocamium 一样为负值。这间接证明 MHC-1 是由 Plocamium 产生的，然后从水相中释放出来，然后被 Halichondria 和 Mastocarpus sp. 生物浓缩。这与 MHC-1 在 Halichondria 和 Mastocarpus sp. 中的浓度远低于 Plocamium 的事实相符。此外，在 Heligoland 的所有样本中都检测到了 MHC-1 的一种潜在异构体（化合物 X），其水平约为 MHC-1 的 2%。
